quiz 3/15

Question 1

do capillaries contain smooth muscle or constrict?

Answer 1

no and no

Question 2

why can capillaries withstand high intravascular pressure?

Answer 2

la places law. small radius = low pressure. wall tension = transmural pressure x radius of vessel. wall stress = transmural pressure / wall thickness

Question 3

Is the permeability of the capillary endothelium the same in all the tissues of the body?

Answer 3

no

Question 4

what percentage makes up ECF

Answer 4

20

Question 5

what percentage makes up ICF

Answer 5

40

Question 6

what happens if you give someone 1L of NS

Answer 6

increase ECF, no change in osmolality

Question 7

what does dextrose do

Answer 7

reduces ECF osmo and therefore helps correct the increase in ECF osmo associated w dehydration

Question 8

hypotonic increases ___ volume

Answer 8

intracellular

Question 9

hypertonic increases

Answer 9

extracellular

Question 10

what is capillary filtration

Answer 10

the sum of the hydrostatic and osmotic forces favors the movement of water from the capillary to the interstitial space (+ filtration, arteriolar)

Question 11

what is capillary reabsorption

Answer 11

movement of fluids or h20 back into the capillary (venular end)

Question 12

starling forces - increased capillary pressure and interstitial fluid osmotic pressure moves fluid ____

Answer 12

out of the capillary.

Question 13

increased plasma colloid osmotic pressure causes

Answer 13

inward movement of fluids

Question 14

what is osmosis

Answer 14

h20 moves from areas of high h20 concentration to areas off low h20 concentration through a semi-permeable membrane

Question 15

if net driving forces are positive, does it favor capillary filtration or reabsorption?

Answer 15

filtration

Question 16

if net driving forces are negative what does it favor

Answer 16

reabsorption at venular end

Question 17

are pressures higher at the arteriolar end or the venous end

Answer 17

arteriole side (30 vs 10mmhg)

Question 18

under normal circumstances, what net driving force favors fluid movement into the capillary?

Answer 18

negative pressure - absorption

Question 19

what would the net driving forces be in a patient with CHF? cirrhosis? venous thrombosis?

Answer 19

filtration (positive). d/t increased capillary hydrostatic pressure. and decreased plasma oncotic pressure

Question 20

whats the function of the lymphatic system?

Answer 20

movement of excess fats, fluids, proteins, and albumin back into the circulation.

Question 21

lymphatic system causes ___

Answer 21

negative pressure in the interstitial fluid space

Question 22

4 ways plasma filtrate is returned to the circulation by the lymphatic system

Answer 22

tissue pressure, intermittent skeletal activity, lymphatic vessel contractions and one way valves

Question 23

what 3 things empty into the thoracic duct

Answer 23

left head, left arm, lower body

Question 24

where is the thoracic duct

Answer 24

posterior chest and is connected to the left IJ and left subclavian

Question 25

what things cause edema

Answer 25

*hydrostatic pressure. lymphatic obstruction, changes in permeability, reduced plasma protein

Question 26

name 3 endogenously found vaso-constricting substances

Answer 26

catecholamines (epi, norepi, dopamine), endothelial, serotonin, angiotensin 2, vasopressin

Question 27

name 3 endogenously found vaso-dilating substances

Answer 27

histamine, adenosine, nitric oxide, CO2, K, hydrogen ion, prostaglandins, acetylcholine, bradykin

Question 28

what is the metabolic mechanism

Answer 28

inadequate o2 for metabolic requirements of tissues result in formation of vasodilator substances which increase blood flow to tissues

Question 29

what substances are responsible for metabolic mechanism

Answer 29

adenosine, K, CO2, H+, lactic acid, inorganic phosphate

Question 30

what is the myogenic mechanism

Answer 30

lumen of blood vessel suddenly expanded, the smooth muscles response by contracting in order to restore the vessel diameter and resistance

Question 31

what is reactive hyperemia

Answer 31

transient increase in organ blood flow that occurs following a brief period of ischemia, usually produced by temporary arterial occlusion

Question 32

give an example of reactive hyperemia

Answer 32

tourniquet to a limb, arterial vessel clamped and released later in surgery, transient coronary occlusion

Question 33

what is autoregulation

Answer 33

intrinsic ability of an organ to maintain constant blood flow despite changes in perfusion pressure

Question 34

what 2 mechanisms of blood flow regulation is thought to be involved in autoregulation

Answer 34

myogenic and metabolic

Question 35

name 3 endothelial factors that help regulate blood flow

Answer 35

nitric oxide, prostacyclin, endothelial-derived, hyperpolarizing factor, endothelin

Question 36

prostacyclin dilator or constrict?

Answer 36

dilator

Question 37

EDHF dilator or constrict

Answer 37

dilator

Question 38

endothelin dilate or constrict

Answer 38

potent constrict

Question 39

what is nitric oxide

Answer 39

regulates blood flow under normal physiologic conditions; generated from amino acid L-arginine to synthesize NO synthase; relaxes smooth muscle via activation of intracellular guannyly cycllase to form cgmp

Question 40

how might nitric oxide be useful during one lung ventilation

Answer 40

inhaled Nirtric oxide delivered only to ventilated alveoli thus improving v/q relations by vasodilation capillaries and improving blood flow to areas participating in gas exchange

Question 41

why are blood vessels prone to vasoconstriction, vasospasm, and thrombosis when the endothelium is damaged

Answer 41

when a decrease of nitric oxide and prostacyclin production occurs, an increase of endothelin production causes vasoconstriction, vasospasm, and thombosis

Question 42

what causes dehydration

Answer 42

decreased capillary hydrostatic pressure. increased oncotic pressure (push into cap so - )

Question 43

what causes edema

Answer 43

increased capillary hydrostatic pressure. decreased plasma oncotic pressure (push into interstitum so + overall)

Question 44

plasma colloid osmotic pressure goes ___, interstitial fluid colloid osmotic pressure goes ___

Answer 44

in, out