Nervous Tissue (Since Exam 1) Flashcards
Consist of the brain and spinal cord
central nervous system (CNS)
consists of nerves extending toward or away from CNS and ganglia
peripheral nervous system (PNS)
aggregations of nerve cell bodies outside CNS
ganglia
cells responsible for conduction, propagation and reception of nervous impulses. Axons and dendrites extend from these
neurons
cells associated with neurons. No axons or dendrites. involved with nutrition, support, insulation, and protection of neurons
glial cells
_____ matter: neuron perikarya (cell bodies), glial cells, axons, dendrites, synapses
gray
______ matter: axons + myelin sheaths and glial cells. No neuron perikarya, no synapses.
white
nerve cell body, contains nucleus and typical cell organelles
perikaryon
in the perikaryon, large, large amount of euchromatin, Barr body in females
nucleus
in the perikaryon, has a bunch of this for synthesis of structural and transport proteins, Nissle Bodies
Rough endoplasmic reticulum (RER)
in perikaryon, pigments vessels/deposits, function unknown, lipofusion deposits that increase with age
inclusions
pigment that increases with age
lipofuscin
cell process, may be branched, forms receptive area for synaptic contacts from other neurons. neurons have more than one of these
dendrite
a single, long, thin cell process extending away form the perikaryon, may be branched, ends of branches form synapses with other neurons or muscle cells. each neuron only has one of these
axon
myelinates in the CNS
oligodendroglia
myelinates in the PNS
Schwann cells
pyramid shape region where axon originates from the perikaryon
axon hillock
unmyelinated initial portion of axon
initial segment
axons carry electrical impulses ( ____ ____) to synapses at ends of axons.
action potentials
specialized junctions with other cells that are along the length or at end of an axon
- act as transmission points for electrical impulses
synapse
synapses at the end of an axon or axon branches are swollen into a club shape
boutons terminaux
synapses along the length of axon result in _______ (swellings) in the axon called
Varicosities
boutons en passage
this is a space between the presynaptic membrane of the axon and the plasmalemma of the cell the receives the synaptic input
synaptic gap or cleft
part of the plasmalemma of a cell that receives input
postsynaptic membrane
name two neurotransmitters
acetylcholine and serotonin
many small vesicles in the bouton that contain neurotransmitters
synaptic vesicles
more than two processes (one axon plus multiple dendrites)
most of the neurons of the brain and spinal cord are this type
multipolar neurons
two major processes (axon and dendrite) but may be branched at ends, in sensory structures . retina, cochlea, and olfactory epithelium
bipolar neurons
two major process that are fused along portions closest to perikaryon, found in spinal ganglia and some cranial ganglia
psuedounipolar neurons
type of neuron, efferent, action potential moves from CNS to effector organ (e.g. muscle)
motor neurons
type of neuron: afferent, action potential moves from sensory organ to CNS, associated with pancinian corpuscles ( touch, pressure)
sensory neurons
type of neuron, form connections between neurons
interneurons
glial cells in the CNS
Astrocytes
Oligodendroglia
microglia
ependymal cells
two types of astrocytes
- protoplasmic astrocytes
2. fibrous astrocytes
glial cell in the PNS
Schwann cells
satellite cells
provide physical support for neurons, store glycogen, isolate synaptic areas form one another
contribute to BLOOD BRAIN BARRIER
astrocytes
type of astrocyte
thicker and shorter
found in gray matter
protoplasmic astrocytes
type of astrocyte
long and slender
found in white matter
fibrous astrocytes
Myelinate in the CNS
must be cultured with neurons in order to get neurons to grow in tissue culture
oligodendrocyte
type of glial cell, elongated, stain dark and dense, can move around in brain tissue
microglia
line the cavities within the CNS
circulates cerebrospinal fluid
ependymal cells
in peripheral nervous system (PNS)
form myelin sheaths
Schwann cells
nerves are surrounded by a thick connective tissue sheath called the _______. It extends into the nerve and between the fascicles
epineurium
groups of axons, each one of which is unsheathed by single or multiple folds of a sheath shell
nerve fibers
each bundle (or fascicle ) of axons is surrounded by a layer of connective tissue called the
perineurium
each axon within a bundle is individually surrounded by a lever of reticular connective tissue called the
endoneurium
_____ acts to insulate axons, speeds up the conduction of electrical impulses
myelin
these slow down the condition due to gaps in the myelin sheath
nodes of ranvier
the _____ the nodes of Ranvier along a given axon , the faster the transmission
fewer
involuntary component to the nervous system called
autonomic nervous system
autonomic nervous system is important int
control of smooth muscle
secretion of some glands
cardiac rhythm
neurotransmitter is norepinephrine (enhances activity)
sympathetic nervous system
neurotransmitter is acetylcholine (slows activity)
parasympathetic nervous system
neurotransmitter for sympathetic
norepinephrine (speeds up activity)
neurotransmitter for parasympathetic
acetylcholine (slows down activity)
cerebellum is composed of many folds called
folia
cerebrum is composed of many folds called
gyri
three regions of gray matter in cerebellum
outer: molecular layer
middle: purkinje layer (largest in the brain)
inner: granular layer (smallest neurons in the human body)
5 types of receptors of sensory structures
- somatic (skin) and visceral (organs) receptors
- proprioceptors
- chemoreceptors
- audio receptors
- photoreceptors
type of receptors of sensory structures: pain pressure, vibration and temperature
somatic (skin) and visceral (organs) receptors
type of receptors of sensory structures: sensitive to ones position in space, ear and receptors of muscular info
proprioceptors
type of receptors of sensory structures: taste and smell
chemoreceptors
type of receptors of sensory structures: hearing
audioreceptors
type of receptors of sensory structures: sight
photoreceptors
the most numerous sensory structure in your body,
found in hairless skin (tips of fingers, palms, soles of feet, lips, nipples)
TOUCH: meissner’s corpuscles
found in deep layer of dermis, hypodermis, loose CT, external genitalia, respond to vibrations and pressure function in proprioception
PRESSURE AND VIBRATIONS: Pancinian corpuscles
glial cell in the PNS, found surrounding neurons in ganglia
satellite cells
