Cardiovascular Disease Blood Vessels

Diagram of the Heart ©http://www. nhlbi. nih

Most incidences of heart disease originate in the blood vessels

Anatomy of Blood Vessels ©http://www.unm.edu/~jimmy/vessels.jpg

Both Arteries and Veins Have 3 Layers: Tunica adventitia Tunica media Tunica intima

Tunica Adventitia Outer layer of the blood vessel Composed of connective tissue with different amounts of elastic fibers Elasticity of the wall aids in maintaining blood pressure

Tunica Media Middle layer Composed of smooth muscle cells arranged in a circular pattern around the vessel Larger arteries contain more smooth muscle cells

Tunica Intima Inner layer Composed of endothelial cells Endothelial cells reduce friction of blood flow; they are the cells cover/line all internal and external body parts

Artery © http://www. nlm. nih

Arteries carry blood away from the heart and towards the tissue Large arteries actually have their own system of blood vessels = vasa vasorum Large arteries leave the heart and divide into smaller arteries These arteries called ARTERIOLES

Arterioles: Medium size arteries Have very muscular walls which control the amount of blood flow to specific organs through vasoconstriction and dilatation Become smaller the further they are from the artery

Arterioles: Very small arterioles consist only of a thin layer of endothelial tissue with smooth muscle cells Endothelial cells reduce friction Smooth muscle cells assist with vasoconstriction and vasodilatation

Capillaries Arterioles branch into the CAPILLARIES found throughout tissue Capillaries exchange oxygen and nutrients for carbon dioxide and waste with surrounding tissue

Capillaries Capillaries do not contain any smooth muscle cells

Venules After gases exchange occurs and capillaries leave the tissue, they are called VENULES Venule walls contain smooth muscle cells As venules become larger, they are called VEINS

Veins Veins return blood from the tissue to the heart Veins have a very thin layer of muscle tissue and elastic fibers Walls of veins are much thinner than arteries…why?

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Veins Veins do not need to withstand high internal pressure

Valves Along the inner lining of veins, there are valves Valves are composed of endothelial tissue which reduces friction assisting with blood flow When blood flows toward the heart, the “flaps” of the valves are pressed back against the walls of the vessels

Valves If a back pressure develops, the valves close Why? Prevents blood from flowing back into the capillaries Very important with lower extremities

Valve in Vein ©http://www.dkimages.com/discover/previews/740/77408.JPG

Valves in Vein ©http://www.adronline.org/images/evlt/blueVein.gif

Arteries to Know Aorta Very large Extends from the left side of the heart Runs along the backside of the heart Oriented downward Carries oxygenated blood to all parts of the body

Aorta ©http://www.teamt.us/images/Aorta_Structure.jpg

Pulmonary Artery Large artery Located on the right side of the heart Carries deoxygenated blood to the lungs

Pulmonary Artery (blue) ©http://medpics. findlaw

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Carotid Arteries Located in the neck Carries blood to the face and scalp (not the brain)

Carotid (Cartoid) Artery ©http://www. carolinavascular

Cerebral Artery Supplies blood to the lobes of the brain

Cerebral Artery ©http://www.transonic.com/brain1.gif

Renal Arteries (left and right) Supply the kidneys with blood

Renal Arteries ©http://www. ivy-rose. co

Iliac Arteries Carry oxygenated blood from the abdominal aorta to the pelvic region Near the femur ends

Iliac Arteries ©http://www. medicalook

Iliac Arteries ©http://home.comcast.net/~wnor/pelvicarteries.jpg

Femoral Artery Continuation of the external iliac artery Large artery located in the thigh

Femoral Artery ©http://content. answers

Popliteal Artery Extension of the superficial femoral artery Goes through calf muscle (down backside) Supplies blood to the knee and foot

Popliteal Artery ©http://www. clevelandclinic

Coronary Arteries Supply blood to the heart Located on front of heart Right coronary artery supplies blood to right front of heart Left coronary artery supplies blood to left side of heart

Left circumflex artery Supplies blood to the backside of the heart

Coronary Arteries ©http://www.kmu.lt/Card_surg/img/smallbypass.gif