Explain what the process of atherosclerosis is
build up of fatty deposits in the coronary ateries
Explain what atheroma is
fatty deposits
Explain what agina is
pain in the heart
Explain what blood pressure is
force exerted by the blood against the blood vessel wall
Explain the effect of low density lipoproteins
increased risk of heart disease
transport cholesterol in the blood tissues
Explain the effect of high density lipoproteins
lower the risk of heart disease
transport excess cholesterol in the blood back to the liver where it is broken down
Explain what an ischaemic stroke is
blood clot stops the blood supply
Explain what a haemorrhagic stroke is
weakened blood vessel supplying to the brain bursts
Explain how the stroke volume can be increased
venous return
elasticity of cardiac fibres
contractility of cardiac tissue
How can the maximum heart rate be calculated
220 - age
Define bradycardia
resting heart rate below 60 bpm
Define cardiac hypertrophy
heart becomes bigger and stronger due to a thickening of the muscular wall
How can the cardiac output be calculated
stroke volume x heart rate
Explain the cardiac conduction system
SAN (sino-atrial node) sends a wave of excitation across the atrial walls
AVN (atrio-ventricular node) delays the impulse to enable the atria to empty and ventricles to fill
Bundle of His sends impulse down the ventricular walls
Purkjne fibres recieve impulse and the ventricles contract
Describe what myogenic is
heart muscle generates its own heart beat
Define the sympathetic system
increases heart rate
‘flight or figh response’
Define the parasympathetic system
decreases the heart rate
‘rest and relax’
Explain the process of anticipatory rise before exercise
hormone adrenaline is released by the nervous system
stimulates heart rate to increase both the speed and force of contraction
increases cardiac output
more oxygenated blood pumped to the working muscles
Define the medualla oblongata
regulates the processes that keeps us alive
What do chemoreceptors detect
changes in blood acidity (carbon dioixide levels)
What do proprioreceptors detect
muscle movement
What do baroreceptors detect
changes in the blood pressure
Where are the chemoreceptors found
carotid atery
aortic arch
Describe what vascular shunting is
redistribution of cardiac output to where oxygen is needed most