Cardiovascular System

Question 1

what are the main functions of the cardiovascular system? (3)

Answer 1

1) trasport system
- bring nutrients for metabolism -> cells and take away waste byproducts from them
2) distributes and secretes hormones
- cardiovascular transports hormones from site of production to the target cells/organs
3) homeostatic mechanism
- has a role in maintaining homeostasis and regulating body temperature

Question 2

Function of heart

Answer 2

• muscular pump

- creates an environment by which blood can circulate through vessels around the body

Question 3

What brings blood towards the heart

Answer 3

veins

Question 4

what brings blood away from the heart

Answer 4

arteries

Question 5

What is a driving pressure

Answer 5

blood pressure generated by the contraction of vesicles in the heart

Question 6

What does the amount of blood flow depend on?

Answer 6

• resistance (inversely proportionsl)
• pressure difference (directly proportional)
• radius of blood vessels (blood flow increases with an increase in the radius cuz resistance will decrease)

Question 7

What does the velocity of blood flow depend on

Answer 7

• total cross sectional area of blood vessels (indirectly proportional)

Question 8

What is the fibrous sac which surrounds the heart

Answer 8

pericardium

Question 9

what are the layers in the pericardium

Answer 9

pericardium -> epicardium -> myocardium

- there is pericardial fluid in between pericardium and epicardium

Question 10

What is the function of the pericardial fluid?

Answer 10

• provide lubrication between the pericardium and epicardium to prevent inflammation from occuring
• also anchors heart to against diaphragm and spine to prevent excess movement

Question 11

What is the pathway for deoxygenated blood?

Answer 11

• blood enters into the heart through the superior and inferior vena cava
• blood goes into the the RA -> tricuspid valve -> RV
• blood passes through -pulmonary valves -> pulmonary arteries -> lungs

Question 12

What is the pathway for oxygenated blood?

Answer 12

• blood enters heart through pulmonary vein -> LA

- LA -> mitral valves -> LV -> aortic valves -> aorta + arteries which supply blood to head and arms

Question 13

how does the sinoatrial node cells generate an action potential without external stimuli from nerves?

Answer 13

there are sodium ion channels which allow for the constant influx of sodium ions into the SA node cells -> depolarise the membrane -> generate an action potential

Question 14

what are the 3 main factors which determine the rate of firing of action potential?

Answer 14

1) influence from autonomic system
2) initial membrane potential
3) gradient of drift towards threshold potential