PAPER 1 - Cardiovascular & Respiratory System Flashcards
- Cardiovascular system at rest. - Cardiovascular system during exercise of differing intensities and recovery. - Respiratory System at rest. - Respiratory system during exercise of differing intensities and recovery.
CARDIOVASCULAR SYSTEM
Pulmonary Circuit
- Carries deoxygenated blood to the lungs.
- Carries oxygenated blood back to the heart.
CARDIOVASCULAR SYSTEM
Systemic Circuit
- Carries oxygenated blood to the body.
- Carries deoxygenated blood back to the heart.
CARDIOVASCULAR SYSTEM
Diastole
CARDIAC CYCLE
- Both Atria and Ventricles relax
- Draws blood back into the atria
CARDIOVASCULAR SYSTEM
Atrial Systole
CARDIAC CYCLE
- Contraction of the Atria
- Blood forced into the Ventricles
CARDIOVASCULAR SYSTEM
Ventricular Systole
CARDIAC CYCLE
- Contraction of the Ventricles
- Blood forced into the Arteries
Arteries - Aorta & Pulmonary Artery
CARDIOVASCULAR SYSTEM
Myogenic
The Conduction System
Cardiac Muscle = Myogenic
- Has capacity to generate it’s own electrical impulses…
- Pass them through muscular walls
- Causing them to contract
CARDIOVASCULAR SYSTEM
FEATURES OF THE CONDUCTION SYSTEM
Sino-atrial node - SA node
LOCATION: Right Atria Wall
Generates electrical impulse & fires it through atria wall - forces them to contract
Aka “pacemaker” - Firing Rate wil determine Heart Rate.
CARDIOVASCULAR SYSTEM
FEATURES OF THE CONDUCTION SYSTEM
Atrio-Ventricular node - AV node
Collects impulse & delays it [for approximately 0.1s]
Allows Atria to finish contracting
Releases impulse to **Bundle of His…
**
CARDIOVASCULAR SYSTEM
FEATURES OF THE CONDUCTION SYSTEM
Bundle of His
LOCATION: Septum of Heart
Splits impulse in two, ready to be distributed through each seperate ventricle.
CARDIOVASCULAR SYSTEM
FEATURES OF THE CONDUCTION SYSTEM
Bundle Branches
Carry the impulse to the base of each ventricle.
CARDIOVASCULAR SYSTEM
FEATURES OF THE CONDUCTION SYSTEM
Purkinje Fibres
Distribute the impulse through the ventricle walls, causing them to contract.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Heart Rate
Equation for Maximal Heart Rate
Resting HR -
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
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Heart Rate - Response to Exercise
Sub-maximal Exercise
Heart Rate can plateau once a comfortable, steady state is reached.
Represents the supply meeting demand for O2 delivery & Waste Removal.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Heart Rate at submaximal intensity exercise
Graph Explaination
- an initial anticipatory rise in HR before exercise - adrenaline.
- rapid increase in HR at the start of exercise - increase blood flow and oxygen delivery in line with exercise intensity .
- Steady state HR throughout sustained intensity exercise - oxygen supply meets demand.
- Initial rapid decrease in HR - recovery/ reduction in muscle pump action.
- Gradual decrease in heart rate to resting levels.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Heart Rate at maximal intensity exercise
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
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Stroke Volume
Definition
The volume of blood ejected from the left ventricle per beat.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Average Heart Rate, Stroke Volume and Cardiac Output
Untrained Performer
HR = 72 bpm
SV = 70ml
Cardiac Output = 5l/ min
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Average Heart Rate, Stroke Volume and Cardiac Output
Trained Performer
HR = 50 bpm
SV = 100ml
Cardiac Output = 5L/min
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Sub-maximal Exercise
A low-to-moderate intensity of exercise
* within a performer’s aerobic capacity or below the anaerobic threshold.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Maximal Exercise
High intensity exercise
* above a perfomers aerobic capacity - take a performer to exhaustion
Often associated with anaerobic work/fatigue
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Stroke Volume’s general response to exercise.
- SV increases with exercise intensity
PLATEAUS at around 40% - 60% of working capacity
CARDIAC RESPONSE TO EXERCISE & RECOVERY
What are the 2 reasons why stroke volume is able to increase?
- Venous Return
- Starling’s Law
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Venous Return Response to Exercise
Stroke Volume
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
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Starling’s Law Response to Exercise
Stroke Volume
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.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Why does SV reach a plateau during sub-maximal exercise?
A high HR does not have time for the ventricles to completely fill
This limits Sterlings Law
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Cardiac Output
Equation:
The volume of blood ejected from the left ventricle per minute.
Cardiac Output (litres per minute) = Heart Rate x Stroke Volume.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Cardiac Output’s response to exercise.
Cardiac Output increases in line with intensity of exercise.
- Plateau’s during maximal activity.
CARDIAC RESPONSE TO EXERCISE & RECOVERY
Cardiac Output’s response to recovery.
Initial rapid decrease
Follows more slow decrease to resting level.
HEART REGULATION
What is the Cardiac Control Centre?
CCC
A control centre in the medulla oblongata responsible for HR regulation.
Medulla Oblongata - The Brain
HEART REGULATION
What are the 3 control mechanisms which provide information to the CCC?
- Neural Control
- Intrinsic Control
- Hormonal Control
HEART REGULATION
Methods of Neural Control
CCC
Examples -
-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
Chemoreceptors - Increased levels of CO2 and Lactic Acid
HEART REGULATION
Methods of intrinsic control
CCC
- Temperature changes affect
- blood viscosity
- speed of nerve impulse transmission - Venous Return changes affect
- the stretch of ventricle walls
- force of ventricular contraction
- stroke volume
HEART REGULATION
Method of hormonal control
CCC
Adrenaline & Noradrenaline are released from the adrenal glands.
- Increases force of ventricular contraction
- Stroke Volume
- Increases speed of conduction system
THE VASCULAR SYSTEM
Artery
STUCTURE
Large layer of smooth muscle and elastic tissue
THE VASCULAR SYSTEM
Artery
FUCTION
- transports blood back to the heart
- allows smooth muscle to vasodilation & vasoconstriction
THE VASCULAR SYSTEM
Veins
STRUCTURE
Small layer of smooth muscle
Veins have one way POCKET VALVES
THE VASCULAR SYSTEM
Capillaries
STRUCTURE
- Composed of single cell walls
- Thin to allow gaseous exchange
Venous Return
Mechanisms of VR
Definition-
- Pocket Valves
- Smooth Muscle
- Gravity
- Muscle Pump
- Respiratory Pump
return of blood to the heart through the venules and veins back to RA
Venous Return
Pocket Valves
One-Way valves located in the veins
prevent the backflow of blood
Venous Return
Smooth Muscle
Layer of smooth muscle in the vein wall vasoconstricts
creates venomotor tone which aids the movement of blood
Venous Return
Gravity
Blood from the upper body {above the heart}
is helped to return by gravity
Venous Return
Muscle Pump
During exercise…
Skeletal muscles contract compressing the veins located between them
Blood is squeezed back to the heart
Venous Return
Respiratory Pump
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
