Question

Which organ system do the heart and blood vessels belong to?

• A. Digestive system
• B. Circulatory system
• C. Excretory system
• D. Immune system

Answer 1

The correct option is (A):

Explanation of the correct option:

1. An organ system is a group of organs working together to carry out a particular physiological function.
   
2. The circulatory system is an organ system made up of heart and network of blood vessels which helps with circulation of blood throughout the body.
3. Heart is made up of cardiac tissues that helps with the pumping of blood and the blood vessels carry the blood to the tissues of the body.
   

Explanation of the incorrect options:

Option (B):

1. ​The system made up of kidneys, urinary bladder and urethra, which helps with the secretion of excretory materials outside the system is called excretory system.
   
2. The nitrogenous waste products are removed by the excretory system in the form of urine.
   

Option (C):

1. The alimentary canal and the digestive glands together forms the digestive system.
   
2. ​The digestive enzymes are secreted in the system that can digest the nutrients present in food.
   

Option (D):

1. The immune system includes the immune cells that can act against pathogens.
   
2. This includes lymphatic systems, WBC and also secretions from the immune cells.
   

Final Answer: The heart and blood vessels belong to the circulatory system.