PAPER 1 - Cardiovascular & Respiratory System

Question 1

CARDIOVASCULAR SYSTEM

Pulmonary Circuit

Answer 1

• Carries deoxygenated blood to the lungs.
• Carries oxygenated blood back to the heart.

Question 2

CARDIOVASCULAR SYSTEM

Systemic Circuit

Answer 2

• Carries oxygenated blood to the body.
• Carries deoxygenated blood back to the heart.

Question 3

CARDIOVASCULAR SYSTEM

Diastole

CARDIAC CYCLE

Answer 3

• Both Atria and Ventricles relax
• Draws blood back into the atria

Question 4

CARDIOVASCULAR SYSTEM

Atrial Systole

CARDIAC CYCLE

Answer 4

• Contraction of the Atria
• Blood forced into the Ventricles

Question 5

CARDIOVASCULAR SYSTEM

Ventricular Systole

CARDIAC CYCLE

Answer 5

• Contraction of the Ventricles
• Blood forced into the Arteries

Arteries - Aorta & Pulmonary Artery

Question 6

CARDIOVASCULAR SYSTEM

Myogenic

The Conduction System

Answer 6

Cardiac Muscle = Myogenic
- Has capacity to generate it’s own electrical impulses…
- Pass them through muscular walls
- Causing them to contract

Question 7

CARDIOVASCULAR SYSTEM

FEATURES OF THE CONDUCTION SYSTEM

Sino-atrial node - SA node

Answer 7

LOCATION: Right Atria Wall
Generates electrical impulse & fires it through atria wall - forces them to contract

Aka “pacemaker” - Firing Rate wil determine Heart Rate.

Question 8

CARDIOVASCULAR SYSTEM

FEATURES OF THE CONDUCTION SYSTEM

Atrio-Ventricular node - AV node

Answer 8

Collects impulse & delays it [for approximately 0.1s]
Allows Atria to finish contracting

Releases impulse to **Bundle of His…
**

Question 9

CARDIOVASCULAR SYSTEM

FEATURES OF THE CONDUCTION SYSTEM

Bundle of His

Answer 9

LOCATION: Septum of Heart

Splits impulse in two, ready to be distributed through each seperate ventricle.

Question 10

CARDIOVASCULAR SYSTEM

FEATURES OF THE CONDUCTION SYSTEM

Bundle Branches

Answer 10

Carry the impulse to the base of each ventricle.

Question 11

CARDIOVASCULAR SYSTEM

FEATURES OF THE CONDUCTION SYSTEM

Purkinje Fibres

Answer 11

Distribute the impulse through the ventricle walls, causing them to contract.

Question 12

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Heart Rate

Equation for Maximal Heart Rate

Resting HR -

Answer 12

The number of cardiac cycles completed in one minute.

HR Max = 220 - age

Untrained Athlete - 60-75bpm
Trained Athlete - 50bpm

KEY WORD - Bradycardia
A resting heart rate below 60 bpm

Question 13

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Heart Rate - Response to Exercise

Sub-maximal Exercise

Answer 13

Heart Rate can plateau once a comfortable, steady state is reached.

Represents the supply meeting demand for O2 delivery & Waste Removal.

Question 14

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Heart Rate at submaximal intensity exercise

Graph Explaination

Answer 14

1. an initial anticipatory rise in HR before exercise - adrenaline.
2. rapid increase in HR at the start of exercise - increase blood flow and oxygen delivery in line with exercise intensity .
3. Steady state HR throughout sustained intensity exercise - oxygen supply meets demand.
4. Initial rapid decrease in HR - recovery/ reduction in muscle pump action.
5. Gradual decrease in heart rate to resting levels.

Question 15

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Heart Rate at maximal intensity exercise

Answer 15

Heart Rate DOES NOT PLATEAU
Due to…
Growing demand of oxygen and water removal which HR must continually strive to meet.

Intensity is always increasing

Question 16

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Stroke Volume

Definition

Answer 16

The volume of blood ejected from the left ventricle per beat.

Question 17

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Average Heart Rate, Stroke Volume and Cardiac Output

Untrained Performer

Answer 17

HR = 72 bpm
SV = 70ml
Cardiac Output = 5l/ min

Question 18

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Average Heart Rate, Stroke Volume and Cardiac Output

Trained Performer

Answer 18

HR = 50 bpm
SV = 100ml
Cardiac Output = 5L/min

Question 19

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Sub-maximal Exercise

Answer 19

A low-to-moderate intensity of exercise
* within a performer’s aerobic capacity or below the anaerobic threshold.

Question 20

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Maximal Exercise

Answer 20

High intensity exercise
* above a perfomers aerobic capacity - take a performer to exhaustion

Often associated with anaerobic work/fatigue

Question 21

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Stroke Volume’s general response to exercise.

Answer 21

• SV increases with exercise intensity
  PLATEAUS at around 40% - 60% of working capacity

Question 22

CARDIAC RESPONSE TO EXERCISE & RECOVERY

What are the 2 reasons why stroke volume is able to increase?

Answer 22

• Venous Return
• Starling’s Law

Question 23

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Venous Return Response to Exercise

Stroke Volume

Answer 23

Venous Return increases

• Greater volume of blood is retuning to the heart and filing the ventricles.

Increased VR = Increased SR

Stroke Volume is DEPENDANT ON Venous Return

Question 24

CARDIAC RESPONSE TO EXERCISE & RECOVERY

Starling’s Law Response to Exercise

Stroke Volume

Answer 24

Increase in Venous return = Increases end-diastolic volume in ventricles
Causes greater stretch of ventricle walls
- therefore an increased force of contraction.

Means that a larger volume of blood is ejected from the heart.

Question 25

# **CARDIAC RESPONSE TO EXERCISE & RECOVERY** Why does SV reach a plateau during sub-maximal exercise?

Answer 25

A high HR does not have time for the ventricles to completely fill | This limits Sterlings Law

Question 26

# **CARDIAC RESPONSE TO EXERCISE & RECOVERY** Cardiac Output | Equation:

Answer 26

The volume of blood ejected from the left ventricle per minute. | Cardiac Output (litres per minute) = Heart Rate x Stroke Volume.

Question 27

# **CARDIAC RESPONSE TO EXERCISE & RECOVERY** Cardiac Output's response to exercise.

Answer 27

Cardiac Output increases in line with intensity of exercise. - Plateau's during maximal activity.

Question 28

# **CARDIAC RESPONSE TO EXERCISE & RECOVERY** Cardiac Output's response to recovery.

Answer 28

Initial rapid decrease Follows more slow decrease to resting level.

Question 29

# **HEART REGULATION** What is the Cardiac Control Centre? | CCC

Answer 29

A control centre in the medulla oblongata responsible for HR regulation. | Medulla Oblongata - The Brain

Question 30

# **HEART REGULATION** What are the 3 control mechanisms which provide information to the CCC?

Answer 30

1. Neural Control 2. Intrinsic Control 3. Hormonal Control

Question 31

# **HEART REGULATION** Methods of Neural Control | CCC ## Footnote Examples -

Answer 31

-Chemoreceptors LOCATION: muscles, aorta & cartoid arteries **Inform the CCC of chemical changes in the blood stream** -Proprioceptors LOCATION: muscles, tendons & joints **Inform the CCC of increased motor activity** -Baroreceptors LOCATION: Blood vessel walls **Inform the CCC of increased blood pressure** ## Footnote Chemoreceptors - Increased levels of CO2 and Lactic Acid

Question 32

# **HEART REGULATION** Methods of intrinsic control | CCC

Answer 32

1. Temperature changes affect - blood viscosity - speed of nerve impulse transmission 2. Venous Return changes affect - the stretch of ventricle walls - force of ventricular contraction - stroke volume

Question 33

# **HEART REGULATION** Method of hormonal control | CCC

Answer 33

Adrenaline & Noradrenaline are released from the adrenal glands. - Increases force of ventricular contraction - Stroke Volume - Increases speed of conduction system

Question 34

# **THE VASCULAR SYSTEM** Artery | STUCTURE

Answer 34

Large layer of smooth muscle and elastic tissue

Question 35

# **THE VASCULAR SYSTEM** Artery | FUCTION

Answer 35

* transports blood back to the heart * allows smooth muscle to *vasodilation & vasoconstriction*

Question 36

# **THE VASCULAR SYSTEM** Veins | STRUCTURE

Answer 36

Small layer of smooth muscle Veins have one way **POCKET VALVES**

Question 37

# THE VASCULAR SYSTEM Capillaries | STRUCTURE

Answer 37

- Composed of single cell walls - Thin to allow **gaseous** **exchange**

Question 38

# Venous Return Mechanisms of VR | Definition-

Answer 38

1. Pocket Valves 2. Smooth Muscle 3. Gravity 4. Muscle Pump 5. Respiratory Pump | return of blood to the heart through the venules and veins back to RA

Question 39

# Venous Return Pocket Valves

Answer 39

One-Way valves located in the veins prevent the backflow of blood

Question 40

# Venous Return Smooth Muscle

Answer 40

Layer of smooth muscle in the vein wall ***vasoconstricts*** creates venomotor tone which aids the movement of blood

Question 41

# Venous Return Gravity

Answer 41

Blood from the upper body {above the heart} is helped to return by gravity

Question 42

# Venous Return Muscle Pump

Answer 42

During exercise... *Skeletal* *muscles* contract compressing the veins located between them Blood is squeezed back to the heart

Question 43

# Venous Return Respiratory Pump

Answer 43

During inspiration and expiration a pressure difference between the thoracic and abdominal cavity created blood = squeezed back to the heart | increased respiratory rate = increased respiratory pump maximised