U7 Flashcards
(15 cards)
What are the 2 main parts of the nervous system?
- Central nervous system 2.Peripheral nervous system
What are the 2 categories of the PNS (peripheral nervous system)?
Autnomic (involuntary; internal organs) and Somatic (voluntary; muscles and sense organs)
What are the 2 categories of the autonomic nervous system?
sympathetic (arousing) and parasympathetic (relaxing)
What are the 2 categories of the somatic nervous system?
Sensory (afferent) and Motor (efferent)
What conducts a nerve cell towards the cell body and what conducts it away from the cell body?
Dendrite = towards the cell body
Axon = away from the body
What are nodes of ranvier?
interrupted areas not coated with the myelin sheath
What do the nodes of ranvier do?
speeds up transmission of impulse
What are ganglia?
a collection of cell bodies outside the central nervous system
What are the 3 main types of neurons in the nervous system?
Sensory neuron, interneuron, and motor neuron
What neurons are part of afferent pathways? efferent pathways?
sensory = afferent & motor = efferent
What do interneurons make up?
the brain and spinal cord
What is a myelinated nerve fiber? What affect does it have?
Myelinated = shwann cells wrap around nerve fibres
Benefit: results in impulse skipping from node to node meaning quicker impulse transmission. 200m/s rather than 0.5m/s
Why is their a major difference in speed between myelinated and unmyelinated?
Action potential is able to jump over the myelin sheath, with depolarization only happening at the nodes of ranvier
Two areas of the brain that regulate the responses of the autonomic nervous system are?
anterior and posterior pituitary
