Neural signalling - neurones Flashcards
What are the two main parts of the human nervous system?
Central nervous system (CNS) and peripheral nervous system (PNS)
CNS includes the brain and spinal cord, while PNS encompasses all nerves in the body.
What is the function of the nervous system?
To make sense of our surroundings, respond to them, and coordinate and regulate body functions.
How is information sent through the nervous system?
In the form of electrical impulses.
What is a bundle of neurones called?
A nerve.
What role does the CNS play in the nervous system?
Acts as a central coordinating centre for impulses.
What is the main long fibre in neurones called?
Axon.
What is the function of Schwann cells in neurones?
They form the myelin sheath which prevents loss of nerve impulses.
What structures are contained in the cell body of a neurone?
Nucleus and other cellular structures.
What are extensions called that allow neurones to connect to other neurones?
Dendrites.
What are the three main types of neurones?
Sensory, relay, and motor neurones.
What do sensory neurones do?
Carry impulses from receptors to the CNS.
Where are relay neurones found?
Entirely within the CNS. They connect sensory and motor neurons.
What do motor neurones carry?
Impulses from the CNS to effectors (muscles or glands).
What is a distinctive feature of motor neurones?
A large cell body at one end within the spinal cord or brain.
Where is the nucleus located in motor neurones?
Always in the cell body.
What do motor neurones have that provides a large surface area for axon terminals?
Many highly-branched dendrites.
What characterizes relay neurones?
Short, but highly branched axons and dendrites.
How is the cell body of sensory neurones structured?
Branches off in the middle of the cell.
Fill in the blank: Sensory neurones have a single long _______ that carries impulses to the cell body.
dendron.
Fill in the blank: Sensory neurones have a single long axon that carries impulses _______ from the cell body.
away.
