3.3 Cells of the Nervous System and Neurotransmitters Flashcards
Function of neurons
Recieve and transmit electrical signals
Function of glial cells
Support and maintain the neurons
Composition of neurons
- Nerve cell body
* Nerve fibres
The three types of neurons
- Sensory
- Inter
- Motor
Function of dendrites
Nerve fibres that recieves nerve impulses
Function of the cell body
Contains the nucleus, containing DNA, coding for a neurotransmitter, or a receptor, or enzymes needed for the synthesis or degredation of neurotransmitters
Funtion of axons
Nerve fibre that carries inpulses away from the cell body
Order in which nerve impulses travel
Dendrite -> Cell Body -> Axon
Funtion of sensory neurons
Passes information from sense organs to neurons in the CNS
Function of Inter neurons
Link sensory neurons to motor neurons within the CNS
Function of motor neurons
Passes information from the CNS to an effector (a muscle or a gland)
Why axon terminals of a neuron contain many mitochondria
- Provide ATP for synthesis reactions
* Privide ATP for the creation of vesicles which are able to store, carry and release neurotransmitters
Definition of myelination
The development of myelin around the axon fibres if individual neurons
The two jobs of the myelin sheath
- Insulates the axon fibres of neurons
* Increases the soeed of impulse conduction
The two jobs of the glial cells
- Maintain a homeostatic environment around the neurons
* Remove debris by phagocytosis
Definition of synapse
The junction between an axon of one neuron and the dendrite of another
Definition of synaptic cleft
The narrow space between the plasma membranes of the two neurons at the synapse
Where neurotransmitters are stored in neurons
Vesicles
Where neurotransmitters are released from
Vesicles from the presynaptic membrane
What neurotransmitters do after diffusing across the synaptic cleft
Bind to receptors on the postsynaptic membrane
What a neurotransmitter is
Protein molecules produced by ribosomes
Jobs of receptors on the postsynaptic membrane
Determine whether the signal is excitory or inhibitory