OSSF Exam III Complete Questions And
Answers
what are the three main functions of the nervous system? CORRECT ANSWERS
gather sensory input
integration
effects a motor output
how does the nervous system gather sensory input? CORRECT ANSWERS by
monitoring internal and external (environment) stimuli (changes) using billions of
sensory receptors
how does the nervous system integrate input? CORRECT ANSWERS processes and
interprets sensory input and makes decisions about what should be done
how does the nervous system effect.a motor output (response)? CORRECT ANSWERS
by activating muscles or glands
what is the afferent nervous system? CORRECT ANSWERS part of peripheral system -
input cells/sensory
what is the efferent nervous system? CORRECT ANSWERS part of peripheral system -
output cells/motor
what is the fundamental functional unit of the nervous system? CORRECT ANSWERS
neuron (nerve cell)
how do neurons function? CORRECT ANSWERS sends and receives information via
electrochemical transmission
what is a nuclei? CORRECT ANSWERS a collection of cell bodies located within the
CNS
what is a ganglion? CORRECT ANSWERS a collection of cell bodies located outside
the CNS
what is a nerve? CORRECT ANSWERS a group of fibers (axons) outside the CNS
what is a tract? CORRECT ANSWERS a group of fibers inside the CNS
what is a funiculus? CORRECT ANSWERS bundles of fiber tracts
what is gray matter? CORRECT ANSWERS an area of unmyelinated neurons
containing cell bodies, dendrites, and some axons
,where synaptic contacts occur
what is white matter? CORRECT ANSWERS an area of myelinated fiber tracts in the
CNS
what do exterorecptors sense? CORRECT ANSWERS stimulation arising outside of the
body (touch, pain, temperature)
what do interoceptors sense? CORRECT ANSWERS stimulation arising inside the body
(chemical messengers, stretching of tissue, and internal temperature)
what do proprioreceptors sense? CORRECT ANSWERS responds to internal stimuli,
but located only in skeletal muscle, tendons, joints, and ligaments as well as in
connective tissue covering bones and muscles
what are the 5 main receptor types and their detected stimuli? CORRECT ANSWERS
mechanoreceptors (touch, pressure, vibrations)
thermoreceptors (temperature)
photoreceptors (light)
chemoreceptors (smell, taste, blood chemistry)
nociceptors (pain)
what are Aa afferent fibers? CORRECT ANSWERS includes both 1a fibers from muscle
spindles and 1b fibers for the golgi tendon organ - types of proprioceptors
fastest, largest diameter
what are AB afferent fibers? CORRECT ANSWERS non-noxious mechanoreceptors
what are A- afferent fibers? (idk what that second symbol is) CORRECT ANSWERS
noxious mechanoreceptors for quick, intense pain
what are C fibers? CORRECT ANSWERS classic pain receptors - deep pain, visceral
aching pain
can also respond to other stimuli - cat response to petting
slowest, smallest diameter
what contributes to afferent input? CORRECT ANSWERS spinal nerves via dorsal root
ganglion (sensory)
cranial nerves (I, II, V, VII, VIII, IX, X) - some sensory, some motor, mixed
what are the efferent somatic outputs? CORRECT ANSWERS upper motor neurons
and lower motor neurons
what are upper motor neurons? CORRECT ANSWERS motor cortex
brain stem
project to motor nuclei of brainstem or spinal cord - active voluntary movement in LMN
,what are lower motor neurons? CORRECT ANSWERS final common pathway
project to muscles
also have reflexive actions - don't require UMN
what are the actions of sympathetic and parasympathetic systems usually? CORRECT
ANSWERS reciprocal or antagonistic
what is the sympathetic system involved in? CORRECT ANSWERS autonomic
response to stressful external stimuli
what is the parasympathetic system involved in? CORRECT ANSWERS controls
autonomic functions in the resting, unstressed animal
what are efferent signals to viscera, glands, smooth muscle, cardiac muscle, etc.
influenced by? CORRECT ANSWERS afferent feedback
how does autonomic output work in the CNS? CORRECT ANSWERS preganglionic -
autonomic nuclei in brainstem, autonomic nuclei in spinal cord, project to autonomic
ganglia
how does autonomic output work in the PNS? CORRECT ANSWERS postganglionic -
autonomic ganglia, project to smooth and cardiac muscles, glands, and adipose tissue
what are the three main basic neuron types? CORRECT ANSWERS bipolar, unipolar,
multipolar
what is the structure of most neurons? CORRECT ANSWERS multipolar
what are the functions of the plasma membrane of the cell body? CORRECT
ANSWERS phospholipid bilayer functions as a capacitor
provides structural support
determines morphology
maintains electrochemical gradients - ion channels, activated transport pumps
what is myelin and how does it affect conduction? CORRECT ANSWERS lipid rich
substance that serves as insulation around the axon, resulting in increased speed and
efficiency of conduction
how does the AP move in myelinated axons? CORRECT ANSWERS jumps from node
to node
what is the impact of damage to the myelin sheath? CORRECT ANSWERS major
impact on conduction - demyelinating diseases
inefficient/ineffective communication
, what is the structure of multipolar neurons? CORRECT ANSWERS dendrites extend
from cell body
only one axon but that axon can have many collaterals
what are some examples of multipolar neurons? CORRECT ANSWERS alpha motor
neurons in the spinal cord (LMN) and pyramidal neurons in the cerebral cortex
what is the structure of bipolar neurons? CORRECT ANSWERS two processes
extending from the cell body - dendrite and axon w/ collateral branches - dendrite
almost looks like an axon
how do bipolar neurons work? CORRECT ANSWERS dendrites receive signal from
sensory cell which is then transmitted centrally via the axon
where are bipolar neurons found? CORRECT ANSWERS in retina, olfactory epithelium,
and vestibulocochlear nerve
what is the structure of unipolar or pseudounipolar neurons? CORRECT ANSWERS
have 2 axons rather than dendrites and an axon
one axon extends from sensory receptors in the periphery
one axon extends centrally towards the spinal cord
what is the only example of unipolar neurons in mammals? CORRECT ANSWERS
dorsal root ganglion cells (sensory neurons)
what are the roles of glia? CORRECT ANSWERS provide mechanical and physical
support
provide nutrients, including oxygen, to neurons
remove cellular debris
remove substances that may be toxic to neurons, this includes the rapid uptake of
glutamate from the synaptic cleft
provide electrical insulation
what is the function of Schwann cells? CORRECT ANSWERS myelinate peripheral
axons (nerves) - one Schwann cell only myelinates one segment of axon
provide important trophic factors and nutrients important for axonal health
how are Schwann cells involved in axonal regeneration? CORRECT ANSWERS by
phagocytizing damaged axons and guiding new growth
what does recent evidence suggest about Schwann cell degeneration? CORRECT
ANSWERS cell degeneration and subsequent demyelination may underlie early
symptoms of feline diabetic neuropathy
what are satellite cells? CORRECT ANSWERS support cells of the PNS (similar to
astrocytes in CNS)