lecture 16: hemodynamics (blood vessels and flow) Flashcards

Question

tunica media

Answer 1

circular smooth muscle affects resistance vasoconstriction and vasodilation

Answer 2

elastic fibers and connective tissue

Answer 3

ensure continuous flow of blood through circulatory system pretty hard to expand as potential energy is stored in aorta during contraction L ventricle relaxes ---> no more pressure pushing blood in aorta lots of elastic fibers, elastic recoil aorta as biggest blood vessel

Answer 4

characteristic of aorta and arteries goes back to normal shape, cause blood to go forward, prevents back and forth SL valve closed

Answer 5

less elastic, not as much elastic fibers in tunica externa several layers of smooth muscle resistance blood vessels ----> significantly able to vasoconstrict and vasodilate

Answer 6

one cell thick endothelial cells due to diffusion, exchange blood vessels no smooth muscle lowest velocity of flow WBCs too big to go through

Answer 7

convergent pattern smooth muscle in larger ones

Answer 8

relatively thin walled easy to stretch

Answer 9

not completely surrounded by smooth muscle like arterioles WBCs too big to go through capillaries so they go through these instead have continuous blood flow even though capillary bed is closed sometimes

Answer 10

rings of smooth muscle between arterioles and veins

Answer 11

blood flow from arteriole through capillary bed, through capillaries to the venules

Answer 12

blood bypasses capillaries no pathway for them blood goes straight from arterial to the venal through metarterioles which has continuous flow some blood flows through even with closure

Answer 13

most common type of capillary connective, neural, muscle tissues, etc. endothelial cell tight junctions at capillary wall have some material that will leak out/into the capillaries allow water and some small dissolved solutes to pass

Answer 14

in liver and kidney ---> need bulk movement in and out of them endothelial cell tight junctions capillary wall has bigger gaps or pores to allow for more material to move in/out of capillaries more permeable

Answer 15

bulk flow filtration absorption

Answer 16

mass movement of fluid and materials as a result of hydrostatic or osmotic pressure gradients

Answer 17

fluid movement out of capillaries, some solute too 1. capillary blood pressure (Pc) 2. oncotic interstitial pressure (pi i) net filtration at arterial/beginning end

Answer 18

Pc correlated to BP ----> increase in BP = increase in flow rate to capillary bed = increase Pc hydrostatic pressure ---> blood against walls of capillaries

Answer 19

pressure exerted by fluid against walls of a compartment

Answer 20

pi i other force causing filtration in capillaries solutes in interstitial compartment generating pressure and "sucking" up fluid to capillary

Answer 21

fluid movement into capillaries 1. oncotic capillary pressure (pi c) ---> albumin 2. interstitial tissue pressure (Pi) net absorption at venous/end of capillary

Answer 22

pi c albumin is main solute causing this (protein made in liver) due to solutes inside capillary cant move because theyre too big ---> suck fluid into capillary to cause absorption

Answer 23

Pi pressure generated by interstitial fluid pushing against walls of capillary and pushing fluid back in

Answer 24

severe malnutrition cause by lack of protein intake liver doesnt have the proteins to make albumin symptoms ---> edema/swelling in abdominal area, ankles, feet, underneath jaw, poor wound healing, poor growth filtration > absorption low oncotic capillary pressure (pi c) moving fluid back into capillaries

Answer 25

inadequate energy intake in all forms (no food intake) symptoms ----> reduced muscle mass, skinny, no edema, lethargy

Answer 26

filtration/absorption not balanced OR lymphatic system not working properly normal exchange between circulatory system and the lymphatic system is disrupted fluid pushing against walls and not being absorbed correctly accumulation of fluid in tissues ----> swelling increasing hydrostatic/capillary pressure

Answer 27

1. inadequate drainage of lymph: obstruction of the lymphatic system (parasites, cancer) 2. filtration greater than absorption

Answer 28

1. increase in hydrostatic pressure (elevated venous pressure, caused by heart failure) -----Pc -----ex: heart failure, R. ventricle not pumping blood properly, even when L. ventricle is working ------backup of pressure, excessive blood in venous circulation, higher BP and capillary pressure -----increase in filtration 2. increase in interstitial proteins (pi i) -----affects sucking things out 3. decrease in plasma protein concentration (severe malnutrition or liver failure) -----absorption decrease, cant keep up with filtration (stays the same) -----cant produce albumin ------ pi c affected

Answer 29

blind end lymph capillaries return fluid and proteins to the circulatory system serve as filter for pathogens (immune function) lymph vessels pick up whatever filtration doesnt ----filters pathogens, preventing accumulation of fluid in interstitial compartment

Answer 30

ultrafiltration flux = K[(Pc + pi i) - (Pi + pi c)] flux = filtration coefficient [(capillary pressure + oncotic interstitial pressure) - (interstitial pressure + oncotic capillary pressure)] flux = K ( what is forced out - what is forced in) flux = amount of fluid moving out of capillaries K = filtration coefficient, constant for each tissue, how easy it is for fluid to move out of capillary (ex: brain has small K) Pc is only value that changes, HIGHER at arterial end

Answer 31

fluid leaves the capillary net filtration forces out > forces in

Answer 32

influx of fluid into the capillary net absorption forces out < forces in

Answer 33

arterial flux = [(30 + 8) - (0+25)] ---> 13 mmHg = net filtration (more moving out than in at beginning of capillary) venous flux = [(15+8) - (0+25)] ----> - 2 mmHg = net absorption (mainly fluid moving in, bringing back into circulation, dont want fluid in interstitial compartment)