CV System - Regulation of Heart Responses

Question 1

what is the definition of stroke volume SV

Answer 1

The volume of blood that leaves the heart during each contraction

Question 2

What is the unit for cardiac output

Answer 2

L / Min or Ml / Min

Question 3

What is the equation of cardiac output

Answer 3

HR X SV

Question 4

what is the definition of cardiac output

Answer 4

The amount of blood The heart pumps out per minute

Question 5

what would the difference be between an a trained person and untrained persons resting heart rate

Answer 5

Trained Individuals Resting HR are much lower than untrained individuals

Question 6

why is a trained person resting heart rate lower than untrained person

Answer 6

cardiac hypertrophy -> heart is bigger -> pumps more blood -> larger SV ->increased size of chambers -> bigger SV -> heart doesn’t have to beat as many times

Question 7

What is the sympathetic system

Answer 7

A part of the autonomic nervous system that speeds heart rate

Question 8

What is the Parasympathetic System

Answer 8

A part of the autonomic nervous system that decreases heart rate

Question 9

What is the medulla oblongata

Answer 9

The most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate

Question 10

What is the ANS

Answer 10

Autonomic nervous system

Question 11

What does the ANS do

Answer 11

Determines the rate at which the SAN sends out impulses

Question 12

How does the sympathetic nervous system increase HR

Answer 12

It releases adrenaline

Question 13

What does adrenaline increase in the sympathetic nervous system

Answer 13

It increases the strength of ventricular contraction which then increases stroke volume

Question 14

In the sympathetic nervous system what does noradrenaline do

Answer 14

Aids the spread of electrical impulse throughout the heart, increasing HR

Question 15

In the sympathetic nervous system what does an increased metabolic rate cause

Answer 15

Increased CO2 and lactic acid, decrease in blood PH (more acidic)

Question 16

How are the changes of an increased metabolic rate picked up

Answer 16

By the chemoreceptors and they inform the sympathetic system to increase HR to flush out the waste products. This results in an increased cardiac output

Question 17

What is the parasympathetic nervous system

Answer 17

The nervous system that slows the speed of the heart down which decreases HR

Question 18

What does the parasympathetic nervous system do to lower the heart rate

Answer 18

Releases Acetylocholine which slows the spread of impulses throughout the heart, this results in a lower heart rate

Question 19

What are receptors

Answer 19

Part of the nervous system that detects changes in the body.

Question 20

What do chemoreceptors do

Answer 20

Detect changes in CO2 - an increased concentraton in The blood will stimulate The sympathetic nervous system- which means The heart will beat faster

Question 21

What do baroreceptors do

Answer 21

Detect changes in blood pressure- Baroreceptors establish set points for blood pressure - an increase or decrease above or below this set point results in The Baroreceptors sending signals to The medulla oblongata

Question 22

What do proprioceptors do

Answer 22

Increases HR when muscle movement increases

Question 23

What is adrenaline

Answer 23

A stress hormone that is released by the sympathetic nerves and cardiac nerve during exercise which causes an increase in heart rate

Question 24

What is ejection fraction

Answer 24

The percentage of blood pumped out by the left ventricle per beat

Question 25

What is the diastole phase

Answer 25

When the heart relaxes to fill with blood

Question 26

What does stroke volume depend on

Answer 26

Venous return - The elasticity of cardiac fibres - contractility of cardiac tissue

Question 27

How does venous return affect stroke volume

Answer 27

If the venous return increases then stroke volume will increase

Question 28

What is venous return

Answer 28

The volume of blood return to the heart via veins

Question 29

How does the elasticity of cardiac fibres affect stroke volume

Answer 29

The more the cardiac fibres can stretch, the greater the force of contraction (which also increases ejection fraction - starlings law)

Question 30

What is starlings law

Answer 30

Increased venous return -> greater diastolic filling of the heart -> cardiac muscle stretched -> more force of contraction -> increased ejection fraction

Question 31

What is cardiac output

Answer 31

The volume of blood pumped out by the hearts ventricles per minute

Question 32

How does the contractility of cardiac tissue affect stroke volume

Answer 32

The greater the contractility of cardiac tissue, the greater the force of contraction

Question 33

How do you calculate cardiac output

Answer 33

Cardiac Output (Q) = Stroke volume (SV) x Heart Rate (HR)

Question 34

What is cardiac hypertrophy

Answer 34

The thickening of the muscular wall of the heart so it becomes bigger and stronger

Question 35

What is bradycardia

Answer 35

A decrease in resting heart rate to below 60 beats per minute

Question 36

How does having a bigger heart affect cardiac output

Answer 36

Enables more blood to be pumped out and as a result the blood doesn’t need to pump as often so resting HR decreases

Question 37

How do u calculate maximum heart rate

Answer 37

220 - your age

Question 38

what is cardiovascular drift

Answer 38

Cardiovascular drift occurs after a period of exercise -> HR increase -> stroke volume decreases -> because fluid is lost as sweat -> resulting in a reduced plasma volume -> reduced venous return -> cardiac output increases (no energy needed to cool the body)