Arteries of the Human Body: Aortic, Subclavian, Iliac & Femoral
Aorta
The aorta is the largest blood vessel in the human body. The first arteries arising from the aorta are the coronary arteries. The left coronary artery is much more developed than the right. The right coronary artery is posterior, and the left is anterior. The lack of irrigation in the right ventricle (RV) is more bearable and has a better prognosis than the lack of irrigation in the left ventricle (LV). The diaphragm is in contact with the RV, protecting the heart when myocardial cells fail. Furthermore, the RV does not need to exert as much effort as the LV. The aortic valve has three leaflets; it opens during systole and closes during diastole. The aorta follows an ascending path and then descends, forming the arch of the descending aorta. The aorta passes through the diaphragm via the hiatus, or diaphragmatic hole, and becomes the abdominal aorta.
Aortic Arch
At the level of the aortic arch, there are three arterial trunks extending upward in a fork:
- The first is the brachiocephalic trunk, which divides into two arteries: one that goes to the upper limb (right subclavian) and another that goes to the head (right common carotid).
- The second trunk is the left common carotid artery (carotid sinus -> left carotid and right carotid).
- The third trunk is the left subclavian artery.
Subclavian, Axillary, Brachial, Radial, and Ulnar Arteries
The subclavian artery moves between the scalene muscles and goes below the clavicle. Once it leaves, it sinks to the bottom of the armpit and changes its name to the axillary artery.
After leaving the axilla, the axillary artery goes down the arm and becomes the brachial artery. It splits into two: a very thick anteromedial artery called the superficial brachial artery, and a smaller one that runs behind the arm to the biceps muscles, called the deep brachial artery. The superficial brachial artery runs through the front of the arm, with very few branches; it is an artery of passage. The deep brachial artery supplies all the posterior muscles of the arm.
The upper brachial artery bifurcates into three areas:
- The radial artery, which runs along the outside.
- The ulnar artery, which runs along the inside.
- The interosseous artery, which runs between the two bones, between the ulna and radius, via the interosseous membrane.
The radial and ulnar arteries branch out to different radial and ulnar muscles. The radial artery supplies the radial muscles to the epicondyle. The ulnar artery supplies the ulnar muscles of the medial epicondyle.
At the level of the wrist, the radial and ulnar arteries unite. In the vascular system, when an area is without arterial supply, collateral circulations are formed to try to remedy the lack of arterial blood flow.
Deep palmar arch: The radial artery crosses the palm over the five metacarpals to the ulnar artery, thus ensuring the vascularization of the hand and fingers. From the superficial and deep palmar arches, some arteries emerge, called collateral arteries, which extend the entire length of the finger to the pad.
Iliac and Femoral Arteries
The aorta transitions from the thoracic aorta to the abdominal aorta as it passes through the aortic hiatus of the diaphragm. The abdominal aorta divides into two branches at the level of the fourth lumbar vertebra, called the right and left iliac arteries. Each iliac artery is subdivided into two branches: the internal iliac artery and the external iliac artery. The internal iliac artery supplies the bladder, uterus, rectum, genitalia, etc. Once it passes beneath the inguinal ligament, it is called the femoral artery. The femoral artery, in turn, bifurcates into the deep femoral artery, which supplies the deep muscles of the lower limb, and the superficial femoral artery, which supplies the anterior muscles.