sensory systems

somatosensory system

tactile

thermoreception

proprioception

nociception

tactile

touch, pressure, texture, vibration

thermoreception

temperature

proprioception

body position and movement

nociception

harmful stimuli, injury

sensitivity

ability to detect a stimulus

resolution

ability to distinguish separate stimuli

receptive field

area within which stimulus can be detected

somatosensory system: what kind of receptors?

unipolar sensory neurons

somatosensory systems: dendrites

encapsulated

• unencapsulated: free nerve endings

somatosensory tactile system

merkel disks

meissner corpuscles

lamellar (pacinian) corpuscles

merkel disks

high resolution; shape, size, texture

meissner corpuscles

movement; gripping—detect slippage

lamellar (pacinian) corpuscles

deep pressure and vibration; tool use

structures involved in proprioception

muscle spindle

tendon organs

joint kinesthetic receptors

muscle spindle

detect stretch of muscle

tendon organs

detect force generated by muscles

joint kinesthetic receptors

detect movements at joint; various receptors

systems for chemical senses

olfactory system

gustatory system

olfactory system

smell; airborne (or waterborne) chemicals

olfactory epithelium with receptors in nasal cavity

olfactory system receptors

receptors are modified bipolar cells

gustatory system

taste

taste buds

located in papillae

chemoreceptor cells

have different types of taste receptors: respond to different stimuli