Circulatory System II: Aorta and Great Vessels

Circulatory System II

• Venules have the lowest pressure.
• The aorta emerges from the left ventricle.
• It initially moves upwards, then curves downwards, and further downwards.
• Parts of the aorta are named ascending aorta, aortic arch, and descending aorta.
• The descending aorta divides into thoracic and abdominal aorta, based on location.

Great Vessels

• The aorta is closest to the heart.
• All systemic arteries are direct or indirect branches of the aorta.
• The aorta is the largest artery.
• It originates from the left ventricle.
• It ascends slightly, then curves downwards.
• Branches of the aorta are named based on their position, such as ascending aorta, aortic arch, and descending aorta.
• Descending aorta branches into thoracic and abdominal aorta, determined by location.

Aortic Arch

• The aortic arch curves like an inverted U, superior to the heart.
• It branches into three major arteries: the brachiocephalic trunk, left common carotid artery, and left subclavian artery.

Coronary Arteries

• Coronary arteries originate from the beginning of the aorta.
• They supply blood to the heart.

Arteries of the Upper Limb

• The subclavian artery is the artery for the upper extremity/
• It continues as the axillary artery.
• Then, it is the brachial artery.
• The brachial artery gives rise to ulnar and radial arteries.

Measuring Pulse

• Pulse is measured at the radial artery.

Common Carotid Artery

• The common carotid artery branches into internal and external carotid arteries.
• The internal carotid artery enters the skull and supplies the brain.
• The external carotid artery supplies the head and neck, excluding the brain.
• The external carotid artery and internal carotid artery are attached via foramina.

Aorta Termination

• The aorta terminates at the level of the 4th lumbar vertebra.
• It bifurcates (divides) into two terminal branches, the right and left common iliac arteries.

Termination of the Aorta

• The right and left common iliac arteries proceed to give rise to internal and external iliac arteries.
• The internal iliac arteries supply the pelvic organs.
• The external iliac arteries continue in the lower limb as the femoral arteries.

Femoral Artery

• The femoral artery travels down the lower limb.
• It becomes the popliteal artery after passing the knee.

Popliteal Artery

• The popliteal artery branches into anterior and posterior tibial arteries.

Veins of the Upper Limb

• Superficial veins are close to the surface, whereas deep veins are close to bones.
• The superficial and deep veins share the same names as the corresponding arteries.
• The basilic and cephalic veins unite at the elbow to form the median cubital vein.

Veins of the Lower Limb

• The superficial veins include the great saphenous vein, which travels from the foot to the groin, and the small saphenous vein, which travels from the foot to the popliteal region.
• The femoral vein is formed from the merging of smaller veins.

Deep Veins of the Lower Limb

• The deep veins include the anterior and posterior tibial veins and the fibular veins, which merge into the popliteal vein, then the femoral vein.

Intravenous Injection

• Intravenous injection involves inserting a needle into a vein.
• Appropriate anatomical regions are utilized for insertion, taking care to consider factors such as needle angle, site, and depth.

Explore the intricacies of the circulatory system with a focus on the aorta and its branches. This quiz covers the structure, function, and classification of the major vessels responsible for systemic circulation. Test your knowledge on the characteristics and divisions of the aorta.