Flashcards in Nervous tissue II Deck (19):
Gray matter consists of:
Nerve cell bodies and neuroglia
White matter consists of:
Myelinated nerve cell axons with some unmyelinated axons and neuroglia
What are ganglia?
Collections of nerve cell bodies in the PNS
Thoracolumbar outflow corresponds to what spinal levels?
T1 - L2
Craniosacral outflow corresponds to what spinal levels?
Cranial nerves + S2 - S4
What does the enteric division of the nervous system control?
Peristalsis, gland secretions, blood flow through GI tract
What are the classifications of synapses (based on morphology)?
1. Axodendritic2. Axosomatic3. Axoaxonic
Where are electrical synapses located in humans?
1. Brain stem2. Retina3. Cerebral cortex
Electrical synapses have what kind of intercellular communication?
What are the components of a chemical synapse?
1. Presynaptic element2. Synaptic cleft3. Postsynaptic membrane
What is kiss-and-run fusion?
When a synaptic vesicle only partially unloads contents
What is collapse fusion?
When synaptic vesicle unloads entire contents and fuses to membrane, to be recycled later when membrane gets too large
What is choroid plexus located?
Ventricles of brain
What are the components of choroid plexus?
1. Folds of pia mater2. Ependymal cells - simple cuboidal epithelium held together by zonulae occludentes
Does the brain have lymphatics?
Where is CSF reabsorbed?
Arachnoid villi in superior sagittal sinus
What is Wallerian degeneration?
Segment of PNS axon distal to injury degenerates (anterograde)
What is involved in anterograde changes in PNS nerve injury?
1. Segment distal to injury degenerates (Wallerian degeneration)2. Phagocytic cells derived from Schwann cells and blood-derived monocytes clean up debris3. Schwann cells proliferate and along with their external lamina form tubules