Review for test 2 (Nervous tissue) Flashcards
Neurons are classified on
Morphology
Function
NT
No synapses on cell body of
unipolar
Multipolar neuron has
cell body
Axon,
Dendrites
Nissle bodies contain
RER and Free ribosome
Key neuron functions
Protein synthesis
Axonal transport
Synaptic transmission
Nerve impulse conduction
Organelles , Amino acids , nucleotides and NT are associated with
Anterograde
Cellular macromolecules, viruses and toxins associated with
Retrograde
6 steps of synaptic transmission
- Depol
- Cal channels open
- Exocytosis of synaptic vesicles
- Release of NT
- NT reacts with receptors
- Promotes post synaptic membrane depol
- Membrane retrieval by coated vesicles
Nerve impulse rate depends on
Diameter of axon
Myelin sheath
Large diameter
motor and proprioception
Medium diameter
fine touch
Small diameter
crude touch and pain
Small unmyelinated fibers
postganglionic sympathetic and parasympathetic axons
slow diffuse pain fibers
Components of axon “SAMMI”
SER Axoplasm Mito MT IF
Process of myelination
- Wraps around axon
- Schwann cell, cytoplasm , and plasma membrane begin to form layers around axon
- Overlapping inner layers of Schwann cell and plasma membrane form the myelin sheath
- Schwann cel, cytoplasm and nucleus are pushed to periphery of cell as the myelin sheath is formed
Regulation of myelination is dependent on
Neuregulin
A transmembrane protein on the neurolemma of the axons
Unmyelinated axons
Neurolemmocyte starts to wrap axons
The unmyelinated axons are enveloped by the neurolemmocyte , but no myelin sheath wraps around each axon
Dense irregular CT
epineurium (contains vasa vasorum)
specialized CT
perineurium
Loose CT
endoneurium
Peripheral ganglia house
cell bodies of peripheral nerves outside the CNS
Dorsal root ganglia (pseudounipolar) (somatic and visceral afferent)
no synaptic stations
Autonomic ganglia (multipolar)
house cell bodies of autonomic neurons .. there are synaptic stations
Neurons concentrated at periphery of ganglion
Sensory ganglia