Sensory system (Alice Witney lecture 1)

… … is the brain’s lifelong ability to reorganize its …, … and … in response to …, … and …

neural plasticity, structure, functions, connections, learning, experience and injury

sensory … is how … … sensory input is ignored

cancellation, self generated

… receptors are specialized sensory … located throughout the skin’s … and … that detect environmental stimuli including …, …, …, …. and … (TPVTP)

cutaneous, neurons, dermis, epidermis, touch, pressure, vibrations, temperature and pain

… is the body’s ability to sense its own …, … and … in space

proprioception, movement, position and location

… is the sensory system responsible for …, …, …, … and …, (TPTPM) it involves … receptors transmitting signals via the … … to the brain’s … cortex

somatosensation, touch, pain, thermoception, proprioception, movement, peripheral, spinal cord, somatosensory

two major types of somatosensation

conscious and unconscious

two types of unconscious somatosensation

proprioception and interoception

… is the sense which allows the brain to percieve the internal state of the body, including sensation like …, …, … …, … and internal …

interosensation, hunger, thirst, heart rate, breathing and pain

… proprioception provides awareness of limb … and … allowing … actions while … proprioception regulates …, … and … movement

conscious, position, movement, intentional, unconscious, posture, balance and automatic

two types of conscious somatosensation

proprioception and exteroception

… is the perception of … stimuli originating … the body, processed via the five senses (sight, smell, hearing, touch and taste)

exteroception, environmental, outside

what are the two types of conscious proprioception

position and kinesthetic sense

… sense is the awareness of static body part … in space while … sense is the awareness of …

position, positions, kinesthetic, movement

… … receptors are specialized sensory … within skeletal muscles that detect changes in muscle … and … of …

muscle spindle, proprioceptors, length and velocity of stretching

… receptors located in joints are specifically involved in … sense and … sense

articular, position, kinesthetic

what kind of receptors are found in the skin?

tactile, thermoreceptors and pain receptors

another name for hairy skin

non glabrous

another name for hairless, smooth skin

glabrous

… skin found on palms and soles specializes in … touch using … receptors and … discs, while … skin specializes in … movement and … touch featuring … … receptors

glabrous, precise, Meissner, Merkel, non glabrous, hair, broader, hair follicle

types of tactile mechanoreceptors in skin (in context of glabrous and non glabrous skin)

1. Meissners corpuscles

2. Merkels discs

3. Ruffini endings

4. Pacinian corpuscles

which type of skin receptor is missing in glabrous skin and which is usually absent in non glabrous skin respectively?

hair follicle receptor and meissners corpuscle

label the skin receptors

1. Meissners corpuscle

2. Merkels disc

3. Ruffini ending

4. Pacinian corpuscle

two functional classes of somatosensory receptors

rapidly and slowly adapting

what sensations does each of the following detect

1. Meissner’s corpuscles

2. Merkel’s disks

3. Ruffini endings

4. Pacinian corpuscles

1. fine touch, pressure and low frequency vibrations

2. light touch

3. muscle stretch and deformations within joints

4. pressure and high frequency vibrations

… field in cutaneous receptors is the specific … of skin that, when stimulated, alters the … rate of a particular sensory neuron

receptive, area, firing

… and … have receptive fields 5-10x larger than … and …

pacinian and ruffini, meissners and merkels

… input in feet has an important role in … and …

cutaneous, balance and posture

the … … ratio is how many sensory … feed into one … at the next stage in the …

central convergence, receptors, neuron, CNS

the … … ratio tells you how much … is being pooled together

central convergence, input

if the … … ratio is low this means there is a few … connected to one central … and if the ratio is high this means there are many … connected to one central …

central convergence, receptors, neuron, receptors, neuron

is spatial precision better when the central convergence ratio is low or high?

low

if the central convergence ratio is low:

1. … receptive field

2. … spatial resolution

3. … sensitivity

1. small

2. higher

3. lower

if the central convergence ratio is high:

1. … receptive field

2. … spatial resolution

3. … sensitivity

1. large

2. lower

3. higher

is the receptive field larger or smaller when the central convergence ratio is high?

larger

is spatial resolution lower or higher when the central convergence ratio is high?

lower

are hair follicle receptors rapidly or slowly adapting?

rapidly

… are specialized … nerve endings that detect intense … stimuli (such as pressure, piercing and pinching) which threaten or cause tissue …

mechano nociceptors, sensory, mechanical, damage

do mechano nociceptors have a high or low treshold?

high

a … adapting receptor continues to fire … … and sends … to the brain throughout the entire duration of a constant …

slowly, action potentials, signals, stimulus

a … adapting receptor only fires an … … and sends … at the start and end of a …

rapidly, action potential, signals, stimulus

… are … and … conducting neurons which detect intense … stimuli and produce slow, aching pain, whereas … … are … and … conducting neurons which signal sharp and immediate pain

C fibers, unmyelinated, slow, mechanical, Aδ fibers, myelinated, fast

label

1. muscle spindle

2. golgi tendon organs

the … … … (GTO) is a … sensory receptor located at the … junction detecting changes in muscle …

golgi tendon organ, proprioceptive, musculotendinous, tension

spinal cord … are cruicial middle men neurons which integrate … input and modulate … output acting as the primary controllers of … and … coordiantion

interneurons, sensory, motor, reflexes and movement

spinal cord interneurons form complex … and … circuits that relay signals between … and … neurons and between the … and …

inhibitory, excitatory, sensory, motor, brain and muscles

only the nerve fibers from … … synapse directly with … neurons in the spinal cord

muscle spindles, motor

the … … … are two distinct clusters of neurons in the … … and are essential for relaying … touch and … signals from the … … to the …

posterior column nuclei, caudal medulla, fine, proprioception, spinal cord, thalamus

the … root carries … information into the spinal cord while the … root carries … information away from the spinal cord to the muscles

dorsal, sensory, ventral, motor

the dorsal root of a spinal nerve splits into … and … divisions upon entering the spinal cord

lateral and medial

in the dorsal root, the … division consists of … and both myelinated and unmyelinated fibers carrying … and … sensations while the … division contains … and myelinated fibers responsible for … and …

lateral, thin, pain, temperature, medial, thick, proprioception and touch

… and … horns are regions of … matter within the spinal cord that … both … and … information

dorsal, ventral, grey, organise, sensory and motor

the … acts as the brain’s central relay station filtering and transmitting nearly all … and … information to the … …

thalamus, sensory, motor, cerebral cortex

through the thalamo-cortical loop, the … has reciprocal … connections with the … …

thalamus, excitatory, cerebral cortex

… areas 1, 2 and 3 compose the primary … cortex

Brodmann, somatosensory

the … areas are the 52 distinct regions of the … … based on cytoarchitecture

Brodmann, cerebral cortex

… area 4 composes the primary … cortex

Brodmann, motor

the Merzenich monkey experiment found that if the … nerve is cut, the part of the … that used to receive input from that nerve does not stay permanently inactive

median, cortex

from Merzenich’s experiments it is though that … plasticity underlies … plasticity

synaptic, cortical

the fact that we can’t tickle ourselves is an example of sensory … of … sensation

sensory cancellation of tactile sensation

… … is a copy of a … command sent from the … cortex to … areas, informaing them of impending movement

corollary discharge, motor, motor, sensory

corollary discharge prevents … overload by suppressing reactions to self-generated … and …

sensory, sounds and movements