section 2

Labelled lines

info travels along particular nerve

Sensory transduction

energy conversion stimulus to receptor

Pacinian corpuscle

skin receptor; vibration and deep pressure

Meissner’s corpuscles

skin receptor; light pressure, changes in stimuli

Merkel’s discs

skin receptor; object form (edges and points)

Ruffini corpuscles

skin receptor; stretching

Receptive field

region of space that effects sensory potentials

Sensory adaptation

sustained stimulation leads to decreased response

Phasic receptors

responsive to sensory adaptation

Tonic receptors

resistant to sensory adaptation

Physical suppression

physical means to reduce stimulus intake

Central modulation

reciprocal neurons to alter peripheral pathways

Dorsal column system

peripheral somatosensory system

Primary somatosensory cortex

postcentral gyrus

Polymodal neurons

respond to multiple sensory modalities

Dermatome

section of skin innervated by spinal nerve

Nociceptors

specialized free nerve endings; pain, itch, heat, cold

SCN9A

sodium channels that act as nociceptors

TRPM3

primary channel that responds to pain/temperature; no capsaicin response

TRPV1

primary channel that responds to pain/temperature; capsaicin response

A delta fibers

fast TRPM3

C fibers

slow TRPV1

Anterolateral tract

pain and temp pathway

Anterolateral tract decussation

instant decussation; at same level

Anterolateral tract primary NT

glutamate

Substance P

peptide in spine that boosts pain signals

Cingulate cortex

primary pain center; distinguishes emotional and sensory pain

Neuropathic pain

pain that continues after healing

Gait control theory

spinal gates modulate pain

Analgesic drugs

pain relieving drugs

epidural/intrathecal injection

opiates into gait to relieve pain

Addiction

is bad

Naloxone/Narcan

opioid antagonist injection to prevent OD death

Transcutaneous electrical nerve stimulation (TENS)

stimulation around damaged site releases endorphins

Psychogenic relief

placebo, hypnosis, stress, cognition

Movement

relocation of a body part

Reflex

unconscious motor response to stimulus

Act

group of movements to form a behavior

Motor plan

series of choreographed contractions to produce an act

Electromyography

records muscle activity

Antagonist muscle

muscle contraction, related muscle relaxation

Synergists

muscles that act with each other

Motor neuron

transmits signals to muscles/glands

neuromuscular junction

where motor neurons synapse with muscle fibers

Motor neuron primary NT

acetylcholine

Final common pathway

final location of directed movement

Proprioception

sensation of the position and movement of the body

Muscle spindle

responds to muscle lengthening

Intrafusal fiber

small muscle fibers within the muscle spindle

Golgi tendon organ

responds to muscle tension

Stretch reflex

contraction in response to stretch

Pyramidal system

motor system through medullary pyramids

Extrapyramidal system

motor system outside the pyramids of the medulla

Primary motor cortex (M1)

locus of conscious motor coordination; precentral gyrus

Nonprimary motor cortex

modulate primary motor cortex; frontal lobe

Supplementary motor area

region of nonprimary motor cortex that modulates M1 via input from the basal ganglia

Premotor cortex

just anterior to M1; guides movements based on external stimuli

Plegia

paralysis

Paresis

muscular weakness

Apraxia

inhibition of complex movement

Mirror neuron

active during copied movements

Basal ganglia

modulate info from M1 and sends to thalamus

Cerebellum

fine tunes movements

Ataxia

loss of fined tuned movement

decomposition of movement

movements segmented

parkinson’s

reduction of movement; substantia nigra degeneration

huntington’s

overactive movement; basal ganglia degeneration