Exam 5: Chapters 12-13
The resting membrane potential in neurons is: __________ millivolts
-70 mv
The spinal cord extends from the medulla oblongata to the:
2nd lumbar vertebra
Which of the following nerve fibers would have the highest speed of conduction?
A fibers
Chromatolysis and Wallerian Degeneration occur as part of the repair process for nerves in the _________.
PNS
Which nervous system division contains spinal nerves, ganglia, and peripheral nerves?
PNS
The period of time during which the neuron cannot generate another action potential, even with a very strong stimulus is called the:
absolute refractory period
Once a(n) ________ potential is generated, the amplitude is always the same and does not depend on stimulus intensity.
action
To communicate over short and long distance neurons use the:
action potentials
Which is not a process used to remove the neurotransmitter from the synaptic cleft?
active transport
Which neurons carry information to the brain?
afferent
The membrane potential temporarily becomes more negative than the resting level during the _________ phase.
after hyperpolarizing phase
Which subdivision of the Peripheral Nervous System is involuntary?
autonomic nervous system
Which is a synapse that transmits a nerve impulse from an axon to a cell body:
axosomatic
What collection of spinal nerves connects the sensory and motor nerves to the upper limbs?
brachial plexus
At the neuromuscular junction, a nerve impulse is converted into a/an:
chemical signal
Unmyelinated axons transmit action potentials through _______ conduction while myelinated axons use _____ conduction.
continuous, saltatory
The spinal cord ends by tapering to a conical portion called the:
conus medullaris
A reflex that causes contraction of muscles that extend joints in a limb opposite the painful stimulus is called:
crossed extensor reflex
Which is commonly the "receiving" structure of a neuron?
dendrite
An area of skin that provides sensory input via the spinal nerves is called:
dermatome
What is the correct order of the connective tissue layers that protect the spinal cord from the outermost layer to the innermost layer?
dura mater, arachnoid, pia mater
Which neurons carry information out of the brain?
efferent
The movement of materials in both directions on microtubules in axons referes to:
fast axonal transport
A withdrawal of a part of the body in response to a painful stimulus is called a:
flexor reflex
What principle function of the nervous system analyzes information, stores some aspects, and makes decisions about appropriate behavior?
integrative
Which neurotransmitter receptor is a type of ligand-gated channel which contains a binding site and an ion channel?
ionotropic receptiors
When the motor nerve impulse goes out the same side as the sensory neuron came in it is called:
ipsilateral reflex
Channels that open in response to a specific chemical stimulus are:
ligand gated channels
Which group of nerves supplies the anterolateral abdominal wall, the external genitals, and part of the lower limb?
lumbar plexus
What is the collective term for the connective tissue coverings that surround the spinal cord and the brain?
meninges
An autoimmune disease where the body's immune system attacks the myelin sheaths in multiple regions causing the myelin sheaths to deteriorate to scleroses or hardened scars.
multiple sclerosis
White matter primarily consists of ______ of many neurons. Grey matter consists of ______.
myelinated axons; neuron cell bodies
Chemical substances that neurons use to communicate with other neurons are called:
neurotransmitters
Depression is linked to an imbalance of ____________ like serotonin, norepinephrine and dopamine in the brain.
neurotransmitters
A patient has suffered a spinal cord injury at the C6 level. Will this patient need to be on a ventilator to breathe for them?
no
A positive Babinski Sign in a 1 yr old is a(n):
normal
Neuroglial cells in the brain that form a myelin sheath around several adjacent axons are:
oligodendrocytes
Damage to the sensory or motor nerves to the muscle or to the integrating centers in the lumbar segments of the spinal cord in diabetes patients can be indicated by the absence of a knee jerk when testing this reflex:
patellar reflex
Which of the following structures of the spinal nerves contains the sensory axons?
posterior root
The contraction of one muscle and the relaxation of it's antagonistic muscle is called;
reciprocal innervation
Which group of nerves supplies the buttocks, perineum, and lower limbs?
sacral plexus
The following is a description of which type of neural circuit? A presynaptic neuron stimulates a single postsynaptic neuron.
simple series
What occurs when neurons one and two both act on neuron three at the same time to cause an action potential?
spatial summation
Graded potentials vary in amplitude depending on the strength of the ________.
stimulus
The resting membrane potential is maintained primarily by two factors:
the Na+/K+ pump and the leakage of K+ out to the cell
In the stretch reflex, the end result is:
the muscle that was stimulated contracts
What is the arrangement of white and gray matter in the spinal cord?
the white matter surrounds grey matter
A sensory neuron that has one process that extends from the cell body:
unipolar
Sensory and motor tracts are found in the _____ of the spinal cord.
white matter