Nerve Tissue Flashcards
What neurons are found in the cerebral cortex?
multipolar neurons -> pyramidal cells
What type of matter is the cerebral cortex, astrocytes, and pyramidal cells found in?
gray matter
What neurons are found in the cerebellar cortex?
multipolar neurons -> purkinje cells
What is the order of layers in the cerebellar cortex from top to bottom?
molecular layer > purkinje cell layer >granule cell layer > white matter
In what matter are purkinje cells found?
gray matter
In what matter are axons found?
white matter
What type of neurons do dorsal horns have?
interneurons
What type of neurons do ventral horns have?
motor neurons
Tau tangles are apart of what disease?
alzheimers
What forms intracellular lesions?
tangle clumps
What happens when tau binds to other taus, what happens to microtubules?
microtubule breaks down
What is the marker of astrocyte activation?
GFAP
During development, embryonic axons are surround by what type of cells?
Schwann
What type of axons are ONLY found in the PNS?
unmyelinated
One Schwann cell can enclose many …. but can only enclose one ….
unmyelinated axons; myelinated axon
What occurs in multiple sclerosis?
macrophages and microglia directly attack myelin stripping fragments of myelin, leaving “naked” demyelinated axons
In what matter does the demyelination occur in multiple sclerosis?
White matter
What is the most common form of Gullain-Barre syndrome?
acute inflammatory demyelinating polyneuropathy
What causes AIDP ?
autoimmune response directed against Schwann cell membranes
What is the difference between Gullain-Barre syndrome and multiple sclerosis?
GBS: in PNS (Schwann cells)
MS: CNS (microglia)
What are examples of sensory receptors in the skin?
Pacinian corpuscle and Meissner’s corpuscle
Where can the Pacinian corpuscle be found?
deep in the dermis
Where can the Meissner’s corpuscle be found?
closer to epidermis
Which corpuscle allows for edge detection?
Meissner’s
Which corpuscle allows for a sense of pressure and vibration?
Pacinian
What type of connective tissue surrounds the nerve?
epineurium (dense irregular)
What type of connective tissue surrounds the nerve fasicle?
perineurium (specialized tissue)
What type of connective tissue surrounds the nerve fiber?
endoneurium (loose tissue)
What are the 2 types of blood-nerve barrier?
perineurium and endoneurium
What is the perineurium?
specialized connective tissue with tight junctions
What is the endoneurium?
blood capillaries that have tight junctions
What are gangli?
cell bodies in PNS arranged in structures
The cell bodies have specialized glial cells called what?
satellite cells
What do the satellite cells in the ganglia surround?
outer neuron
In the gangli, what is a sensory pseudo-unipolar neuron?
dorsal root ganglion
What is the role of the satellite cells in ganglia?
- serve as supportive cells around the neuronal body in the ganglion
- provide electircal insulation
Do the satellite cells in the ganglia produce myelin?
NO
What is the PNS response to injury?
Wallerian degeneration
What is the process of Wallerian degeneration?
- nerve fiber is cut/crushed
- part of the axon separates
- degenerates distal to the injury
What is needed for regeneration in the PNS?
Schwann cells
What is Wallerian degeneration?
after significant injury, the nerve will begin to degrade in an anterograde fashion
What is a nogo protein?
negative regulator of neuronal growth in CNS
What is the role of nogo proteins?
impair growth cones
Which nervous system lacks nogo proteins?
PNS
What can nogo antibodies do?
enhance axon elongation after spinal cord crush injuries
