The portions of a neuron that extend off of the roughly spherical cell body are usually collectively called
projections
Neurotransmitter is stored and released from
axon terminals and axon varicosities.
The afferent and efferent axons together form
peripheral nervous system
Exocrine glands, smooth muscles, and cardiac muscles are controlled by the
autonomic nervous system
Autonomic motor neurons are subdivided into the
sympathetic and parasympathetic divisions
The enteric nervous system is a network of neurons that function in controlling
digestion
nervous system is composed of which two types of cells
neurons and glial
The multiple thin, branched structures on a neuron whose main functions is to receive incoming signals are
dendrites
The axon is connected to the cell body by the
axon hillock
The term axonal transport refers to
transport of proteins and organelles down the axon
these glial cells act as scavengers
microglial
Which ion is higher in concentration inside the cell compared to outside?
potassium
What ion is responsible for rising phase of action potential?
sodium
The rising phase of the action potential is due to
Na+ flow into the cell
The falling phase of the action potential is due primarily
K+ out of the cell
The point during an action potential when the inside of the cell has become more positive than the outside is called
overshoot
The absolute refractory period of an action potential
ensures one way travel down an axon allows a neuron to ignore a second signal sent that closely followed first, and prevents summation of action potential.
The all-or-none principle states that
all stimuli great enough to bring the membrane to threshold will produce action potentials of identical magnitude.
In the membrane of a resting nerve cell, when chemically gated Cl¬- channels open the cell becomes
depolarized
Action potentials are primarily associated with the membranes of
axons only
Graded potentials may
initiate an action potential, depolarize the membrane to the threshold voltage, hyperpolarize the membrane, be called EPSPs or IPSPs.
Some neurotoxins work essentially the same way as some local anesthetics, which is to
bind to Na+ channels and inactivate them and prevent depolarization by blocking Na+ entry into the cell.
A chemical synapse ALWAYS includes
presynaptic cell, synaptic cleft, and postsynaptic cell.
Which type of synapse is most prevalent in the nervous system
electrical
Which is the most common inhibitory neurotransmitter of the CNS?
GABA and glycine
The inhibitory neurotransmitters of the CNS, GABA and glycine, act by opening
only Cl- channels.
Excitatory neurotransmitters of the CNS usually act by opening
Na+ channels
Once the action potential reaches the axon terminal, what happens next?
release of the neurotransmitter into the synaptic cleft
Calcium is important in the synapse because it
signals exoctytosis
Spatial summation refers to
multiple graded potentials arriving at one location simultaneously.
A damaged neuron has a better chance of survival and repair if the _______ is not damaged
cell body
graded or action potential
May be hyperpolarizing
graded
graded or action potential
originates at the trigger zone
action
graded or action potential
originates on dendrites and cell bodies
graded
graded or action potential
can involve ion channels regulated by chemicals
graded
graded or action potential
requires a minimum stimulus to occur
action
graded or action potential
size increases if stimulus strength increases
graded
graded or action potential
result from influx of sodium
both
The two types of electrical signals in neurons are
graded and action
T/F
The minimum amount of stimulus required to depolarize an excitable membrane and generate an action potential is known as the threshold
true
the two factors that influence the membrane potential.
The concentration gradients of ions across the membrane. The membrane permeability to those ions.
internal clock of mammals appears to be located in the
pituitary gland
Substances that have been isolated form the blood and have been shown to induce sleep linked to the
immune system
Which brain area is considered to be a key integrating center for homeostasis
hypothalamus
hormone that is released to enhance the fight-or-flight reaction
epinephrine
brain area acknowledged as the center for emotions
amyglada
important structure in both learning and memory is the
hippocampus
inability to remember newly acquired information is called
anterograde amnesia.
point during action potential when the inside if the cell becomes more positive than outside:
overshoot
Action potentials are associated with membranes of:
axons only
Portions of a neuron that extend off rough cell body are called
processes
Nervous system is composed of 2 types
neurons and glial
which part of the neuoron receive incoming signal
dendrites