Vascular pt 4

Question 0

Venoconstriction increases venous return to the heart for enhanced ?

Answer 0

SV and CO.

Question 1

Venous pressure is determined by?

Answer 1

– Venoconstriction and other mechanisms of venous return (input)
– CO: pumping by the heart (output)

Question 2

___overcome the effects of gravity by pushing blood up a staircase of valves increasing venous return and minimizing venous pressure in the lower extremity

Answer 2

Contracting skeletal muscles (walking, running)

Question 3

___reduces intrathoracic pressure thus drawing blood up from the abdomen

Answer 3

Respiratory inhalation

Question 4

explain Chronic venous insufficiency (CVI):

Answer 4

veins cannot pump enough venous blood back to the heart

Question 5

Explain the complications associated with perforating veins

Answer 5

• Perforating veins interconnect superficial and deep veins
• Valves in perforating veins become incompetent
• Contractions of calf muscles cause a reverse flow externally through the perforating veins
• superficial & perforating veins become varicose.

Question 6

Cardiac Function Curve = Frank-Starling

Answer 6

CO is a function of venous pressure (preload)

Question 7

Vascular function Curve:

Answer 7

Venous pressure is a function of CO.

Question 8

Venous pressure drops with increasing

Answer 8

• CO; heart draws on incoming venous blood

Question 9

Equilibrium point

Answer 9

where the opposing actions of CO and venous pressure are equal and opposite

Question 10

Increasing heart contractility moves the cardiac curve?

Answer 10

upward

• Cardiac contractility alone would be expected to increase CO But, venous pressure drops with increase in CO.

Question 11

Vascular response to increase in CO will change equilibrium point to where?

Answer 11

CO is enhanced and venous pressure is reduced.

- CO is balanced between the effects of cardiac and vascular changes.

Question 12

Venoconstriction or a drop in systemic vascular resistance ____venous flow (preload) into heart.

Answer 12

increases

Question 13

Cardiac stimulation and increased venous input together produce significant increases of CO for relatively less preload.

Answer 13

Combining lower arterial blood pressure (or venoconstriction) with greater cardiac contractility, the heart becomes more efficient, i.e. it pumps more blood per amount of preload.