neurons Flashcards
what are the three types of neurons
afferent
efferent
interneuron
how can you classify a neuron
structure and function
what is the function of an afferent neuron
take nerve impulses from receptors to the central nervous system
what is the function of an efferent neuron
take nerve impulses from the central nervous system to effector structures
what is another name for afferent neurons
sensory/receptor
what is another name for efferent neuron
motor/effector
what is another name for interneuron
association neuron
connector
relay
what is the structure of a unipolar neuron
has only one type of extension from the cell body, not found in humans
what is the structure of a bipolar neuron
they have a distinct axon and a dendritic fibre separated by a cell body (off to the side) e.g found in the ear, eye and nose
what is the structure of a multipolar neuron
have a single axon and several dendritic fibres. all somatic motor neurons and most interneurons are multipolar
what is the structure of pseudounipolar neurons
has properties of both unipolar and bipolar neurons. there is a single axon from the cell body, which then branches off into dendrites and axon terminals. usually sensory neurons
what are other names for an end of a neuron
synaptic terminal/knob/button/axon terminal
what is the cell body also known as
the soma or cyton
explain the cell body
granular cytoplasm is due to clusters of ribosomes (nissl granules)
there are abundant organelles, especially mitochondria
neuron=
nerve cell
nerve fibre=
dendrite or axon
nerve =
bundle of nerve fibres
explain dendrites
usually short and highly branched
synapse with other neurons or receptors
transmit the electrochemical impulse towards the cell body
explain axons
typically a single, long nerve fibre
terminate at a synaptic end bulbs
connect with muscles (neuromuscular junction), glands (neuroglandular junction), or other neurons
the gap between neuron and muscle
neuromuscular junction
the gap between neuron and gland
neuroglandular junction
the gap between neuron and neuron
synapse
what is the myelin sheath?
the myelin sheath is a white, fatty sheath surrounding the axon of most neurons
the myelin sheath of peripheral nerve fibres is produced by Schwann cells (glial cells)
what is it called when a nerve fibre has a myelin sheath
myelinated
what does the myelin sheath do
speeds up nerve transmission, acts as an insulator and protects the nerve fibre
what are the gaps between the myelin sheath on an axon called
the nodes of Ranvier
