The Circulatory and Respiratory Systems MCQs

1. What is the main function of the circulatory system?
(A) Digestion of food
(B) Exchange of gases
(C) Transport of blood and nutrients
(D) Production of hormones

2. Which organ is primarily responsible for pumping blood throughout the body?
(A) Brain
(B) Liver
(C) Lungs
(D) Heart

3. What is the function of red blood cells?
(A) Fight infections
(B) Help in blood clotting
(C) Transport oxygen
(D) Produce antibodies

4. What gas is absorbed from the lungs into the bloodstream?
(A) Carbon dioxide
(B) Hydrogen
(C) Nitrogen
(D) Oxygen

5. Which component of blood helps in clotting?
(A) Plasma
(B) White blood cells
(C) Red blood cells
(D) Platelets

6. What is the main function of the respiratory system?
(A) Pump blood
(B) Remove waste
(C) Exchange of gases
(D) Control body temperature

7. Where does gas exchange occur in the lungs?
(A) Bronchi
(B) Trachea
(C) Alveoli
(D) Diaphragm

8. Which blood vessels carry blood away from the heart?
(A) Veins
(B) Capillaries
(C) Arteries
(D) Lymph nodes

9. What muscle helps in the process of breathing?
(A) Biceps
(B) Diaphragm
(C) Sternum
(D) Pelvis

10. What part of the brain controls the breathing rate?
(A) Cerebrum
(B) Cerebellum
(C) Medulla oblongata
(D) Hypothalamus