Artery. Large human veins and arteries

The vessels of the circulatory system are elastic formations with thick walls, through which blood moves throughout the body. All vessels are tubular in shape. The impetus for the movement of blood is the contraction of the heart. There are several types of vessels, different in diameter, functionality and tissue composition. Most of them are lined from the inside with a single layer of endothelium.

Blood vessels are named according to the names of the organs they supply with blood (hepatic, gastric arteries and veins) or depending on the location of the vessels in parts of the body (ulnar, femoral arteries and veins), their depth (superficial epigastric, deep femoral arteries and veins). There are parietal (parietal) arteries and veins that supply blood to the walls of body cavities, and splanchnic (visceral) arteries and veins that supply blood to internal organs. Arteries before they enter the organ are called extraorganic (extraorganic), in contrast to the intraorganic (intraorganic) arteries located in the thickness of the organ.

You will find the most complete information about the main vessels of the pulmonary and systemic circulation on this page.

The walls of the vessels of the circulatory system

At the walls of blood vessels, the inner, middle and outer shells are distinguished. Arteries have thicker walls than veins. Inner shell ( tunica intima) consists of a layer of endothelial cells (endotheliocytes) with a basement membrane and a subendothelial layer. The middle, or muscular, shell (tunica media) is built from several layers of smooth muscle cells and a small amount of connective tissue fibers. Arteries have structural features of this shell. There are arteries of the elastic type (aorta, pulmonary trunk), in which the middle shell consists of elastic fibers, giving greater elasticity to these vessels. Arteries of the muscular-elastic (mixed) type (subclavian, common carotid arteries) in their middle shell have an approximately equal presence of smooth muscle cells and elastic fibers. In muscular arteries (medium and small caliber), the middle layer consists of smooth muscle cells that regulate blood flow within organs and maintain the pressure level in human blood vessels.

Outer shell ( tunica externa) , or adventitia (adventitia), is formed by loose fibrous connective tissue. Vessels and nerves pass through the adventitia, ensuring the vital activity of these vessels.

In the microcirculatory bed, located in organs and tissues, there are arterioles, which are the thinnest arterial vessels, precapillary arterioles (precapillaries), capillaries (hemocapillaries), postcapillary venules (postcapillaries), venules and arteriovenular anastomoses. The arteriole, which is the beginning of the microvasculature, has a diameter of 30-50 microns; its walls contain smooth muscle cells that form one layer. Precapillaries (arterial capillaries) depart from the arterioles, at the beginning of which there are 1-2 smooth myocytes in the walls, forming precapillary sphincters that regulate blood flow in the capillaries.

Precapillaries pass into capillaries, the walls of which are formed by a single layer of endotheliocytes, a basement membrane, and pericyte pericapillary cells. The diameter of blood capillaries is from 3 to 11 microns. The capillaries pass into wider postcapillaries (postcapillary venules), the diameter of which varies from 8 to 30 µm. Postcapillaries pass into venules with a diameter of 30-50 microns, which flow into small veins with a diameter of 50-100 microns. In the walls of the venules, a non-continuous layer of smooth muscle cells and single connective tissue fibers appear on the outside. The composition of the microvasculature includes arteriovenular anastomoses (shunts) connecting the arteriole and venule. In the walls of these anastomoses there is a layer of smooth myocytes.

The walls of the veins are built in the same way as the walls of the arteries. The structure of these blood vessels includes three thinner than those of the arteries, membranes: internal (intima), middle (media) and external (adventitia).

In accordance with the structural features of the body and the distribution of blood vessels in it, a person distinguishes between large and small circles of blood circulation. The large (or bodily) circulation begins in the left ventricle and ends in the right atrium. The small (or pulmonary) circulation originates in the right ventricle and ends in the left atrium.

The main vessels of the human pulmonary circulation system

Small (pulmonary) circulation includes the pulmonary trunk, which begins in the right ventricle and carries venous blood to the lungs, the right and left pulmonary arteries with their branches, the microvasculature in the lungs, two right and two left pulmonary veins that carry arterial blood from the lungs and flow into the left atrium.

pulmonary trunk ( truncus pulmonalis) about 50 mm long and 30 mm in diameter, leaving the right ventricle of the heart, It is located anterior to the aorta and left atrium. Heading up and backwards, the pulmonary trunk divides into the right and left pulmonary arteries and forms a bifurcation Precise barrel ( bifurcatio trunci pulmonalis) . Between the bifurcation of the pulmonary trunk and the aortic arch there is a thin arterial ligament (ligamentum arteriosum), which is an overgrown arterial (botall) duct (ductus arteriosus). The right and left pulmonary arteries travel to the right and left lungs, where they branch into capillaries.

Right pulmonary artery ( a. pulmonalis dextra) , departing to the right of the bifurcation of the pulmonary trunk, goes to the gates of the lung behind the ascending aorta and the terminal section of the superior vena cava. At the hilum of the right lung, under the right main bronchus, the right pulmonary artery divides into superior, middle, and inferior lobar branches, each of which, in turn, divides into segmental branches.

Left pulmonary artery ( a. pulmonalis sinistra) departs from the bifurcation of the pulmonary trunk to the gates of the left lung, where it is located above the main bronchus. This vessel of the pulmonary circulation at the gates of the lung is divided into the upper lobe branch (ramus (obi superiors) and the lower lobe branch (ramus lobi inferioris), which break up into segmental branches.

pulmonary veins ( venae puimonales) , two pores for each lung, are formed from capillaries and small venous vessels, which are connected to larger veins. Eventually, two pulmonary veins form in each lung.

Right superior pulmonary vein ( vena pulmonalis dextra superior) formed by the confluence of the veins of the upper and middle lobes of the right lung. The tributaries of this vessel of small circulation in the upper lobe of the right lung are the apical, anterior and posterior veins venae apicalis anterior and posterior) .

Right inferior pulmonary vein ( vena pulmonalis dextra inferior) It is formed by the confluence of the superior and common basal veins. superior vein ( vena superior) is formed in the apical segment of the lower lobe from intrasegmental and intersegmental veins (venae intrasegmentales et intersegmentales). Common basal vein ( vena basalis communis) It is formed by the confluence of the inferior basal vein (vena basalis inferior) and the superior basal vein (vena basalis superior), into which the anterior basal vein flows, as well as the intrasegmental and intersegmental veins (venae intrasegmentales et intersegmentales).

Left superior pulmonary vein ( vena pulmonalis sinistra superior) It is formed from the posterior apex, anterior and reed veins (venae apicoposterior, anterior et lingualis). Each of these vessels of the human pulmonary circulation, in turn, is formed by the confluence of the intrasegmental and intersegmental veins (venae intrasegmentalis et intersegmentalis) in the apical, posterior and anterior, as well as the upper and lower reed segments of the upper lobe of the left lung.

Left inferior pulmonary vein ( vena pulmonalis sinistra inferior) It is formed in the lower lobe of the left lung from the superior vein and the common basal vein. The superior vein (vena superior) is formed by the confluence of the intrasegmental and intersegmental veins (venae intrasegmentalis et intersegmentalis) of the apical segment. The common basal vein (vena basalis communis) is formed from the superior and inferior basal veins (venae basales superior et inferior). The anterior basal vein (vena basalis anterior) flows into the superior basal vein. This blood vessel of the pulmonary circulation is formed from the intrasegmental and intersegmental veins.

Blood vessels of the systemic circulation: scheme of human arteries

The blood vessels of the large (corporeal) circulation include the aorta and numerous arteries and their branches extending from the aorta, vessels of the microvasculature, small and large veins, including the superior and inferior vena cava, which flow into the right atrium.

Aorta ( aorta) located in the thoracic and abdominal cavities, at the level from the III-IV thoracic vertebrae to the IV lumbar vertebrae, where the aorta divides into the right and left common iliac arteries. The aorta lies anterior to the spine. The aorta has an ascending part, an arch and a descending part. At the descending aorta, the thoracic and abdominal parts are distinguished.

ascending aorta ( pars ascendens aortae) , leaving the left ventricle, forms an extension - aortic bulb ( bulbus aortae) , then the frame rises from the pulmonary trunk and at level II of the right costal cartilage passes into the aortic arch. At the level of the aortic bulb, the right and left coronary arteries depart from it, supplying the heart.

Aortic arch ( arcus aortae) bends to the left and posteriorly and at the level of the body of the IV thoracic vertebra passes into the descending part of the aorta. The right pulmonary artery passes under the aortic arch, and to the left of the arch is the bifurcation of the pulmonary trunk. The concave side of the aortic arch and the bifurcation of the pulmonary trunk are connected by an arterial ligament (lig. arteriosum). From the concave side of the aortic arch, thin arteries depart to the trachea and to the main bronchi. From the convex side of the aortic arch, the brachiocephalic trunk, the left common carotid artery and the left subclavian artery depart upward.

descending aorta ( pars descendens aortae) subdivided into thoracic and abdominal parts. The thoracic aorta (pars thoracica aortae), which is a downward continuation of the aortic arch, is initially located in the posterior mediastinum, anterior and to the left of the esophagus.

From the arch of the aorta, its large branches extend upward: brachiocephalic trunk, left common carotid and left subclavian arteries.

Shoulder trunk ( truncus brachiocephalicus) begins at level II of the costal cartilage, goes from the aortic arch up and to the right. At the level of the right sternoclavicular joint, the brachiocephalic trunk divides into the right common carotid artery and the right subclavian artery. The left common carotid artery and the left subclavian artery arise directly from the aortic arch.

Common carotid artery ( a. carotis communis) , right and left, is directed vertically upward anterior to the transverse processes of the cervical vertebrae. Lateral to the common carotid artery are the internal jugular vein and the vagus nerve. Inward from the common carotid artery are the esophagus and pharynx, trachea and larynx, thyroid gland and parathyroid glands. At the level of the upper edge of the thyroid cartilage (within the carotid triangle), such a vessel of the systemic circulation as the common artery is divided into the external and internal carotid arteries.

External carotid artery ( a. carotis externa) located under the superficial plate of the cervical fascia and under the skin, first goes medial to the internal carotid artery, and then shifts laterally from it. At the level of the neck of the articular process of the lower jaw, this vessel of great circulation is divided into the superficial temporal and maxillary arteries. Behind the angle of the mandible, the external carotid artery gives off branches from it in the anterior, posterior, and medial directions.

superior thyroid artery ( a. thyroidea superior) departs from the carotid artery at its beginning, goes forward and down to the thyroid gland. The superior laryngeal artery (a. laryngea superior) departs from the superior thyroid artery - to the larynx, the hyoid branch (g. infrahyoideus) - to the hyoid bone, the sternocleidomastoid branch (g. cricothyroideus) - to the muscle of the same name.

lingual artery ( a. lingualis) departs from the external carotid artery at the level of the large horn of the hyoid bone, goes forward and up along the lower medial side of the hyoid-lingual muscle (within the lingual triangle). In the thickness of the tongue, this vessel of the systemic circulation gives off the dorsal branches (rr. dorsales) and the deep artery of the tongue (a. profunda linguae) - the final branch that penetrates to the top of the organ. From the lingual artery, the suprahyoid branch (g. suprahyoideus) and the hyoid artery (a. sublingualis) depart - to the sublingual salivary gland.

facial artery ( a. facialis) departs from the external carotid artery at the angle of the mandible, just above the lingual artery, bends over the edge of the mandible and goes up and medially towards the corner of the mouth. In the neck region, this vessel of the circulatory system gives off: glandular branches (rr. glandulares) - to the submandibular salivary gland, mental branch (r. mentalis) - to the suprahyoid muscles, ascending palatine artery (a. palatina ascendens) - to the soft palate and tonsil branch (g. tonsillaris) - to the palatine tonsil.

occipital artery ( a. occipitalis) departs from the beginning of the external carotid artery, goes posteriorly under the posterior belly of the digastric muscle and lies in the occipital groove of the temporal bone.

Posterior ear artery ( a. auricularis posterior) departs from the external carotid artery above the posterior belly of the digastric muscle, goes backwards and upwards. The ear branch (r. auricularis) departs from this vessel of the systemic circulation - to the back of the auricle, the occipital branch (r. occipitalis) goes backwards and upwards to the base of the mastoid process and to the skin of the occiput, the stylomastoid artery (a. stylomastoidea) goes through sciatica mastoid opening into the canal of the facial nerve.

Superficial temporal artery ( a. temporalis superficialis) goes up (in front of the auricle), into the temporal region. This artery of great circulation passes outward from the zygomatic arch, under the skin, where the pulse of this artery can be felt. Branches of the parotid gland depart from the superficial temporal artery under the zygomatic arch.

maxillary artery ( a. maxillaris) goes forward to the infratemporal, and then to the pterygo-palatine fossa, where it is divided into terminal branches. In this artery of the systemic circulation, the jaw, pterygoid and pterygo-palatine sections are distinguished, within which numerous branches extend to the organs and tissues of the head.

internal carotid artery ( a. carotis interna) , supplying the brain and the organ of vision, passes into the cranial cavity through the canal of the internal carotid artery. In its initial part (cervical), the internal carotid artery rises up between the pharynx and the internal jugular vein to the external opening of the carotid canal

ophthalmic artery ( a. ophthalmica) goes to the orbit through the optic canal (together with the optic nerve) and gives off numerous branches to the eyeball, to the lacrimal gland, to the oculomotor muscles and to the eyelids. Long and short posterior ciliary arteries (aa. ciliares posteriores longae et breves) penetrate into the eyeball.

Anterior cerebral artery ( a. cerebri anterior) departs from the internal carotid artery above the ophthalmic artery and goes forward. Anterior to the optic chiasm, the anterior cerebral artery approaches the anterior cerebral artery of the opposite side and connects to it with the transverse anterior communicating artery (a. communicans anterior).

middle cerebral artery ( a. cerebri media) , the largest branch of the internal carotid artery, goes laterally and upwards into the lateral sulcus of the brain. Located in this groove on the lateral surface of the insular lobe (islet) of the brain, the middle cerebral artery gives off numerous branches (arteries, cortical branches, rr. corticales) heading towards the islet, as well as up, into the furrows of the frontal and parietal lobes, and down - to the temporal lobe of the brain.

subclavian artery ( a. subclavia) is a branch of the aortic arch (left) and the brachiocephalic trunk (right).

As shown in the diagram, the human subclavian artery from its origin goes up and laterally above the dome of the pleura and exits the chest cavity through its upper aperture:

vertebral artery ( a. vertebralis) departs from the subclavian artery immediately upon exiting its chest cavity (at the level of the VII cervical vertebra), goes up and passes through the holes in the transverse processes of the cervical vertebrae (cervical part).

Basilar artery ( a. basilaris) , located in the basilar groove of the bridge (brain), is formed when the right and left vertebral arteries join. At the level of the anterior edge of the bridge, this artery of the systemic circulation of a person is divided into its terminal branches - the right and left posterior cerebral arteries.

Posterior cerebral artery ( a. cerebri posterior) , steam room, leaves laterally above the cerebellar mantle and branches on the lower and upper lateral sides of the temporal and occipital lobes of the brain, gives cortical branches (rr. corticales) to these parts of the brain.

Internal mammary artery ( a. thoracica interna) departs from the subclavian artery, goes down behind the subclavian vein, then descends along the edge of the sternum along the back side of the cartilaginous part of the ribs.

musculophrenic artery ( a. muscleophrenica) goes down and laterally along the line of attachment of the diaphragm to the ribs and gives off branches to the diaphragm, to the abdominal muscles, to the five lower intercostal spaces (anterior intercostal branches).

Thyroid trunk ( truncus thyrocervicalis) departs from the upper semicircle of the subclavian artery before entering the interstitial space and soon divides into the inferior thyroid, suprascapular, ascending and superficial cervical arteries.

Ascending cervical artery ( a. cervicalis ascendens) goes up the front side of the anterior scalene muscle and gives branches to the prevertebral muscles and spinal branches (rr. spinales) to the spinal cord.

Costo-cervical trunk ( truncus costocervicalis) departs upward from the subclavian artery in the interstitial space and immediately divides into the deep cervical and highest intercostal arteries. The deep cervical artery (a. cervicalis profunda) goes backwards and upwards between the 1st rib and the transverse process of the 7th cervical vertebra and gives off a branch to the semispinous muscles of the head and neck. The highest intercostal artery (a. intercostalis suprema) goes down anterior to the neck of the first rib and is divided into the first and second posterior intercostal arteries (aa. intercostales posteriores I-II). These arteries anastomose with the anterior intercostal branches from the internal mammary artery. From the posterior intercostal arteries depart dorsal branches (rr. dorsales) to the muscles and skin of the back, and spinal branches (rr. spinales), going into the spinal canal.

Transverse artery of the neck ( a. transverse colli) departs from the subclavian artery after its exit from the interstitial space. This vessel of the systemic circulation of a person is directed laterally and posteriorly to the upper angle of the scapula.

axillary artery ( a. axillaris) is a continuation of the subclavian artery in the axillary cavity (below the 1st rib), gives off branches to the shoulder joint and adjacent muscles.

Pay attention to the diagram of the arteries of the great circle - at the level of the lower edge of the pectoralis major muscle, the axillary vessel passes into the brachial:

brachial artery ( a. brachialis) begins at the level of the lower edge of the pectoralis major muscle, passes anterior to the coracobrachial muscle, and then lies in the groove on the medial side of the shoulder. In the cubital fossa, under the aponeurosis of the biceps brachii, the artery enters the groove between the pronator teres medially and the brachioradialis muscle laterally. At the level of the neck of the radius, the brachial artery divides into the radial and ulnar arteries.

ulnar artery ( a. ulnaris) starts from the brachial artery at the level of the neck of the radius, goes under the round pronator to the ulnar side, gives off muscle branches along the way. Approximately in the middle of the forearm, it lies in the ulnar groove along with the ulnar nerve between the superficial flexor of the fingers laterally and the ulnar flexor of the wrist medially. Muscular branches (rr. musculares) depart from the ulnar artery to neighboring muscles, the ulnar recurrent artery, the common interosseous artery, the palmar and dorsal carpal branches, and the deep palmar branch.

radial artery ( a. radialis) , formed at the level of the elbow joint, first goes down between the round pronator medially and the brachioradialis muscle laterally. At the level of the lower third of the forearm in the radial groove, the radial artery is covered only by the skin, here its pulse can be felt. Further, the radial artery goes around the styloid process of the radius and passes to the back of the hand, passes through the first intermetacarpal space to the palm, where it anastomoses with the deep palmar branch of the ulnar artery and together with it forms a deep palmar arch.

Deep palmar arch ( arcus palmaris profundus) located at the level of the bases of the metacarpal bones, under the tendons of the deep flexor of the finger. In the distal direction from the deep palmar arch, the palmar metacarpal arteries (aa. metacarpales palmares) depart, which are located in the second, third and fourth intermetacarpal spaces on the palmar side of the interosseous muscles.

Here you can see the diagram of the arteries of the systemic circulation:

Below is a description of the thoracic and abdominal parts of the aorta.

Branches of the thoracic and abdominal aorta

The descending aorta is divided by the aortic opening of the diaphragm into the thoracic and abdominal parts. The branches of the thoracic aorta are divided into two groups: visceral and parietal.

thoracic aorta ( pars thoracica aortae) located in the posterior mediastinum, anterior to the spine. Parietal branches supply blood to the walls of the chest cavity, visceral branches go to the organs located in the chest cavity.

The parietal branches of the thoracic aorta include the paired posterior intercostal arteries and the superior phrenic arteries.

Posterior intercostal arteries ( a.a. intercostales posteriores) , paired, depart from the aorta in the intercostal spaces, from the third to the twelfth. Each intercostal artery is located at the lower edge of the overlying rib (together with the vein and nerve of the same name), between the external and internal intercostal muscles, to which the arteries give off muscle branches.

Superior phrenic artery ( a. phrenica superior) , steam room, departs from the thoracic part of the aorta above the diaphragm, goes to its lumbar part and the pleura covering the diaphragm.

The abdominal part of the aorta is located on the back wall of the abdominal cavity (on the spine) from the diaphragm to the level of the V lumbar vertebra, where the aorta is divided into the right and left common iliac arteries. The parietal branches of the abdominal aorta are the paired inferior phrenic and lumbar arteries.

The inferior phrenic artery, which originates from the aorta directly below the diaphragm at the level of the XII thoracic vertebra, supplies the diaphragm and the peritoneum that covers it. From the lower phrenic artery departs up to 24 upper adrenal arteries (aa. suprarenales superiores).

lumbar arteries ( a.a. lumbales) , in the amount of four pairs, depart from the posterior semicircle of the abdominal aorta at the level of I-IV lumbar vertebrae. These arteries run behind the crura of the diaphragm (upper two) and behind the psoas major muscle, then are located between the transverse and internal oblique muscles of the abdomen, give off branches to them. Each lumbar artery gives off a dorsal branch (g. dorsalis), which goes posteriorly to the muscles and skin of the back, and a spinal branch (g. spinalis), which goes through the intervertebral foramen to the spinal cord and to its membranes.

Unpaired visceral branches of the abdominal aorta

The unpaired visceral branches of the abdominal aorta are the celiac trunk, left gastric, common hepatic, splenic, superior and inferior mesenteric arteries.

celiac trunk ( truncus coeliacus) is a short vessel 1.5-2 cm long, which departs anteriorly from the aorta at the level of the XII thoracic vertebra, just below the aortic opening of the diaphragm. Above the upper edge of the body of the pancreas, the celiac trunk divides into the left gastric, common hepatic, and splenic arteries.

Left gastric artery ( a. gastric sinistra) goes up and to the left between the sheets of the hepatogastric ligament. Approaching the cardial part of the stomach, this branch of the abdominal part of the aorta turns to the right, goes along its lesser curvature and anastomoses with the right gastric artery, which originates from its own hepatic artery. The left gastric artery gives off esophageal branches (rr. oesophageales) to the abdominal part of the esophagus and numerous branches to the anterior and posterior walls of the stomach.

Common hepatic artery ( a. hepatica communis) goes from the celiac trunk to the right along the upper edge of the pancreas. This unpaired visceral branch of the aorta enters the thickness of the hepatogastric ligament (lesser omentum) and divides into its own hepatic and gastroduodenal arteries. Own hepatic artery (a. hepatica propria) goes to the gates of the liver in the thickness of the hepatoduodenal ligament.

splenic artery ( a. lienalis) goes to the spleen next to the splenic vein, along the upper edge of the pancreas. From this unpaired branch of the abdominal aorta, pancreatic branches (rr. pancreatici) depart to the pancreas, anastomosing with the branches of the pancreatic-duodenal arteries.

Superior mesenteric artery ( a. mesenterica superior) departs from the aorta at the level of the XII thoracic - I lumbar vertebrae, goes down between the lower part of the duodenum at the back and the head of the pancreas at the front and enters the mesentery of the small intestine. At the level of the lower (horizontal) part of the duodenum, the lower gastroduodenal artery departs from the superior mesenteric artery (a. pancreato-duodenalis inferior). This unpaired visceral branch of the abdominal aorta runs to the right and up, where it gives off branches to the anterior side of the pancreatic head and to the duodenum and anastomoses with the branches of the anterior and posterior superior pancreaticoduodenal arteries.

inferior mesenteric artery ( a. mesenterica inferior) departs from the left semicircle of the abdominal aorta at the level of the III lumbar vertebra, goes down and to the left along the anterior surface of the psoas major muscle, behind the parietal peritoneum. From this unpaired branch of the abdominal aorta, the left colon, sigmoid, and superior rectal arteries depart.

Paired visceral branches of the abdominal aorta

Paired visceral branches of the abdominal part of the aorta are the middle adrenal, renal, testicular (ovarian) arteries, going to the paired internal organs located behind the peritoneum.

Middle adrenal artery ( a. suprarenalis media) departs from the aorta at the level of the 1st lumbar vertebra. This visceral branch of the abdominal aorta also goes to the hilum of the adrenal gland, gives off branches to it, which anastomose with the branches of the superior adrenal arteries (from the inferior phrenic artery) and the inferior adrenal artery (from the renal artery).

renal artery ( a. renalis) departs from the aorta at the level of 1-11 lumbar vertebrae, goes to the hilum of the kidney, where it divides into the anterior and posterior branches that go into the renal parenchyma. The right renal artery is longer than the left, it goes to the kidney behind the inferior vena cava. From this visceral branch upward departs the lower adrenal artery (a. suprarenalis inferior). At the gates of the kidney, the anterior and posterior branches (rr. anterior et posterior) are divided into segmental arteries (aa. segmentales), penetrating the substance of the kidney.

Testicular (ovarian) artery ( a. testicularis, s. ovarica) is a thin vessel that departs from the aorta at the level of the II lumbar vertebra (slightly below the beginning of the renal artery). This visceral branch of the aorta goes down and laterally along the anterior surface of the psoas major muscle, crosses the ureter in front and gives it ureteral branches (rr. ureterici).

Major pelvic arteries

common iliac artery ( a. iliaca communis) , right and left, formed as a result of the division of the abdominal part of the aorta, goes in the lateral direction and at the level of the sacroiliac joint is divided into the external and internal iliac arteries.

internal iliac artery ( a. iliaca interna) goes from its beginning down into the cavity of the small pelvis along the line of the sacroiliac joint. At the level of the greater sciatic foramen, this artery divides into anterior (visceral) branches that go to the organs of the small pelvis and the muscles of its anterior wall, and posterior branches (parietal), supplying the muscles of the lateral and posterior walls of the pelvis.

umbilical artery ( a. umbilicalis) departs from the internal iliac artery, forward and upward, goes to the inside of the anterior abdominal wall. From the umbilical artery depart ureteral branches (rr. ureterici), blood supply to the lower parts of the ureter, two or three upper vesical arteries (aa. vesicales superiores), suitable for the upper part of the bladder, and the artery of the deferent proton (a. ductus deferentis), which goes nearby with the vas deferens up to the epididymis and giving branches to the duct.

Inferior vesical artery of the pelvis ( a. vesicalis inferior) goes to the bottom of the bladder, where in men it gives off branches to the seminal vesicle and prostate gland (prostate branches, rr. prostatici), in women this artery gives off vaginal branches (rr. vaginales).

Uterine artery of the small pelvis ( a. uterina) first goes retroperitoneally forward and medially, crossing the ureter, then passes between the sheets of the broad ligament of the uterus. On the way to the edge of the uterus, the uterine artery gives off the vaginal branches (rr. vaginales) and the vagina, and in the region of the bottom of the uterus it gives off a tubal branch (r. tubarius), going up and the fallopian tube, and an ovarian branch (r. ovaricus), which is involved in blood supply ovary and anastomosing with branches of the ovarian artery.

Middle rectal artery ( a. gestalis media) goes to the lateral wall of the ampulla of the rectum, anastomoses with the branches of the superior rectal artery (a branch of the inferior mesenteric artery), and also gives branches to the seminal vesicles and the prostate gland in men, to the vagina in women and to the levator ani muscle.

Internal pudendal artery ( a. pudenda interna) goes down the posterolateral side of the small pelvis and exits the pelvic cavity through the piriform opening. Further, the artery goes around the sciatic spine and through the small sciatic foramen, together with the pudendal nerve, enters the ischiorectal fossa.

iliac-lumbar artery ( a. iliolumbalis) departs from the internal iliac artery at the level of the sacroiliac joint, goes up and laterally and is divided into the lumbar and iliac branches. Lumbar branch (g. lumbalis) blood supply to the large and small lumbar muscles, the square muscle of the lower back, the skin of the lumbar region, and also gives off the spinal branch (g. spinalis), which goes through the spinal foramen to the roots of the spinal nerves. The iliac branch (g. iliacus) supplies blood to the iliac muscle, ilium and lower parts of the anterior abdominal wall.

Lateral sacral artery ( a. sacralis lateralis) departs from the internal iliac artery in the medial direction, then goes down the pelvic surface of the sacrum, where it gives spinal branches (rr. spinales) to the roots of the spinal nerves, leaving the sacral canal through the pelvic sacral openings.

obturator artery ( a. obturatoria) goes down to the obturator foramen along the lateral wall of the pelvis. At the entrance to the obturator canal, the artery gives off a pubic branch (g. pubicus), which goes up and anastomoses with the pubic branch of the inferior epigastric artery at the level of the pubic symphysis. At the outlet of the obturator canal, the obturator artery divides into anterior and posterior branches. The anterior branch (r. anterior) goes down the outer side of the obturator internus muscle, supplies blood to its adductor muscles of the thigh, as well as the skin of the external genital organs. The posterior branch (g. posterior) goes down and posteriorly and gives branches to the external obturator muscle, ischium, to the hip joint, to which the acetabular branch (g. acetabularis) passes in the thickness of the ligament of the femoral head.

Superior gluteal artery ( a. glutea superior) exits the pelvic cavity through the epipiriform opening and divides into superficial and deep branches. The superficial branch (r. superficialis) passes between the gluteus maximus and medius and supplies blood to these muscles. The deep branch (g. profundus) goes between the middle and small gluteal muscles, supplies them with blood and the capsule of the hip joint. The branches of the superior gluteal artery anastomose with the branches of the deep gluteal artery and the circumflex iliac artery (from the external iliac artery).

inferior gluteal artery ( a. glutea inferior) exits the pelvic cavity through the piriform opening and gives branches to the gluteus maximus muscle, the square muscle of the thigh, to the hip joint, anastomosing with other arteries supplying it, to the skin of the gluteal region, as well as the artery accompanying the sciatic nerve (a. comitans n. ischiadici) .

External iliac artery ( a. iliaca externa) goes forward and down along the medial edge of the psoas major muscle and exits the pelvic cavity through the vascular lacuna, continuing at the level of the inguinal ligament into the femoral artery. The inferior epigastric artery and the deep circumflex iliac artery originate from the external iliac artery.

inferior epigastric artery ( a. epigastric inferior) departs from the external iliac artery near the inguinal ligament, goes forward and up the inside of the anterior abdominal wall, under the peritoneum, and then pierces the intra-abdominal fascia of the abdomen and enters the sheath of the rectus abdominis muscle.

Deep circumflex iliac artery ( a. circumflexa ilium profunda) , also departs near the inguinal ligament, goes in the pelvic cavity to the lateral side along the inner surface of this ligament. The artery then travels upward between the transverse and internal oblique muscles of the abdomen, to which it supplies blood.

Arteries of the human lower extremities (with photo and diagram)

In the lower limb, a large femoral artery is distinguished, into which, at the level of the inguinal ligament, the external iliac artery passes, the popliteal, anterior and posterior tibial arteries, from which branches (arteries) depart to all organs and tissues of the limb.

The femoral artery of the lower limb ( a. femoralis) is located within the femoral triangle in the iliopectineal groove, on a deep sheet of the wide fascia of the thigh. At the apex of the femoral triangle, the femoral artery enters the adductor (gunter) canal and through its lower opening enters the popliteal fossa, where it continues into the popliteal artery. The superficial epigastric artery, the superficial circumflex iliac artery, the external pudendal arteries, the deep artery of the thigh and the descending artery of the knee, as well as muscular branches depart from the femoral artery.

Superficial epigastric artery ( a. epigastric superficialis) departs from the femoral artery directly under the inguinal ligament, rises up and medially towards the umbilical ring, giving branches to the skin of the anterior abdominal wall and its subcutaneous tissue.

Superficial circumflex iliac artery ( a. circumflexa ilium superficialis) , is directed laterally and upward under the inguinal ligament towards the anterior superior iliac spine, where it anastomoses with the deep circumflex iliac artery.

External pudendal arteries ( a.a. pridendae externae) go medially, supply the inguinal ligament (inguinal branches, rr. inguinales), form the anterior scrotal branches (rr. scrotales anteriores), the scrotum branching in the skin in men, the anterior labial branches (rr. labiales anteriores), which in women branch in the thickness of the large labia.

Deep femoral artery ( a. profunda femoris) departs from the posterior side of the femoral artery, goes down between the medial wide muscle on the lateral side and the adductor muscles of the thigh medially. The anatomy of the arteries of the lower extremities is such that the medial and lateral arteries that go around the femur and the perforating arteries depart from the deep artery of the thigh.

Lateral circumflex artery of the femur ( a. circumflexa femoris lateralis) , goes laterally under the sartorius muscle and is divided into ascending, descending and transverse branches. The ascending branch (g. ascendens) goes up under the rectus femoris muscle and the muscle that strains the wide fascia of the thigh, to the neck of the femur, where it anastomoses with the branches of the medial circumflex artery of the femur.

Medial circumflex artery of the femur ( a. circumflexa femoris medialis) , goes medially, gives ascending, transverse and deep branches (g. ascendens, g. transversus, g. profundus) to the iliopsoas, pectinate, external obturator, piriformis and square muscles of the thigh.

Perforating arteries ( a.a. perforantes) , in the amount of three, go to the back of the thigh, to its muscles and other organs and tissues.

As shown in the diagram, the first perforating artery of the lower limb passes under the lower edge of the pectineus muscle, the second - under the short adductor muscle, the third - under the long adductor muscle:

The arteries anastomose with each other, and the third perforating artery is involved in the formation of the arterial network of the knee joint.

Descending genicular artery ( a. descendens genicularis) departs from the femoral artery in the adductor canal, goes under the skin (together with the saphenous nerve) through the tendon plate between the large adductor and medial wide muscles. The artery gives off the subcutaneous branch (r. saphenus) to the medial wide muscle and articular branches (rr. articulares), which are involved in the formation of the arterial network of the knee joint.

Popliteal artery ( a. poplitea) is a continuation of the femoral artery after its exit from the adductor canal, in the popliteal fossa passes from top to bottom to the entrance to the ankle-popliteal canal. At the lower angle of the popliteal fossa, before entering the ankle-popliteal canal, the popliteal artery divides into the anterior and posterior tibial arteries.

Posterior tibial artery ( a. tibialis posterior) , which is a direct continuation of the popliteal artery, goes into the ankle-popliteal canal under the tendinous arch of the soleus muscle. Further, the posterior tibial artery descends down the back of the long flexor of the fingers, giving branches to the muscles and other structures of the back of the leg.

peroneal artery ( a. regopea) goes from the top of the posterior tibial artery down and laterally into the inferior musculoperoneal canal. The final section of the peroneal artery of the lower limb of a person and its calcaneal branches (rr. calcanei) are involved in the formation of the calcaneal arterial network (rete calcaneum). Branches depart from the peroneal artery to the soleus and peroneal muscles, to the long muscles that bend the fingers. The connecting branch (r. communicans) also departs from the peroneal artery to the posterior tibial artery and the perforating branch (r. regforans), which passes forward through the interosseous membrane of the leg and anastomoses with the lateral anterior ankle artery (from the anterior tibial artery). Lateral ankle branches (rr. malleolares laterales) of the peroneal artery are involved in the formation of the lateral ankle network (rete malleolare laterale).

Medial plantar artery ( a. plantaris medialis) on the foot, it first goes under the muscle that removes the thumb, then passes between this muscle medially and the short flexor of the fingers laterally. In the posterior part of the medial sulcus, this artery divides into a superficial branch (r. superficialis) and a deep branch (r. profundus), which go to neighboring muscles, to bones, joints, and to the skin of the foot.

Lateral plantar artery ( a. plantaris lateralis) goes along the lateral groove of the sole to the base of the fifth metatarsal bone, where it forms a bend in the medial direction and forms a plantar arch.

plantar arch ( arcus plantaris) at the lateral edge of the I metatarsal bone, it forms an anastomosis with the medial plantar artery and with the deep plantar branch (from the dorsal artery of the foot). The lateral plantar artery supplies the adjacent muscles, skin, joints, and ligaments of the foot.

Anterior tibial artery ( a. tibialis anterior) departs from the popliteal artery at the lower edge of the popliteal muscle, goes forward through the hole in the interosseous membrane of the leg and lies on the front surface of this membrane.

Pay attention to the photo - this artery of the lower limb is located along with two veins of the same name and a deep peroneal nerve:

Dorsal artery of the foot ( a. dorsalis pedis) , which is a continuation of the anterior tibial artery on the foot, runs along the front side of the ankle joint under the skin and is available here to determine the pulse. In the region of the first intermetatarsal space, the dorsal artery of the foot gives off the first dorsal metatarsal and deep plantar arteries.

deep plantar artery ( a. plantaris profunda) perforates the first intermetatarsal space, the first dorsal interosseous muscle and anastomoses on the sole with the plantar arch (arcus plantaris), which is the terminal branch of the lateral plantar artery.

The lateral and medial tarsal arteries and the arcuate artery depart from the dorsal artery of the foot. medial tarsal arteries ( a.a. tarsales mediates) , go to the medial edge of the foot, supply its bones and joints with blood, take part in the formation of the ankle network.

Lateral tarsal artery ( a. tarsalis lateralis) goes laterally, gives branches to the short extensor of the fingers, to the bones and joints of the foot. At the base of the fifth metatarsal bone, the lateral tarsal artery anastomoses with the arcuate artery, which is the terminal branch of the dorsalis artery of the foot.

arcuate artery ( a. arcuata) begins at level II of the tarsal bone, goes forward and laterally and forms an arc convex towards the fingers, anastomosing with the lateral tarsal artery. Four dorsal metatarsal arteries (aa. metatarsales dorsales) extend forward from the arcuate artery, each of which gives two dorsal digital arteries (aa. digitales dorsales) at the interdigital spaces, going to the back sides of adjacent fingers. From each dorsal digital artery to the plantar metatarsal arteries, perforating branches (rami perforantes) pass through the interdigital spaces, connecting with the plantar metatarsal arteries.

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Useful articles

The most important task of the cardiovascular system is to provide tissues and organs with nutrients and oxygen, as well as to remove the products of cell metabolism (carbon dioxide, urea, creatinine, bilirubin, uric acid, ammonia, etc.). Enrichment with oxygen and removal of carbon dioxide occurs in the capillaries of the pulmonary circulation, and saturation with nutrients in the vessels of the systemic circulation during the passage of blood through the capillaries of the intestine, liver, adipose tissue and skeletal muscles.

a brief description of

The human circulatory system consists of the heart and blood vessels. Their main function is to ensure the movement of blood, carried out thanks to the work on the principle of a pump. With the contraction of the ventricles of the heart (during their systole), blood is expelled from the left ventricle into the aorta, and from the right ventricle into the pulmonary trunk, from which, respectively, the large and small circles of blood circulation (BCC and ICC) begin. The large circle ends with the inferior and superior vena cava, through which venous blood returns to the right atrium. And the small circle is represented by four pulmonary veins, through which arterial, oxygenated blood flows to the left atrium.

Based on the description, arterial blood flows through the pulmonary veins, which does not correspond to everyday ideas about the human circulatory system (it is believed that venous blood flows through the veins, and arterial blood flows through the arteries).

After passing through the cavity of the left atrium and ventricle, the blood with nutrients and oxygen enters the capillaries of the BCC through the arteries, where it exchanges oxygen and carbon dioxide between it and the cells, delivers nutrients and removes metabolic products. The latter with the blood flow reach the excretory organs (kidneys, lungs, glands of the gastrointestinal tract, skin) and are excreted from the body.

BPC and ICC are connected sequentially. The movement of blood in them can be demonstrated using the following scheme: right ventricle → pulmonary trunk → small circle vessels → pulmonary veins → left atrium → left ventricle → aorta → large circle vessels → inferior and superior vena cava → right atrium → right ventricle.

Functional classification of vessels

Depending on the function performed and the structural features of the vascular wall, the vessels are divided into the following:

1. 1. Shock-absorbing (vessels of the compression chamber) - aorta, pulmonary trunk and large arteries of the elastic type. They smooth out periodic systolic waves of blood flow: soften the hydrodynamic shock of blood ejected by the heart during systole, and ensure the movement of blood to the periphery during diastole of the ventricles of the heart.
2. 2. Resistive (vessels of resistance) - small arteries, arterioles, metarterioles. Their walls contain a huge number of smooth muscle cells, thanks to the contraction and relaxation of which they can quickly change the size of their lumen. Providing variable resistance to blood flow, resistive vessels maintain blood pressure (BP), regulate the amount of organ blood flow and hydrostatic pressure in the vessels of the microvasculature (MCR).
3. 3. Exchange - ICR vessels. Through the wall of these vessels there is an exchange of organic and inorganic substances, water, gases between blood and tissues. The blood flow in the MCR vessels is regulated by arterioles, venules and pericytes - smooth muscle cells located outside the precapillaries.
4. 4. Capacitive - veins. These vessels are highly extensible, due to which they can deposit up to 60–75% of the circulating blood volume (CBV), regulating the return of venous blood to the heart. The veins of the liver, skin, lungs and spleen have the most depositing properties.
5. 5. Shunting - arteriovenous anastomoses. When they open, arterial blood is discharged along the pressure gradient into the veins, bypassing the ICR vessels. For example, this happens when the skin is cooled, when the blood flow is directed through arteriovenous anastomoses to reduce heat loss, bypassing the skin capillaries. At the same time, the skin turns pale.

Pulmonary (small) circulation

The ICC serves to oxygenate the blood and remove carbon dioxide from the lungs. After the blood has entered the pulmonary trunk from the right ventricle, it is sent to the left and right pulmonary arteries. The latter are a continuation of the pulmonary trunk. Each pulmonary artery, passing through the gates of the lung, branches into smaller arteries. The latter, in turn, pass into the ICR (arterioles, precapillaries and capillaries). In the ICR, venous blood is converted into arterial blood. The latter enters from the capillaries into venules and veins, which, merging into 4 pulmonary veins (2 from each lung), flow into the left atrium.

Bodily (large) circle of blood circulation

BPC serves to deliver nutrients and oxygen to all organs and tissues and remove carbon dioxide and metabolic products. After the blood has entered the aorta from the left ventricle, it is directed to the aortic arch. Three branches depart from the latter (brachiocephalic trunk, common carotid and left subclavian arteries), which supply blood to the upper limbs, head and neck.

After that, the aortic arch passes into the descending aorta (thoracic and abdominal). The latter at the level of the fourth lumbar vertebra is divided into common iliac arteries, which supply blood to the lower limbs and pelvic organs. These vessels are divided into external and internal iliac arteries. The external iliac artery passes into the femoral artery, supplying arterial blood to the lower extremities below the inguinal ligament.

All arteries, heading to tissues and organs, in their thickness pass into arterioles and further into capillaries. In the ICR, arterial blood is converted into venous blood. Capillaries pass into venules and then into veins. All veins accompany arteries and are named similarly to arteries, but there are exceptions (portal vein and jugular veins). Approaching the heart, the veins merge into two vessels - the inferior and superior vena cava, which flow into the right atrium.

Blood vessels are the most important part of the body, which is part of the circulatory system and permeates almost the entire human body. They are absent only in the skin, hair, nails, cartilage and cornea of ​​​​the eyes. And if they are assembled and stretched into one straight line, then the total length will be about 100 thousand km.

These tubular elastic formations function continuously, transferring blood from the constantly contracting heart to all corners of the human body, saturating them with oxygen and nourishing them, and then returning it back. By the way, the heart pushes more than 150 million liters of blood through the vessels in a lifetime.

The main types of blood vessels are: capillaries, arteries, and veins. Each type performs its specific functions. It is necessary to dwell on each of them in more detail.

Division into types and their characteristics

The classification of blood vessels is different. One of them involves division:

• on arteries and arterioles;
• precapillaries, capillaries, postcapillaries;
• veins and venules;
• arteriovenous anastomoses.

They represent a complex network, differing from each other in structure, size and their specific function, and form two closed systems connected to the heart - circulatory circles.

The following can be distinguished in the device: the walls of both arteries and veins have a three-layer structure:

• an inner layer that provides smoothness, built from the endothelium;
• medium, which is a guarantee of strength, consisting of muscle fibers, elastin and collagen;
• top layer of connective tissue.

Differences in the structure of their walls are only in the width of the middle layer and the predominance of either muscle fibers or elastic ones. And also in the fact that venous - contain valves.

arteries

They deliver blood saturated with useful substances and oxygen from the heart to all cells of the body. By structure, human arterial vessels are more durable than veins. Such a device (a denser and more durable middle layer) allows them to withstand the load of strong internal blood pressure.

The names of arteries, as well as veins, depend on:

Once upon a time it was believed that the arteries carry air and therefore the name is translated from Latin as “containing air”.

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There are such types:

Arteries, leaving the heart, become thinner to small arterioles. This is the name of the thin branches of the arteries, passing into the precapillaries, which form the capillaries.

These are the thinnest vessels, with a diameter much thinner than a human hair. This is the longest part of the circulatory system, and their total number in the human body ranges from 100 to 160 billion.

The density of their accumulation is different everywhere, but the highest in the brain and myocardium. They consist only of endothelial cells. They carry out a very important activity: the chemical exchange between the bloodstream and tissues.

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The capillaries are further connected to the post-capillaries, which become venules - small and thin venous vessels that flow into the veins.

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These are the blood vessels that carry oxygen-depleted blood back to the heart.

The walls of the veins are thinner than the walls of the arteries, because there is no strong pressure. The layer of smooth muscles in the middle wall of the vessels of the legs is most developed, because moving up is not an easy job for the blood under the action of gravity.

Venous vessels (all but the superior and inferior vena cava, pulmonary, collar, renal veins and veins of the head) contain special valves that ensure the movement of blood to the heart. The valves block the return flow. Without them, the blood would drain to the feet.

Arteriovenous anastomoses are branches of arteries and veins connected by fistulas.

Separation by functional load

There is another classification that blood vessels undergo. It is based on the difference in the functions they perform.

There are six groups:

There is another very interesting fact regarding this unique system of the human body. In the presence of excess weight in the body, more than 10 km (per 1 kg of fat) of additional blood vessels are created. All this creates a very large load on the heart muscle.

Heart disease and overweight, and even worse, obesity, are always very tightly linked. But the good thing is that the human body is also capable of the reverse process - the removal of unnecessary vessels while getting rid of excess fat (precisely from it, and not just from extra pounds).

What role do blood vessels play in human life? In general, they do a very serious and important job. They are a transport that ensures the delivery of essential substances and oxygen to every cell of the human body. They also remove carbon dioxide and waste from organs and tissues. Their importance cannot be overestimated.

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The venous and arterial network perform many important functions in the human body. For this reason, physicians note their morphological differences, which manifest themselves in different types of blood flow, but the anatomy of all vessels is the same. The arteries of the lower extremities consist of three layers, external, internal and middle. The inner membrane is called the intima.

It, in turn, is divided into two layers presented: endothelium - it is the lining part of the inner surface of arterial vessels, consisting of flat epithelial cells and subendothelium - located under the endothelial layer. It consists of loose connective tissues. The middle shell consists of myocytes, collagen and elastin fibers. The outer shell, which is called "adventitia", is a fibrous loose tissue of the connective type, with vessels, nerve cells and a lymphatic vascular network.

Human arterial system

The arteries of the lower extremities are blood vessels through which the blood pumped by the heart is distributed to all organs and parts of the human body, including the lower extremities. Arterial vessels are also represented by arterioles. They have three-layered walls consisting of intima, media and adventitia. They have their own classifiers. These vessels have three varieties, which differ from each other in the structure of the middle layer. They are:

• Elastic. The middle layer of these arterial vessels is composed of elastic fibers that withstand the high blood pressure that is formed in them when the blood flow is ejected. They are represented by the aorta and pulmonary trunk.
• Mixed. Here, in the middle layer, a different amount of elastic and myocyte fibers is combined. They are represented by the carotid, subclavian and popliteal arteries.
• Muscular. The middle layer of these arteries consists of separate, circumferentially arranged, myocyte fibers.

The scheme of arterial vessels according to the location of the internal is divided into three types, presented:

• Trunk, providing blood flow in the lower and upper limbs.
• Organic, supplying blood to the internal organs of a person.
• Intraorganic, having their own network, branched out in all organs.

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The human venous system

Considering the arteries, one should not forget that the human circulatory system also includes venous vessels, which, in order to create an overall picture, must be considered together with the arteries. Arteries and veins have a number of differences, but still their anatomy always involves a cumulative consideration.

Veins are divided into two types and can be muscular and non-muscular.

The venous walls of the muscleless type are composed of endothelium and loose connective tissue. Such veins are found in bone tissues, in internal organs, in the brain and retina.

Venous vessels of the muscular type, depending on the development of the myocyte layer, are divided into three varieties, and are underdeveloped, moderately developed and highly developed. The latter are located in the lower extremities providing them with tissue nutrition.

Veins transport blood, which does not contain nutrients and oxygen, but it is saturated with carbon dioxide and decay substances synthesized as a result of metabolic processes. The blood flow travels through the limbs and organs, moving directly to the heart. Often, blood overcomes the speed and gravity at times less than its own. A similar property provides hemodynamics of venous circulation. In the arteries, this process is different. These differences will be discussed below. The only venous vessels that have different hemodynamics and blood properties are the umbilical and pulmonary.

Peculiarities

Consider some of the features of this network:

• Compared to arterial vessels, venous vessels have a larger diameter.
• They have an underdeveloped subendothelial layer and fewer elastic fibers.
• They have thin walls that fall off easily.
• The middle layer, consisting of smooth muscle elements, is poorly developed.
• The outer layer is quite pronounced.
• They have a valve mechanism created by the venous wall and inner layer. The valve consists of myocyte fibers, and the inner leaflets consist of connective tissue. Outside, the valve is lined with an endothelial layer.
• All venous membranes have vascular vessels.

The balance between venous and arterial blood flow is ensured due to the density of the venous network, their large number, venous plexuses, larger than the arteries.

Net

The artery of the femoral region is located in a lacuna formed from vessels. The external iliac artery is its continuation. It passes under the inguinal ligamentous apparatus, after which it passes into the adductor canal, which consists of a wide medial muscle sheet and a large adductor and membranous membrane located between them. From the adducting canal, the arterial vessel exits into the popliteal cavity. The lacuna, consisting of vessels, is separated from its muscular area by the edge of the wide femoral muscular fascia in the form of a sickle. Nerve tissue passes through this area, providing sensitivity to the lower limb. Above is the inguinal ligamentous apparatus.

The femoral artery of the lower extremities has branches represented by:

• Superficial epigastric.
• Surface envelope.
• External sex.
• Deep femoral.

The deep femoral arterial vessel also has a branching, consisting of a lateral and medial artery and a network of perforating arteries.

The popliteal arterial vessel starts from the adductor canal and ends with a membranous interosseous junction with two holes. In the place where the upper opening is located, the vessel is divided into anterior and posterior arterial sections. Its lower border is represented by the popliteal artery. Further, it branches into five parts, represented by arteries of the following types:

• Upper lateral / middle medial, passing under the knee joint.
• Inferior lateral / middle medial, passing through the knee joint.
• Middle genicular artery.
• Posterior artery of the tibial region of the lower limb.

Then there are two tibial arterial vessels - posterior and anterior. The posterior one passes in the popliteal-shin area, located between the superficial and deep muscular apparatus of the posterior part of the leg (there are small arteries of the leg). Next, it passes near the medial malleolus, near the flexor digitorum brevis. Arterial vessels depart from it, enveloping the fibular bone area, a peroneal-type vessel, calcaneal and ankle ramifications.

The anterior arterial vessel passes close to the muscular apparatus of the ankle. It is continued by the dorsal foot artery. Further, an anastomosis occurs with an arcuate arterial area, the dorsal arteries and those that are responsible for blood flow in the fingers depart from it. The interdigital spaces are a conductor for the deep arterial vessel, from which the anterior and posterior sections of the recurrent tibial arteries, the medial and lateral ankle-type arteries, and muscular ramifications depart.

Anastomoses that help people maintain balance are represented by the calcaneal and dorsal anastomosis. The first passes between the medial and lateral arteries of the calcaneus. The second is between the external foot and arcuate arteries. Deep arteries make up an anastomosis of the vertical type.

Differences

What is the difference between the vascular network and the arterial network - these vessels have not only similarities, but also differences, which will be discussed below.

Structure

Arterial vessels are thicker-walled. They contain a large amount of elastin. They have well-developed smooth muscles, that is, if there is no blood in them, they will not fall off. They provide fast delivery of oxygen-enriched blood to all organs and limbs due to the good contractility of their walls. The cells that make up the wall layers allow blood to circulate through the arteries without obstruction.

They have an internal corrugated surface. They have such a structure due to the fact that the vessels must withstand the pressure formed in them due to powerful blood emissions.

Venous pressure is much lower, so their walls are thinner. If there is no blood in them, then the walls fall off. Their muscle fibers have weak contractile activity. Inside the veins have a smooth surface. The blood flow through them is much slower.

Their thickest layer is considered to be the outer one, in the arteries - the middle one. There are no elastic membranes in veins; in arteries, they are represented by internal and external sections.

The form

Arteries have a regular cylindrical shape and a round cross section. Venous vessels have flattening and tortuous shape. This is due to the valve system, thanks to which they can narrow and expand.

Quantity

Arteries in the body are about 2 times less than veins. There are several veins for each middle artery.

valves

Many veins have a valve system that prevents blood flow from moving in the opposite direction. The valves are always paired and are located along the entire length of the vessels opposite each other. Some veins do not have them. In the arteries, the valve system is only at the outlet of the heart muscle.

Blood

More blood flows in veins than in arteries.

Location

Arteries are located deep in tissues. They come to the skin only in the zones of listening to the pulse. All people have approximately the same heart rate zones.

Direction

Through the arteries, blood flows faster than through the veins, due to the pressure of the force of the heart. First, the blood flow is accelerated, and then it decreases.

Venous blood flow is represented by the following factors:

• The force of pressure, which depends on the blood tremors coming from the heart and arteries.
• Suction of cardiac force during relaxation between contractile movements.
• Suction venous action during breathing.
• Contractile activity of the upper and lower extremities.

Also, the blood supply is located in the so-called venous depot, represented by the portal vein, the walls of the stomach and intestines, the skin and the spleen. This blood will be pushed out of the depot in the event of a large blood loss or strong physical exertion.

Color

Since arterial blood contains a large number of oxygen molecules, it has a scarlet color. Venous blood is dark because it contains decay elements and carbon dioxide.

During arterial bleeding, the blood gushes out, and during venous bleeding, it flows in a jet. The first carries a serious danger to human life, especially if the arteries of the lower extremities are damaged.

Distinctive features of veins and arteries are:

• Transportation of blood and its composition.
• Different wall thickness, valvular system and strength of blood flow.
• number and depth of location.

Veins, unlike arterial vessels, are used by physicians to draw blood and inject drugs directly into the bloodstream to treat various ailments.

Knowing the anatomical features and the layout of the arteries and veins, not only on the lower extremities, but throughout the body, you can not only correctly provide first aid for bleeding, but also understand how blood circulates through the body.

Anatomy (video)

Human arteries and veins perform different jobs in the body. In this regard, one can observe significant differences in the morphology and conditions for the passage of blood, although the general structure, with rare exceptions, is the same for all vessels. Their walls have three layers: inner, middle, outer.

The inner shell, called intima, without fail has 2 layers:

• the endothelium lining the inner surface is a layer of squamous epithelial cells;
• subendothelium - located under the endothelium, consists of connective tissue with a loose structure.

The middle shell is made up of myocytes, elastic and collagen fibers.

The outer shell, called "adventitia", is a fibrous connective tissue with a loose structure, equipped with vascular vessels, nerves, and lymphatic vessels.

arteries

These are blood vessels that carry blood from the heart to all organs and tissues. There are arterioles and arteries (small, medium, large). Their walls have three layers: intima, media and adventitia. Arteries are classified according to several criteria.

According to the structure of the middle layer, three types of arteries are distinguished:

• Elastic. Their middle layer of the wall consists of elastic fibers that can withstand the high blood pressure that develops when it is ejected. This species includes the pulmonary trunk and aorta.
• Mixed (muscular-elastic). The middle layer consists of a variable number of myocytes and elastic fibers. These include carotid, subclavian, iliac.
• Muscular. Their middle layer is represented by individual myocytes located circularly.

By location relative to the organs of the artery are divided into three types:

• Trunk - supply blood to parts of the body.
• Organ - carry blood to the organs.
• Intraorganic - have branches inside the organs.

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They are non-muscular and muscular.

The walls of non-muscular veins consist of endothelium and loose connective tissue. Such vessels are found in bone tissue, placenta, brain, retina, and spleen.

Muscular veins, in turn, are divided into three types, depending on how myocytes are developed:

• poorly developed (neck, face, upper body);
• medium (brachial and small veins);
• strongly (lower body and legs).

In addition to the umbilical and pulmonary veins, blood is transported, which gave up oxygen and nutrients and took away carbon dioxide and decay products as a result of metabolic processes. It moves from the organs to the heart. Most often, she has to overcome gravity and her speed is less, which is associated with the peculiarities of hemodynamics (lower pressure in the vessels, the absence of its sharp drop, a small amount of oxygen in the blood).

The structure and its features:

• Larger in diameter than arteries.
• Poorly developed subendothelial layer and elastic component.
• The walls are thin and fall off easily.
• The smooth muscle elements of the middle layer are rather poorly developed.
• Pronounced outer layer.
• The presence of a valvular apparatus, which is formed by the inner layer of the vein wall. The base of the valves consists of smooth myocytes, inside the valves - fibrous connective tissue, outside they are covered with a layer of endothelium.
• All shells of the wall are endowed with vascular vessels.

The balance between venous and arterial blood is ensured by several factors:

• a large number of veins;
• their larger caliber;
• dense network of veins;
• formation of venous plexuses.

Differences

How are arteries different from veins? These blood vessels have significant differences in many ways.

Arteries and veins, first of all, differ in the structure of the wall

According to the structure of the wall

Arteries have thick walls, many elastic fibers, well developed smooth muscles, and do not collapse unless filled with blood. Due to the contractility of the tissues that make up their walls, oxygenated blood is quickly delivered to all organs. The cells that make up the layers of the walls ensure the unhindered passage of blood through the arteries. Their inner surface is corrugated. The arteries must withstand the high pressure that is created by the powerful ejections of blood.

The pressure in the veins is low, so the walls are thinner. They fall off in the absence of blood in them. Their muscle layer is not able to contract like that of the arteries. The surface inside the vessel is smooth. Blood moves slowly through them.

In veins, the thickest shell is considered to be the outer, in the arteries - the middle one. Veins do not have elastic membranes; arteries have internal and external.

By shape

Arteries have a fairly regular cylindrical shape, they are round in cross section.

Due to the pressure of other organs, the veins are flattened, their shape is tortuous, they either narrow or expand, which is associated with the location of the valves.

In count

There are more veins in the human body, fewer arteries. Most medium arteries are accompanied by a pair of veins.

By the presence of valves

Most veins have valves that prevent blood from flowing backwards. They are located in pairs opposite each other throughout the vessel. They are not found in the portal caval, brachiocephalic, iliac veins, as well as in the veins of the heart, brain and red bone marrow.

In the arteries, valves are located at the exit of the vessels from the heart.

By blood volume

The veins circulate about twice as much blood as the arteries.

By location

Arteries lie deep in the tissues and approach the skin only in a few places where the pulse is heard: on the temples, neck, wrist, and instep. Their location is about the same for all people.

The veins are mostly located close to the surface of the skin.

The location of the veins may vary from person to person.

To ensure the movement of blood

In the arteries, blood flows under the pressure of the force of the heart, which pushes it out. At first, the speed is about 40 m/s, then it gradually decreases.

Blood flow in the veins occurs due to several factors:

• pressure force, depending on the impulse of blood from the heart muscle and arteries;
• the suction force of the heart during relaxation between contractions, that is, the creation of negative pressure in the veins due to the expansion of the atria;
• suction action on the chest veins of respiratory movements;
• contraction of the muscles of the legs and arms.

In addition, about a third of the blood is in the venous depots (in the portal vein, spleen, skin, walls of the stomach and intestines). It is pushed out from there if it is necessary to increase the volume of circulating blood, for example, with massive bleeding, with high physical exertion.

By color and composition of blood

Arteries carry blood from the heart to the organs. It is enriched with oxygen and has a scarlet color.

Veins provide blood flow from tissues to the heart. , which contains carbon dioxide and decomposition products formed during metabolic processes, has a darker color.

Arterial and have different signs. In the first case, the blood is ejected in a fountain, in the second, it flows in a jet. Arterial - more intense and dangerous for humans.

Thus, the main differences can be identified:

• Arteries transport blood from the heart to the organs, veins carry it back to the heart. Arterial blood carries oxygen, venous blood returns carbon dioxide.
• Arterial walls are more elastic and thicker than venous ones. In the arteries, blood is pushed out with force and moves under pressure, in the veins it flows calmly, while valves do not allow it to move in the opposite direction.
• There are 2 times less arteries than veins, and they are deep. Veins are located in most cases superficially, their network is wider.

Veins, unlike arteries, are used in medicine to obtain material for analysis and to deliver drugs and other fluids directly into the bloodstream.