Body Fluids and Circulation quiz

The normal lifespan of human RBCs is about:

The most abundant WBCs in human blood are:

The pacemaker of the heart is the:

The QRS complex in an ECG represents:

The universal donor blood group is:

The protein that forms a network of threads in a clot is:

The 'lub' sound of the heart is produced by the closure of:

Which animals have a three-chambered heart with two atria and one ventricle?

Erythroblastosis foetalis is caused by incompatibility of:

The vein that carries blood from the intestine to the liver is the:

What are the functions of plasma proteins? (2 marks)

Why are RBCs in mammals without a nucleus? (2 marks)

What is the role of calcium ions in blood clotting? (2 marks)

Distinguish between open and closed circulatory systems. (2 marks)

What is the function of the bundle of His and Purkinje fibres? (2 marks)

How is cardiac activity regulated by the nervous system? (2 marks)

What is the significance of the ECG in diagnosis? (2 marks)

What is angina pectoris? (2 marks)

What is coronary artery disease? (2 marks)

Distinguish between systemic and pulmonary circulation. (2 marks)

A person's heart rate is 75 beats per minute. Calculate the duration of one cardiac cycle in seconds. (3 marks)

During exercise, cardiac output rises to 15 litres per minute at a heart rate of 150 per minute. Calculate the stroke volume in mL. (3 marks)

An adult has 5.5 litres of blood, of which 55% is plasma. Calculate the volume of plasma and formed elements. If plasma proteins form 7% of plasma, calculate their volume. (3 marks)

A sample shows 2.5 lakh platelets per cubic mm. How many platelets are present in 1 mL of blood? (1 mL = 1,000 cubic mm) (3 marks)

A person has haemoglobin of 14 g per 100 mL. If each gram of haemoglobin carries 1.34 mL of oxygen, calculate the oxygen carried by 100 mL of blood and by 5 litres of blood. (3 marks)

Read the passage and answer the questions. Mrs X is Rh negative and her husband is Rh positive. Her first child is Rh positive and is born healthy. During delivery, some of the foetal blood enters her circulation. In her second pregnancy, the foetus is again Rh positive. (i) Why was the first child not affected? (ii) What happens to the second foetus? (iii) How can this be prevented? (5 marks)

Read the passage and answer the questions. The heart is a mesodermally derived organ situated in the thoracic cavity, slightly tilted to the left. It is protected by a double-walled membranous bag, the pericardium. The heart has four chambers. The opening between the right atrium and right ventricle is guarded by a valve formed of three muscular flaps, the tricuspid valve. (i) Name the valve between the left atrium and left ventricle. (ii) Why are the walls of the ventricles thicker than those of the atria? (iii) What is the function of the pericardium? (5 marks)

Read the passage and answer the questions. An electrocardiograph is used to obtain an ECG. To obtain a standard ECG, a patient is connected to the machine with three electrical leads, one to each wrist and to the left ankle. Each peak in the ECG is identified with a letter from P to T that corresponds to a specific electrical activity of the heart. (i) What does the P wave represent? (ii) How can the heart rate be determined from an ECG? (iii) What does the T wave represent? (5 marks)

Read the passage and answer the questions. When there is an injury, blood clotting stops bleeding. A clot is formed mainly of a network of threads called fibrins, in which dead and damaged formed elements of blood are trapped. Fibrins are formed by the conversion of inactive fibrinogens in the plasma by the enzyme thrombin. (i) How is thrombin formed? (ii) What role do platelets play? (iii) Name the ions needed for clotting. (5 marks)

Read the passage and answer the questions. Hypertension is the term for blood pressure that is higher than normal (120/80). In this measurement, 120 mm Hg is the systolic pressure and 80 mm Hg is the diastolic pressure. If repeated checks of blood pressure of an individual are 140/90 or higher, it shows hypertension. (i) What is systolic pressure? (ii) What are the effects of hypertension? (iii) Suggest two lifestyle changes to control it. (5 marks)

Describe the composition of blood and the functions of its components. Draw labelled diagrams of the different types of WBCs. (6 marks)

Explain the ABO and Rh blood groups. What precautions are needed during blood transfusion and pregnancy? (6 marks)

Describe the structure of the human heart with a labelled diagram. Explain how the heartbeat is initiated and conducted. (6 marks)

Explain the cardiac cycle and the ECG with a labelled diagram. How are cardiac output and heart rate related? (6 marks)

Explain double circulation and the regulation of cardiac activity. Describe two disorders of the circulatory system. (6 marks)