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DAT Bootcamp - Nervous System

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a _____ is the basic functional unit of the nervous system
neuron
what are the 3 main parts of neuron?
cell body (soma); dendrites; axon
what is the name for the cell body of a neuron, and what organelle does it contain?
soma; nucleus
_____ are processes that receive signals from previous neurons
dendrites
_____ are long processes that transduce signals to the next neuron
axons
graded potential summation occurs at the _____, which connects the soma to the axon
axon hillock
what will happen if a summation is more positive than the threshold potential?
an action potential will fire
_____ is a fatty insulation of the axon, which helps for faster axon conduction
myelin sheath
how is myelin sheath formed in the central nervous system?
oligodendrocytes
how is myelin sheath formed in the peripheral nervous system?
schwann cells
_____ are gaps between myelin sheath of the axon
nodes of Ranvier
_____ occurs when action potentials "jump" between nodes of Ranvier
saltatory propagation
what is the benefit of saltatory propagation?
faster conduction than propagating the signal down the entire axon
what is the resting potential for a typical neuronal cell?
-70 mV
a cell's resting potential is maintained by _____
Na+/K+ ATPases
more Na+ is _____ the neuron at the resting state
outside
more K+ is _____ the neuron during the resting state
inside
the Na+/K+ ATPase (pump) exchanges _____ out of a cell for _____ into the cell, and it consumes _____
3 Na+; 2 K+; 1 ATP
the Na+/K+ pump maintains a (positive/negative) charge in the neuron
negative

(extracellular environment is more positive)
what happens when a neuron is stimulated by an excitatory potential?
depolarization

(membrane potential is made less negative)
gated Na+ channels open/close when a neuron is depolarizing
open
Na+ flows in/out of a neuron during depolarization?
in
what is the threshold potential of a neuron?
minimum potential for an action potential

(typically -55 mV)
after a neuron reaches threshold, it will experience an action potential that is always the same size - what is the typical charge of an action potential?
+30 mV
what happens at +30 mV (peak action potential)?
repolarization

(membrane potential becomes more negative)
Na+ channels (open/close), while K+ channels (open/close) to initiate repolarization
close; open
K+ flows (in/out) of the neuron during repolarization
out
eventually, a neuronal cell will _____, meaning the membrane potential falls below the normal resting potential of -70 mV
hyper-polarize
what is the typical charge of a hyperpolarized neuronal cell?
-90 mV
a neuron's refractory period occurs during _____ & _____, and it extends into _____
actionpotential; repolarization; hyperpolarization
what are the 2 stages of the refractory period?
absolute; relative
a 2nd stimulus cannot generate another action potential during the _____ of an action potential/repolarization
absolute refractory period
describe Na+ and K+ channels during the absolute refractory period?
gated Na+ channels are open until peak action potential, then they close

K+ channels open at peak action potential until the end of repolarization
a 2nd stimulus can stimulate an action potential if it is strong enough during a _____
relative refractory period
the relative refractory period occurs after the _____
absolute refractory period

(or onset of hyperpolarization)
describe Na+ and K+ channels during the relative refractory period:
the Na+ channels remain closed

the K+ channels remain open until the resting potential is acheived
neurons are _____ during the relative refractory period
hyperpolarized
a _____ is the space between 2 neurons
synapse (synaptic cleft)
the _____ neuron releases neurotransmitters into the synapse
presynaptic
the _____ neuron receives neurotransmitters that crossed the synapse
postsynaptic
what happens when an action potential reaches the end of the presynaptic axon?
voltage-gated Ca2+ channels open, allowing Ca2+ to flow into the neuron
what happens when voltage-gated Ca2+ channels open to allow Ca2+ influx into the presynaptic neuron?
synaptic vesicles release neurotransmitters into the synapse by exocytosis
postsynaptic graded potentials can be _____ or _____ depending on the neurotransmitter
excitatory; inhibitory
excitatory postsynaptic potentials (EPSPs) occur when the neuron _____ due to _____ that open
depolarizes; Na+ gates
Na+ flows (into/out of) the cell during an excitatory postsynaptic potential (EPSP)
into
excitatory postsynaptic potentials (EPSPs) bring the neuron _____ to the threshold
closer
inhibitory postsynaptic potentials (IPSPs) occur when the neuron _____ due to _____ & _____ channels that open
hyperpolarizes; Cl-; K+
in which directions do Cl- and K+ flow during an inhibitory postsynaptic potential (IPSP)?
Cl- = into the cell
K+ = out of the cell
inhibitory postsynaptic potentials (IPSPs) bring the neuron _____ from the threshold
further
graded potentials vary in _____ and _____ (EPSP v. IPSP)
magnitude; direction
_____ occurs when all graded potentials (EPSPs and IPSPs) are added together at the _____
summation; axon hillock
an _____ and ensuing _____ occur if the sum of EPSPs and IPSPs is higher than the threshold
action potential; refractory periods
there will not be an action potential (or refractory periods) if the sum of EPSPs and IPSPs is _____
below threshold
what are neurotransmitters?
chemical messengers used during chemical neurotransmission
_____ is an amino acid neurotransmitter, and it is the main excitatory NT of the CNS
glutamate
glutamate is the most abundant NT of the _____ nervous system
vertebrate
_____ is an amino acid neurotransmitter, and it is an inhibitory NT of the brain
gamma-aminobutyric acid (GABA)
_____ is an amino acid neurotransmitter, and it is an inhibitory NT of the spinal cord, brainstem, retina
glycine
epinephrine and norepinephrine are _____ (class of NTs)
amino acid-derived
epinephrine and norepinephrine are _____ postsynaptic NTs of the _____
excitatory; SNS
another name for epinephrine and norepinephrine is _____ and _____
adrenaline; noradrenaline
dopamine is an _____ neurotransmitter, and it is an _____ NT of the brain
amino acid-derived; excitatory
_____ is an amino acid-derived neurotransmitter that is involved with reward-motivated behavior
dopamine
_____ is an amino acid-derived neurotransmitter that is involved with mood, appetite, sleep, and learning
serotonin
serotonin is an inhibitory NT of the _____, and it _____ contraction of the GI tract in response to food intake
brain; increases
short chain amino acid neurotransmitters (neuropeptides) have diverse roles for many _____ functions - what is a common example?
brain; ex: substance P
_____ is a gaseous neurotransmitter (gasotransmitter)
nitric oxide
nitric oxide gasotransmitter causes relaxation of the smooth muscle in blood vessels (_____)
vasodilation
nitric oxide gasotransmitter is synthesized and released _____
on demand
what is the excitatory NT of a neuromuscular junction?
acetylcholine
acetylcholine is the _____ NT of the sympathetic and parasympathetic nervous systems
presynaptic
acetylcholine is the _____ NT of the parasympathetic nervous system
postsynaptic
_____ are non-neuronal cells that nourish, support, and protect neurons
glial cells
what are the 2 subcategories of glial cells?
microglia; macroglia (various types)
_____ are specialized macrophages that protect the CNS
microglia
what are the various types of macroglial cells?
schwann cells; oligodendrocytes; astrocytes; satellite cells; ependymal cells
_____ form the myelin sheath in the peripheral nervous system
schwann cells
_____ form the myelin sheath in the central nervous system
oligodendrocytes
what is the most abundant type of CNS neuroglia?

hint: it is a type of macroglial cell
astrocytes
astrocytes provide blood to _____ neurons and help form the _____
CNS; blood brain barrier
_____ are macroglia that recycle neurotransmitters and maintain ion levels
astrocytes
satellite cells ensheathe the _____ of _____ nerves
soma; peripheral
_____ are similar to astrocytes; however, they function in the peripheral nervous system
satellite cells
ependymal cells are macroglia that create the _____
cerebrospinal fluid
what are the components of the central nervous system (CNS)?
the brain and spinal cord
what are the components of the peripheral nervous system?
all the nerves that branch off the CNS
what are the 3 areas of the brain seen during embryonic development?
forebrain; midbrain; hindbrain
what does the forebrain develop into?
telencephalon and the diencephalon
the telencephalon gives rise to the _____
cerebrum
the _____ gives rise to the thalamus, hypothalamus, pineal gland, and retina
diencephalon
what does the midbrain develop into?
mesencephalon
the mesencephalon gives rise to the _____
midbrain
what does the hindbrain develop into?
metencephalon; myelencephalon
the metencephalon gives rise to the _____ & _____
pons, cerebellum
the myelencephalon gives rise to the _____
medulla oblongata
the _____ is the brain cortex, which has 2 hemispheres and is involved in higher cognitive functions
cerebrum
what are the 4 lobes of the cerebrum?
frontal; temporal; occipital; parietal
where is the cerebellum located?
under the occipital lobe of the cerebrum
what is the function of the cerebellum?
coordinate and refine movement
the reptilian brain includes the main structures found in a reptile's brain: the _____ and the _____
brainstem; cerebellum
the _____ controls much of the body's basic functions; such as, breathing, heart rate, instincts, etc.
reptilian brain
what is the relay center of the brain, and where is it located?
thalamus; between cerebrum and midbrain of the brainstem
where is the limbic system located?
superior to the brainstem, and encased by the cerebrum
what is the function of the limbic system?
emotion; memory and learning; motivation
what 3 structures does the limbic system include?
amygdala; hippocampus; thalamus; hypothalamus
the _____ lobe works with limbic system, and it is involved with higher function processes such as attention/concentration
frontal

(remember this because we might push our eyebrows together at the front of our head when we're concentrating)
the _____ lobe is involved with speech, language, and hearing
temporal

(remember this because the temporal lobes are located near the ears)
the occipital lobe is involved with _____
vision

(remember this because bumping the back of one's head could lead to a concussion --> blurry vision)
the _____ is involved with spatial/visual perception, as well as touch/pain/temperature sensation and integration
parietal lobe
the _____ is the major receptive area for touch
somatosensory cortex
the _____ is involved with the initiation of motor impulses
somatomotor cortex
what connects the 2 hemispheres of the brain?
the corpus callosum
the _____ is involved with balance & coordination, as well as fine tuning motor inputs
cerebellum
the _____ relays senses to higher functioning parts of the brain (vision; hearing)
midbrain
the _____ relays messages from the cerebellum to the cerebrum, and it is involved with sleep and dreaming
pons
the _____ maintains vital body functions (HR/BP), breathing rate, and senses toxins
medulla oblongata
the _____ is a "relay center" that directs sensory impulses to other areas of the brain
thalamus (limbic system)
the _____ produces ADH, controls the pituitary, and is involved with homeostasis
hypothalamus (limbic system)
the hippocampus (limbic system) is involved with..?
learning/long-term memories
the _____ of the limbic system is involved with emotion, motivation, and libido
amygdala
the spinal cord runs within the _____ to connect the brain to the body
vertebral column
_____ are where _____ neurons enter to innervate the spinal cord
dorsal roots; sensory (afferent)
_____ are where _____ neurons exit the spinal cord to innervate effector tissues
ventral roots; efferent
what are the membranes that protect the CNS?
meninges
what are the 3 layers of the meninges (from outer to inner)?
DAP

Dura mater; Arachnoid; Pia mater
what are the 5 main types of sensory (afferent) receptors?
mechanoreceptors; nociceptors; thermoreceptors; chemoreceptors; electromagnetic (light) receptors
_____ respond to a mechanical stimuli, such as touch and/or sound
mechanoreceptors
_____ respond to painful stimuli
nociceptors
thermoreceptors respond to _____
temperature-related stimuli
_____ respond to chemical stimuli
chemoreceptors
_____ respond to light, electricity, and magnetic stimuli
electromagnetic (light) receptors
what are the 2 subgroups of the peripheral nervous system
somatic and autonomic nervous systems
the _____ nervous system controls the voluntary movement of the body, specifically the activity of skeletal muscles
somatic
the _____ nervous system controls in involuntary muscles/movements
autonomic
what are the 2 subdivisions of the autonomic nervous system?
sympathetic nervous system and the parasympathetic nervous system
the _____ is responsible for the fight or flight response
sympathetic nervous system (SNS)
what are the main effects of the fight or flight response?
glucose release from the liver; HR increase; airway dilation; pupil dilation
the _____ is responsible for rest and digestion
parasympathetic nervous system (PNS)
the _____ is the major nerve of the PNS
vagus nerve
what are the main effects of rest & digestion?
muscles relax; decrease HR; homeostasis; increase GI activity
a _____ is a cluster of neuronal soma in the peripheral nervous system
ganglion
how do neurons synapse in a ganglion?
preganglionic axon terminals synapse with dendrites of postganglionic nerves
_____ nerves come from the CNS to synapse with postganglionic neurons (at a ganglion)
preganglionic
_____ nerves are nerves that exit a ganglion
postganglionic
what are the lengths of pre-/postganglionic nerves in the PNS?
long/short
what is the distance of PNS ganglia from effector organs?
close
what is the length of pre-/postganglionic nerves in the SNS?
short/long
what is the distance of SNS ganglia from effector organs?
far
which neurotransmitters are used for pre-/postganglionic nerves in the PNS?
acetylcholine for both pre-/postganglionic
which neurotransmitters are used for pre-/postganglionic nerves in the SNS?
pregangionic = acetylcholine

postganglionic = epinephrine or norepinephrine
SNS preganglionic neurons can directly stimulate the adrenal _____ to release _____&_____ into the blood
medulla; epinephrine & norepinephrine
which hormones help generate the fight or flight response?
epinephrine & norepinephrine
where do sound waves enter the ear?
outer ear structures
the _____ transfers sound wave vibrations from the outer to middle ear
tympanic membrane
an _____ is a very small bone, especially one of those in the middle ear
ossicle
what are the 3 ossicles of the middle ear?
(MIS)

malleus; incus; stapes
the _____ is a membrane bound opening, which separates the middle ear from the inner ear
oval window
the oval window transfers vibrations from the _____ to the _____
stapes; cochlea
the _____ is a fluid filled "snail shell" in the inner ear, and it has a basement membrane lined by hairs that transduce mechanical waves to nerve signals
cochlea
_____ is the process of taking a mechanical signal, and converting it to a nerve signal
transduction
the flexible _____ provides room for the cochlear fluid to expand against
round window
_____ are found in the inner ear, and they tell the brain about orientation & balance
semicircular canals
what is the transparent front portion of the eye, which has no blood vessels?
the cornea
what is the opening in the center of the iris?
pupil
pupil _____ influences the amount of light that can enter the eye
diameter
the _____ is a pigmented ring that changes shape to influence the diameter of the pupil
iris
what is the transparent "window" behind the pupil, which bends/focuses light onto the retina?
lens
the _____ change the curvature of the lens to affect the focal distance
ciliary muscles
what is the innermost layer of the eye, which contains photoreceptors?
retina
what are the 2 types of photoreceptors?
rods and cones
rods are used for _____ because they function at _____ levels of light
night vision; low
cones transmit _____ images because they function at _____ levels of light
color and shape; high
what is the region of the retina that is most densely packed with photoreceptors (mainly cones)?
the fovea
how do photoreceptors synapse with the optic nerve?
photoreceptors --> horizontal & amacrine & bipolar cells --> ganglion cells --> optic nerve
the _____ exits the back of the eye at the optic disk and carries visual info to the brain
optic nerve
what is the blind spot of the eye?
the optic disc

(where the optic nerve exits)
what is the white, protective, connective tissue layer of the eye?
the sclera
what is the connective vascular tissue between the sclera and the retina called?
the choroid
what is our sensation of taste called?
gustation
what are the 5 gustatory senses?
salty, sour, bitter, sweet, and umami
what part of the brain gives us perception of taste/flavor?
gustatory cortex
what is our sensation of small called?
olfaction
what cortex in the brain give us the perception of smell?
olfactory cortex
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