Question 1

Q1: 1. Briefly describe the structure of the Brain

Accepted Answer

The human brain is the central information processing organ and is protected by the skull. It is covered by three layers of cranial meninges: dura mater (outer), arachnoid (middle), and pia mater (inner). The brain is divided into three major parts: 1.  Forebrain (Prosencephalon): This is the larges...

Question 2

Q10: 10. Distinguish between: (a) afferent neurons and efferent neurons (b) impulse conduction in a myelinated nerve fibre and unmyelinated nerve fibre (f)...

Accepted Answer

(a) Afferent Neurons and Efferent Neurons | Feature                  | Afferent Neurons (Sensory Neurons)                               | Efferent Neurons (Motor Neurons)                                    | | ------------------------ | ---------------------------------------------------------------...

Question 3

Q2: 2. Compare the following: (a) Central neural system (CNS) and Peripheral neural system (PNS) (b) Resting potential and action potential

Accepted Answer

(a) Comparison between Central Neural System (CNS) and Peripheral Neural System (PNS): | Feature             | Central Neural System (CNS)                               | Peripheral Neural System (PNS)                                     | | ------------------- | ------------------------------------...

Question 4

Q3: 3. Explain the following processes: (a) Polarisation of the membrane of a nerve fibre (b) Depolarisation of the membrane of a nerve fibre (c) Transmis...

Accepted Answer

(a) Polarisation of the membrane of a nerve fibre: In the resting state, a neuron's membrane is said to be polarised. This is due to a difference in the distribution of ions across the axonal membrane. The axoplasm (fluid inside the axon) has a high concentration of potassium ions ($K^+$) and negati...

Question 5

Q4: 4. Draw labelled diagrams of the following: (a) Neuron (b) Brain

Accepted Answer

Since drawing is not possible in this format, a description of the key labelled parts for each diagram is provided below, based on the textbook figures. (a) Neuron (based on Figure 18.1): A labelled diagram of a neuron would show the following parts:    Cell Body (Soma/Cyton): The main part of the n...

Question 6

Q5: 5. Write short notes on the following: (a) Neural coordination (b) Forebrain (c) Midbrain (d) Hindbrain (e) Synapse

Accepted Answer

(a) Neural coordination: Neural coordination is the process through which the neural system, an organised network of neurons, provides quick, point-to-point connections to coordinate and integrate the functions of various organs and organ systems. This rapid communication allows the body to respond...

Question 7

Q6: 6. Give a brief account of Mechanism of synaptic transmission.

Accepted Answer

The mechanism of synaptic transmission, particularly at a chemical synapse, involves the transfer of a nerve impulse from a pre-synaptic neuron to a post-synaptic neuron using neurotransmitters. The process occurs in the following steps: 1.  Arrival of Action Potential: An action potential travels d...

Question 8

Q7: 7. Explain the role of $\mathrm{Na}^{+}$ in the generation of action potential.

Accepted Answer

Sodium ions ($Na^+$) play a crucial role in the generation of an action potential in a neuron. The process can be explained as follows: 1.  Resting State: In a resting neuron, the concentration of $Na^+$ is much higher in the extracellular fluid than inside the axon (axoplasm). The axonal membrane i...

Question 9

Q8: 8. Differentiate between: (a) Myelinated and non-myelinated axons (b) Dendrites and axons (c) Thalamus and Hypothalamus (d) Cerebrum and Cerebellum

Accepted Answer

(a) Myelinated and Non-myelinated Axons | Feature             | Myelinated Axon                                                                     | Non-myelinated Axon                                               | | ------------------- | ----------------------------------------------------------...

Question 10

Q9: 9. Answer the following: (a) Which part of the human brain is the most developed? (b) Which part of our central neural system acts as a master clock?

Accepted Answer

(a) The cerebrum is the most developed part of the human brain. It forms the major part of the brain and its outer layer, the cerebral cortex, is responsible for complex functions like memory, communication, intelligence, and consciousness. (b) The hypothalamus acts as a master clock for the body. I...

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