arterial pressure regulation

Question 1

is flow constant ?

Answer 1

yes , 5-6 L/m

Question 2

speed of blood in aorta, capillaries

Answer 2

aorta 330mm/s

capillaries 0,33 mm/ s

Question 3

pressure in aorta, capillaries and vena cava

Answer 3

aorta
SAP: 120
MAP 100
DAP 80

capillaries
arterial end: 35 mmhg
venous end : 10 mmhg

vena cava: 0 mmhg

Question 4

speed formula

Answer 4

v=Flow/area

Question 5

3 basic principles of circulatory function

Answer 5

1- the speed of blood flow in each tissue is controlled according to the need of each tissue
2- CO controlled by the sum of all blood flows
3- blood pressure regulation is generally independent of local blood flow controller cardiac output control

Question 6

ohm’s law

Answer 6

flow= volume /time
flow= pressure Dif btw extremes/ vascular resistance

Question 7

what does vascular distensibility allow

Answer 7

it allows pulsatile flow of the arteries to be continuous

Question 8

MAP (MEAN ARTERIAL PRESSURE)

Answer 8

average of the arterial pressures measured millisecond by millisecond over a period of time
IT IS NOT DAP +SAP /2 CAUSE DIASTOLE IS LONGER THAN SISTOLE

Question 9

VENOUS TREE : WHAT DO VALVES DO

Answer 9

valves help compensate for pressure changes

Question 10

Autoregulation

Answer 10

mechanism applied to a whole organ that allows the organ to have a constant flow regardle of the pressures in a very wide range of pressures

Question 11

Self-regulation

Answer 11

Every tissue in the body is able to self-regulate the flow

Question 12

MAP FORMULA

Answer 12

MAP = 2·DAP + SAP /3

Question 13

IF MAP INCREASES OR DECREASES WHAT HAPPENS?

Answer 13

INCREASES: vascular damage
DECREASES: hypo perfusion

total peripheral resistance is connected to cardiac output, they vary antagonistically

Question 14

SYSTEMS TO CONTROL MAP

Answer 14

FAST: BARORRECEPTORS
SLOW: RAAS

Question 15

BARORRECEPTORS

Answer 15

they are near the carotid and sense the pressure in the arteries and change it if neccesary

Question 16

ANS SYMP AND PARASYM

Answer 16

symp VASOCONSTRICTION: ganglion chain, spinal nerves, simpathetic nerves
Parasympathetic NEGATIVE CHRONOTROPIC (low participation) : vagus nerve

Question 17

rapid pressure control

Answer 17

baja el Parasympathetic y sube el symp

map solubles in 5-10 sec
map divides by 2 in 10-40 seconds

Question 18

valsalva maneuver

Answer 18

aguantar la resp
increased intratorathic pressure
vena cava collapes
less vr
less cardiac output
less MAP

compensating tachycardia- restored map

when stopping- compensating bradycardia

Question 19

LONG TERM CONTROL OF MAP

Answer 19

RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM (RAAS)
Control thorugh volume
slow control

Question 20

Angiotensin 2 (Brain, arterioles, adrenal , kidney)

Answer 20

Brain - sensation of thirst - high adh
Arterioles: vasoconstriction
Adrenal: High aldosterone
kidney : High reabsorption of na and indirectamente aldosterone

Question 21

receptors regulate systems

Answer 21

1. carotid body chemoreceptors and aortic arch
2. central chemoreceptors
3. pulmonary baroreceptors