Cardiovascular System Flashcards
What is heart disease?
- build up of fatty deposits which causes coronary arteries to become blocked
- insufficient oxygen delivered to the heart
- increases risk of heart attack
Impact of sport on heart disease
- exercise makes heart bigger and stronger
- allows more blood to be pumped from the heart
- reduces risk of heart disease
What is high blood pressure?
- extra strain on arteries and heart
- can lead to heart attack, heart failure and stroke
Impact of sport on high blood pressure
- regular aerobic exercise can reduce blood pressure
- reduces risk of a heart attack
What are cholesterol levels?
- low density lipoproteins
(bad cholesterol)
(increase risk of heart disease)
(transport in blood to tissues) - high density lipoproteins
(excess transport to liver)
Impact of sport on cholesterol levels
- lowers bad LDL levels
- increases good HDL levels
What is a stroke?
- occurs when blood supply to the brain is cut off
- causes damage to brain cells
Impact of sport on stroke
- lowers blood pressure
Define heart rate
The number of times the heart beats per minute
Define stroke volume
The volume of blood pumped from the heart per beat
Define cardiac output
The volume of blood pumped from the heart per minute
What is the equation for cardiac output
Heart rate x stroke volume
Define anticipatory rise
Increase in heart rate in anticipation of an activity
Define venous return
The volume of blood returning to the heart via veins
Define elasticity of cardiac fibres
Stretching on cardiac fibres during diastole
Define ejection fraction
The percentage of blood pumped out of the left ventricle per beat
Effect of elasticity of cardiac fibres on ejection fraction
More the fibres stretch, increased force of contraction, more percentage of blood pumped out of left ventricle per beat (ejection fraction)
Define cardiac tissue contractility
Ability of heart muscle to contract and pump blood
Effect of contractility on stroke volume
Increased contractility, increased force of contraction, increased ejection fraction, increased stroke volume
What does Starling’s Law state?
The greater venous return, the greater the stroke volume
Use Starling’s Law to explain how stroke volume increases during exercise
- during exercise, venous return increases
- this increases the diastolic filling of the heart which leads to the cardiac muscle being stretched
- this results in a more powerful contraction which leads to an increased ejection fraction
- this increases the stroke volume
How will heart rate differ between a trained and untrained athlete at rest?
Lower resting heart rate in trained athlete
How will stroke volume differ between a trained and untrained athlete at rest?
Higher resting stroke volume in trained athlete
How will cardiac output differ between a trained and untrained athlete at rest?
Stays the same
Define systole
The phase of the heart beat when the heart contracts to pump blood
Define diastole
The phase of the heart beat when the heart relaxes to fill with blood
Define myogenic
Originating in the muscle as an impulse or sensation
Define the sino-atrial node
Small mass of cardiac muscle that generates the heart beat
Define the atrioventricular node
Relays the impulse between upper and lower sections of the heart
Define the bundle of His
Collection of muscle cells that transmit electrical impulses from the atrioventricular node via bundle branches to Purkinje fibres
Definitely bundle branches
Carries an electrical impulse from the bundle of His to Purkinje fibres
Define Purkinje fibres
Muscle fibres that conduct impulses in the walls of ventricles
What happens in the first stage of the cardiac conduction system?
Sino-atrial node sends an impulse across atria causing them to contract
What happens in the second stage of the cardiac conduction system?
Impulse arrives at the atrioventricular node where it is delayed, allowing ventricles to fully fill with blood
What happens in the third stage of the cardiac conduction system?
The impulse travels down the bundle of His located in the septum
What is the fourth stage in the cardiac conduction system?
Impulse travels along Purkinje fibres branched along the base of right and left ventricles causing them to contract
Sally Always Aims Balls Past Vicky
Sino-atrial node
Atrial systole
Atrioventricular node
Bundle of His
Purkinje fibres
Ventricular systole
4 factors affecting change in rate of the conduction system
- neural control mechanism
- chemoreceptors
- baroreceptors
- proprioceptors
