Question

The involuntary actions in the body are controlled by

• A. Spinal cord
• B. Cerebellum
• C. Medulla in forebrain
• D. Medulla in hindbrain

Answer 1

The correct option is D

Medulla in hindbrain

The correct option is D.

Explanation of the correct option:

1. While voluntary actions are governed by the cerebellum, involuntary actions are those that are under the control of the medulla oblongata, a region of the autonomous nervous system.
2. Heart rate, blood pressure, breathing, and digestion are all directly regulated by the medulla oblongata.
   

Explanation of the incorrect option:

Option A:

1. Specifically, the spinal cord's role is to transmit nerve impulses from the motor cortex to the body and from the afferent fibers of sensory neurons to the sensory brain.
2. Your movements are controlled by brain signals that are sent to various body components.
3. They also control autonomic (involuntary) processes like your heart rate, breathing rate, and bowel and bladder operations.
4. Your brain records and processes sensations like pressure or discomfort with the aid of signals from other areas of your body.

Option B:

1. Making postural changes to keep one's equilibrium depends on the cerebellum.
2. It modifies instructions to motor neurons to account for changes in body posture or variations in the strain placed on muscles through its input from vestibular receptors and proprioceptors.

Option C:

1. The medulla oblongata is essential for signal transmission between the spinal cord and upper brain regions as well as for controlling autonomic functions like breathing and heartbeat.
2. The medulla is made up of a substantial wall with a mass of axons that create nerve fiber tracts that link the spinal cord to various regions of the brain.

Final answer: The involuntary actions in the body are controlled by the medulla in the hindbrain.