Neurons & Nervous System Flashcards
This where the nervous system develops
ectoderm
developmentally important cell that separates from the neuroepithelium and becomes mesenchymal
neural crest
Thickening of the embryo of ectoderm on the mid-dorsal side forms _____________
neural plate
functional unit in both the CNS and PNS
neurons
synthetic or trophic center for the entire neuron
cell body (perikaryon)
specialized to receive stimuli from other neurons at unique sites called synapses
dendrites
specialized to generate and conduct nerve impulses to other cells
axon
receives information that modifies the transmission of action potentials to those neurons
axons
one axon, two or more dendrites
multipolar neurons
one dendrite and one axon
bipolar neurons
serve the senses of sight, smell, and balance
bipolar neurons
many dendrites, no true axon
anaxonic
receive stiumuli from the receptors throughout the body
sensory neurons
Sending impulses to effector organs
Motor neurons
SaMe
Sensory neurons (Afferent)
Motor neruons (Efferent)
Voluntary control, innervate most skeletal muscle
Somatic neurons
Involuntary activities, innervate glands cardiac muscle and most smooth muscle
automatic neurons
establish relationships among other neurons forming complex functional networks or circuits
interneuron
Interneuron are _______
multipolar
anaxonic
Either
metabolic center of the neuron
cell body (perikaryon)
Filaments abundant both in perikarya and processes
Intermediate filaments
Correct pair:
CNS - gray matter
Axons - gray matter
CNS - white matter
Axons - white matter
CNS - gray matter
Axons - white matter
short, small process emerging and branching off the soma
dendrites
serve as the initial processing sites for synaptic signals
dendritic spine
pyramid-shaped region of the perikaryon where the axon of a neuron originates
axon hillock
plasma membrane of the axon
axolemma
contents of axon
axoplasm
small swelling found at the terminal ends of axons
terminal bouton
contacts another neuron or non-nerve cell at a synapse to initiate an impulse in that cell
terminal bouton
From cell body to axon terminals
anterograde transport
Anterograde transport functions via a protein called ______
kinesin
From the axon terminals to cell body
retrograde transport
Retrograde transport function via a protein called ______
dynein
Mode through which a neuron transports electric signals
nerve impulses
Sites where nerve impulses are transmitted from one neuron to another, or from neruons and other effector cells
synapses
The structure of a synapse ensures that transmission is ___________.
unidirectional
Bind specific receptor proteins to either open or close ion channels or initiate second-messenger cascades
neurotransmitters
Axon forms a synapse with a cell body
axosomatic synapse
Axon forms a synapse with a dendrite
axodentric synapse
Axon forms synapse with another
axoaxonic synapse
how many times are glial cells more abundant in the mammalian brain than the neurons
10 times
support neuronal survival and activities
glial cells
network of fine cellular processes emerging from neurons and glial cells
neurophil
This staining of neurofibrils makes neurophil more apparent
gold staining
provide the electrical insulation for neurons in the CNS
oligodendrocytes
myelin sheaths surrounding axons are damaged by an autoimmune mechanism that interferes with the activity of the affects neurons and produces various neurologic problems
multiple sclerosis
most numerous glial cells of the CNS and most diverse
astrocytes (star-shaped)
Which among the choices are correct:
Typical in white matter - fibrous astrocytes
Predominate in the gray matter - protoplasmic
Both
unique marker for astrocytes, most common source of brain tumors
glial fibrillary acid protein
- facilitate movement of cerebrospinal fluid
- involved in absorption
- cilia
- microvilli
major mechanism of immune defense in CNS
microglia
Origin of microglia
circulating blood monocytes
importantly allow axons for their myelination
schwann cells
exert a trophic or supportive effect on these neurons, insulating, nourishing, and regulating their microenvironments
satellite cells
where most synapses occur
gray matter
containing very few neuronal cell bodies, but astrocytes and microglia are present
white matter
integration of sensory information and the initiation of voluntary motor responses
cerebral cortex
coordinates muscular activity throughout the body
cerebellar cortex
generally shaped as letter H
spinal cord
membranes of connective tissue found between the bone and nervous tissue
meninges
A functional barrier that tightly regulates the passage of substance from blood CN
blood brain barrier
main structural component in which the cells are tightly sealed together with well- developed occluding junctions and with little or no transcytosis activity
capillary endothelium
Removes water from blood and release it as the CSF
villus
serves to help absorb mechanical shocks
csf
very important because it allows what is called the saltatory conduction (to jump) of nerve impulses, their rapid movement from node to node
myelination
carry information from internal body regions and the environment
afferent fibers
Carry impulses from the CNS to effector organs commanded by these centers
efferent
Nerves composed only of fibers carrying impulses to the effector
motor nerves
serve as relay stations to transmit nerve impulses
ganglia