Test: The Functions of Brain & Spinal Cord - NEET MCQ

The cerebrum is the largest part of the forebrain. It is responsible for the integration of complex sensory and neural functions and the initiation and coordination of voluntary activity in the body. It has specific functional lobe which is controls speech, generates several responses to different stimulus. 
So, the correct answer is option B.

Topic in NCERT: CENTRAL NEURAL SYSTEM

Line in NCERT: "The brain is the central information processing organ of our body, and acts as the 'command and control system'. It controls the voluntary movements, balance of the body, functioning of vital involuntary organs (e.g., lungs, heart, kidneys, etc.), thermoregulation, hunger and thirst, circadian (24-hour) rhythms of our body, activities of several endocrine glands and human behaviour."

• Medulla oblongata, also called medulla, is the lowest part of the brain and the lowest portion of the brainstem.
• The medulla oblongata plays a critical role in transmitting signals between the spinal cord and the higher parts of the brain.
• Medulla contains cardiovascular reflexes, gastric secretions and the centres that control respiration.

Topic in NCERT: Hindbrain

Line in NCERT: "The medulla contains centres which control respiration, cardiovascular reflexes and gastric secretions."

Respiration is controlled by the respiratory centers located in the medulla oblongata. It receives the signal and generates the rhythmic nerve impulse which stimulates the movement of the diaphragm and other respiratory muscles.

Topic in NCERT: Hindbrain

Line in NCERT: "The medulla contains centres which control respiration, cardiovascular reflexes and gastric secretions."

The part of the brain that regulates body temperature, hunger, and water balance is the Hypothalamus. Here's why:
- Hypothalamus:
- Regulates body temperature by triggering mechanisms like sweating or shivering.
- Controls hunger by responding to hunger hormones and signals.
- Manages water balance by regulating thirst and controlling the release of antidiuretic hormone (ADH).
In summary, the hypothalamus plays a crucial role in maintaining internal balance (homeostasis) within the body, ensuring optimal functioning.
Topic in NCERT: Forebrain
Line in NCERT: "A very important part of the forebrain called hypothalamus controls the body temperature, eating and drinking."

Reflex action is an inborn central nervous system activity, not involving consciousness, in which a particular stimulus, by exciting an afferent nerve, produces a stereotyped, immediate response of muscle or gland. It is an involuntary and nearly instantaneous movement in response to a stimulus.

Topic in NCERT: HUMAN NEURAL SYSTEM

Line in NCERT: "The CNS includes the brain and the spinal cord and is the site of information processing and control."

• The membrane is permeable to K⁺ at rest because many channels are open.
• In a normal cell, Na⁺ permeability is about 5% of the K⁺ permeability or even less.
• This implies that the permeability of the plasma membrane for K⁺ ions is greater than its permeability for Na⁺ ions.

Topic in NCERT: Generation and Conduction of Nerve Impulse

Line in NCERT: "the axonal membrane is comparatively more permeable to potassium ions (K*) and nearly impermeable to sodium ions (Na+)."

Synaptic vesicles of the synaptic knob secrete the neurotransmitter (e.g. adrenaline).
Myelinated nerve fibres are enveloped with Schwann cells, which form a myelin sheath around the axon.
Non-myelinated nerve fibres are also enclosed by a Schwann cell, but that does not form a myelin sheath.
Spinal cord and cranial nerves are made of myelinated nerve fibres.

The correct answer is B: Post-synaptic membrane.
- Neurotransmitter receptor sites are typically located on the post-synaptic membrane.
- Post-synaptic membrane refers to the membrane on the receiving end of a synapse.
- When a neurotransmitter binds to its specific receptor on the post-synaptic membrane, it triggers a series of events that can lead to either excitation or inhibition of the receiving neuron.
- This process is fundamental to the transmission of signals between neurons in the nervous system.
Topic in NCERT: Transmission of Impulses
Line in NCERT: "The released neurotransmitters bind to their specific receptors, present on the post-synaptic membrane."

Afferent neurons carry nerve impulses from receptors to the CNS.
- Afferent neurons transmit sensory information from receptors to the central nervous system.
- Receptors detect stimuli like touch, temperature, and pain.
- This sensory information is then conveyed to the brain and spinal cord for processing and integration.
- Afferent neurons play a crucial role in our ability to perceive and respond to the environment accurately.
Topic in NCERT: afferent fibres
Line in NCERT: "The afferent nerve fibres transmit impulses from tissues/organs to the CNS."

Involuntary actions are those action that controlled by medulla oblongata which is a part of the autonomous nervous system where as voluntary actions are controlled by the cerebellum. The medulla oblongata directly controls heartbeat, blood pressure, breathing and digestion. It is located in the hindbrain, anterior to the cerebellum. It is a cone-shaped and contains the cardiac, respiratory, vomiting and vasomotor centers. Hence, the correct answer is option C.

Topic in NCERT: Hindbrain

Line in NCERT: "The medulla contains centres which control respiration, cardiovascular reflexes and gastric secretions."

The cerebellum is located down to the occipital lobe of the cerebrum. The cerebellum is the vital part of the brain that controls the motor movements of the body. Its functions include coordinated movement, balance, posture, speech, etc. Thus his movement and speech becomes unbalanced and uncontrolled. Thus, the correct answer is option B.

Topic in NCERT: Hindbrain

Line in NCERT: "it controls the voluntary movements, balance of the body"

The medulla oblongata is the part of the brainstem, that is situated between the pons and the spinal cord.
The medulla contains the cardiac, respiratory, vomiting and vasomotor centers and therefore deals with the autonomic (involuntary) functions of breathing, heart rate and blood pressure. 
Thus compression of the medulla oblongata will lead to instant death.
So, option A is correct here.

The cerebellum controls the timing and pattern of the muscle activation during movement. The main function of the cerebellum receives information from the sensory system, the spinal cord, and other parts of the brain and then regulates motor movements. The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.
So, the correct option is 'thinking'.
Topic in NCERT: Cerebral Cortex
Line in NCERT: "The cerebral cortex is referred to as the grey matter due to its greyish appearance."

Hypothalamus of the brain controls emotions like love, anger and pleasure.
Emotion involves two parts of the nervous system - the limbic system and the autonomic nervous system. The limbic system is a complex set of structures that lies on both sides of the thalamus, just under the cerebrum. It includes the hypothalamus, the hippocampus, the amygdala. The hypothalamus feeds information into the amygdala. The hypothalamus acts as a regulator of emotion, controlling levels of sexual desire, pleasure, aggression and anger.

Topic in NCERT: Limbic System

Line in NCERT: "The inner parts of cerebral hemispheres and a group of associated deep structures like amygdala, hippocampus, etc., form a complex structure called the limbic lobe or limbic system. Along with the hypothalamus, it is involved in the regulation of sexual behaviour, expression of emotional reactions (e.g., excitement, pleasure, rage and fear), and motivation."

Medulla oblongata is responsible to regulate respiration, heartbeat rates, vomiting reflex while body balance and movement is controlled by cerebellum.

The part of the brain that controls body temperature and the urge to eat is the Hypothalamus.
- The Hypothalamus acts as the body's thermostat, helping to regulate temperature.
- It also plays a crucial role in regulating hunger and satiety, influencing our urge to eat.
- Through various signals and feedback mechanisms, the hypothalamus helps maintain homeostasis in the body, ensuring essential functions like temperature and hunger remain balanced.
Topic in NCERT: Hypothalamus and its Functions
Line in NCERT: "The hypothalamus contains a number of centres which control body temperature, urge for eating and drinking."

Afferent nerve fibers in the peripheral nervous system are responsible for transmitting impulses from tissues and organs to the central nervous system. These nerve fibers play a crucial role in carrying sensory information such as touch, pain, temperature, and proprioception from the periphery to the brain and spinal cord for processing. This process is essential for the body to respond to various stimuli in the environment and maintain homeostasis.

Topic in NCERT: afferent fibres

Line in NCERT: "The afferent nerve fibres transmit impulses from tissues/organs to the CNS."

The two main types of synapses that transmit nerve impulses between neurons are chemical synapses and electrical synapses. Chemical synapses involve the release of neurotransmitters across a synaptic cleft, while electrical synapses allow for direct flow of electrical current between neurons. While chemical synapses are more common, electrical synapses play a vital role in rapid signal transmission in certain neural circuits, ensuring swift communication between neurons.

Topic in NCERT: Transmission of Impulses

Line in NCERT: "A synapse is formed by the membranes of a pre-synaptic neuron and a post-synaptic neuron, which may or may not be separated by a gap called synaptic cleft. There are two types of synapses, namely, electrical synapses and chemical synapses."