Question

1. Midbrain, pons varolii and medulla oblongata are together known as the brain stem.
2. Paracoels are connected diocoel through iter.
3. Heartbeat, respiration, swallowing, cough related centres lie in the medulla oblongata.
4. The cerebellum is also called the gyroscope of the body.

Which of the above sentences are correct?
A. 1, 2, 3.
B. 1, 3, 4.
C. 2, 3, 4.
D. 1, 2, 4.

Answer 1

Brain is a central part of the nervous system. Its primary parts are the cerebrum, cerebellum and the brainstem. Each of these parts remain connected with one another and is indispensable to the normal functioning of the brain. In addition, the brain also has a network of cavities called the ventricles.

Complete answer:
The posterior part of the brain is known as the Brainstem. It comprises the Midbrain, Pons and Medulla Oblongata. The brainstem functions to send messages between the cerebrum and the cerebellum. Cranial nerves also emerge from the brainstem.
Diocoel is another name of the third ventricle of the brain. Paracoels are the first and second ventricles. The ventricular system of the brain is an interconnected network of cavities within which the cerebrospinal fluid circulates. This system is continuous with the spinal cord. The diocoel remains connected to the paracoels by the Foramen of Monro. Iter is also known as the Cerebral aqueduct. It connects the third and fourth ventricles of the brain.
The medulla oblongata forms a part of the Brainstem. The medulla oblongata connects the brain to the spinal cord. It serves to regulate autonomic or involuntary functions of the body. Typical involuntary functions include heartbeat and respiration. The medulla also controls the reflex actions like cough, sneezing, swallowing, vomiting, etc.
A gyroscope is an instrument used for maintaining the orientation with respect to gravity. In our body, the inner ear along with the cerebellum helps us to maintain the orientation of the body parts with respect to gravity. They maintain body posture and equilibrium, adjusts the positioning of the eye and regulates the visual field during movements. That is why, we can call the cerebellum to be the gyroscope of the body.

Hence, the correct answer is option (B).

Note: The brain is the center for command of the nervous system. The brain is protected by the skull bones and separated from the bloodstream by the brain-blood barrier. It constitutes 2 percent of an individual’s body weight and is responsible for processing and analyzing information received from the sense organs.