Free Brain MCQs with Answers

1. The part of the brain concerned with intelligence, memory and voluntary action is the

• A. cerebellum
• B. cerebrum
• C. medulla oblongata
• D. hypothalamus

Explanation: The cerebrum is the largest part of the human brain, and its folded cortex carries the sensory, motor and association areas responsible for thought, language, memory and conscious decision. Its folding increases the surface area enormously within the fixed volume of the skull. The cerebellum and medulla handle coordination and vital automatic functions and have nothing to do with conscious thought.

2. Damage to the cerebellum would most likely result in

• A. loss of memory
• B. failure of breathing
• C. loss of balance and jerky, poorly coordinated movement
• D. inability to see

Explanation: The cerebellum receives information from the muscles, joints and balance organs of the ear and smooths the commands sent by the cerebrum, so injury to it leaves movement clumsy and unsteady even though strength is normal. Alcohol depresses the cerebellum, which is why an intoxicated person staggers. Breathing is controlled by the medulla and vision is processed in the occipital lobe of the cerebrum.

3. Heart rate, breathing rate and the diameter of blood vessels are controlled by the

• A. cerebrum
• B. cerebellum
• C. corpus callosum
• D. medulla oblongata

Explanation: The medulla lies at the top of the spinal cord and contains the cardiac, respiratory and vasomotor centres, all of which work without conscious control, so an injury there is very quickly fatal. Because these centres monitor carbon dioxide and blood pressure and correct them, the medulla is a key homeostatic organ. The corpus callosum is only the bundle of fibres joining the two cerebral hemispheres.

4. The part of the brain that regulates body temperature, thirst and hunger, and controls the pituitary gland is the

• A. hypothalamus
• B. cerebellum
• C. medulla oblongata
• D. occipital lobe

Explanation: The hypothalamus is the meeting point of the nervous and endocrine systems: it monitors the temperature and water potential of the blood, generates thirst and hunger, and releases factors that control the anterior pituitary while making the hormones the posterior pituitary stores. Its small size is out of all proportion to its importance in homeostasis. The occipital lobe deals with vision alone.

5. The cerebellum controls

• A. Memory
• B. Balance and coordination
• C. Heart rate
• D. Vision

Explanation: The cerebellum coordinates voluntary movements, balance, posture, and motor learning.

6. Which part of brain controls transition between sleeping and wakefulness?

• A. Medulla oblongata
• B. Cerebellum
• C. Cerebrum
• D. Pons

Explanation: The pons contains the centres that switch the brain between sleep and wakefulness and it also regulates the rhythm of breathing alongside the medulla. The medulla is the tempting answer because it too is part of the brain stem, but its role is the automatic control of heart rate, breathing and blood vessel diameter. The cerebellum handles balance and coordination and takes no part in the sleep cycle.

7. Which part of the brain contains central chemoreceptors that monitor CO2 levels in blood?

• A. Pons
• B. Midbrain
• C. Hypothalamus
• D. Medulla oblongata

Explanation: The respiratory centre of the medulla carries chemoreceptors that detect the fall in pH caused by rising carbon dioxide and increase the rate and depth of breathing until the excess is blown off. Oxygen level is monitored elsewhere, by peripheral receptors in the aorta and carotid arteries, and acts only as a weak backup stimulus. This is why holding the breath becomes unbearable from carbon dioxide build up rather than from lack of oxygen.

8. Which of the following is the auditory relay Centre and Centre that controls reflex movement of eyes?

• A. Forebrain
• B. Cerebellum
• C. Midbrain
• D. Cerebellum

Explanation: The midbrain carries four swellings, the corpora quadrigemina, of which the upper pair handle visual reflexes such as turning the eyes and head towards a movement and the lower pair relay auditory information. The cerebellum coordinates balance and fine movement but relays neither sound nor visual reflexes. Note that options (b) and (d) were printed identically in the original paper, which is a misprint in the paper itself and does not affect the correct answer.

9. Hippocampus plays an important role in the:

• A. Formation of short-term memory
• B. Formation of image on retina
• C. Formation of long-term memory
• D. Formation of emotions

Explanation: The hippocampus consolidates experiences into long term memory, which is why damage to it leaves a patient able to hold a conversation yet unable to form any lasting new memory. Short term working memory depends mainly on the prefrontal cortex, and emotion is handled largely by the amygdala nearby. Image formation on the retina is optical and involves no part of the brain at all.

10. Left and right cerebral hemispheres are connected with each other by:

• A. Corpus luteum
• B. Corpus callosum
• C. A band of dendrites
• D. Dorsal and ventral nerve roots

Explanation: The corpus callosum is a thick band of myelinated axons carrying traffic between the two hemispheres so that they work as one. The corpus luteum is the very similar sounding structure in the ovary that secretes progesterone after ovulation, and it is the deliberate trap here. Dorsal and ventral roots belong to the spinal nerves, not the brain.