Cardiac and respiratory systems

Question 1

5 mechanisms of venous return
(GMRSP)

Answer 1

Gravity- blood from the upper body above the heart is helped by gravity
Muscle Pump- during exercise, muscles contract compressing the veins squeezing blood back to heart
Respiratory pump- pressure different between the thoracic cavity and the abdominal cavity is created squeezing blood back tot the heart
Smooth muscle- smooth muscle in muscle walls venoconstricts which aids movement of blood
Pocket valves- prevent back flow

Question 2

Characteristics of an artery and arterioles

Answer 2

-Large layer of smooth muscle and elastic tissue
-Divides in arterioles to slow down blood flow
-arterioles vasocontrict and vasodilate to regulate blood flow and control blood pressure

Question 3

Characteristics of veins and venules

Answer 3

-small layer of smooth muscle
-one-way pocket valves to prevent back flow

Question 4

What is cardiac output at rest and exercise?

Answer 4

5l/min-rest
up to 20L/min- exercise

Question 5

Vascular shunt mechanism

Answer 5

the distribution of cardiac output around the body from rest to exercise which increases the percentage of blood flow to skeletal muscles

Question 6

What do the pre-capillary sphincters and arterioles do at rest?

Answer 6

art- vasodilator to organs and vasocontrict to muscles
cap- dilate to organs constrict to muscles

Question 7

What do pre-capillary sphincters and arterioles do at exercise?

Answer 7

Reverese of rest