Heart layout and the route blood takes — practice questions

Question 1 · difficulty L1 · recall

The normal pacemaker of the human heart:

• A. Purkinje fibres
• B. SA node
• C. AV node
• D. bundle of His only

Question 2 · difficulty L1 · recall

The two circuits in human circulation:

• A. portal and lymphatic only
• B. arterial and venous only
• C. coronary and renal only
• D. pulmonary and systemic

Question 3 · difficulty L1 · recall

Which chamber of the human heart pumps deoxygenated blood into the pulmonary artery?

• A. Right atrium
• B. Left ventricle of the heart
• C. Right ventricle
• D. Left atrium

Question 4 · difficulty L2 · understanding

Which valve prevents backflow from the left ventricle into the left atrium during ventricular systole?

• A. Aortic semilunar valve
• B. Tricuspid valve
• C. Pulmonary semilunar valve
• D. Bicuspid or mitral valve

Question 5 · difficulty L2 · understanding

What is the name of the blood vessel that carries deoxygenated blood from the body to the heart in a frog?

• A. Pulmonary vein
• B. Vena cava
• C. Aorta
• D. Pulmonary artery

Question 6 · difficulty L3 · application

A red blood cell has just entered the right atrium from the vena cava. Which route will it normally follow before reaching the left atrium?

• A. Right ventricle → pulmonary artery → lungs → pulmonary veins
• B. Left ventricle → aorta → lungs → pulmonary veins
• C. Right ventricle → aorta → lungs → vena cava
• D. Pulmonary veins → lungs → pulmonary artery → right ventricle

Question 7 · difficulty L3 · application

Why is human circulation described as double circulation?

• A. The heart has two atria
• B. Blood passes through the heart twice during one complete circuit through pulmonary and systemic pathways
• C. Two arteries leave the heart
• D. Blood passes through two separate capillary beds in every organ before returning to the heart

Question 8 · difficulty L3 · understanding

A unique vascular connection between the digestive tract and liver is called______.

• A. Hepato-cystic system
• B. Hepato-pancreatic system
• C. Hepatic portal system
• D. Renal portal system

Question 9 · difficulty L4 · analysis

A defect allows blood to flow directly between the right and left ventricles. Which normal structure has failed to maintain separation?

• A. Tricuspid valve
• B. Interatrial septum between the two atria
• C. Interventricular septum
• D. Pericardium

Question 10 · difficulty L5 · analysis

A blood cell leaves the left ventricle, supplies the small intestine, then travels through the hepatic portal circulation before returning to the right atrium. Which organ does it visit immediately after leaving intestinal capillaries through the portal route?

• A. Spleen
• B. Lung
• C. Kidney
• D. Liver