neuronal communication paper 1

what are neurones

specialised nerve cells vital for transmitting electrical impulses quickly through the body

list the key structural components of the mammalian neurone

1. dendrons

2. dendrites

3. cell body

4. axon

describe the cell body of the mammalian neurone

contains the nucleus and cytoplasmic organelles, such as mitochondria and the endoplasmic reticulum, which are crucial in the production of neurotransmitters

describe dendrons in the mammalian neurone

short branches extending from the cell body, further branching into highly branched dendrites to receive nerve impulses from many other neurones and transmit them towards the cell body

describe the axon in the mammalian neurone

a singular long nerve fibre responsible for carrying impulses away from the cell body to other neurones or effectors

what do myelinated neurones contain

Schwann cells

what are the three functions of Schwann cells

1. their membranes form the Myelin Sheath

2. they remove debris via phagocytosis

3. they aid regeneration

what is the myelin sheath and what does it do

in myelinated neurones, it surrounds part of the axon, acting as an insulator that prevents the passage of ions into or out of the axon at the regions it covers.

what is ‘saltatory conduction’

the process at which myelinated axons conduct conduct impulses rapidly

what happens in ‘saltatory conduction’

the electrical impulse ‘jumps’ between gaps in the myelin sheath known as the nodes of Ranvier, increasing transmission speed.

out of myelinated axons and non-myelinated axons, what transmits impulses the slowest?

non-myelinated axons

what is the function of sensory neurones

carry impulses from the sensory receptors to the central nervous system

what is the function of relay neurones (intermediate neurones)

carry impulses within the central nervous system, between other neurones

what is the function of motor neurones

carry impulses from the central nervous system to effectors

what is the structure of sensory neurones

• one axon and one dendron

• dendron leads to several smaller dendrites

what is the structure of relay neurones

• numerous short axons and dendrons

what is the structure of motor neurones

• one long axon and multiple dendrites

what is the typical pathway of an impulse

receptor - sensory neurone - relay neurone - motor neurone- effector