Histology: Neuro (Exam 2) Flashcards
Who won the nobel prize in physiology or medicine in 1906
Camillo Golgi and
Santiago Ramon y Cajal
Where are purkinge cells found
cerebellum
What do Prukinje fibers aid in
motor coordination
How do Purkinje fibers change in autism patients
reduced size
How do Purkinje fibers change in alcoholics
reduced cell volume
Where does nerve tissue develop from
embryonic ectoderm
What are the 3 major components of the nervous system
nerve cells
supporting cells
blood vessel cells
What are the nerve cells
neurons
What are the supporting cells
neuroglia
What are blood vessel cells
blood brain barrer
What is the function of neurons
conducting cells: specialized to conduct electrical activity
What are the types of neurons
sensory neurons
motor neurons
interneurons
What are sensory neruons
somatic or visceral afferent
What are motor neurons
somatic efferent or visceral efferent
What are interneurons
communication between sensory and motor neurons
Most neurons belong to what category of neurons
interneurons
Do neurons form cancers, why or why not
mostly terminally differentiated so no
What is the function of neuroglia
non conducting cells that provide
-physical support
metabolic support
electrical insulation
Where are neuroglia found
surface fo the brain and ventricles
Can neuroglia cells divide
yes
What type of cancers are formed from neuroglia
glioma
What are the 3 classes of neurons
Pseudounipolar
Bipolar
Multipolar
What type of neurons are pseudounipolar
sensory
Where are pseudounipolar neurons found
spinal and most cranial sensory ganglia
What type of neurons are bipolar neurons
sensory–special senses
Where are bipolar neurons found
retina, cochlear, and vestibular ganglia
What type of neurons are multipolar
motor and interneurons
What type of neurons are found in the dorsal root ganglia
pseudounipolar
Do synapses occur in the DRG
no
Where will the cell body and axons of motor neurons be found in the spinal cord
cell body in ventral horn
axons in the ventral root
What are the different types of multipolar cells
motor neuron
pyramidal
granule cell
cerebellar purkinje
What are the layers of cortical cells
- molecular layer
- external granular layer
- External pyramidal cells layer
- Internal granular layer
- Ganglionic layer (inner pyramidal cells)
- Multiform (polymorphic) cell layer
How many cortical layers are there
6
What is the axon hillock
origin of the axon from the perikaryon
What organelles are contained in the axon hillock
free of cell organelles
What are Nissl bodies
rER in neurons
Describe the nucleus of the neurons
large, lightly stained with prominent nucleolus
What are the supporting cells of the PNS
Schwann cells
satellite cells
What is the function of schwann cells
myelinates axons in the PNS
What is the function of satellite cells
surround neuron cell bodies of spinal ganglia
What are the glial cells of the CNS
oligodendrocytes
astrocytes
microglia
ependyma
What is the function of oligodendroglia
myelinates axons in the CNS
What is oligodendroglia responsible for production of
white matter of the CNS
What is the function of astrocytes
forms the blood brain barrier
What is the most numerous glial cell
astrocytes
How are astrocytes stained
stained to identify GFAP which is a unique easily stained protein contained within astrocytes
What are the different types of astrocytes
fibrous type
protoplasmic type
Where are fibrous type of astrocytes found
white matter
Where are protoplasmic type of astrocytes found
grey matter
What are microglia cells derived from
bone marrow
Where are all but microglia cells derived from
neural tube
What is the function of microglia
phagocytosis in CNS
Where are ependymal cells found
line the ventricles and central canal
What is the myelin sheath composed of
multiple layers of cell membrane wrapped around the axon
What is the function of myelin
electrically isolates the axon from surorundings
What cells produce myelin
schwann cells and oligodendrocytes
What is a node of Ranvier
gap in the myelin sheath of a nerve, between adjacent Schwann cells
What is the myelin between two ranvier nodes called
internodal segment
What is the function of the nodes of ranvier
allows fast conduction of the nerve impulse–action potential develops at the node only, jumping over the internodal segment, saving time
What is a Schmidt-Lanterman cleft
small islands of membrane that contain cytoplasm at node of ranvier
Guillan-Barre syndrome is what type of disease and causes what
autoimmune disorder, acute inflammatory demyelinating polyneuropathy that affects the PNS
What type of cells are affected in GUillain Barre syndrome
Schwann cells
How do autonomic axons establish synapse
axons penetrate between satellite cells to establish synapse
How do oligodendrocytes differ from Schwann cells
Schwann cells only form one segment of a myelin sheath but oligodendrocytes have multiple flat processes that can coil around as many as 60 axons at the same time
Oligodendrocytes don’t have an external lamina like schwann cells
oligodendrocytes have fever schmidt lanterman clefts
How do unmyelinated axons in CNS differ from those in the PNS
truly unmyelinated, not embedded in the cytoplasm like in the PNS
Where do microglial cells originate from
migrate from the vascular system to CNS–mesenchymal origin
How many microglial cells are found in adults
small number, activated at site of injury for debris removal
What are the protoplasmic astrocytes look like
short branching processes
What are the processes of the fibrous astrocyte look like
longer, straight processes
What is GFAP
glial fibrillary acidic protein
Where is GFAP found
mostly in fibrous astrocyte
What is the function of the foot processes of astrocytes
covers vessels, myelin sheath, and innersurface of the pia matter to form the blood brain barrier
What does the ependymal cells form
simple epithelial lining of the CSF-filled cavities of the CNS
What shape of cell is an ependymal cell
cuboidal or columnar cells
What is on the apical surface of ependymal cells
cilia and microvilli
What is on the basal surface of ependymal cells
interdigitations with astrocyte processes
What cells are responsible for making CSF
ependymal cells
What are the components of a neuron
dendrites cell body axon terminal arborization end bulbs synapses
What is anterograde transport
movement down the axon away from the soma
What are the two speeds of anterograde transport
slow and fast
What is slow speed of anterograde transport
0.2-4mm/day
What is fast speed of anterograde transport
20-400mm/day
What does slow anterograde transport carry
structural proteins
What is fast anterograde mediated by
mediated by kinesin bound to the microtubules–carries mitochondria and other large structures
What is retrograde transport
movement up the axon toward the soma
What speed does retrograde transport occur
fast rate
What is retrograde transport mediated by
dynein bound to microtubules
What are the different types of synapses
axodendritic
axosomatic
axoaxonic
dendrodendritic
What is the classical synapse
axodendritic
What is axosomatic synapse
axon to cell body
What is axoaxonic
axon to axon
What is dendrodendritic
dendrite to dendrite
What is a commonly inhibitory synapse
axoaxonic
What are the different neurotransmitter
excitatory: opening Na channels
Inhibitory: opening Cl- channels
How will neurotransmitter be released from an axon
- action potential reaches terminal
- voltage gated calcium channels open
- calcium binds to proteins on vesicles permitting fusion with terminal membrane
- release of neurotransmitters
What are the envolopes around the nerve
endoneurium
perineurium
epineurium
Where is endoneurium found
each nerve fiber
What is endoneurium secreted by
Schwann cells
What type of composition is endoneurium
circular longitudinal collagen
Where is perineurium found
around nerve bundles
Tight junctions in the perineurium form what
blood-nerve barrier
What type of composition is the perineurium
specialized connective tissue 1-6 layers of flattened contractile cells that possess basal lamina on both surfaces
Where is epineurium found
around nerve and the fascles
What composition is epineurium
dense irregular CT
What does the epineurium contain that the other layers do not
blood vessels
Where are multipolar somatic motor neurons found
ventral horn and ventral root
Where are multipolar autonomic motor neurons found
lateral horn and paravertebral ganglia
Where are the cell bodies for the somatic motor nerves
anterior horn of spinal cord
How many layers of cells are in the neocortex
6
What functional type of cells are found in the DH
interneurons
What functional type of cells are found in the VH
multipolar neurons