CNS Part 3 Flashcards
Special senses vs somatosensory differences in receptors
Special- high density of receptors in target organ, discrete travel and bundle processing
Somatosensory- diffuse pattern, covers a large field
Same second messengers can have __ responses based on cell
Different
Sensory receptors transduce enviro changes into electronic signals. Connect to __ __ neurons which relay info via __ __ to brain and spinal cord. __ __ neuron cell bodies housed in __ __ and __ __ __
Primary afferrent
Action potentials
Primary afferrent, dorsal root, cranial nerve ganglia
Cranial nerve ganglia have a __ process that extends dismally within a __ __ to sensory receptors, and a __ __ that enters the spinal cord or brain through a __ __ or __ __
Peripheral, peripheral nerve
Central process, dorsal root or cranial nerve
Each __ __ __ has a specific cutaneous field
T4 Dermatome innervated by
DRG
T4 DRG
Exteroceptive info: interaction of __ with the __
2 types
Skin, enviro
Fine discriminatory touch and pain/temp
Fine discrim touch powered by 2
Pain and temp powered by 2
A alpha and a beta
A delta and c (fast and slow pain )
Proprioceptive info: body and limb position informing ___
Receptors in __, __, and __
Movement
Joints, muscles, tendons
Enteroceptive info: __ __ of the body. Ex __ in __ or __
Internal status
Stretch, bladder, gut
One thing all sensory receptors (thermal, chemical, pain, etc) is stimuli causes what
Changing membrane permeability to get action potential
Receptor potentials can change by 5
Mechanical, chemical, temp, electromagnetic radiation, pain
Process same for all receptor potentials when get to what level
Action potential
Sensory receptors will adapt either __ or __ to __ stimulation by a variety of mechanisms
Partially or completely, constant
Mechanosensitive afferrent fibers __ __ __ or __ __
Tactile fibers fast
Slow adaptation
Type I mechanoreceptive afferrent fibers have __ receptive field. Higher density of these fibers leads to better __ __ discrimination
Type II fibers have a ___ receptive field
Small, two point
Large
If a pin pricks finger what would type I vs type II tell you
Type I- exactly where prick is
II- something stabbing your finger but can’t tell where
Fast adapting: get message __ at first and stop __ with time
Slow adapting is ___
Loudly, firing
Opposite
What kind of fibers are:
Meisner corpuscles
Pacinian corpuscles
Fast adapting 1
Fast adapting 2
What kind of fibers are merkels disks and ruffini endings
Slow adapting 1 and slow adapting 2`
More receptors leads to a ___ image
Clearer
Receptor potential vs stimulus intensity is a ___ patterned chart because can’t sense change above ___
Curved not linear
100%
Spatial location: __ of neurons within a __ __
Population, receptive feel
Stimulus intensity: frequency of __, __ of sensory receptors involved
Action potential, number
Stimulus frequency: ___ interval
Inter stimulus
Each nerve tract ___ at a specific point in the CNS and carries a selective sensory modality. (Pain and mechanoreceptors not carried by same tract)
Terminates
Sensation is perceived when a specific stimulated __ leads to specific __ in the CNS. Ex separate dedicated cell populations in __ and __ __
Nerve, areas
Thalamus, somatosensory cortex
Alteration of the specific nerve tracts activity will only change the __ of the stimulus (___) vs changing the __ of stimulus perceived (__)
Intensity, quantitative, type, qualitative
Dorsal column medial leminiscal
- Highly __ touch
- __ sensations (__ gradation of intensity)
- __ sensations (__)
- __ contact sensation
- __ position
- __ sensations
- Localized
- Touch, fine
- Phasic, vibratory
- Skin
- Joint
- Pressure
DCML
Composed of __ __ fibers transmitting signals at __-__m/sec
__ spatial orientation
Large myelinated, 30-110, more
Anterolateral (spinothalamic) system
- __
- ___ sensations
- __ touch and ___
- __ and __
- ___ sensations
Pain Thermal Crude, pressure Tickle and itch Sexual
Spinothalamic system composed of ___ __ fibers carrying signals at __m/sec
__ spatial orientation
Smaller myelinated, 40
Less
DCML
Transmits signals __ to the __ via the __ columns in the spinal cord.
Signals synapse in __ __ nuclei
Upward, medulla, dorsal
Dorsal column
DCML
Where lower body and leg synapses
Where upper body and arm synapses
Nucleus gracilis
Nucleus cuneatus
DCML steps
- Transmits signal to ___
- Signals synapse in __ __ __
- 2nd order neuron axons then __ __ side of medulla and project to the __ via the __ __ (__, __)
- Medulla
- Dorsal column nuclei
- Cross opposite, thalamus, medial lemniscus (pons, midbrain)
Spinothalamic
- Enters the spinal cord from the __ __ __ _ and synapses in the __ __
- Cross to the __ cord
- Travel upward through __ and __ __ columns
- Tracts terminate at all levels of __ __ __ and __
- Dorsal spinal nerve roots, dorsal horns
- Contra lateral
- Anterior and lateral white
- Lower brain stem, thalamus
Which can be modulated by anesthesia more, DCML or spinothalamic
Spinothalamic
Somatosensory pathways in __ __ are where signals help us determine __ signal is __ __
Some areas have a __ field and many signals, __ space dedicated to them in ___
Post central gyrus, where, coming from
Large, larger, trunk
___ pathway allows us to have conscious awareness of body movements and local ___
These pathways carry both __ and __ info to __ and __ __
Spine cerebellar, reflexes
Cutaneous, proprioceptive, cerebellum, spinal cord
A delta (__, __ __ pain) and C fibers (__, __, __ localized) synapse in the __ matter of the __ __ of spinal cord
Fast, well localized
Slow, dull, less
Gray
Dorsal horn
A delta synapses at lamina __, __, and __
C synapses at lamina __ and __
I, V, X
I, II
Central pain pathways 3
Spinothalamic
Spinoreticular
Spinomesencephalic
Dorsal column nuclei: __ order neurons
In the __. The dorsal column __ contain these neurons.
Second
Medulla, nuclei
Diff between dorsal column neurons and primary afferrent neurons:
- receptive fields yield __ area (__ primary afferrent fibers synapse on__ dorsal column neuron)
- several types of __ __ neurons (diff modalities) __ on the __ __ __ allowing greater __ in sensory responses
- dorsal column neurons often modulated by __ __ that provide __ to the served receptive fields
- Greater, multiple
- primary afferrent, converge, second order neurons, diversity
- adjacent interneurons, inhibition
Thalamus: __ order neurons
- these project to __ __
- __ receptive field
- __ and __ circuits
- __ __ cycle and __ influence excitability
- __ and __ have high somatotopic organization
Third
- somatosensory cortex
- small
- inhibitory and excitatory
- sleep wake, anesthesia
- Vpl, vpm
Behavior (reflective and voluntary muscle movement or glandular secretion) is triggered by ___ neurons which activate __ neurons
Central, motor
Upper motor neurons __ synapse on lower motor neurons __ __ or __ __ whose axons leave CNS to affect periphery
Brain, spinal cord or anterior root
Supplementary motor areas help with what
Fine coordinated movements, complex and require more stim
Posture, vocalization, bilateral movements
Premotor area involved in __ __ and have __ neurons which help do what
Complex movement
Mirror neurons- mimic what you see someone else doing
Consulate motor areas. __ stimulus needed, imp in __
Stronger, coordination
Cerebellum: essential for __, highly __ muscle movements. And for __ of movement. Makes __ adjustments to movement. ___ __, learns from mistakes
Complex, coordinated
Sequencing, corrective
Muscle memory
Basal ganglia include __ __, __, __ __, __ __, and __ nucleus
Caudate nucleus Putamen Globus pallidus Substantia Nigra Subthalamic nucleus
Basal ganglia don’t receive input from _ _ but do receive direct input from __ __ via the __
Spinal cord
Cerebral cortex, thalamus
Basal ganglia: lesions here produce __ __ and __
Abnormal movement and posture
Motor neurons controlling somatic musculature form a column of cells in the __ __ of spinal cord
Ventral horn
Interneurons communicating between __ __, descending motor axons from brain, and primary ___ are located __/__ horn unless they supply axial muscles then __ ventral horn
Motor neurons
Affarents, intermediate/lateral
Medial
Corticospinal tract
__ cells send signals at __m/sec
Betz, 70
Upper motor neurons propagate in __ parts of brain depending on __
Different, tract
Memory storage via increased __ of synapses between neurons following previous neural activity
Habituation is what
Sensitivity
How we forget things
What is facilitation
What is declarative and skill memory
Keeping memories
Memory of time and place, interactions
Muscle memory
Short term memory
Lasts a few __ to __
Reverberating circuit- __ circuit if awareness not __ on it
Seconds, minutes
Lose, focused
Intermediate long term memory
Lasts __ to __
Habitiuation: progressive __ __ closure
Facilitation: __ released, activates receptor, activates second messenger __, activates a __ that Inactivates a __ channel in min to weeks, prolonged __ __ with large amounts of __ released
Minutes to weeks Calcium channel Serotonin, Camp, kinase, k Action potential, calcium
Long term memory
__ strengthening
1. Increase in vesicle __ sites for secretion of __
2. Increase in number of __ __ released
3. Increase in number of __ __
4. Changes in structures of __ __ that permit transmission of __ signals
__ of memory
Synaptic Release, transmitter Transmitter vesicles Presynaptic Dendritic spines, stronger Consolidation
