Distinguish between:
afferent neurons and efferent neurons
Afferent neurons transmit impulses from tissues/organs to the CNS (Central Neural System). They carry sensory information from the peripheral body parts to the brain and spinal cord. Efferent neurons transmit regulatory impulses from the CNS to the concerned peripheral tissues/organs. They carry motor commands from the brain and spinal cord to effectors like muscles and glands.
impulse conduction in a myelinated nerve fibre and unmyelinated nerve fibre
The provided context does not contain sufficient information to distinguish between impulse conduction in myelinated and unmyelinated nerve fibres. The context only lists this as a question in Exercise 10(b) but does not provide the explanatory content regarding the mechanism of impulse conduction in these two types of nerve fibres.
cranial nerves and spinal nerves
The provided context does not contain sufficient information to distinguish between cranial nerves and spinal nerves. The context mentions that the PNS comprises all nerves associated with the CNS (brain and spinal cord), but does not provide specific details differentiating cranial nerves from spinal nerves.
Explanation
The provided textbook context contains the exercise questions and partial chapter content. For part (a), the context clearly states in Section 18.2 that 'afferent nerve fibres transmit impulses from tissues/organs to the CNS and the efferent fibres transmit regulatory impulses from the CNS to the concerned peripheral tissues/organs.' However, for parts (b) and (f), while the questions are listed in the exercises section, the actual explanatory content differentiating these concepts is not included in the provided context chunks. The context mentions myelinated and non-myelinated axons in Question 8 but does not provide the comparison content. Similarly, cranial and spinal nerves are not elaborated upon in the available context.