ch. 12. nervous system cell - study guide Flashcards
Consists of the brain and spinal cord
central nervous system
Composed of nerves arising from the brain and spinal cord
peripheral nervous system
PNS subdivision that transmits incoming information from the sensory organs to the CNS
afferent division
produces the “fight or flight” response
sympathetic division
subdivision that carries infromation from the CNS to skeletal muscle
somatic nervous system
subdivision of efferent divsion that transmits information to smooth muscle, cardiac muscle, and glands
autonomic nervous system
consists of all outgoing motor pathways
efferent nervous system
coordinates the body’s normal resting activities
parasympathetic nervous system
has the ability of phagocytosis
microglia
helps to form the blood-brain barrier
astrocyte
produces fatty myelin sheath in the PNS
schwann cell
largest and most numerous of the neuroglia that forms the neurilemma
astrocyte
produces myelin sheath in the CNS
oligodendrocyte
type of neuroglia that forms the neurilemma
schwann cell
“star-cell”
astrocyte
disorder of this cell associated with multiple sclerosis
oligodendrocyte
Which of the following is/are classified as nerve fibers?a) axonb) dendritesc) both a and bd) none of the above
c
Which of the following conduct impulses toward the cell body?a) axonsb) dendritesc) Nissl bodiesd) none of the above
b
A neuron with one axon and several dendrites is a:a) multipolar neuronb) unipolar neuronc) bipolar neurond) none of the above
a
Which type of neuron lies entirely within the CNSa) afferentb) efferentc) interneurond) none of the above
c
Which sequence best represents the course of an impulse over a reflex arc?a) receptor, synapse, sensory neuron, motor neuron, effectorb) effector, sensory neuron, synapse, motor neuron, receptorc) receptor, motor neuron, synapse, sensory neuron, effectord) receptor, sensory neuron, interneuron, motor neuron, effector
d
A complete nerve, consisting of numerous fascicles and their blood supply, is held together by a fibrous coat called the:a) endoneuriumb) perineuriumc) epineuriumd) fascicles
c
Small, distinct regions of gray matter within the CNS are usually called:a) white matterb) nucleic) gangliad) fascicles
b
Nerves that contain mostly efferent fibers are called:a) sensory nervesb) motor nervesc) mixed nervesd) Schwann nerves
b
Gray matter in the CNS consists ofa) nerve fibersb) neurogliac) axonsd) cell bodies
d
Most nerves in the human nervous system are:a) sensory nervesb) motor nervesc) mixed nervesd) reflex nerves
c
True or false? Evidence now indicates that neurons may be replaced.
t
True or false? Regeneration of nerve fibers will occur if the cell body is intact and the fibers have a neurilemma.
t
True or false? There are no differences between the CNS and PNS concerning the repair of damaged fibers.
f
Compared to the inside of the cell, the outside of most cell membranes is:a) positiveb) negativec) equald) none of the above
a
The difference in electrical charge across a plasma membrane is called:a) depolarizationb) membrane potentialc) both a and bd) none of the above
b
A neuron’s resting membrane potential is:a) 70 mVb) -70 mVc) 30 mVd) -30 mV
b
Which of the following statements is true concerning the sodium-potassium pump?a) 3 sodium ions are pumped out of the neuron for every 2 potassium ions into the neuronb) 2 sodium ions are pumped out of the neuron for every 3 potassium ions pumped into the neuronc) 3 sodium ions are pumped out of the neuron for every 3 chloride ions pumped into the neurond) 3 sodium ions are pumped out of the neuron for every 3 potassium ions pumped into the neuron
a
True or false? A membrane that exhibits a membrane potential is said to be polarized.
t
True or false? A slight shift away from the resting membrane potential is a specific region of the plasma membrane often called a stimulus-gated channel
f
True or false? Chlorine ions (Cl-) are the dominant extracellular cations.
f
During a relative refractory period:a) an action potential is impossibleb) an action potential is possible only in response to a very strong stimulic) an action potential is occurringd) none of the above
b
Voltage-gated channels are:a) membrane channels that close during voltage fluctuationsb) membrane channels that open in response to voltage fluctuationsc) membrane channels that are altered from an extremely high stimulusd) none of the above
b
When current leaps across an insulating myelin sheath from node of Ranvier to node of Ranvier, the type of impulse conduction is:a) repolarizationb) refractionc) saltatory conductiond) diffusion
c
The larger the diameter of a nerve fibera) the slower the speed of conductionb) the faster the speed of conductionc) fiber diameter does not influence speed of conductiond) the more the speed fluctuates
b
True or false? Action potential and nerve impulse are synonymous
t
True or false? When repolarization has occurred, an impuls cannot be conducted
f