Nervous tissue Flashcards
Two body systems that work in parallel but independent of each other
- Nervous system
- endocrine system
one part that overlaps
secretes hormones but part of the brain
Hypothalamus
What is comprised of nervous system
Nervous tissue
comprised of endocrine system
cells and glands that releases hormones
what is the response rate of nervous tissue
Precise and Fast
response rate of endocrine tissue
Slow and diffuse more
how long does the effects of nervous tissue last
brief
how long effects of endocrine tissue stay
long lasting
What is CNS
Central nervous system
Two divisions of the nervous system
- CNS
- PNS
what is in the CNS
- brain
- spinal cord
in the PNS
all other nervous tissues
Nervous tissue if part of the 4 basic tissues
true
where does the NT arise from
Embryonic Ectoderm
is NT celullar
it is high in cellularity
does NT have intercellular substances
very little
Is NT mixed with extracellular material
it is DEVOID of ECM except for connective tissues and blood vessels
what is in thr PNS
mainly connective tissues
what is the composition of NT
-NEurons (nerve cells)
- Neurological cells
or known as glial cells
what are glial cells
supporting cells
what is the most functional unit of Nerve tissue
Neuron
what is the most morphological variable cell type in the body
Neuron
3 types of neurons
- stellate
- pyramidal
- flask shaped neurons
where are stellate neurons found
- spinal cord and motor nuclei. grey matter
where are pyramidal neurons found
cerebral cortex
where are the flask shaped cells (purkinje)
found in the middle layer of cerebellar cortex
tree like
irritability of neurons
abilityy to respond to stimuli
conductivity of neurons
ability to transmit stimuli
two processes of neuron cells
- axon
- dendrite
What cannot regenarate in neurons
neurons cannot regenarate
what can regenerate in neurons
-axon
- dendrite
as long as cell body is intact
Parts of a neuron
- dendrites
- nissil granules
- axon hilock
- axon
- rodes of ranvier
- myelin sheet
- axon terminals
what is the name of neuron cell body
Perikaryon (basophilic)
what is in the perikaryon
- nucleus
- cytoplasmic organelles
- inclusions
- neurofibrils in the cytoplasm
- cytoplasm
this is the large spherical or ovoid shaped located centrally of the neuron
nucleus
this has finely dispersed chromatin that actively synthesizes proteins
nucleus
Lm preparations of
Nucleolus
Nucleus
- deep staining
- pale
what are the cytoplasmic organells
- RER
- Nissl bodies
- SER
- Golgi A
- Mitochondria
- Centrosome
- Lysosomes
- Perixosome
This organlle recycle proteins and protects from foreign bodies
Lysosomes
this organells is found in the axon endings
powerhouse
mitochondria
this organelle distributes protein throughout the cell
SER
site of protein synthesis and metabolic processes
Golgi apparatus
This organelle prevents degradation of the neuron
Peroxisomes
organelle present in dendrites and none in axon
basophilic
Nissl Bodies
organelle with basohphilic parts known as nissl bodies
RER
this is fat droplets that represents energy reserves for neurons
inclusions
residuals that are from the result of lysososamal activity
lipofuscin granules
melanin found in cells of spinal and sympathetic ganglia, substanstia nigra
iron: neurons in globus
pigmented granules
this is present in all nerons. extends to axons and dendrites
formed by 3 types
cytoskeleton
3 types that form the cytoskeleton
- microfilaments
- neurofilaments
- microtubules
type of cytoskeleton that is the largest, transports organelles and provides support
Microtubules
type of cytoskeleton that is the thinnest and has F–actin
microtubules
type of cytoskeleton that is also known as intermediate filament, is abundant in axons
and supprts the cells
NeuroFILAMENTS
this transports impulses away
Axon
how many axons are there per neuron
1 one
where does the axon arise from
axon hilock
shape of axons?
long and slender
what is the longest axon in the body
Sciatic nerve
what are the parts found in the axon
- SER
- mitochondira
- neurofibrils
two parts of axons
- axoplasm
- axolemma
small round swelling that acts as site of synapses
- bouton or terminals
bouton with swelling at the end
Bouton TERMINAUX
bouton swelling along the course
bouton EN PASSANT
two movements of axonal transport
- anterograde
- retrograde
this is Perikaryon to Axon
Anterograde
Axon to perikaryon
Retrograde
found in anterograde
a microtuble that uses atp
Kinesin
found in retrograde
mictrotuble associated with protein
dynein
coverings in Axons in PNS
- Neurilemmal sheath (PNS)
- Myelin sheeth
covers the neurons in the PNS
- Neurilemmal sheath
- myelin sheaths
what are sheaths of schwann made of
Schwann cells
these are flat cells with flat nuclei, covers axon.
Sheaths of Schwann
formed by Schwann cell plasmalema spiraled around, refractile
Myelin sheaths
this is the gaps between myelin sheaths, axon is partiall uncovered.
Nodes of Ranvier
envelops schwann cells and present in both kinds of myelinated axons
Basal lamina
What is the counterart of Schwann cells in CNS
Oligodendrocytes
What sheaths are present in CNS
Myelin and Neurilemmal sheath
what forms myelin of axons
oligodendrocytes
where is the amount of cytoplasm less? CNS or PNS
CNS
what composes nerve fibers
Axon + coverings
where does impluse travel faster?
Mylinated sheath
transmits impulse towards the body
Dendrites
what is the most receptive surface of the nueron
Dendrites
parts in the denrites
- mito
- nissl
- neurofibrils
diferent classifcation of process
- unipolar
- pseudo unipolar
- bipolar
- multi polar
most common type of process
1 axon = *** dendrites
Multipolar
single process that breaks into branches
Pseudounipolar
typically seen in vesibular, cocblear and ganglia. axon = 1 dendrite
Bipolar
process functions
- sensory
- motor
- interneurons
transmits impluse from CNS to effector
Motor Efferent
integrate, process, store, analyze, stimulis for appropriate response
Interneurons
receives stimuli and transmit to CNS
Sensory Afferent
this is the point of contact between neurons and cell.
site of transmission
Synapse
types of synapse
- electrical
- chemical
this is tha rare type of synapse. found in the brain for cell to cell communication
made up of gap junctions
Electrical synapse
this synapse uses neurotransmitters, that diffuse at post synaptic sites
Chemical Synapse
where is the electrical synapse present or be seen
brain, cerebral cortex and retina of the eyye
Components of the synapse
- axon terminal
- presynaptic membrane
- synaptic cleft
- post synaptic membrane
part of the presynaptic neuron, has mito, nfibrils, lysosomes
Axon terminals
chemical substance used to transmit neurons
Neurotransmitters
6 types of neurotransmitters
- Acetylcholine
- Catecholamines
- Serotonin
- Amino acid y
- Nitric Acid
- small peptides
type of NeuroT. for gaba, glycin, glutamate and aspartate.
mostly in the CNS
Amino acid Y
type of NeuroT. hypothalamic releasing hormones
enkaphalin, vasoactive, intestinal peptide
Small peptides
type of NeuroT. is for serotonergenic neruons
Serotonin
type of NeuroT. that is a gas that also functions as neurotransmitter
Nitric oxide
type of NeuroT. that’s between axon and striated muscles. serves the ANS
used by choligernic N.
Acetylcholine
type of NeuroT. that releases epinephrine, norepinephrine, dopamine
chemical substance: Catecholaminergic neuron
Catecholamines
occuring between neurons
- axodendritic
- axosomatic
- axoaxonic
axoaxonic
Axon to axon
axosomatic
axon to cell body
rare types
Dendrodendritic, Somatodendritic,
somatosomatic, somatoaxonic,
dendroaxonic, and axoaxodendritic
these cells are smaller than neurons, but greater in number and theyy protect neurosn
Glial Cells or Neuroglial cells
Glial Cells in the CNS
- Macroglia
a. Astrocystes
b. oligodendrocytes - Macroglia
- Ependymal Cells
Tyypes of Macroglia cells
- Astrocytes
- oligodendrocytes
Largest glial cells that are star shaped, involved in: metabolic process covers bare areas regulate potassium
- Astrocytes
2 types of astrocytes
- Protoplasmic- greyshort
- Fibrous- long white
glial cell that are smaller than astrocytes, forms myelin sheaths in cns
Oligodendrocytes
Smaller than Macorglia,
scattred all over CNS
scanty
anitgen presenting cells
Microglia
This forms the secretory epithelial lininng of choroid plexus.
cuboidal and short cilia aiding in CSF
Ependymal cells
what is in the PNS instead of glial cells
Schwann cells
what does schwann cells form
Neurolimal and Myelin sheets
Counterpart of Astrocytes in PNS
surrounds neurons
mantle cells; amphycytes
provide support to cells
Satellite Cells
this sytem is complex but highly integrated.
- receives, stores, process and send out info.
has CNS and PNS
Nervous system
Anatomic divisions of Nervous system
CNS and PNS
this system is very fragile, soft like jelly.
made up of Meninges
CNS
Connective tissue that envelop the brain.
has 3 parts
Meninges
3 parts of meninges
- Dura matter
- Arachnoid M.
- Pia mater
what are pia mater and arachnoid called collectively
LEptomeninges or pia arachnoid
this part if firm, dense irregular tissues and has 3 parts in the meninges
Dura mater
4 surfaces of the Dura mater
- outer surface
- inner surface
- subdural space
- Epidural Space
Meningeal dura
lined by simple Squa Ep.
Inner surface
space between dura mater and arachnoid membrane.
has fluid called CSF
Subdural Space
synonymous to postcranial bones
adhres to inner cranium
“Periosteal Dura”
Outer surface
blood gathered in this space when there is head trauma
to which created pressure
Subdural Hematoma
space between dura and bony wall of vertebral wall
site for drug inroduction
Epidural space
epidural anaesthesia
flat sheet thinner than dura mater
arachnoid membrane
connects the pia mater to arachnoid
Arachnoid trabeculae
a space in the arachnoid where connective tissues are present
subarachnoid space
very vascular, close to the brain. covers entire brain
Pia mater
slightly clear fluid in the brain, in the subarachnoid space
ACTS AS WATER CUCHION
Csf
this drains the CSF into venous system
Arachnoid Vili
Chief source of CSF
Choroid plexus
located at the roof of 3rd and 4th ventricle of the brain
have small blood vessels.
Choroid plexus
forms tight junctions so blood wont become CSF
Ependyma of the choroid plexuses
gross coloration of cns
gray matter
white matter
contains dendrites and proximal portions of axon.
color gray
Grey matter
where is gray mater located in the brain and spina
brain: peripheral area
spinal: central
two types of Golgi found in the Gray matter
Golgi I - long, leaves
Golgi II- short, stays
no nerve cell bodies, have glial cells and myelinated cells
White mater
what makes white mater white
Myelinated sheaths
where is white mater located in brain and spinal
Brain: Central
Spinal: peripheral
leminisci
flattened tract
funiculi
round thick tract
relays all nerve impluse from the CNS to the body
PNS
collection of cell bodies and neurons that have common funtion in PNS
Ganglia
counterpart of Nucles in CNS
Ganglia
counterpart of tracts from cns
Nerves
collection of fibers that are called bundles or fascicles
Nerves
this keep fascicles together
Epineurium
connective tissue are enveloped by this tissue
perineurium
in each fascicle it is covered by
Endoneurium
12 nerves cranial nerves
Cranial nerves
31 pairs. found in the spinal
Spinal nerves
cranial nerve that is a tract
CNII
have axons, transmits impulses to the CNS
Afferent
transmits impluses to the effector or motor
Efferent nerves
functional divisions of nervous system
Anatomically - CNS & PNS
Functionally- SNS & ANS
functionally parts of Nervous system
SNS
ANS
