Chapter 12 - NS Flashcards
What are Nissl bodies?
rough ER and free ribosomes for protein synthesis
Dendrites are… myelinated/unmyelinated
unmyelinated
What are telodendria?
synonymous with axon terminals (which end in synaptic end bulbs)
Describe a bipolar neuron.
The cell body is found between the axon and the dendrites.
Describe a unipolar neuron.
The cell body projects off the axon rather than disrupting it.
Interneurons usually have what structure?
purkinje cell or pyramidal cell structures
Neuroglia make up about __% of the volume of the NS
50%
What is a neurolemma?
the plasma membrane of a Schwann cell which helps form myelin sheaths
The membrane of a NON-CONDUCTING neuron is ____ outside and ____ inside.
POSITIVE OUTSIDE
NEGATIVE INSIDE
What are four types of ion channels in neurons?
leakage channels
ligand-gated (chemical stimuli)
mechanically-gated (vibration or pressure stimuli)
voltage-gated (changes in membrane potential)
In a neuron, __ channels are more numerous than Na+ channels
K+
List some neuropeptides:
substance P
enkephalins (inhibit pain/substance P release)
endorphins
dynorphins
hypothalamic releasing and inhibiting hormones
angiotensin II (stimulates thirst, promotes aldosterone release)
cholecystokinin (CCK - ‘stop eating’ signal)
PNS repair is possible if 3 conditions are met:
- cell body in tact
- schwann cells functional
- scar tissue formation is not too rapid
What are the 3 steps involved in repair of nervous tissue?
- chromatolysis (redistribution of nissl bodies to prep for repair)
- Wallerian degeneration
- formation of a regeneration tube
T/F: dendrites and axons are considered nerve fibres.
True
