Topic 8

Which of the tissue types below are present in the walls of all blood vessels?

1 collagen

2 elastic

3 endothelial

4 smooth muscle

• 1, 2, 3 and 4

• 1, 2 and 4 only

• 2 and 3 only

• 3 only

Which statements about the formation of haemoglobinic acid are correct?

1 It can only occur with the dissociation of oxygen from haemoglobin.

2 It acts to prevent excess hydrogen ions causing acidity in blood.

3 It depends on the release of hydrogen ions by the action of carbonic anhydrase.

• 1, 2 and 3

• 1 and 2 only

• 2 and 3 only

• 1 only

Which blood vessels carry blood into the atria of the heart?

• coronary artery and pulmonary artery

• pulmonary artery and vena cava

• pulmonary vein and vena cava

• vena cava and coronary artery

Which statement describes the effect of increased carbon dioxide concentration on the oxygen dissociation curve of human haemoglobin and its significance?

• The curve shifts to the left allowing haemoglobin to bind more oxygen in active tissues.

• The curve shifts to the left allowing haemoglobin to offload more oxygen in active tissues.

• The curve shifts to the right allowing haemoglobin to bind more oxygen in active tissues.

• The curve shifts to the right allowing haemoglobin to offload more oxygen in active tissues.

What combines with haemoglobin to form carbaminohaemoglobin?

• carbon dioxide

• carbon monoxide

• carbonic acid

• hydrogencarbonate ions

What is systolic blood pressure?

• the blood pressure in the arteries when the heart is relaxing

• the blood pressure in the left ventricle at the end of a contraction

• the maximum blood pressure in the arteries

• the maximum blood pressure in the right ventricle

Haemoglobin can bind to carbon dioxide, carbon monoxide and oxygen.

1 carbon dioxide

2 carbon monoxide

3 oxygen

Which gases share a binding site?

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

Which statement about the human circulatory system is correct?

• Blood passes twice through the heart in one complete circulation.

• Blood, tissue fluid and lymph are all parts of the circulatory system.

• Capillaries have the lowest blood pressure.

• Veins in the circulatory system all carry deoxygenated blood.

Which statement explains why the ventricles contract after the atria?

• The band of fibres between the atria and the ventricles conducts the excitation wave slowly.

• The excitation wave has to pass through a small area of conducting fibres in the septum.

• The excitation wave has to travel further to reach the base of the ventricles than to spread across the atria.

• The excitation wave travels slowly through the Purkyne tissue to reach the base of the septum.

If the left atrioventricular valve in the heart does not close completely it results in blood flowing back into the atrium during ventricular systole. What would be the immediate effect of this back flow?

• blood flowing from the heart carries less oxygen because less blood enters the lungs

• diastolic pressure in the left ventricle falls because less blood enters the pulmonary artery

• lower systolic pressure in the left atrium and less blood enters the pulmonary artery

• raised pressure in the left atrium and less blood enters the aorta