3. Nervous system Flashcards
glial cells
support cells (maintain ideal environemnt for neurons)
- recycling/defense
neurons
sensory role, processing, response generated
inside of the cell is ___ & the outside is ___
a. negative
b. positive
afferent neurons
incoming info
efferent
response going out
ganglion
group of neuron cell bodies outside of central nervous system
autonomic nervous system
involuntary control (ex gut )
somatic nervous system
voluntary control
cell body
central part; includes the nucleus + regulatory parts of cell synthesis
dendrites
recieve info, typically branched
axolemma
membrane in axon
axoplasma
cytoplasm in axon
what is the most common type of neuron?
multipolar
bipolar
two poles coming from cell body
(1 dendite, 1 axon)
in sensory neurons the bipolar neurons are associated with what?
retina, olfactory, inner ear
what are unipolar neurons associated with?
the rest of the senses, pain reception, tactile, heat
anaxonic
neurons without axons
dendrites radiate from cell body
don’t produce action potentials
regulate electrical charge
what are anaxonic neurons involved in?
circuits (functional network)
axosomatic synapses
axon connects to cell body
axodendritic synapses
axon connects to dendrite ; common
axoaxonic synapses
axon connects to another axon; very rare
types of glial cells (4)
- oligodendrocyte
- astrocytes
- ependymal cells
- microglial cells
oligodendrocytes
-helps action potential travel faster
-produce myelin for sheath
astrocytes
- associated w blood vessels and neuron
- radiate from cell body
what do ependymal cells lack?
basement membrane
microglial cells
immune surveillance, phagocytic, migrate around tissue,
glial cells in the PNS (2)
- schwann cells
- satellite cells
schwann cells
- provide a feeding like function
- outside of the brain and spinal cord
satallite cells
- covering layer on large neuron cell body in ganglic
- trophic function
peripheral nerves (PNS)
-sensory + automatic neurons
what are peripheral nerves enclosed by?
schwann cells
how does myelination work?
1) schwann cell starts to wrap around a portion of an axon
2) schwann cell cytoplasm and plasma membrane begin to form consecutive layers around axon
3) overlapping inner layers of the schwann cell plasma membrane form the myelin sheath
4) schwann cell cytoplasm and nucleus are pushed to the periphery of the cell as the myelin sheath if formed
what do nodes of ranvier do in terms of the action potential?
increase the velocity
endoneurium
supports axon
perineurium
blood- nerve barrier
epineurium
outer layer of the axon, collagen for strength
what do ganglia lack?
blood nerve barrier
Which of the following statements about astrocytes is incorrect?
A) Can be identified by GFAP staining using immunohistochemistry.
B)Have radiating processes extending from the cell body.
C) Important glial cell in the peripheral nervous system.
D)None. All of these statements are correct.
E) Important component of the blood brain barrier (BBB).
C) Important glial cell in the peripheral nervous system.
Neuropil (Np) is composed of connective tissue in the central nervous system T/F
false
Which two cell types myelinate nerves in the peripheral (PNS) and central (CNS) nervous systems?
Schwann cells and oligodendrocytes, respectively
