cardiovascular system

Question 1

Cardiac conduction system

Answer 1

1. impulses start at the sinoatrial node
2. electrical impulses spread through the heart
3. atrial systole; sinoatrial node spread to the walls of the atria
4. impulses pass through the atrioventricular node
5. impulse goes down to the bundle of his
6. this branches out into the purkinje fibres
7. ventricular systole

Question 2

Factors affecting the change in rate of conduction system

Answer 2

• Sympathetic nervous system
• Parasympathetic nervous system
• Medulla oblangata

Question 3

sympathetic nervous system

Answer 3

fight or flight= increase heart rate

Question 4

Parasympathetic nervous system

Answer 4

Relax and chill= returns heart rate to its resting rate

Question 5

nervous system

Answer 5

Central nervous system & peripheral nervous system

complex network of nerves and cells

Question 6

cardiac control centre

Answer 6

coordinates the CNS & PNS

responsible for regulating the heart

located in the Medulla oblongata

Question 7

Neural mechanisms

Answer 7

1. Baroreceptors
2. Chemoreceptors
3. Proprioceptors

Question 8

Chemoreceptors

Answer 8

detect a change in blood acidity caused by an increase/ decrease in CO2

Question 9

chemo receptors- increase in CO2

Answer 9

Increase in heart rate

Question 10

Baroreceptors

Answer 10

detect changes in arterial blood pressure

Question 11

Baroreceptor - blood pressure falls

Answer 11

arterial pressure increases (arteries vasoconstrict)

Question 12

Proprioceptors

Answer 12

detect an increase in muscle movement

Located in muscles, tendons and joints

Question 13

Proprioceptor - increase in muscle movement

Answer 13

Increase in heart rate

Question 14

Chemoreceptors - increase CO2

Baroreceptor - decrease in arterial pressure

Proprioceptor- increase muscle movement

Answer 14

Chemoreceptor - increase heart rate

Baroreceptor – decrease heart rate

Proprioceptor - increase heart rate

Question 15

Stroke volume

Answer 15

volume of blood pumped out of the heart per contraction

Question 16

Venous return

Answer 16

volume of blood returning to the heart via the veins

Question 17

Starlings law

Answer 17

1. Increased venous return
2. greater diastolic filling
3. cardiac muscle stretched
4. more force of contraction
5. increased ejection fraction

Question 18

Average resting heart rate

Answer 18

72 BPM

Question 19

Factors that control heart rate

Answer 19

1. Neural controls
2. hormonal controls
3. intrinsic control

Question 20

Cardiac output (Q)

Answer 20

volume of blood pumped out by the heart ventricles per minute

Q=SV x HR

Question 21

Cardiac output (Q)

at rest

Answer 21

70 x 72= 5040ml

Question 22

Cardiovascular drift

Answer 22

1. period of exercise
2. heart rate & stroke volume initially increases
3. fluid lost as sweat
4. resulting in reduced plasma volume
5. reduced venous return & stroke volume
6. Heart rate increases to compensate
7. cardiac output increases due to more energy needed to cool

Question 23

Vascular system

two types of circulation

Answer 23

1. Pulmonary
2. systemic

Question 24

Pulmonary circulation

Answer 24

deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart

Question 25

Systemic

Answer 25

oxygenated blood to the body from the heart and return of deoxygenated blood from the body to the heart

Question 26

Blood pressure

Answer 26

the force exerted by the blood against the blood vessel wall blood flow x resistance

Question 27

Systolic pressure

Answer 27

pressure in arteries when the ventricles are contracting

Question 28

Diastolic pressure

Answer 28

pressure in arteries when the ventricles are relaxing

Question 29

Venous return mechanisms

Answer 29

1. skeletal muscle pump 2. respiratory pump 3. pocket valves

Question 30

Venous return during exercise

Answer 30

venous return increases

Question 31

Vascular shunt mechanism

Answer 31

redirecting of blood to the skeletal muscles that require more oxygen during exercise

Question 32

Vasomotor centre

Answer 32

blood pressure and blow flow is controlled by the vasomotor centre. located in the medulla oblongata of the brain. during exercise chemical changes such as CO2 and lactic acid increases. these are detected by chemoreceptors. these receptors stimulate the vasomotor centre which will redistribute blood flow through vasodilation and vasoconstriction.

Question 33

A-VO2 difference

Answer 33

difference between oxygen content of the arterial blood arriving at the muscles and the venous blood leaving the heart.