The cells of the nervous system and neurotransmitters at synapses Flashcards
What is the function of dendrites
receive nerve impulses and pass them to the cell body
What is the function of cell body
contains the nucleus and most of the cytoplasm
control the cells metabolism and contains ribosomes
What is the function of axon
carries nerve impulses away from a cell body
What is the myelin sheath
a layer of fatty material surrounding the axon
What is the function of a myelin sheath
the myelin sheath increases the speed of impulse conduction (transmission)
What is myelination
the development of myelin round axon fibres of individual neurons
When does myelination occur
continues from birth to adolescence
The neurons in the spinal cord transmitting impulses to the lower body are not fully myelinated until about 2 years of age.
what is the result of this
responses to stimuli in the first 2 years of life are not as rapid or coordinated as those of an older child or adult
Certain diseases damage or destroy the myelin sheath what can this lead too
a loss of muscular coordination
What is the function of Glial cells
produce the myelin sheath
support neurons
What is a synapse
A gap between two neurons
Where do neurons connect with other neurons or muscle fibres at
Synaptic cleft
What are the chemicals that relay the impulse across the synapse called
Neurotransmitters
What is needed for neurotransmitter synthesis
ATP
Describe neurotransmitters
They are released into the cleft on arrival of an impulse
They diffuse across the synaptic cleft and bind to receptors on the membrane of the postsynaptic cleft
