Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
Nervous tissue is made up of __ main cell types
|
2 |
|
Neuroglia of the peripheral nervous system include __ and __
|
oligondendrocytes and astrocytes |
|
___ are the functional units of nervous tissue
|
Neurons |
|
These branching neuron processes serve as receptive regions and transmit electrical signals toward the cell body. They are ___
|
dendrites |
|
True/False
Axons are neuron processes that generate and conduct nerve impulses. |
True |
|
Most axons are covered with a fatty material called ____, which insulates the fibers and increases the speed of neurotransmission.
|
myelin sheath |
|
Neuron fibers (axons) running through the central nervous system form __ of white matter.
|
tracts |
|
Neurons can be classified according to structure. __ neurons have many processes that issue from the cell body.
|
Multipolar |
|
Neurons can be classified according to function. __ or motor neurons carry electrical signals from the central nervous system primarily to muscles or glands.~
|
afferent |
|
Within a nerve, each axon is surrounded by a covering called the __.~
|
endoneurium |
|
The basic functional unit of the nervous system is the neuron. What is the major function of this cell type?
|
To transmit messages from one part of the body to another in the form of nerve impulses |
|
Name four types of neuroglia in the central nervous system.
|
1. astrocytes 2. Oligodendrocytes 3. microglial cells 4. ependymal cells |
|
Function of astrocytes
|
assists in exchanges between blood capillaries and neurons |
|
Function of oligodendrocytes
|
composes myelin sheath |
|
Function of microglial cells
|
can transform into phagocytes in areas of neural damage/inflammation |
|
Function of ependymal cells
|
lines the central cavities of the brain and spinal cord |
|
Name the Peripheral Nervous system (PNS) neuroglial cell that forms myeline
|
Schwann cells |
|
Name the PNS neuroglial cell that surrounds dorsal root ganglian neurons
|
satellite cells |
|
the brain and spinal cord collectively
|
central nervous system |
|
specialized supporting cells in the CNS
|
neuroglia |
|
junction or point of close contact between neurons
|
synapse |
|
a bundle of axons inside the CNS
|
nerve |
|
neuron serving as part of the conduction pathway between sensory and motor neurons
|
interneuron |
|
ganglia and spinal and cranial nerves
|
tract |
|
collection of nerve cell bodies found outside the CNS
|
ganglion |
|
neuron that conducts impulses away from the CNS to muscles and glands
|
efferent neuron |
|
neuron that conducts impulses toward the CNS from the body periphery
|
afferent neuron |
|
chemicals released by neurons that stimulate or inhibit other neurons or effectors
|
neurotransmitters |
|
region of the cell body from which the axon originates
|
axon hillock |
|
secretes neurotransmitters
|
axon terminal |
|
receptive region of a neuron
|
dendrite |
|
insulates the nerve fibers
|
myelin sheath |
|
site of the nucleus and most important metabolic area
|
neuronal cell body |
|
involved in the transport of substances within the neuron
|
neurofibril |
|
essentially rough endoplasmic reticulum, important metabolically
|
chromatophilic substance |
|
impulse generator and transmitter
|
axon |
|
What substance is found in synaptic vesicles of the axon terminal?
|
neurotransmitter |
|
What role does neurotransmitter play in neurotransmission?
|
diffuses across the synaptic cleft to bind to membrane receptors on the next neuron; initiating an electrical current (synaptic potential) |
|
What anatomical characteristic determines whether a particular neuron is classified as unipolar, bipolar, or multipolar?
|
the number of processes attached to the cell body |
|
Which neuron types are unipolar?
|
afferent (sensory) neuron |
|
Which neuron are multipolar?
|
interneuron (association) |
|
Describe how the Schwann cells form the myelin sheath and the outer collar of the perinuclear cytoplasm encasing the nerve fibers.
|
they wrap themselves very tightly around axons in a jellyroll fashion; and the neurilemma is an exposed plasma membrane, has many schwann cells and is a discontinuous sheath |
|
What is a nerve?
|
a bundle of axons (neuron fibers) wrapped in connective tissue covering that extends to and from the CNS and visceral organs/structures of the body periphery |
|
State the location of the endoneurium
|
innermost layer; an additional sheath that surrounds the myelin sheath |
|
State the location of the perineurium
|
middle layer; bounds groups of fibers, forms bundles of fibers |
|
State the location of the epineurium
|
outermost layer; bounds fascicles together, forms the cordlike nerve |
|
What is the function of the connective tissue wrappings found in a nerve?
|
to insulate from other processes and to bind and form bundles, and to protect |
|
Define mixed nerve
|
a nerve carrying both afferent (sensory) and efferent (motor) fibers; most nerves in the body including all spinal nerves are mixed |
|
|
|