50 terms

Ch 12 & 13 Nervous Tissue/Spinal Cord

_____division carries signals to the smooth muscle in the large intestine.
Visceral motor
The_____division tends to prepare the body for action.
_____are examples of effectors of the nervous system.
About 90% of the neurons in the nervous system are_____neurons.
Nerve fibers refers to
an axon.
Most metabolic and regulatory functions in a neuron happen at the...
_____are the primary site for receiving signals from other neurons.
______form myelin in the spinal cord.
In order for a peripheral nerve fiber to regenerate it must have....
the soma and at least some neurilemma intact.
Most of the myelin sheath is composed of....
Opening of sodium gates typically leads to...
depolarization of the plasma membrane.
Which of the following will cause the plasma membrane to hyperpolarize when at its RMP?
Inflow of chloride
Local potentials are_____, meaning they vary in magnitude according to the strength of teh stimulus.
An inhibitory local potential...
hyperpolarizes the plasma membrane.
Local potentials are_____, whereas action potentials are...
nondecremental; decremental
When the voltage of a plasma membranes shifts from +35mV towards )mV, we say the cell is...
All of the following are typical characteristics of neurotransmitters except...
they are released into the bloodstream before reaching the postsynaptic cell.
A cholinergic synapse employ_____as its neurotransmitter.
_____binds to ligand-regulated gates, and is the most common inhibitory neurotransmitter in the brain.
y-aminobutyric acid (GABA)
Which of these happens first in teh cholinergic synaptic transmission?
Synaptic vesicles release acetylcholine.
Some antidepressant drugs act by inhibiting monoamine oxidase (MAO), which is an enzyme...
that breaks down monoamines.
All of these contribute to the cessation of the signal in a synaptic transmission except....
synaptic vesicles secrete neurotransmitter by exocystosis.
The best type of neural pool for producing a prolonged output is.....
a reverberating circuit.
Even though all action potentials are the same, the brain can differentiate a variety of stimuli by source and intensity. The mechanism by which the nervous system converts these action potentials into meaningful information is called neural....
Inhibitory postsynaptic potentials (IPSPs) are associated with
hyperpolarization of the cell membrane.
The upper motor neurons that control skeletal muscles begin with a soma in...
the precentral gyrus of the cerebrum.
The signals that control your handwriting travel down the spinal cord in...
the corticospinal tracts.
Which of the following sensory functions involves neurons in the posterior root ganglia?
Epidural anesthesia is introduced in the epidural space between the_____to block pain signals during pregnancy.
Dural sheath and vertebral bones
Cerebrospinal fluid fills in the space between the....
arachnoid mater and pia mater.
Gray matter contains
neurosomas, dendrites and proximal parts of axons of neurons.
_____carry motor commands from the brain along the spinal cord.
Descending tracts
Second-order neurons synapse with third-order neurons in the....
____keep(s) nerve fibers insulated from one another.
A ganglion is a...
cluster of neurosomas in the PNS.
The ventral rami of the spinal nerves form nerve plexuses in all regions except...
the thoracic region.
Which of the following nerves originates in the lumbosacral plexus?
A mixed nerve consists of both..
afferent and efferent fibers.
The bundle of nerve roots that occupy the vertebral canal from L2 to S5 is called the....
cauda equina.
Somasensory refers to these sensory signals except the sensory signals from...
the viscera.
Which of the following best describes the order of a somatic reflex?
Somatic receptor->afferent nerve fiber->interneuron->efferent nerve fiber->skeletal muscle.
A muscle spindle contains mostly..
muscle fibers.
A nurse pricks your finger to type your blood. You flinch at the pain, pulling your hand back. This is called....
flexor (withdrawal) reflex.
The quickest reflex arcs involve only two neurons, thus following____reflex arcs.
You go to the movies after a long day and you begin to nod off as soon as the movie starts. Your head starts to lower a little but this reflex causes yoru head to rise. This is called the...
stretch (myotatic) reflex.
A reflex where the sensory input and motor output are on opposite sides of the spinal cord is call a(n)______reflex arc.
The tendon reflex
prevents overcontraction of a muscle.
This reflex shows the least synaptic delay.
Tendon reflex
Tendon organs are...
Which of teh following branches of a spinal nerve have somas of solely sensory neurons?
Posterior (dorsal) root.