OSSF Exam III: Questions With Accurate Solutions
what are the three main functions of the nervous system? Right Ans -
gather sensory input
integration
effects a motor output
how does the nervous system gather sensory input? Right Ans - by
monitoring internal and external (environment) stimuli (changes) using
billions of sensory receptors
how does the nervous system integrate input? Right Ans - processes and
interprets sensory input and makes decisions about what should be done
how does the nervous system effect.a motor output (response)? Right Ans -
by activating muscles or glands
what is the afferent nervous system? Right Ans - part of peripheral system
- input cells/sensory
what is the efferent nervous system? Right Ans - part of peripheral system
- output cells/motor
what is the fundamental functional unit of the nervous system? Right Ans -
neuron (nerve cell)
how do neurons function? Right Ans - sends and receives information via
electrochemical transmission
what is a nuclei? Right Ans - a collection of cell bodies located within the
CNS
what is a ganglion? Right Ans - a collection of cell bodies located outside
the CNS
what is a nerve? Right Ans - a group of fibers (axons) outside the CNS
what is a tract? Right Ans - a group of fibers inside the CNS
,what is a funiculus? Right Ans - bundles of fiber tracts
what is gray matter? Right Ans - an area of unmyelinated neurons
containing cell bodies, dendrites, and some axons
where synaptic contacts occur
what is white matter? Right Ans - an area of myelinated fiber tracts in the
CNS
what do exterorecptors sense? Right Ans - stimulation arising outside of
the body (touch, pain, temperature)
what do interoceptors sense? Right Ans - stimulation arising inside the
body (chemical messengers, stretching of tissue, and internal temperature)
what do proprioreceptors sense? Right Ans - 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? Right Ans -
mechanoreceptors (touch, pressure, vibrations)
thermoreceptors (temperature)
photoreceptors (light)
chemoreceptors (smell, taste, blood chemistry)
nociceptors (pain)
what are Aa afferent fibers? Right Ans - 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? Right Ans - non-noxious mechanoreceptors
what are A- afferent fibers? (idk what that second symbol is) Right Ans -
noxious mechanoreceptors for quick, intense pain
what are C fibers? Right Ans - 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? Right Ans - 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? Right Ans - upper motor neurons
and lower motor neurons
what are upper motor neurons? Right Ans - motor cortex
brain stem
project to motor nuclei of brainstem or spinal cord - active voluntary
movement in LMN
what are lower motor neurons? Right Ans - final common pathway
project to muscles
also have reflexive actions - don't require UMN
what are the actions of sympathetic and parasympathetic systems usually?
Right Ans - reciprocal or antagonistic
what is the sympathetic system involved in? Right Ans - autonomic
response to stressful external stimuli
what is the parasympathetic system involved in? Right Ans - controls
autonomic functions in the resting, unstressed animal
what are efferent signals to viscera, glands, smooth muscle, cardiac muscle,
etc. influenced by? Right Ans - afferent feedback
how does autonomic output work in the CNS? Right Ans - preganglionic -
autonomic nuclei in brainstem, autonomic nuclei in spinal cord, project to
autonomic ganglia
how does autonomic output work in the PNS? Right Ans - postganglionic -
autonomic ganglia, project to smooth and cardiac muscles, glands, and adipose
tissue
, what are the three main basic neuron types? Right Ans - bipolar, unipolar,
multipolar
what is the structure of most neurons? Right Ans - multipolar
what are the functions of the plasma membrane of the cell body? Right Ans
- 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? Right Ans - 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? Right Ans - jumps from node
to node
what is the impact of damage to the myelin sheath? Right Ans - major
impact on conduction - demyelinating diseases
inefficient/ineffective communication
what is the structure of multipolar neurons? Right Ans - dendrites extend
from cell body
only one axon but that axon can have many collaterals
what are some examples of multipolar neurons? Right Ans - alpha motor
neurons in the spinal cord (LMN) and pyramidal neurons in the cerebral
cortex
what is the structure of bipolar neurons? Right Ans - two processes
extending from the cell body - dendrite and axon w/ collateral branches -
dendrite almost looks like an axon
how do bipolar neurons work? Right Ans - dendrites receive signal from
sensory cell which is then transmitted centrally via the axon
where are bipolar neurons found? Right Ans - in retina, olfactory
epithelium, and vestibulocochlear nerve