Option A: Neurophysiology

nervous system process

nervous system process

sensor (eye, skin) → integration (brain, spinal cord) → effector (joints, muscles) in peripheral or central nervous system

Peripheral Nervous System

External nerves in muscles

• Autonomic- self regulated action of organs and glands

• Somatic- voluntary movements of skeletal muscles

Central Nervous System

Brain, spinal cord, links to other system

Neurons

• cells of the brain that transmit electrical impulses

• longest is in the whale

• ~86 billion in the body

dendrites vs axons

one is the projections from the cell that receive impulses from other neurones.

the other carries electrical impulses away from neurone to other neurones.

pre-synaptic terminal vs node of ranvier

place at the end of axon where electrical signal (action potential) is converted to a chemical signal (neurotransmitter).

allows ions to diffuse in and out of the neurone, sending signal jumping across gaps in the myelin sheath on the axon.

myelin sheath

myelination of nerve fibres allows for saltatory conduction

• axon is coated in schwann (type of glial) cells

• accelerates the saltatory conduction (travel) of electrical signals from node to node

• no myelin = slow transmission = multiple sclerosis

sensor neurones

receptor cell, myelin sheath, axon, cell body.

receive information from muscle receptors.

relay neurones

dendrite, cell body, pre-synaptic terminal, cell body

pass electrical signals across body.

motor neurones

dendrite, myelin sheath, cell body, node of ranvier, into muscle

send instructions to muscles.

viscal cortex