Reflexes & Sensory Processing

sensory processing

initiated at skin sensation (pressure, temperature), which activates sensory neuron

• impulse from activation enters spinal cord in afferent neuron

• takes info from PNS & conveys it to CNS

• transduce sensory input to motor response

sensory receptors

nerve endings that transduce energy from one form to another

• info conveyed to CNS for processing

• eg. hair cells: acoustic energy to electrochemical energy

motor control activation

efferent process of muscle contraction is voluntary or involuntary

• reflexes: simple response to environmental/internal stimuli

• reflexes organized into central program generators

reflexes

hard-wired responses responsible for

• automated, involuntary responses to stimuli

• present in early postnatal period

agonists

muscle contraction

antagonists

relaxed or graded (controlled, skilled) inhibition

spinal reflex arc

most basic of reflexive systems in body

• receptor organ

• sensory neuron that conveys information

• interneuron

• motor neuron

muscle spindle

sensory receptor in muscle fiber sensing muscle length

• controls muscle tone

• prevents injury from overstretching

• provide sensory feedback to passive stretching & maintain given muscle posture

Golgi tendon organs

sensors within tendons that sense tension

• monitors tension of muscle contraction

somatosensory receptors

body sensations (touch, thermal, etc)

special sensors

vision, taste, hearing, olfaction

exteroceptors

sensation of stimuli from outside the body (pressure from contact)

• mechanoreceptors, thermoreceptors, chemoreceptors

interoceptors

sensation of internal body function (eg. sensation of CO2 in blood)

mechanoreceptors

touch, pressure, kinesthesia, stretching

thermoreceptors

cold & heat

chemoreceptors

presence of chemical stimulis, but only taste & smell