Circulatory System II: Great Vessels and Arteries

Circulatory System II

• Venules have the lowest pressure.
• Capillaries are for gas exchange.

Great Vessels

• The aorta emerges from the left ventricle.
• It first moves upward, then curves downward and further downwards.
• Ascending aorta, aortic arch, and descending aorta.
• Descending aorta divides into thoracic and abdominal aorta, location depending on region.

Aortic Arch

• Curves to the left in a U-shape, superior to the heart.
• Gives off three major arteries: brachiocephalic trunk, left common carotid artery, and left subclavian artery, in that order.
• Brachiocephalic trunk branches into right common carotid artery and right subclavian artery.

Arteries in Arms and Hands

• Subclavian artery is the artery of the upper extremity.
• It continues as axillary, then brachial artery.
• Brachial artery terminates into ulnar and radial arteries.
• Radial pulse is felt on the wrist, under the thumb.
• Ulnar artery is on the medial, or other side of hand.

Common Carotid Artery

• Divides into internal and external carotid arteries.
• Internal carotid artery nourishes the brain. Structures of the head and neck not including the brain are nourished by the external carotid artery.
• Internal carotid artery goes into the skull's cavity.

Aorta Termination

• The aorta terminates by giving two terminal branches at the level of the L4 vertebra in the abdomen.
• Bifurcation of aorta is called the place where branching occurs.
• Right and Left Common Iliac arteries.
• Each common iliac artery ends by giving two terminal branches in the pelvis.
• Internal carotid artery supplies organs in the pelvis.
• External carotid artery continues as the femoral artery, supplying the lower extremity

Femoral Artery

• Reaches the back of the knee, becoming the popliteal artery.
• Popliteal artery branches into anterior and posterior arteries, supplying the knee area.

Veins of the Upper Limb

• Superficial and deep veins.
• Deep veins have the same names as arteries.
• Radial and Ulnar veins unite to form the brachial vein.
• Brachial vein becomes the axillary vein after passing through the pec major muscle.
• Axillary vein changes to subclavian vein after passing under the clavicle.
• Superficial veins are closer to the surface.

Superficial Veins of Upper Limb

• Superficial veins of the upper limb originate on the dorsal side of the hand.
• They are basilic vein (medial side) and cephalic vein (lateral side)
• The two veins unite, forming the shape of an "M".
• Median cubital vein comes from the middle of the forearm, at the elbow level.

Veins of the Lower Limb; Superficial

• Arcus venosus dorsalis pedis is a common structure in this part of the body.
• The great saphenous vein opens into the femoral vein.
• Small saphenous vein empties into the popliteal vein.

Deep Veins of the Lower Limb

• Anterior and posterior tibial veins and fibular veins drain into the popliteal vein.
• Popliteal vein continues as femoral vein in the thigh.
• Superficial veins go deeper down to the body, near the heart, for example.

Intravenous Injection

• Tourniquet is used to allow veins to be easier to find..
• Puncture site covered.
• Specimen retrieved.
• Angle of injection, different injection angles for different tissues.