Question

Which of the following statements regarding the given figure of the human brain is correct?

(i) Labelled part a is involved in the control of blood pressure, salivation and vomiting.
(ii) Labelled part b is responsible for the precision of voluntary actions and maintaining the posture and balance of the body.
(iii) The part labelled c is responsible for the change in the size of the pupil and activity like walking in a straight line.
(iv) The secretions part labelled d is responsible for the functioning of the hypothalamus.
(v) The part labelled e receives and integrates signals from the spinal cord.

• A. (i) and (ii)
• B. (i), (ii) and (iii)
• C. (i) and (v)
• D. (ii), (iii) and (iv)

Answer 1

The correct option is A (i) and (ii)

• The part labeled as 'a' is medulla oblongata. The medulla oblongata connects the higher levels of the brain to the spinal cord and is responsible for respiration, cardiac activity, blood pressure, salivation, and vomiting.
• The part labeled as 'b' is the cerebellum. The cerebellum is located at the base of the brain, just above the brain stem, where the spinal cord meets the brain and is made of two hemispheres. Cerebellum controls and coordinates all voluntary movements like walking, balance, posture, and other smooth muscle activities like "walking in a straight line" or "picking up a pencil".
• The change in the size of the pupil of the eyes is a cerebral reflex action and not a spinal reflex action, and it occurs in the Midbrain.
  
• The part labeled as 'd' is the pituitary gland, secretion of hormones by pituitary gland is controlled by the hypothalamus.
• The part labeled as 'e' is the pineal gland. The main function of the pineal gland is to receive information about the state of the light-dark cycle from the environment and convey this information to produce and secrete the hormone melatonin, not the integration of signals coming from the spinal cord.
  

Thus, the correct answer is option A.