Anatomy of Major Arteries: Lower Limbs, Abdomen, and Head
Anatomy of Major Arteries
Scarpa’s Triangle
Scarpa’s triangle is formed by the vessels and nerves of the lower limbs, covered only by the fascia of the thigh, fat, and skin. It is a vulnerable area because the vessels and nerves are more superficial there.
Key Structures in Scarpa’s Triangle:
- Femoral artery
- Femoral vein
- Crural nerve
- Sartorius muscle
- Pectineus muscle
- Gracilis muscle
- Iliopsoas muscle
Lower Limb Arteries
The popliteal artery, tibial arteries, dorsalis pedis artery, plantar arteries, and collateral arteries supply the lower limb.
The superficial femoral artery reaches the insertion of the femur and knee via the popliteal region on the back of the leg, passing through the two femoral condyles. Once in this region, it becomes known as the popliteal artery. The popliteal artery is located behind the tibia, branching and leading to the posterior and anterior tibial arteries. The posterior tibial artery passes behind the medial malleolus and branches into the arteries supplying the foot. The anterior tibial artery passes just in front of the interosseous membrane between the tibia and fibula. At the ankle, it is called the dorsalis pedis artery, which supplies the dorsum of the foot and tendons and can be felt on the back of the foot. The posterior tibial artery divides into plantar arteries, which run through the foot muscles and anastomose to form an arch, leading to the most important collateral movements. The posterior circulation has more flow, gives more branches, and has several interfaces with the anterior circulation.
Abdominal Arteries
The renal artery, mesenteric artery, and median sacral artery are major abdominal arteries.
The abdominal aorta gives rise to the celiac artery, from which the hepatic arteries and inferior mesenteric artery branch, along with vessels supplying the stomach and part of the small and large intestines. The left and right renal arteries enter the kidneys via the renal hilum and are distributed throughout the renal parenchyma, crucial for kidney function and filtering. The inferior mesenteric artery supplies the distal portion of the small intestine, sigmoid colon, and rectum. The median sacral artery is a remnant of the tail in hominids, now atrophied and rudimentary.
Head and Neck Arteries
The carotid and vertebral arteries supply the head and neck.
The head is attached to the trunk by the neck. The arteries that carry blood to the head pass through the neck, supplying bony, visceral, muscular, and nervous structures. The arteries directed toward the head include:
Major Arterial Trunks:
- Common Carotid Artery: Arises from the brachiocephalic trunk and branches into:
- External carotid artery
- Internal carotid artery
- Vertebral Artery: Arises from the subclavian artery at the level of the 6th cervical vertebra.
The common carotid artery originates directly from the aortic arch or brachiocephalic trunk and is located somewhat superficially, just at the inner edge of the sternocleidomastoid muscle. When the common carotid artery divides into the internal and external carotid arteries, it forms the carotid sinus, a small concretion of nervous tissue with the vegetative system, acting as a baroreceptor and chemoreceptor. The carotid artery divides into internal and external branches at the level of the thyroid cartilage. The internal carotid artery enters the skull through the temporal bone, forming the carotid siphon, from which it branches into its end arteries at the level of the cerebral hemispheres. The external carotid artery branches into the thyroid, facial, and lingual arteries, supplying the face and ending in the superficial temporal and mandibular arteries.