CVD IV

Question 1

What is the general actions of the renal reg system

Answer 1

• control ABP by altertering blood volume
• increased ABP stims kidneys to eliminate h20
• decreased ABP stims kidneys to increase h20 reten

Question 2

What does angiotension II do (3)

Answer 2

powerful vasoconstriction, stims aldosterone release and can directly act on kidney to increase nacl, H20 retention

Question 3

What are the functions of natriuretic peptides (3)

Answer 3

• decreased ABP
• decreased blood volume by inhibiting reabsorbtion of sodium + water
• increased sodium + water excretion
• vasodialation (less resistence)

Question 4

What is the stim, purpose and effect of the CNS ischemic response

Answer 4

Stim- cerebral ischemia (ABP below 50mmhg)

purpose- stims vasomotor center

effect- increase arterial pressure to allow for restoring perfusion to brain

Question 5

What is the metabolic theory of control of blood flow (What metabolites present)

Answer 5

increaed metabilic rate increases amounts of vasodialator substances (H+, Co2, K, lactate) and blood vessels dialate in response

Question 6

What is the myogenic theory of control of blood flow

Answer 6

depends on vascular pressure in the area

Question 7

What is the endothelial theory of control of blood flow (what are the vasodialator/contrictor chems it can release)

Answer 7

Endothelial cells release locally acting chem messengers
NO, Prostacylcin (vasodilators)
Endothelin (vasocontrictor)

Question 8

how is angiogenesis stimulated

Answer 8

lack of o2/nutrients in (cancer tissue, ischemic tissue, exercising mm)

-angiogenic factors (VEGF)

Question 9

What are the 2 diferent types of general capillaries

Answer 9

1. vascular shunts- channel that connects arteriole directly with post capillary venule
2. True capillary- branches of vascular shunts

Question 10

how do lipid soluble and lipid insoluble substances cross the capillary wall

Answer 10

lipid soluble- diffuse directly thru the cell membranes of capillaries

lipid insoluble- cross capillary walls via intracellular clefts (fenstrations)

Question 11

continous capillaries (non fenestrated) and where found

Answer 11

least permeable

CNS, lymph ndes, mm, skin, lung, heart

Question 12

Continous capillaries (fenestrated) and where found

Answer 12

Greater permeability
(endocrine glands, kidney)

Question 13

Discontinous capillaries and where found

Answer 13

Leaky, greatest permiability

liver, bone marrow, spleen

Question 14

what are 3 factors affecting capillary permiability

Answer 14

1. type of capillary
2. Inflammatory substances
3. Plasma pros

Question 15

What are the 2 pressures that allow for filtration

Answer 15

1. Capillary hyrostatic pressure

2. Interstitial fluid osmotic pressure

Question 16

What are the 2 pressures that allow for reabsorbtion

Answer 16

1. Plasma osmotic pressure

2. interstitial fluid hydrostatic pressure

Question 17

What is higher filtration or reabsorbtion

Answer 17

rate of filtration is higher than rate of reabsorbtion

Question 18

why does venoconstriction during sympathetic stim increase SV

Answer 18

Usually veins function as a reseviour for blood but venocontriction decreases amount of blood contained in Blood vessels which increases SV

Question 19

What are the helping pumps to move blood around (4)

Answer 19

1. Respiratory pump
2. Cardiac suction
3. Muscle pumo
4. Arterial pulsations (press on the veins from outside)

Question 20

What is increased central venous pressure (what is normal)

Answer 20

normal CVP is around 5mmHg

can be increased to 20-30mmHg due to increase in total blood volume, severe heart failure

Question 21

What are 4 causes of Edema

Answer 21

1. increased capillary hydrostatic pressure (bp)
2. decreased plasma osmotic pressure (less prod of plasma)
3. Decreased lymph flow
4. Increased capillary permeability (due to inflammation)