Physiology and Anatomy - Circulatory System

Where is the tricuspid valve?

Between right atrium and right ventricle

Where is bicuspid valve?

Between left atrium and left ventricle

Where is aortic valve?

between left ventricle and aorta

Where is pulmonary valve?

between right ventricle and pulmonary artery

What are the 3 stages of the cardiac cycle?

Ventricular filling - mid-late diastole

Ventricular systole

Early diastole

Valves during ventricular filling?

AV valves open

SL valves closed

Valves during atrial contraction?

AV valves open

SL valves closed

valves during isovolumetric contraction?

AV valves closed

SL valves closed

Valves during ventricular ejection?

AV valves closed

SL valves open

Valves during isovolumetric relaxation?

AV valves closed

SL valves closed

During depolarisation (20) of a normal cardiac cell, what's the movement of ions?

Sodium and calcium in

During small repolarisation (10) of a normal cardiac cell, what's the movement of ions?

Potassium out

During long repolarisation (0) of a normal cardiac cell, what's the movement of ions?

Calcium in, potassium out

During full repolarisation (-85) of a normal cardiac cell, what's the movement of ions?

Calcium in stops, potassium in

During the return to resting potential of a normal cardiac cell, what's the movement of ions?

Potassium out

What are the 5 stages of action potential in normal heart cells?

0 - Depolatisation

1 - Small repolarisation

2 - Long repolarisation

3 - Full repolarisation

4 - return to resting potential

What stage of action potential do pacemaker cells miss compared to normal heart cells?

Stage 1

What happens during stage 0 of action potential in a pacemaker cell in terms of ions?

Calcium in

What happens during stage 2 of action potential in a pacemaker cell in terms of ions?

Calcium in stops

Potassium out

What happens during stage 3 of action potential in a pacemaker cell in terms of ions?

Potassium out stops

What happens during stage 4 of action potential in a pacemaker cell in terms of ions?

Potassium out

What is stroke volume?

Vol of blood pumped by each ventricle in one contraction (70mL per heatbreat)

What is the heart rate?

Number of contractions per min (beats/min)

What is the cardiac output and what's the formula for it?

Amount of blood pumped by each side of the heart in one minute

Heart rate * stroke volume

In an ECG, where are the stickers placed?

Upper right

Upper left

Mid-left

Lower-left apex

What does the P reflect in an ECG wave?

Ventricular filling, start of impulse in SA node

What does the Q represent in an ECG wave?

Atrial contraction

What does R represent in an ECG wave?

Isovolumetric contraction

What does S represent in an ECG wave?

Ventricular ejection

What does the T reflect in an ECG wave?

Isovolumentric relaxation, repolarisation of ventricles

What does the QRS complex in an ECG represent?

Depolarisation of ventricles

What is the RR interval between two ECG waves?

Instantaneous heartbeat

What is hyperkalemia?

Increase in potassium ions causing a tent shaped T wave

Where are chemoreceptors found?

Carotid and aortic bodies

Where is the respiratory center located?

Medulla oblongata

Which nerves send information from chemoreceptors to respiratory center?

Cranial nerves IX and X

Where are baroreceptors located?

Carotid sinuses and aortic arch

What happens if adrenaline or noradrenaline bind to beta adrenergic receptors?

Causes vasodilation

What happens if adrenaline or noradrenaline bind to alpha adrenergic receptors?

Causes vasoconstriction

What are the layers of the heart wall from the outside onwards?

Parietal pericardium

Serous pericardium aka visceral space

Visceral pericardium

Myocardium

Endocardium