Animal transport Flashcards
What seperates the right atrium and ventricle?
Atrioventricular valve (tricuspid valve)
What seperates the left atrium and ventricle?
Bicuspid valve
What seperates the right ventricle and the pulmonary artery?
Pulmonary valve
What seperates the left ventricle and the aorta?
Aortic valve
What happens to the valves in systole?
Atrioventricular valves close and semilunar valves open
What happens to the valves in diastole?
Atrioventricular valves open and semilunar valves close
What is stroke volume?
The volume of blood pumped out of the left ventricle during one cardiac cycle
How to calculate cardiac output?
Cardiac output = heart rate x stroke volume
What is the first stage in the cardiac cycle?
Sinoatrial node sends out a wave of depolarisation causing the atria to contract.
What is the second stage in the cardiac cycle?
Depolarisation is carried to the atrioventricular node (AVN)- which is a region of conducting tissues between atria and ventricles
What is the third stage in the cardiac cycle?
After a slight delay, the AVN is stimulated and passes the stimulation along the bundle of His.
What is the fourth stage in the cardiac cycle?
The bundle of His divides into two conducting fibres called Purkyne tissue. The Purkyne fibres spread around the ventricles and initiate depolarisation of the ventricles from the apex (bottom) of the heart.
What is the fifth stage in the cardiac cycle?
Ventricles contract and blood is forced out of the pulmonary artery and aorta.
Why is there a delay before the AVN is stimulated?
Means the ventricles contract after the atria
What is the order of the letters in the ECG?
PQRST
What is the P wave?
Caused by depolarisation of the atria, which results in atria contraction (systole)
What is the QRS complex?
Depolarisation of the ventricles, results in ventricular contraction (systole)
What is the T wave?
Repolarisation of the ventricles, results in ventricular relaxation (diastole)
What is tachycardia?
Heart beats too fast
What is bradycardia?
Heart beats too slowly
What is an ectopic heartbeat?
Early heart beat, followed by a pause
What is fibrillation?
An irregular heartbeat
Does foetal haemoglobin have a higher or lower affinity for oxygen?
Higher, so it lies further to the left
What is hydrostatic pressure?
Pressure exerted by fluid
What is oncotic pressure?
Pressure exerted by plasma proteins within a blood vessel
