Venous Circulaiton And Control Of Cardiac Output

Question 1

Lymph function

Answer 1

Valve allow for unidirectional flow
Flow via muscle contractio (skeletal and smooth) and respiration
Approximately 1x total volume passes through lymph system daily

Question 2

Lymph dysfunction

Answer 2

Edema
Increases filtration pressure beyond the capacity of the lymphatics
- arterioles dilation
- increase venous pressure - low pressure obstructions, conceive heart failure, increases volume (pregnancy), valve dysfunction
- increased capillary permeability

Question 3

Venous return is dependent upon

Answer 3

The pressure gradient between:
Peripheral venous pressure (12-18 mmHg)
Great veins (5-6 mmHg)
RAP (0-3 mmHg)

Question 4

Differences between peripheral and central venous pressure determine

Answer 4

Venous return

Question 5

What factors determine peripheral venous pressure

Answer 5

Venous sympathetic nerve activity
Blood volume
Skeletal muscle pump

Question 6

What factor determines venous return

Answer 6

Inspiratory movements

Question 7

Blood volume and venous tone infleunces

Answer 7

Venous return curves

Question 8

Rise in central venous pressure causes

Answer 8

An increase in diastolic filing or preload

Question 9

Anatomy of lymph and venous circulation

Answer 9

Vessels converge and empty into right and left subclavian veins

Question 10

Increases contractility allows for an

Answer 10

Increase in cardiac output even in the face of decreased central venous pressure

Question 11

Cardiac factors influencing cardiac output

Answer 11

Heart rate

Myocardial contractility

Question 12

Coupling factors influencing cardiac output

Answer 12

Preload

Afterload

Question 13

Peripheral venous pool

Answer 13

Blood returning from the capillaries to the venous system