the cardiovascular system- week 5

Question 1

what is the role of the heart?

Answer 1

creates pressure to pump blood

Question 2

what is the role of arterioles and arteries ?

Answer 2

carry blood away from heart

Question 3

what is role of capillaries ?

Answer 3

exchange of O2, Co2 and nutrients with tissues

Question 4

what is the role of veins and venules?

Answer 4

carry blood towards the heart

Question 5

what is the pulmonary circuit ? (3)

Answer 5

right side of the heart

pumps deoxygenated blood to the lungs via pulmonary arteries

returns oxygenated blood to the heart from the lungs via pulmonary veins

Question 6

what is the systemic circuit ?

Answer 6

left side of the heart

pumps oxygenated blood around the body via arteries

return deoxygenated blood to the right side of the heart via veins

Question 7

what do the arteries contain which help maintain its shape ?

Answer 7

collagen and elastin

Question 8

what do the arterioles do in terms of pressure?

Answer 8

help change resistance through vasoconstriction/vasodilation

Question 9

what is a structure that aids blood flow in veins ?

Answer 9

one way valves help prevent back flow

Question 10

what is plasma ?

Answer 10

liquid of blood

contains ions, proteins and hormones

Question 11

what cells are found in the blood and their role? (3+3)

Answer 11

red blood cells
- haemoglobin carries oxygen

white blood cells
- prevents infection

platelets
- important for blood clotting

Question 12

what is a hematocrit ?

Answer 12

% of blood composed of erythrocytes

Question 13

what is total peripheral resistance ?

Answer 13

sum of resistances to flow in all individual organs

Question 14

what is resistance ?

Answer 14

measure of hinderance to blood flow through a vessel caused by friction between the blood in the vessel wall

Question 15

what the sum for blood flow ?

Answer 15

blood flow= change in pressure/resistance

blood flow proportional to pressure
blood flow inversely proportional to resistance

Question 16

what is the greatest influence on resistance of blood flow ?

Answer 16

radius of the vessel

Question 17

what is the calculation for resistance ?

Answer 17

resistance = length x viscosity / radius to power of 4

Question 18

what is arteriovenous difference ?

Answer 18

amount of O2 taken up from 100 ml of blood

Question 19

where does the initial signal to drive the CV system come from ? (2)

Answer 19

higher brain centres

centrally generated motor signals

Question 20

where does fine tuned afferent feedback come from? (3)

Answer 20

heart mechanoreceptors

muscle chemoreceptors - sensitive to metabolites

pressure sensitive receptors -braoreceptors

Question 21

what is the exercise pressor reflex ?

Answer 21

peripheral feedback to the medulla oblongata to ament the CV response to exercise

Question 22

what is role of baroreceptors ?

Answer 22

sensitive to changes in arterial BP

Question 23

what is role of muscle mechanoreceptors ? (2)

Answer 23

muscle spindles and gogli tendon organs

sensitive to force and speed of muscular movement

Question 24

what is role of muscle chemoreceptors ?

Answer 24

sensitive to changes in chemical environment
e.g. H+ ions, CO2, pH changes , metabolites

Question 25

what happens to baroreflex during exercise ?

Answer 25

central command and exercise pressor play active role in resetting arterial baroreflex during exercise