The Aorta and Its Branches

The aorta is the biggest artery in the body and also is split into 3 parts: the ascending aorta, arch that the aorta, and also descending aorta.

You are watching: Which of the following veins is located inferior to the trunk


Key Takeaways

Key PointsThe blood is pumped from the left ventricle right into the aorta and from there branches come all components of the body.The aorta is divided into 3 parts: the ascending aorta (where the aorta initially leaves the heart and points toward the head), the arch of the aorta (where the aorta transforms direction), and the descending aorta (where the aorta points towards the feet).The ascending aorta has two little branches, the left and also right coronary arteries, that administer blood come the love muscle.The arch of the aorta has three branches: the brachiocephalic artery (which divides right into right usual carotid artery and also the appropriate subclavian artery), the left typical carotid artery, and the left subclavian artery. These arteries administer blood to both arms and also the head.Within the abdomen, the to decrease aorta branches right into the two usual iliac arteries; these carry out blood to the pelvis and, eventually, the legs.Key Termsdescending aorta: The an ar of the aorta the passes inferiorly in the direction of the feet.ascending aorta: The region of the aorta directly attached to the heart the passes superiorly in the direction of the head.arch of the aorta: The an ar of the aorta that changes direction between the ascending and also descending aorta.

The aorta is the biggest artery in the systemic circulatory system. Blood is pumped native the left ventricle right into the aorta and also from there branches to all components of the body. The aorta is an elastic artery, definition it is able come distend. Once the left ventricle contract to pressure blood right into the aorta, the aorta expands. This stretching generates the potential energy that helps keep blood pressure during diastole, because during this time the aorta contract passively.


*

Diagram of human being Heart: This chart of the human being heart reflects all the significant vessels, and arrows indicate the direction of circulation through the heart.


The aorta is divided into three parts: the ascending aorta, where the aorta initially leaves the heart and also points superiorly towards the head; the arch that the aorta whereby the aorta transforms direction; and the descending aorta where the aorta clues inferiorly toward the feet.



The ascending aorta has two small branches, the left and right coronary arteries. These arteries carry out blood come the love muscle, and also their blockage is the cause myocardial infarctions or love attacks.

The arch that the aorta has three branches: the brachiocephalic artery, which itself divides right into right typical carotid artery and also the ideal subclavian artery, the left common carotid artery, and the left subclavian artery. This arteries provide blood come both arms and also the head.

The descending aorta is the biggest artery in the body; it runs from the heart down the size of the chest and abdomen. The is divided into 2 portions, the thoracic and also abdominal, in correspondence through the two an excellent cavities of the tribe in which it sits. Within the abdomen, the diminish aorta branches into the two usual iliac arteries that carry out blood come the pelvis and, eventually, the legs.


Ascending Aorta

The ascending aorta is the very first portion the the aorta; it consists of the aortic sinuses, the bulb of the aorta, and also the sinotubular junction.


Learning Objectives

Describe the duty of the ascending aorta in circulation


Key Takeaways

Key PointsThe ascending aorta overcome diagonally upward, forward, and to the right, in the direction the the heart ‘s axis.The aortic sinuses finish at the sinotubular junction, the allude in the ascending aorta wherein the aorta becomes a tubular structure.The ascending aorta has actually two branching vessels, the left and right coronary arteries, which it is provided blood come the love muscle.Key Termsaortic sinuses: one aortic sinus is one of the anatomic dilations of the ascending aorta, which wake up just above the aortic valve.sinotubular junction: The sinotubular junction is the suggest in the ascending aorta wherein the aortic sinuses end and the aorta becomes a tubular structure.bulb of the aorta: at the union that the ascending aorta through the aortic arch, the caliber the the vessel increases with a bulging that its appropriate wall. This dilation is termed the bulb of the aorta, and on transverse section presents a rather oval figure.

The ascending aorta is a section of the aorta beginning at the upper component of the base of the left ventricle, ~ above a level with the reduced border that the 3rd costal cartilage behind the left half of the sternum; it passes diagonally upward, forward, and also to the right, in the direction the the heart’s axis, together high as the top border of the 2nd right costal cartilage. Its complete length is about five centimeters.



The aortic source is the part of the ascending aorta beginning at the aortic annulus, the fibrous attachment in between the heart and also the aorta, and extending to the sinotubular junction. Just above the aortic valve room three small dilations referred to as the aortic sinuses. The 2 anterior sinuses offer rise come the coronary arteries, while the 3rd posterior sinus does not usually provide rise to any vessels and also so is known as the non-coronary sinus.

The sinotubular junction is the allude in the ascending aorta whereby the aortic sinuses end and also the aorta i do not care a tubular structure.

At the junction of the ascending aorta with the aortic arch, the caliber the the vessel boosts with a bulging of its right wall. This dilatation is termed the “bulb of the aorta.” The ascending aorta is contained within the pericardium. That is fastened in a pipe of the serous pericardium, which also encloses the pulmonary artery.

The ascending aorta is spanned at its beginning by the stems of the pulmonary artery and, higher up, is separated indigenous the sternum by the pericardium, the right pleura, the anterior margin the the best lung, some loosened areolar tissue, and the remains of the thymus. Posteriorly, it rests upon the left atrium and right pulmonary artery.


Arch the the Aorta

The arch the the aorta complies with the ascending aorta and also begins at the level that the 2nd sternocostal coupling of the appropriate side.


Learning Objectives

Describe the function of arch that the aorta


Key Takeaways

Key PointsThree vessels come out of the aortic arch: the brachiocephalic artery, the left usual carotid artery, and also the left subclavian artery.These vessels supply blood to the head, neck, thorax and upper limbs.In some individuals, the left typical carotid artery and left subclavian artery might arise native the brachiocephalic artery quite than the aortic arch.Key Termsarch the the aorta: likewise called the transverse aortic arch, is constant with the upper border the the ascending aorta and also begins in ~ the level that the top border that the second sternocostal coupling of the ideal side.

The arch that the aorta, or the transverse aortic arch, is constant with the upper border the the ascending aorta and also begins in ~ the level the the upper border the the second sternocostal coupling of the best side. The arch of the aorta operation at first upward, backward, and to the left in prior of the trachea; that is climate directed behind on the left side of the trachea and also finally overcome downward on the left side of the human body of the fourth thoracic vertebra. At the reduced border, this vertebra becomes constant with the diminish aorta.

Three vessels come the end of the aortic arch: the brachiocephalic artery, the left typical carotid artery, and also the left subclavian artery. These vessels supply blood to the head, neck, thorax and upper limbs. In approximately 20% that individuals, the left typical carotid artery occurs from the brachiocephalic artery fairly than the aortic arch, and also in about 7% of individuals the left subclavian artery also arises here.

Thoracic Aorta

The thoracic aorta is the section of the aorta the travels through the thoracic cavity to bring blood come the head, neck, thorax and arms.


Learning Objectives

Explain the function of the thoracic aorta


Key Takeaways

Key PointsThe thoracic aorta is included in the posterior mediastinal cavity, begins at the fourth thoracic vertebra whereby it is consistent with the aortic arch, and also ends in prior of the reduced border the the twelfth thoracic vertebra.Branches indigenous the thoracic aorta include the bronchial arteries, the mediastinal arteries, the esophageal arteries, the pericardial arteries, and also the exceptional phrenic artery.The thoracic aorta and the esophagus run parallel for many of the length, v the esophagus lying top top the appropriate side the the aorta. In ~ the lower component of the thorax, the stomach is put in front of the aorta, situated on its left next close to the diaphragm..Key Termsmediastinal cavity: The main compartment that the thoracic cavity. It includes the heart, the good vessels that the heart, the esophagus, the trachea, the phrenic nerve, the cardiac nerve, the thoracic duct, the thymus, and also the lymph nodes that the central chest.Thoracic Aorta: consisted of in the posterior mediastinal cavity, it starts at the lower border of the 4th thoracic vertebra where it is constant with the aortic arch, and also ends in prior of the reduced border that the twelfth thoracic vertebra, at the aortic hiatus in the diaphragm whereby it becomes the ab aorta.

The thoracic aorta forms component of the descending aorta and also is continuous with the aortic arch in ~ its origin before ending up being the abdominal muscle aorta. Consisted of within the posterior mediastinal cavity, it begins at the lower border the the 4th thoracic vertebra wherein it is continuous with the aortic arch, and also ends in former of the lower border of the twelfth thoracic vertebra in ~ the aortic hiatus in the diaphragm. In ~ its commencement, the thoracic aorta is positioned on the left the the vertebral column; it ideologies the median line as it descends, and at its termination lies straight in front of the column.

The thoracic aorta’s relation, from over downward, is as follows: anteriorly with the root of the left lung, the pericardium, the esophagus and also the diaphragm; posteriorly v the vertebral column; top top the appropriate side with the hemiazygos veins and thoracic duct; and on the left side v the left pleura and lung. The stomach lies ~ above the best side that the aorta for many of the length, but at the lower part of the thorax is inserted in front of the aorta and also close come the diaphragm, positioned on that left side.

As that descends in the thorax, the aorta gives off numerous paired branches. In descending stimulate these are the bronchial arteries, the mediastinal arteries, the esophageal arteries, the pericardial arteries, and also the exceptional phrenic artery. The posterior intercostal arteries room branches that originate throughout the size of the posterior facet of the thoracic aorta.


Abdominal Aorta

The abdominal aorta is the largest artery in the ab cavity and also supplies blood to many of the ab organs.


Learning Objectives

Describe the ab aorta


Key Takeaways

Key PointsThe abdominal muscle aorta lies contempt to the left of the midline that the body.The abdominal aorta has a venous equivalent called the worse vena cava the travels parallel to it ~ above its right side.The ab aorta branches into plenty of arteries the supply blood to the ab organs.Key Termsabdominal aorta: The biggest artery in the abdominal muscle cavity. As component of the aorta, that is a direct continuation of the descending aorta (of the thorax).omentum: either of two folds that the peritoneum that assistance the viscera.inferior vena cava: The huge vein which return blood native the reduced extremities and the pelvic and ab organs come the best atrium that the heart.

The ab aorta is the largest artery in the abdominal cavity. As part of the diminish aorta, that is a direct continuation of the thoracic aorta.

It begins at the level the the diaphragm, cross it via the aortic hiatus. This feet in the diaphragm that enables the passage of the good vessels at the vertebral level that T12. The ab aorta travels under the posterior wall surface of the abdomen, anterior to the vertebral column, complying with the curvature the the lumbar vertebrae. The ab aorta runs parallel to the inferior vena cava, located simply to the best of the abdominal aorta.

The abdominal muscle aorta lies slightly to the left that the midline the the body. That is spanned anteriorly by the lesser omentum and stomach. Posteriorly, the is separated from the lumbar vertebrae by the anterior longitudinal ligament and also left lumbar veins.

The abdominal aorta offers blood to lot of the abdominal muscle cavity through countless branches that end up being smaller in diameter as it descends. Terminally that branches right into the paired common iliac arteries, which it is provided the pelvis and lower limbs.


Arteries of the Pelvis and also Lower Limbs

The ab aorta divides into the significant arteries the the leg: the femoral, popliteal, tibial, dorsal foot, plantar, and fibular arteries.


Learning Objectives

Outline blood circulation in the arteries of the pelvis and lower limbs


Key Takeaways

Key PointsThe pelvic cavity is provided by the paired internal iliac arteries.The interior iliac artery divides into posterior and also anterior trunks which supply the reproductive and other organs of the pelvis through blood.Key Termsinternal iliac arteries: developed when the typical iliac artery divides the inner iliac artery at the vertebral level L5 descends inferiorly right into the lesser pelvis.

The pelvic cavity is largely supplied by the paired inner iliac arteries, formed when the typical iliac artery divides the inner iliac artery in ~ the vertebral level L5 descends inferiorly right into the lesser pelvis. The exterior iliac artery passes into the thigh, ending up being the femoral artery.

At the most superior border the the greater sciatic foramen, the large opening to the behind of the pelvis, the inner iliac artery divides into anterior and also posterior trunks.

The anterior trunk offers rise to countless arteries that supply the offal of the pelvis and also the gluteal and also adductor muscle of the leg. An essential branches incorporate the obturator artery, the inferior vesical artery in men and also the equivalent vaginal artery in females, and the rectal and also gluteal arteries.

The posterior trunk gives rise come arteries the supply the posterior pelvic wall surface and the gluteal region, including the iliolumbar artery that provides the psoas major muscle, the lateral sacral arteries, and the remarkable gluteal artery.

Principal Veins

Veins space blood ship that bring blood in the direction of the heart, have actually thin, inelastic walls, and contain numerous valves.


Learning Objectives

Distinguish amongst the primary veins that the circulatory system


Key Takeaways

Key PointsVeins, blood ship which return blood come the heart, are different in structure and role from the arteries, which carry blood to the circulation.Most veins lug deoxygenated blood from the tissues ago to the heart. The exceptions space the pulmonary and also umbilical veins, both the which bring oxygenated blood come the heart, yet the umbilical vein deteriorates shortly after birth.The venae cavae are two large veins which drainpipe into the ideal atrium that the heart, returning the bulk of blood indigenous the systemic circulation.Key Termsvein: A blood vessel the transports blood from the capillaries ago to the heart.

In the circulatory system, veins room blood vessels that carry blood towards the heart. Veins have thin, inelastic walls, and also contain many valves in order to stop backflow of blood. Many veins lug deoxygenated blood from the tissues ago to the heart through the exception of the pulmonary and umbilical veins, both that which bring oxygenated blood to the heart.


*

Principle Veins: This diagram reflects the principal veins the the person body and their locations.


Veins have the right to be broadly classified based upon their depth in ~ the body. Superficial veins are located close come the surface of the body and also have no matching arteries, such together the good saphenous vein which operation the size of the leg. The deep veins lie depths in the body and often run nearby to corresponding arteries, such together the femoral vein which sits adjacent to the femoral artery in the thigh. Deep veins are frequently of larger caliber than superficial veins and also carry the bulk of the blood within the circulatory system. Connecting veins, or perforator veins if lock pass with a huge muscle mass, directly attach superficial and direct veins. The above veins form part that the systemic circulatory system. The pulmonary veins and venules that operation from the lungs to the heart form part that the pulmonary circulatory system and also are distinctive from other veins in the they lug oxygenated blood.

Venae Cavae

The venae cavae space the veins with the largest diameter. Both get in the best atrium that the heart through the premium vena cava transferring blood native the arms, head, and thoracic cavity and also the worse vena cava moving blood indigenous the legs and also abdomen. The inferior vena cava operation parallel come the ab aorta.

The exceptional vena cava is developed from the brachiocephalic veins which are in turn created from the subclavian and internal jugular veins that offer the arm and also head respectively. The inferior vena cava is created from the typical iliac veins that offer the legs and also abdomen. The renal and also hepatic veins from the kidneys and liver respectively likewise feed into the worse vena cava.

Other essential Veins

Other important venous systems incorporate the cardiac veins, i beg your pardon return blood native the heart tissue ago to the basic circulation. The cardiac veins merge right into the coronary sinus, i m sorry empties directly into the ideal atrium.

The pulmonary veins are huge blood vessels which receive oxygenated blood indigenous the lungs and return it to the left atrium the the heart. Over there are 4 pulmonary veins, two from every lung, every of which creates from three to four bronchial veins. In around 25% of individuals, the left pulmonary veins may merge right into a single vein; the same effect on the right side is only seen in around 3% the individuals.

The hepatic portal vein carries blood from the gastrointestinal tract to the liver. The portal vein is often described as a false vein since it conducts blood between capillary networks fairly than between a capillary network and the heart. It features to supply the liver through blood and also required metabolites, but likewise ensures that ingested building materials are very first processed in the liver prior to reaching the more comprehensive systemic circulation.


Veins of the Head and also Neck

In the head and also neck, blood circulates from the top systemic loop, which originates in ~ the aortic arch.


Key Takeaways

Key PointsThe dural sinuses within the dura mater neighboring the mind receive blood indigenous the brain. From this sinuses, blood eventually enters the inner jugular vein.The head and neck are cleared of blood by the internal and external jugular veins.Key Termsjugular vein: any type of of several veins on every side the the neck that drain the brain, face and also neck the deoxygenated blood.

The superficial exterior jugular vein is formed from the retromandibular vein and also the posterior auricular vein in ~ a point surrounding to the mandible. The outside jugular vein passes down the neck and also underneath the clavicle prior to draining right into the subclavian vein.

The deep-lying internal jugular vein obtain blood native the dural venous sinuses in the brain as well as the cerebral and also cerebellar veins. Dural sinuses room composed of dural mater lined v endothelium, making them unique from arteries, veins, and also capillaries. The dural sinuses receive blood from the veins that drainpipe the brain and skull.

Formed at the base of the mind from the worse petrosal sinus and also the sigmoid sinus, the interior jugular vein runs down the side of the neck surrounding to the interior carotid artery. And also removing blood indigenous the brain, the anterior retromandibular, facial, and also lingual veins likewise drain right into the inner jugular. Top top exiting the neck, the interior jugular vein merges v the subclavian vein to form the brachiocephalic vein.

Additional veins such as the occipital, deep cervical, and also thyroid veins drain straight into the brachiocephalic vein.

Veins that the upper Limbs

The veins the the top extremity are split into superficial and also deep veins, denote their family member depths from the skin.


Key Takeaways

Key PointsThe brachial, radial, and also ulnar veins are the significant deep veins that drainpipe blood from the arm.The major superficial veins the the arm include the cephalic and also basilic veins, and the median cubital vein which joins the 2 at the elbow.At the shoulder, the brachial and also basilic veins unify to form the axillary vein, come which the cephaliac vein merges to form the subclavian vein.Key Termsbrachial vein: operation from the elbow to the shoulder parallel to the brachial artery.cephalic vein: arises from the dorsal venous network the the hand and also passes the elbow anteriorly, continuing up the upper arm to the shoulder.median cubital vein: The vein that web links the basilic and also cephalic veins.basilic vein: located medially to the cephalic vein, complying with a similar path.

(a) Deep veins the the top extremity (b) Superficial veins the the upper extremity: The veins of the top extremity are divided into two sets, superficial and deep. The deep veins are shown in blue. The superficial veins that the upper extremity are presented in blue.


Veins that the arm room either deep or superficial and are responsible for draining the hand and arm.

The significant deep veins the the arm are the radial and also ulnar veins, which run along the size of their particular bones and also merge in ~ the elbow to form the combine brachial vein. The brachial vein runs from the elbow approximately the shoulder parallel to the brachial artery.

The significant superficial veins that the top limb are the cephalic, mean cubital and basilic veins. The cephalic vein arises from the dorsal venous network of the hand and also passes the elbow anteriorly, proceeding up the top arm come the shoulder. The basilic vein follows a comparable path but is situated medially to the cephalic vein. In ~ the elbow, the basilic and also cephalic veins are attached by the mean cubital vein, from which blood is often drawn.

At the shoulder, the basilic vein overcome deep right into the arm and also merges v the brachial veins to form the axillary vein, come which the cephaliac vein merges, developing the subclavian vein.


Veins of the Thorax

The veins that the thorax drain deoxygenated blood indigenous the thorax region for go back to the heart.


Key Takeaways

Key PointsMajor veins that the thorax include the superior and also inferior vena cava.The exceptional vena cava is formed by the left and right brachiocephalic veins, which receive blood from the upper limbs, head and neck.The inferior vena cava returns blood native the abdomen and lower limbs. The hepatic veins the the liver and also renal veins that the kidney drain straight into the inferior vena cava.Key Termssupreme intercostal vein: A paired vein the drains the an initial intercostal room on its equivalent side.internal thoracic vein: Drains the chest wall surface and breasts.inferior vena cava: returns blood native the abdomen and also lower limbs to the appropriate atrium of the heart.superior vena cava: developed from the left and right brachiocephalic veins, this vein return deoxygenated blood indigenous the upper fifty percent of the body and carries blood native the top limbs, head, and also neck via the thyroid and jugular veins.

Two venae cavae return deoxygenated blood native the systemic circulation to the appropriate atrium of the heart.

The remarkable vena cava, created from the left and also right brachiocephalic veins, returns deoxygenated blood indigenous the upper fifty percent of the body and also carries blood from the upper limbs, head, and also neck via the thyroid and also jugular veins. It is join just before entering the love by the azygos vein, which runs up the appropriate side that the thoracic vertebral column and transports blood native the external thoracic cavity.

The inner thoracic vein is a vessel the drains the chest wall and breasts. Bilaterally, it arises from the superior epigastric vein, accompanies the inner thoracic artery follow me its course, and also terminates in the brachiocephalic vein.

The supreme intercostal vein is a combine vein that drains the an initial intercostal an are on its corresponding side. It commonly drains into the brachiocephalic vein.

The inferior vena cava return blood native the abdomen and lower limbs to the best atrium that the heart. The renal veins native the kidney and also hepatic veins of the liver drain straight into the worse vena cava. Additionally, the superior and inferior phrenic veins drain the diaphragm and also usually open right into the interior mammary vein and also inferior vena cava, respectively.


Veins the the Abdomen and also Pelvis

The major veins of the abdomen and pelvis return deoxygenated blood native the abdomen and also pelvis to the heart.


Key Takeaways

Key PointsThe external iliac vein, the upward continuation of the femoral vein, passes upward follow me the pelvis and also ends to kind the typical iliac vein.The tributaries that feed right into the external iliac vein encompass the worse epigastric, deep iliac circumflex, and pubic veins.The worse epigastric vein refers to the vein that drains right into the exterior iliac vein and also arises native the premium epigastric vein.Key TermsExternal iliac vein: big veins that attach the femoral veins come the usual iliac veinsCommon iliac vein: developed by the exterior iliac veins and also internal iliac veins.

A variety of veins eliminate deoxygenated blood native the abdomen and pelvis. The external iliac vein, the upward continuation of the femoral vein, overcome upward along the pelvis and ends to form the typical iliac vein.The tributaries that the external iliac vein room the worse epigastric, deep iliac circumflex, and pubic veins.

The internal iliac vein starts near the upper component of the higher sciatic foramen, the large opening in ~ the behind of the pelvis, passes increase behind and slightly medial to the interior iliac artery and, at the brim that the pelvis, joins with the exterior iliac vein to type the common iliac vein.


The left and also right usual iliac veins come with each other in the abdomen in ~ the level the the fifth lumbar vertebra, developing the abdominal vena cava. They drainpipe blood indigenous the pelvis and also lower limbs.

The premium epigastric vein describes a blood vessel the carries deoxygenated blood and drains into the interior thoracic vein. The anastomoses with the worse epigastric vein at the level the the umbilicus and also drains the anterior component of the abdominal wall surface and few of the diaphragm.

The worse epigastric vein describes the vein that drains into the external iliac vein and also arises from the premium epigastric vein.

The deep circumflex iliac vein is created by the union the the venae comitantes the the deep iliac circumflex artery, and also joins the outside iliac vein about 2 cm over the inguinal ligament.


Veins of the reduced Limbs

The deep veins of the lower extremity have valves because that unidirectional flow and also accompany the arteries and their branches.


Key Takeaways

Key PointsThe tibial veins unite to kind the popliteal vein.The femoral vein is the ascending component of the popliteal vein.The femoral vein accompanies the femoral artery right into the thigh. The is later on joined by the great saphenous vein forming the exterior iliac vein.Key Termspopliteal vein: acquired from the merger of the tibial veins it develops the femoral vein mid thigh.great saphenous ve: A lengthy vein which runs the length of the leg before joining the femoral vein to type the exterior iliac vein.Femoral Vein: A blood vessel the accompanies the femoral artery in the thigh. It merges through the an excellent saphenous vein to type the outside iliac vein.Tibial Vein: Blood vessel of the calves i beg your pardon return blood from the foot, ankle and calf and merges into the popliteal vein behind the knee.

The deep veins the the leg companion the arteries and also their branches and possess countless valves that help in unidirectional blood flow. The musculature the the foot is an essential in generating pressure in the veins to avoid pooling.

The posterior and anterior tibial veins return blood native the calf, ankle, and foot and also merge into the popliteal vein behind the knee. The popliteal vein climate carries blood native the knee joint up with the thigh. Mid-thigh, it becomes the femoral vein, which is closely connected with the femoral artery. The femoral vein merges through the great saphenous vein in the groin to kind the outside iliac vein.


(a) Veins of the reduced extremities and also (b) Veins the the reduced extremities: The an excellent saphenous vein and also its tributaries, presented in blue, drain blood native the lower limbs. The popliteal vein, presented here in blue, extends indigenous the hip come the knee and also helps drainpipe blood indigenous the reduced extremities.

See more: What Is Dover The Capital Of Dover, Delaware, Dover, Delaware


Running the complete length of the leg, making that the longest vein in the body, the an excellent saphenous vein is a superficial vein the returns blood indigenous the foot and superficial muscles of the leg before merging with the femoral vein to kind the exterior iliac vein.