Cardiovascular Flashcards
what are the two major subdivision of the ciruclatory system
cardiovascular system
lymphatic system
cardiovascular system
- a closed system that pumps blood from the heart to tissues back to heart
- contains the heart, blood, blood vessels
lymphastic system
- open, pumpless system of lymph cessels and lymph organs that are vital to ridding excess waste + fluid between cells
elephantiasis
swelling in areas due to leaking of lfuid into intersititial fluid
anatomy of arteries and veins
- tunica intima
- tunica media
- tunica externa
tunica intima
- composed of endothelium + subendothelial layer of areolar connective tissue
- aka lumen
tunica media
- comprised of circulatory arranged smooth muscle (larger arteries)
- innervated via sympathetic and parasympathetic NS
tunica externa
- connective tissue that helps anchor the blood vessels to an organ
- requires their own blood suppply via vaso vasorum
vaso vaorum
smaller arteries that supple the larger artieries/veins with blood
arteries
carry blood away from heart and become progressively smaller as they branch
what are the three types of arteries
elastic arteries
muscular arteries
arterioles
elastic arteries
- more elastic fibers found in all 3 tunics
- largest arteries
- stretch under increased pressure generated by blood ejected by the heart
- branch into mucsular arteries
muscular arteries
- medium sized arteries
- posses elastic fibers in two concentric rings (internal and external elastic lamina)
do muscular arteries have more muscle?
no just proportionally due to decreased diameter but maintained muscles in the lamina
arterioles
- smallester arteries
- few elastic and muscle fibers
what does innervation affect in the arterioles
the constriction and dilation
veins
- drains capillaries and return blood to the herat
- become progressively larger as it reaches the heart
how much blood do veins hold at rest
approx 60% body’s blood
venules
- companion vessels to arterioles
- merge to form veins
postcapillary venules
collect blood from capillaries + drain to veins
characteristics of arteries
lumen diameter: narrower than vein lumen
general wall thickness: thicker than companion vein
cross sectional shape: retains its circualr cross sectional shape
elastic and collagen fivers in tunics: more than in vein
valves: none
blood pressure: higher than in veins
blood flow: trasnports blood away from heart
blood oxygen levels: systemic arteries trasnport nlood high in O2, pulmonary arteries transport blood low in O2
characteristics of veins
lumen diameter: wider tahn artery lumen often appears collapes when cut in cross section
general wall thickness: thinner than companion artery
cross sectional shape: tends to flatten
elastic and collagen fibers in tunics: less than in artery
blood pressure: lower than in arteries
blood flow: transports blood to heart
blood oxygen levels: systemic veins trasnport nlood low in O2, pulmonary veins transport blood high in O2
capillaries
smallest blood vessels
- wall only consists of tunica intimia with single layer of endothelial cells
- more metabolic exchange occurs
what are the factors that affect venous return
- skeletal muscle pump
- respiratory pump