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Histology: Nerves
WVSOM: Nervous Tissue
Question | Answer |
---|---|
3 main features of a nueron | Cell body (soma), axon, dendrite |
What is a Lewey body | Brown or yellow inclusions in the soma. Usually a sign of degenerative disease |
3 types of nuerons | unipolar, multipolar, and pseundounipolar |
Location of psuedounipolar | dorsal root ganglion, SENSORY |
Description/Location of Bipolar | 1 dendrite, one axon, used in ganglion for sensroy type signaling, found in Retina |
Description/Location of Mulitpolar | multiple dendrites feed to a single soma. These make up most nuerons and are found in the endo/excrine system, muscle, and ventral horns MOTOR |
What is an ogliodendrocyte | found in CNS, responsible for mylenation |
Two types of transport in an axon | Orthograde (from cell body to nerve endings) or retrograde (from nerve endings to cell body) |
What type of transports does rabies utilize | Retrograde |
what is an astrocyte | carry nutrients from cappilaries to the nueron, maintains ionic conditions, are mitotically active and form glial scarsAlso maintain blood brain barrier, and absorb/recycle nuerotransmitters |
what is a microglia | arise from monocytes, act as a phagocyte to remove waste and debris |
What is a Ependymal cell | line the brain and spinal cord. Assist in making and moving CSF, produce choroid process |
What is a Schwann cell | found in PNS, produces mylen and helps in repair after injury |
What is a sattelite cell | surround cell bodies in ganglia, PNS, regulates 02, CO2 and nutrients |
what do schwann cells origniate from | nueral crest cells |
how do schwann cells mylenate | wrap around the axon over and over again to |
Name the three layers that make up the divisions of neurons (from outtermost to innermost) | Epineurium, Parineurium, and Endoneurium |
How many axons can a schwann cell mylenate | many |
What is a node of Ranvier | a gap in the myelination. Has a high concentration of Na+ channels to regenerate the action potential |
What are the two types of ganglia | Dorsal Root Ganglia and ganglia of cranial nerves |
type of tissue that surrounds sensory ganglia | dense connective tissue |
What are the three types of snesroy receptors in the integument | Pacinian corpuscles, Meissners corpuslces, and intrafusal fibers/muscle spindles |
Describe Pacini's corpuscles | onion shaped, stimulated by pressure, vibration and tension in the deep layer of the skin, finger pads, tendons and ligaments around viscera |
Describe Messner's corpuscles | fine touch recpetors (mechanoreceptor) in dermis or finger pads. Look like 'tornado' or bee hive. Found in lips, gential skin and eyelids |
Describe Intrafusal fibers/muscle spindles | made of 3-12 fibers, responsible for contraction, monitor amount and rate of stretch |
Cell types responsible for CNS tumors | Glial cells |
Can nerves in the PNS regenrate | YES |
what happens when a PNS nueron is cut | cell membrane permiability increases, takes on water, nissel bodies disappear, and the end proximal to the nueron undegoes RETROGRADE DEGENERATION |
What is it called when a axon in the PNS is cut and looses color | chromatolysis |
What is Wallerian Degeneration | takes place in an axon distal to the cut. Terminal swells, myelen sheath breaks down and macrophages clean it up |
Name the cell membrane of the axon | axolemma |
Name the cytoplasm of the axon | axoplasm |