31. Cardiovascular System

Question 1

why do mammals need a circulatroy system?

Answer 1

exchange of nutrients across membranes via a moving fluid so diffusion can occur at specific sites

Question 2

whats the difference between an open and closed circulatory system?

Answer 2

in an open circultory system there is no distinction between blood and intestinal fluid, in closed circulatroy system blood is contained in blood vessels

Question 3

what are three advantages of a closed circulatroy system

Answer 3

1. better at transporting circulatroy fluids to meet high metabolic demand
2. good for large animals
3. ability for highly developed mammals

Question 4

what seperates the heart from oxygenated and deoxygenated blood?

Answer 4

the septum!

Question 5

what are the two types of circulation and what do they do in the body?

Answer 5

pulmonary circulation - moves blood between the heart and lungs via the pulmonary vein and arteries

systematic circulation- moves blood to the entire body via the aorta and returns it via the vena cava

Question 6

what are the two functions of the right side of the heart

Answer 6

1. recieves deoxygenated blood from the systemetic circuit
2. pumps deoxygenated blood to the lungs of oxygenation (pulmonary circuit)

Question 7

what are the two functions of the left side of the heart?

Answer 7

recieves oxygenated blood from the lungs (via the pulmonary circuit)

pumps oxygenated blood into the body (systematic ciruclation)

Question 8

what is stroke volume (SV)

Answer 8

the amount of blood pumped from the left ventricle per heart beat

Question 9

whats the definition of a heart rate?

Answer 9

the number of beats (cardiac cycles) per minute

Question 10

what is cardiac output? (Q)

Answer 10

the stroke volume multiplied heart rate

Q = SV x HR

Question 11

what is the normal cardiac output?

Answer 11

5 liters per minutes (for a 70kg male)

Question 12

what do arteries branch into and then what do they branch into?

Answer 12

arteries branch into arterioles

arteioles branch into capilaries

Question 13

what is the structure and function of arteioles?

Answer 13

arteioles are made of two layers of smooth muscle which can alter their diamete

this menas they reguate blood flow - eg thermoreguate and exerciese

Question 14

how does the venous system continue push blood back to the vena cava? 2 points

Answer 14

veins have valves! this assists blood flow so its unidirectional (no back flow)

skeletal muscle pump - deep viens which veins are assited by muscle contractions

Question 15

what is precapillary sphincters?

Answer 15

the opening or closing of capillaries to control blood distribution

Question 16

what occurs in the cardiac cycle?

Answer 16

1. right ventricle fills with blood passivley and active from atrium contractions
2. pressure in right ventricle causes semilunar valves to open and blood travels to lungs
3. heart relaxes and semilunar valves close

Question 17

what is systoleand diastole?

Answer 17

systole is when the ventricle contracts (the pulse is felt)

diastole is when the ventricle relaxes (no pulse felt)

Question 18

what is the normal systolic and diastolic pressure in a person?

Answer 18

120 mmHg : 80 mmHg

Question 19

what is Lubb Dup?

Answer 19

Lubb indicates the closing of the atrioventricular valves

Dup indicates the closign of semilunar valves

Question 20

what are the four parts of the intrinsic regulation of the heart?

Answer 20

the SA node

AV node

bundles of His

purkinje fibres

Question 21

what does the SA node do?

Answer 21

atrial depolarisation

Question 22

what does the AV node do?

Answer 22

atrial contraction occurs

Question 23

what occurs at the AV bundle?

Answer 23

ventricle depolarisation

Question 24

what does the purkinje fibres do?

Answer 24

signals spread through ventricles