FINAL EXAM: Unit 2 Flashcards
afferent / sensory neurons
take into TO the CNS
efferent / motor neurons
take info FROM the CNS
what do Schwann cells do?
myelination of PNS
what do oligodendrocytes do?
myelination of CNS
what do satellite cells do?
protective layer around cell bodies
what do astrocytes do?
form BBB, NT uptake
what opens mechanically-gated channels?
pressure, stretch
what opens chemically-gated channels?
ligand & receptor
what opens voltage-gated channels?
cell membrane potential (depo, hyper)
which type of potential, graded or action, is excitatory and inhibitory?
graded potential
which type of potential, graded or action, contains only voltage-gated channels for K+ and Na+?
action potential
what happens during the depolarization stage of an action potential?
Na+ entry
-IG open
-AG open
what happens during the repolarization stage of an action potential?
K+ exits
-IG close
-AG open
what is an absolute refractory period?
no stimulus can trigger AP
what is a relative refractory period?
larger than normal stimulus can trigger
how does hyperkalemia impact action potentials?
RMP increases
-a smaller stimulus can trigger AP
how does hypokalemia impact action potentials?
RMP decreases
-need a larger stimulus to trigger AP
what receptors does ACh use? whats the difference b/w them?
nicotinic: ionotropic (receptor/ion), Na+ entry, excitatory
muscarinic: metabotropic (GPCR)
what type of receptor do amines use?
NE, E, dopamine
-metabotropic (alpha, beta)
what type of receptor do amino acids use? describe the effects of each major type of AA
ionotropic
-glutamate: excitatory, Na+ entry
-GABA, glycine: inhibitory, Cl- entry
what type of receptor do purines use?
adenosine, ATP, cAMP
-metabotropic
what type of receptor do gases use?
NO RECEPTOR
what type of receptor do lipids use?
eicosanoids
-metabotropic
what is the pathway of exocytosis to release a NT?
- AP -> depolarization
- Ca2+ entry
- exocytosis of vesicle
- NT release
- goes to postsynaptic receptor
what are three ways NT activity is terminated?
diffuse out of synapse
inactivated by enzymes
uptake by neighbor cells
what is an EPSP?
depolarization
-open Na+ or Ca2+ channels
-close K+ channels
what is an IPSP?
hyperpolarization
-open K+ or Cl- channels
what is the difference b/w divergence and convergence?
divergence: axon synapses with multiple targets
convergence: multiple axons synapse w/ one target
what is the difference b/w spatial and temporal summation?
spatial: several axons fire simultaneously
temporal: one axon fires multiple times close together
what happens when there is postsynaptic inhibition?
summed potential is below threshold -> no AP
what happens when there is presynaptic inhibition?
decreased NT release
-global: all of the branches
-selective: only at one branch of the axon
what does long term potentiation do to synpases?
enhances synapse effect (speed, release)
what is the pathway of LTP for glutamate?
- glutamate release
- releases AMPA & NMDA
- AMPA releases Na+
- depolarization of NMDA ejects the Mg+ ion to release Ca2+
- paracrine is released
- increases glutamate release
what is long term depression?
changes receptor itself or the amount of receptors to decrease synapse effect
what is the difference b/w white and gray matter?
gray: unmyelinated
white: myelinated
what are the four parts of the brainstem?
midbrain
pons
medulla oblongata
reticular formation
what does the midbrain do?
pupil reflex, auditory & visual reflex
what does the pons do?
relay center b/w cerebellum & cerebrum, breathing
what does the medulla oblongata do?
spinal tracts, BP, breathing, swallowing, vomitting
what does the reticular formation do?
arousal, consciousness
what does the cerebellum do?
body coordination
what are the four parts of the diencephalon?
thalamus
pineal gland
hypothalamus
pituitary gland
what does the thalamus do?
relay center
what does the pineal gland do?
melatonin secretion
what does the hypothalamus do?
homeostasis, thirst, hunger
what does the pituitary gland do?
hormone secretion
what are the four lobes in the cerebrum? what does each of the do?
temporal: audio, smell
frontal: motor, decisions, taste
parietal: touch, homeostasis
occipital: vision
what are the three parts of the cerebrum?
cerebral cortex
basal ganglia
limbic system
what does the cerebral cortex do?
senses, voluntary movement
what does the basal ganglia do?
inhibit skeletal muscle, DA secretion, gray matter
what does the limbic system do?
emotion, bx, memory, learning
-amygdala, hippocampus
what is CN1?
olfactory
-smell
what is CN2?
optic
-vision
what is CN3?
oculomotor
-pupil reflex
-ciliary muscle
what CN4?
trochlear
-down eye movement
what is CN5?
trigeminal
-chewing
what is CN6?
abducens
-outward eye movement
what is CN7?
facial
-taste, face sensations
what is CN8?
vestibulochoclear
-hearing, equilibrium
what is CN9?
glossopharyngeal
-swallowing
what is CN10?
vagus
-parasympathetic NS, GI tract
what is CN11?
spinal accessory
-shoulders
what is CN12?
hypoglossal
-tongue
what part of the brain controls sleep-awake cycles?
suprachiasmatic nucleus -> hypothalamus
what type of waves are there when you are awake, non-REM, REM?
awake & REM: alpha waves
non-REM: delta waves
what is the difference b/w associative and non-associative learning?
associative: 2 stimuli associated together, Pavlovian
non-associative: change bx after repeated exposure, habituation & sensitization
what is the difference b/w habituation & sensitization?
habituation: decreases response to annoying stimulus
-repeating loud noise
sensitization: increase response to bad stimulus
-puking whiskey
what is the difference b/w short term, working, and long-term memory?
short: gone w/in a day
working: used for decisions (crossing the street)
long-term
-reflexive/implicit: muscle memory
-declarative/explicit: facts, figures
what is the pathway of language in the brain?
- sensory info (vision, audio)
- cerebral cortex (left side)
- Wernicke’s Area (understand info)
- Broca’s Area (integrate info)
- motor output (frontal lobe)
what is the difference b/w the dorsal and ventral root in the spinal cord?
dorsal: afferent signals
ventral: efferent signals
what types of senses do receptive fields activate?
somatic senses
vision
how does sensitivity and convergence change with a larger receptive field?
less sensitive
more convergence
what is 1-point discrimination?
overlapping fields
-more convergence
-perceived as a single point
what is 2-point discrimination?
small fields, less convergence
-more points = more sensitive
what does modality refer to?
specific neurons activated
what does location refer to?
which receptive fields are activated
what does intensity refer to?
number of receptors activated
-frequency of APs
what does duration refer to?
longer stimulus leads to longer APs
what is the difference b/w tonic and phasic receptors?
tonic: slow adapting, rapid fire -> maintain firing
phasic: fast adapting, rapid fire -> stop firing if stim. is constant
what is the pathway for fine touch, proprioception, and vibration?
skin -> medulla -> thalamus -> somatosensory cortex
what is the pathway for nociception, temp, and coarse touch?
skin -> cross over in SC -> thalamus -> somatosensory cortex
what do free nerve endings respond to?
temp, pain
what do pacianian corpuscles respond to?
vibration (phasic)
what do meissner corpuscles respond to?
flutter (phasic)
what do ruffini corpuscles respond to?
stretch (tonic)
what do merkel receptors respond to?
texture, pressure (tonic)
what do nociceptors detect?
pain, itch
what are the two fibers in nociceptors? what type of pain do they correlate to?
A-delta: fast pain, local
C: slow pain, diffuse
what is the nociceptor pathway?
- protective spinal reflex -> withdrawal reflex
- ascending pathway -> cerebral cortex -> feel pain
- dorsal horn of spinal cord
what do chemoreceptors detect?
smell and taste
what is the smell pathway?
- olfactory neuron binds to odor (1)
- activate G(olf) -> GPCR
- increase cAMP
- depolarization
- CN1 (2)
- olfactory bulb
- olfactory tract
- olfactory cortex
- cerebral cortex & limbic system
what are the five tastes and what do they respond to? what type are they?
sweet: glucose, sugar, TYPE 2 (meta)
sour: H+, TYPE 3 (iono)
salty: Na+
bitter: alkalines, TYPE 2 (meta)
umami: glutamate, TYPE 2 (meta)
what is the gustation pathway?
- taste binds TRC
- GPCR
- TYPE2: release ATP, TYPE3: release serotonin
- CN7, 9, 10 (1)
- medulla (2)
- thalamus (3)
- gustatory cortex
what is pitch?
frequency
-low pitch: hair cells bend toward helicotrema, SLOW vibration
-high pitch: hair cells bend toward oval window, FAST vibration
what is loudness?
amplitude
-more hair cells activated = louder
what is the hearing pathway?
- ear canal
- tympanic MB
- auditory ossicles
- oval window
- cochlea
- perilymph (vestibular duct)
- endolymph (cochlear duct)
- basilar MB shifts (toward tallest = depo, toward shortest = hyper)
- hair cells move in tectorial MB
- NT release
- CN8
- medulla
- midbrain
- thalamus
- auditory cortex
what happens when hair cells are bent toward the kinocilium?
depolarization
-bent away = hyperpolarization
what is horizontal rotation? posterior? superior?
horizontal: spin
posterior: side to side
superior: forward & backward
what does the semicircular canals detect?
rotational movement
what does the otolith organ detect?
linear movement
what does the saccule detect? utricle?
saccule: vertical drop
utricle: forward & backward acceleration
what is the equilibrium pathway?
- head movement
- endolymph movement
- inertia (fluid moves opposite direction first)
- cupula shifts
- hair cells bend
- depolarization
- NT release
- CN8 (1)
- medulla (2)
- reticular formation (3)
- thalamus
- motor cortex
what do circular muscles of the eye control?
pupil constriction
-parasymp NS
what do radial muscles of the eye control?
pupil dilation
-symp NS
what do cilliary muscles of the eye control?
lens accomodation
-FLAT: suspensory lig. tight, cill. muscles relax
-ROUND: suspensory lig. relax, cill. muscles tight
where are photoreceptors located at? what are the two types of photoreceptors?
in the retina
-rods: low light, B&W
-cones: high light, color
what is the process of a photoreceptor cell?
photoreceptor -> bipolar cell -> ganglion cell
what type of light causes rhodopsin to be active and lead to a hyperpolarization with low glutamate release?
high light
what is the pathway of vision?
- light
- cornea
- pupil
- lens
- macula (retina)
- photoreceptor
- CN2 (1)
- optic chiasm (2)
- thalamus
- visual cortex
