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Advanced Human Physiology > Hemodynamics > Flashcards

Flashcards in Hemodynamics Deck (20):
1

How much O2 is still in deoxygenated blood at rest?

70%

2

Flow (arteries and veins) = 

Pressure/resistance

3

Resistance in the system is determined by

arterioles

4

The pressure gradient in the systemic system is

125 (aorta) to 25 (capillaries)

5

The pressure gradient in the pulmonary circuit is 

10 (pulmonary vein) to 5 (vena cava)

6

Why is the systemic pressure so much higher?

Systemic pressure is higher because it experiences 5 times the resistance.

7

Which side of the heart works harder?

the left ventricle

8

Flow (capillaries) =

velocity and cross-sectional area 

9

Poisuelle's Law

 

      = π/8 (Initial pressure – End Pressure) x radius4

                        Distance x viscosity of blood

10

According to the carotid baroreceptor reflex

increased BP stretches the carotid arteries causing baroreceptors to

  1. Decrease HR
  2. Decrease stroke volume
  3. Cause vasodilation 

11

According to the Bainbridge reflex

increased venous return and increased pressure in the vena cavae and right atrium causes

  1. an increase in HR

12

The components of the cardiac cycle are

  1. Fast rapid filling phase
  2. Diastasis
  3. 2nd rapid filling phase
  4. isovolumetric contraction
  5. Rapid ejection
  6. Isovolumetric contraction

13

During the first rapid filling phase

  • 2/3 ventricular volume filled
  • Atrial P exceeds ventricular P

14

During the diastasis phase

  • Atrial P exceeds Ventricular P
  • slow filling of ventricles (small amount)

15

2nd rapid filling phase

  • Atrial P exceeds Ventricular P
  • Atria contract filling the ventricles
    • remaining 1/3 of ventrical volume filled
  • Fourth heart sound

16

During the isovolumetric contraction 

  • Ventricular P exceeds Atrial P
  • AV valves slam shut
    • First heart sound
  • All heart valves are closed at this time

17

During rapid ejection

  • Ventricular P exceeds Arterial P
  • Ventricles isotonically contract pushing blood out of the heart

18

During isovolumetric relaxation

  • Arterial P exceeds Ventricular P
  • Semilunar valves slam shut
    • Second Heart sound
  • All heart valves are closed at this time.

19

Capillary filtration = 

Capillary filtration = (HBP + PPOP) - (TPOP + THP)

20

Capillary absorption =

Capillary absorption = (HBP + TPOP) - (THP + PPOP)