Nervous system and PNS Flashcards
The _________ division tends to prepare the body for action
The _________ division carries signals to smooth muscles in the intestines.
The term "nerve" or nerve fiber refers to
A bundle of axons
Which glial cell wraps segments of several axons in the Central Nervous System?
Nerve impulse conduction speed of a nerve fiber is fastest in
Large diameter myelinated axons
Local potentials form on the _______ of a neuron
What ion has the greatest effect on the resting membrane potential of a neuron
Local potentials are ___________ whereas action potentials are ____________.
During absolute refractory period no stimulus of any strength will cause another action potential
Opening ________ gates produces a _________.
Motor commands are carried by __________ from the brain along the spinal cord.
Which of the following types of receptor senses pain?
Which of the following branches of a spinal nerve has the Soma's of only sensory neurons?
Posterior (dorsal) root
An intensely painful stimulus is distinguished from a mildly painful one by
A higher frequency of action potentials initiated
Neurons move material towards the cell body in __________ transport
Edendymal cells line the inner cavities of the CNS.
In the brain, neurons are more abundant than neuroglia.
Norepinephrine is a bioamine
Which of these channels responds to changes in membrane potential?
The myelin sheath is formed by
In order for a peripheral nerve fiber to regenerate it must have
The soma and at least some neurilemma intact
Most local potentials happen at the
Opening of sodium gates typically leads to
Depolarization of the plasma membrane
Local potentials are _________, meaning they vary in magnitude according to the strength of the stimulus.
When the voltage of a plasma membrane shifts from +35mV towards 0mV, we say the cell is
During the absolute refractory period
No stimulus of any strength will trigger a new action potential
A cholinergic synapse employs _________ as it's neurotransmitter
The type of circuit in a neruonal pool which oscillates rhythmically in tasks like walking is termed a
A ganglion is a swelling along a nerve containing cell bodies of peripheral neurons.
The tough fibrous sheath which encloses all the fascicles to form the nerve
A disorder of the Central Nervous System would involve
Brain and spinal cord
The neuronal voltage considered to be "threshold" before graded potentials can cause an action potential is
Which of the following are effectors?
What is another name for the autonomic nervous system?
Visceral motor division
Nerves are _______ of the nervous system
Some _________ neurons are specialized to detect stimuli, whereas _________ neurons send signals to the effectors of the nervous system.
About 90% of the neurons in the nervous system are _________ neurons
What is the most common type of neuron?
Most metabolic and regulatory functions in a neuron happen where?
Which glial cell is found wrapped around nerve fibers in the PNS?
In which part of a neuron is the postsynaptic membrane usually found?
What is the primary site on a neuron for receiving signals from other neurons?
Which cells form myelin in the spinal cord?
A myelin sheath is composed primarily of
In a neuron, the 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 it's RMP
An inflow of chloride
While a neuron membrane is depolarizing it's
Sodium gates are fully open
A neuron receives a stimulus. Which of the following events happens next?
A local potential develops
In an action potential, which event directly follows repolarization?
Hyperpolarization of the membrane
What occurs during hyperpolarization of a neuron membrane!
Potassium ions are leaving the cell
A traveling wave of excitation is known as a
What would be the best explanation for why myelinated fibers conduct signals faster than unmyelinated fibers?
Diffusion of ions along the axoplasm is faster.
A cholinergic synapse uses ________ as it's neurotransmitter
What is the most common inhibitory neurotransmitter in the brain?
Y-aminobutyric acid (GABA)
Which of these happens first in a cholinergic synapse transmission?
The synaptic vesicles releases acetylcholine
Which happens first in an adrenergic synaptic transmission?
G protein dissociates from the NE receptor.
Some antidepressant drugs act by inhibiting monoamine oxidase (MAO). What is the function of this enzyme?
It breaks down monoamines
Which neurotransmitter excited skeletal muscles and inhibits cardiac muscles?
Inhibitory postsynaptic potentials (IPSPs) are associated with which of the following?
Hyperpolarization of the cell membrane
Which is an example of an EPSP in a typical neuron?
A voltage change from -70mV to -69.5mV
A neuron can receive thousands of EPSPs from different neurons, and responds by triggering or not triggering an action potential. This addition and response to the net effect of postsynaptic potentials is called
What is the opposite of presynaptic inhibition?
What type of neural circuit is best for producing a prolonged output?
A reverberating circuit
Where does saltatory conduction occur?
From node to node in myelinated fibers