Nervous Tissue Histology

Where are nissl bodies found?

They are found in the cell body of the neuron and are a specialized form of rough E.R.

what do motor neurons do

They carry impulses from the CNS to effectors.

what is the purpose of an axon on a neuron

conducts nerve impulse towards synaptic terminals

What is glia

connective tissue in the nervous system

what do astrocytes do

cover neurons in the cns but also maintain homeostasis

what is dendrosomatic

dendrite to cell

what is dendrodendritic

dendrite to dendrite

what are the small branches that come off dendrites

dendritic spines

what is another name for motor neruons

efferent

what are functional synapses

electrical chemical

what stimulates dendrites

environmental changes or the activities of other cells

what do schwann cells do

form myelin sheath in PNS

does is anterograde

from cell body to terminal

in the CNs what is a group of neuronal cell bodies called

ganglia

In the PNS what are the neuronal cell bodies called

ganglion

what do sensory neurons do?

general sensations (touch, pain, temp) special sensations like vision, taste, balance

what are unipolar neurons

have a short single process leaving the cell body that turns into both an axon and a dendrite

which directions do sensory neurons flow

in towards the cns or pns

how does a schwann cell wrap multiple axons when unmyelinated

is surrounds multiple axons and then pushes them out the the surface and never totally wraps a lamellae around them

what can cell cam myelinate multiple axons

oligodendrocytes

what is the glia in the CNS

oligodendrocytes astrocytes microglia

what are bipolar neurons

one axon and one dendrite but has multiple branches off the dendrite

what are the portions of the autonomic nervous system

sympathetic parasympathetic enteric

what is retrograde

terminal to cell body

what does an axodendritic synapse look like

the axon connects to a dendritic spine on the dendrite

what is the process of a schwann cell wrapping around a neuron

the schwann cells wraps around and continues to wrap around inside of the outer layer forming many layers of lamellae

what do astrocytes induce

tight junctions in the extra cellular matrix

where do presynaptic neuron carry signals

towards the synapse

what is the most efficient kind of neuron

unipolar

how many lamellae can cover the axon

up to 100

what is another name for the autonomic nervous system

visceral efferent nervous sytem

when can a schwann cell encase multiple axons

when its unmylinated

can a neuron have multiple dendrites

yes

what are the 4 layers surrounding the axons in the pns

(inner) myelin sheath endonuerium perineurium (outter) epineurium

how many axons are there per neuron

1

how many axons can one oligodendrocyte myelinate

50

what are satellite cells apart of

PNS glia cells

what are Nissl bodies

RER in neurons

what is the purpose of the terminals on a neuron

affect another neuron or effector organ

what is another name for sensory nerves

afferent

where do postsynaptic neurons carry signals to

away from the synapse

how is a local synapse described

axodendric axosomatic axoaxonal dendrodentritic dendrosomatic

what is axonaxonal

axon to axon

what is axosomatic

axon to cell body

what is axodendritic

axon to dendrite

where are nodes of ranvier located

between myelin sheaths in both the cns and pns

what do astrocytes contribute to

blood brain barrier

is an axon anterograde or retrograde

both

can an axon be myelinated

can be myelinated or not

what is a perikaryon

cell body of a neuron

what is small and has many dendritic like process but not a dendrite (glia)

microglia cell

how many schwann cells are on an axon

multiple 1 per internodal segment

what is a fasicle

mutliple axons surrounded by myelin and endoneurium as well as perinuerium

what are schwann cells derived from

neural crest cells

what are multipolar neurons

neurons with 3 or more processes of dendrites

what does an axon terminal release

neurotransmitter

Are dendrites myelinated?

no

can we control the autonomic nervous system

no

what is this

nucleus

what does the cell body contain on a neuron (4)

nucleus mitochondria ribosomes other organelles

what are oligodendrocytes derived from

nueroepithelial cells

which direction do motor neurons go

out from the cns and pns

what cell can only myelinate one axon

schwann cell

in the PNS what is the glia called

schwann cells