11 C Flashcards
How does sensory information flow?
From neuron to neuron
What are neurons functionally connected by?
Synapses
What are synapses?
Junctions that mediate information transfer (neuron to neuron or from one neuron to an effector cell)
What are the two common types of synapses?
Axodendritic and axosomatic
Where do axodendritic synapses occur?
Between axon terminals of one neuron and dendrites of others
Where do axosomatic synapses occur?
Between axon terminals of one axon and the body (soma) of another
What are the 3 less common types of synapses?
Axoaxonal
Dendrodendritic
Somatodendritic
Where does a presynaptic neuron send impulses?
Towards the synapse
Where do postsynaptic neurons send impulses?
Transmits electrical signals away from synapse (receives information)
In the PNS what are postsynaptic neurons?
Muscle cells, neurons or gland cells
What kind of synapses are more common, electrical or chemical?
chemical
What are electrical synapses?
Neurons that are electrically coupled (joined by gap junctions)
Synchronize activity
Nerve impulses remain electrical
Where are electrical synapses most abundant?
Embryonic nervous tissue
What are chemical synapses specialized for?
Release and reception of chemical neurotransmitters
What are the two parts of chemical synapses?
Axon terminal and neurotransmitter receptor region
Where is the axon terminal
Presynaptic neuron
has synaptic vesicles with neurotransmitters to be released
Where is the neurotransmitter receptor region?
On the postsynaptic neuron’s membrane
On dendrite or cell body
What are the two parts of the chemical synapse separated by?
Synaptic cleft (fluid filled space)
What is allowed because of electrical impulses changing to chemical across synapse and then back into electrical?
Nerve impulse regulation (allows for decision for propagation or termination of impulse)
More fine tune regulation
What does the synaptic cleft prevent?
Nerve impulses from directly passing from one neuron to the next (its a barrier)
What does the transmission across a synaptic cleft depend on?
Release, diffusion, and receptor bind of neurotransmitters to their receptors
What direction of communication does synaptic cleft allow for between neurons?
Unidirectional communication
Does a chemical or electrical event happen across the synaptic cleft?
Chemical event
What arrives at the axon terminal of presynaptic neuron to start transmission across chemical synapses?
Action potential