The majority of CO2 transport is in the form of

• hydrogen carbonate (bicarbonate)

• carbomino haemoglobin

• CO2 in solution

What enzyme is required for CO2 to be combined with water to make carbonic acid?

• carbonic anhydrase

• carbonic acid

• carbonase

Blood returning from the body enters the

• right atrium

• left atrium

• left ventricle

• right ventricle

as the left ventricle contracts, the blood moves to the

• aorta

• vena cava

• arteries

• veins

blood returning to the heart from the lungs enters the

• right atrium

• left atrium

• right ventricle

• left ventricle

the excitation wave begins at the

• sinoatrial node

• atrioventricular node

• perkyne fibers

the pacemaker region of the heart

• SA node

• AV node

During atrial systole, the pressure of the blood s __________ in the atrium than the ventricle.

• higher

• lower

• the same

In an ECG, the QRS complex signals the

• contraction of the ventricles

• relaxation of the atrium

• the repolarization of the Ventricle

The T wave in an ECG indicates...

• repolarization

• depolarization

• excitation