Final Flashcards
Graded vs action potentials?
Graded: short distance/lived, low energy
Action: long distance, high threshold
What is frequency?
More impulses, stronger the stimulus
2 things that affect conduction rate?
axon diameter (larger, faster) and degree of myleination (salatory vs. continuos)
White matter vs grey matter
white matter- myleinated
grey matter- unmyleinated
Three groups of neurons (A, B, C)
A is biggest, C smallest
speed decreases with size
A is most myleinated, C is least
What groups of neurons are in ANS?
Group B and C
What is neuronal pool?
functioning group of neurons, intergrates and forwards info
Draw AP graph, with chemicals going in and out
DRAW
What is a simple neuronal pool?
1 fiber branches into a pool
Discharge zone vs facilitated zone?
Discharge- closer to fiber, more likely to generate impulse
Facilitated- less likely to generate impulse, must be excited by external source
Excitatory postsynaptic potentials (EPSP)
excitatory, depolarization, Na and K
Inhibitory postsynaptic potentials (IPSP)
inhibitory, hyperpolarizes, Cl or K
Indirect vs direct transmission?
Indirect- neurotransmitters w/ G proteins
Direct- ion binds to channel, faster, shorter
How are post synaptic potentials different from APs?
Short distance, chemical channels (not voltage), voltage dependant, no refractory period, no + feedback, use Na, K, Cl
4 steps of GPCR binding?
1- neurotransmitter binds to GPCR
2- GDP released, GTP bind to g protein w/ adenylate cyclase
3- AC converts ATP to CAMP
4- CAMP opens channels, changes permeability
GABA (gamma-aminobutyric acid)
inhibitory neurotransmitter - opens cl- channels
- controls retina of eye
ACh (acetylcholine)
excitatory or inhibitory depending on tissue
PNS - neuromuscular junction
CNS - cortex, hippocampus, brain stem
Norepinephrine
inhibitory or excitatory
- sympathetic NS
- related to dopamine release
- basal ganglia in the CNS (Parkinson’s disease)
Serotonin
Affects mood, hunger, sleep, and arousal
- hypothalamus has to do with wakefulness
Substance P
A neurotransmitter that is involved in the transmission of pain messages to the brain.
- endorphins block the pain
Nitic Oxide (NO)
excitatory in CNS for memory formation
VGAT (vesicular GABA transporter)
hyperpolarizing / inhibitory
VGLUT1
glutamate
depolarizing / excitatory
4 kinds of circuts?
Parallel after discharge, diverging, converging, reverberating (DRAW)
Serial vs parallel processing?
Serial- 1 input, 1 path, all or nothing, produces specific reflex
Parallel- 1 input, multiple paths, 1 stimulus, multiple responses
Dermatomes
Sensory territories
What is referred pain?
pain in appendix cant be felt, does to stomach wall
Receptor potential?
type of graded potential, produced of sensory receptor
Exteroceptors vs interoceptors?
extero- stimuli outside body (senses, pain)
intero- stimuli inside body (viscera, temp, chem)
what is enkephalin?
released by interneurons, blocks pain by acting on receptors
What nerves innervate the face?
Trigeminal nerve- opthalmic, maxillary, mandibular
Noicorecpetors?
pain receptors
histamine, K, ATP, bradykinin cause depolarization to treat pain
Can cells regenerate in CNS?
No
Encapsulated vs free nerves.
Encapsulated- more specific, low sensitivity (muscle spindle)
Free- sensitive, less specific, everywhere
Propriceptors
spatial awarness (vestibular kinethetic sense)
Mechanoreceptors
touch, pressure, etc
thermoreceptors
change in temp, sense you percieve is dependant of protein being triggered
Lateral inhibition:
capacity of an excited neuron to reduce the activity of its neighbors.
Less axon terminals…
increases specificty of neuron
Senses use what kind of receptor?
complex- 2 step transduction, uses receptor cell to signal afferent neuron
what is a muscle spindle?
contained in muscle, covered in sensory nerves, sends info to spine
tendon organ capsule?
same as muscle spindle, sends sensory info to dorsal horn
What are first-order neurons?
Sensory
cell body in dorsal root or cranial ganglia
skin to spinal cord/ brain stem
What are second order neurons?
Interneurons
Soma in dorsal horn or meduallry nuclei
axons decussate
transmission to thalamus or cerebellum
What are third order neurons?
Located in thalamus- somatosensory cortex
3 steps of vision?
- bipolar cells
- ganglion cells
- optic chiasm (sensory processing)
3 steps of auditory?
- bipolar cells in spiral ganglion
- superior olivary nucleus in brain stem
- thalamus (sensory processing)
3 steps of taste?
- geniculate ganglia
- solidary nucleus (medulla)
- Thalamus- gustatory cortex
perceptual detection?
detecting stimuli that as occured
Magnitude estimation?
how much stim is acting (frequency)
spatial discrimination?
site or pattern of stim (finding key in pocket w/ lots of stuff)
feature abstraction?
indentify things based off texture and shape (keys in pocket)
Quality discrimination?
differentiate sensory (sweet vs sour)
where does the thalamus project its fibers?
somatosensory cortex, sensory association areas
How does knee jerk reaction work? (3 steps)
- stretch (muscle spindle) from patella hit
- muscle spindle fires AP, dorsal root to spinal cord grey matter
- quad motor neurons excited
Laternal vs Ventral spinothalamic
interneurons in dorsal horn
decussate before ascending vs descending
projects to thalamus
faster vs. slower
more specific (pain, temp) vs. less specific (touch, pressure)
