Physiology of Haemodynamics

Question 1

one cardiac cycle

Answer 1

1. atrial contractions
2. isovolumic contraction
3. ventricular ejection
4. isovolumic relaxation
5. passive ventricular filling
6. atrial contraction

Question 2

between left and right, which has the greatest pressure

Answer 2

LEFT

Question 3

in passive filling is the atria doing any work

Answer 3

no, no work is being done by the atria

Question 4

atrial waves

Answer 4

a - atrial contraction
c - AV close and bulge into the atria
v - atria is filling with blood before the AV valves open (max atrial filling pressure)

Question 5

how and where are the atrial waves measured

Answer 5

in the RAuding CVP

Question 6

two key principles that determine blood flow/cardiac output

Answer 6

1. CO = SV * HR
2. CO = (MAP - AP)/ R

Question 7

vessels with the greatest pressure

Answer 7

• large arteries and left ventricle

Question 8

vessels with the lowest pressure

Answer 8

capillaries and venules/veins

Question 9

radius and resistance relationship

Answer 9

inversely proportional

Question 10

vasocon extrinsic factors

Answer 10

• SNS - a1 from NA
• angiotensin II - hormone that increases BP

Question 11

vasocon intrinsic (local) factors - PEMELO

Answer 11

Prostaglandin
Endothelin
Myogenic responses
Endothelial factors
Local metabolites
Oxygen

Question 12

vasodi extrinsic factors

Answer 12

• SNS - B2 from NA
• PNS - Ach - NO
• ANP

Question 13

vasodi intrinsic (local) factors - HELP

Answer 13

Histamine
Endothelial factors = NO
Local metabolites = adenosine, carbon monoxide
Prostaglandin

Question 14

3 dterminants of SV

Answer 14

• preload
• contractility
• afterload

Question 15

preload

Answer 15

• how much the ventricles fill BEFORE they contract
• it is the EDV
• exclusive to ventricles
• associated with VR

Question 16

5 factors affecting preload

Answer 16

• venous return
• changes in blood volume
• diastolic dysfunction
• decreased filling time - HR >180
• decreased volume ejected

Question 17

effects of a HR greater than 180

Answer 17

• doesnt give tehe ventricles enough time to fill properly
• fast filling time = less time to fill = less blood going to the body (SV) less blood going to the lungs for oxygenation

Question 18

does breath holding increase or decrease VR

Answer 18

decrease - chest is tight or presurrised

• it is NOT the same as breathing in please

Question 19

preload in constriction vs dilatation

Answer 19

• constriciton increases VR while dilation decr it - which is weird..

Question 20

contractility

Answer 20

• doesnt have to do with the stretching of the heart - SQUEEZING (pushing blood out)

Question 21

4 things increasing contractility

Answer 21

• SNS- B1 agonist
• PDEi incr cAMP
  -long acting calcium channels
• Na-K ATPase pumps or Na-Ca exchange pump

Question 22

4 things decreasing contractility

Answer 22

• oxygen
• depressants
• cell death
• adenosine type 1 receptors

Question 23

a2 modulation of SNS

Answer 23

• inhibits VMC
• inhibits NA release from presynaptic terminals

Question 24

examples of PDEi

Answer 24

• caffeine
• milrinone
• amrinone

Question 25

afterload

Answer 25

- th resistance that the ventricles have to push against - arterial pressure (aortic pressure)

Question 26

increase in after load

Answer 26

decreases stroke volume - if AL is increased it means the resistance is increased so less blood leaves the ventricles and goes to the body.. so decr SV

Question 27

tension formular

Answer 27

pressure x radius / 2x wall thickness

Question 28

increase in tension

Answer 28

- increased oxygen demand - reduced systolic function

Question 29

what factors can increase afterload

Answer 29

- incr resistance to flow which incr p - acute incr in contractility which incr p - incr filling volumes which incr radius - geometric changes in incr r and decr h - incr HR which incr oxygen demand - basically anything that increases pressure

Question 30

SV relationship with AL and PL

Answer 30

AL - inversely proportional PL- directly proportional

Question 31

Apoptosis examples - 6

Answer 31

- activation of SNS - activiation of RAAS - calcium overload - cytokines - decreased oxygen - oxygen free radicals (superoxides)

Question 32

Necrosis examples - 7

Answer 32

- activation of SNS (NE excess) - calcium overload - decreased oxygen - oxygen free radicals - toxins - infectious agents - anticancer and immunosuppressive drugs

Question 33

CHP vs COP

Answer 33

- CHP - out - COP - in

Question 34

oedema (starling's forces)

Answer 34

incr CHP and decr COP

Question 35

systemic venous side

Answer 35

low pressures, allows fluid reabsorption

Question 36

systemic arterial side

Answer 36

high pressures, promotes fluid filtration out