ALL DEFINITIONS AQA SPEC Flashcards
Everything but balls angular and projectile motion, all PGE retake topics
Anticipatory rise
An increase in heart rate prior to exercise, due to the release of adrenalin.
A-VO2 diff
The difference in oxygen content of the blood between arterial blood and venous blood
Systolic blood pressure
Blood pressure while the heart is contracting
Blood pressure
Blood pressure is a measure of the force that your blood exerts against blood vessel walls.
Diastolic blood pressure
Blood pressure when the heart is relaxing
High blood pressure
Can occur due to obesity, too much salt, stress or smoking.
Bohr shift
When the oxyhaemoglobin dissociation curve moves to the right during exercise.
Why does Bohr shift occur?
as a result of increased co2 in blood, increased blood acidity, decreased blood PH, increased blood temperature.
Cardiac conduction system
A group of specialised cardiac muscle cells in the walls of the heart sending signals causing it to contract.
Why does cardiovascular drift occur?
Due to sweating which reduces blood volume and increases viscosity (thickening). Decreasing venous return, in line with starlings law, decreases stroke volume.
Heat
Humidity
Bradycardia (Athletes heart)
A reduction in resting heart rate below 60 bpm.
Bundle of HIS
Conducts the impulse down the septum.
Sino-atrial node (SAN)
The hearts pacemaker, sends an impulse through the atria making it contract.
Atrio-ventricular node (AVN)
Delays the impulse to allow ventricular filling.
0.1 s
Purkinje fibres
Spread the impulse through the ventricles causing them to contract.
Cardiac Output
Amount of blood which leaves the left ventricle per minute.
Cardiac Hypertrophy
Increase in thickness of the muscular heart wall, especially around the left ventricle.
Heart rate
Number of times the heart contracts per minute.
Stroke volume
The amount of blood which leaves the left ventricle per contraction.
Cardiovascular Drift
A reduction in stroke volume when exercising in warm conditions for longer than 10 minutes.
Heart Disease
Occurs when coronary blood vessels become blocked by fatty deposits, called atheroma.
Haemoglobin
Found in red blood cells.
Combines with oxygen to form oxyhaemoglobin transporting it around the body.
Myoglobin
Found in muscle cells, stores and transports oxygen.
Higher affinity for oxygen then haemoglobin.
Baroreceptors
Located in blood vessels, these detect changes in blood pressure.