7.0 Sensory Receptors and the Vestibular System

What are the special senses?

- hearing and balance

- olfaction

- gustation

- visual system

Special senses have receptors _____________ placed in unique ___________

strategically; organs

Sensory receptors respond to stimuli by changing their conductance to _____ which results in a change in ___________ ___________

ions; membrane potential

Sensory transduction is

the conversion of a stimulus to a change in membrane potential

____________ and _______ receptors are usually formed by dendrites of afferent neuron

temperature and pain

Mechanoreceptors, photoreceptors, and chemoreceptors are examples of receptors formed by a cell that _____________ with an afferent neuron

synapses

What is an example of a sensory receptor?

hair cell in ear is a sensory receptor that releases neurotransmitters that bind to afferent neurons

Mechanoreceptors detect changes in ______ ________, __________, and ____________

body position, pressure, and acceleration

What is an example of a mechanoreceptor?

auditory receptor in ear

Photoreceptors detect _________ and are located in the ____

light; eye

Chemoreceptors detect specific __________ or __________ such as ____________

molecules or conditions; acidity

What is an example of a chemoreceptor?

taste buds

Thermoreceptors detect __________________

temperature

Nociceptors detect ________ _________ or _____________ chemicals

tissue damage; noxious

Activity of nociceptors leads to _________

pain

insert skin neuron diagram

Proprioception is the sense of the relative position of neighboring ________ of the ______

parts; body

Proprioceptive sense is composed of info from sensory neurons located in ___________ ____ and _________ receptors located in muscles and joint-supporting ______________

inner ear; stretch; ligaments

Stretch receptors are a type of ______________

proprioceptor

Stretch receptors are found in ____________ and ____________

muscles and tendons

In tendons, stretch receptors are called ________________ which are nerve fibers with __________ strands that connect the ____________ and _________

golgi tendon organs; collagen; muscle and tendon

Stretch receptors in the muscle detect position and movement in ________ by detecting how much and how _______ a muscle is stretched

limbs; fast

When a muscle generates force, ___________ _______ can be compressed, opening ___________________ cation channels on afferent axon. axon is _____________ and fires AP to spinal cord

sensory terminals; stretch-sensitive; depolarized

The vestibular apparatus is found in the ear and is composed of _____ semicircular canals and ____ fluid filled chambers called ________ and _________

3; 2; utricle and saccule

The vestibular apparatus perceives the _________ and ________ of the head using ____________

position and motion; mechanoreceptors

The semicircular canals are filled with fluid called ___________ which is rich in _____ and detects ___________ motion

endolymph; K+; rotational

The _________ is fluid found between the membrane and bone of the __________ canal. it is rich in ______

perilymph; semicircular; Na+

The ampulla is a region at the base of the _____________ canal with sensory _______ cells

semicircular; hair

When the head is rotated, the ____________ within the semicircular canal moves and displaces the __________ and bends sensory _______ cells which generate AP in afferent neurons

endolymph; cupula; hair

The cupula is

gelatinous membrane inside semicircular canal that covers hair cells

The utricle and saccule are oriented _____ degrees to each other

30

The utricle and saccule give info about _______ position (___/_____) and changes in rate of ________ motion of body

head; up/down; linear

The utricle and saccule contain sensory hair cells with ____________ and a membrane that contains __________

stereocilia; otoliths

The otolithic membrane is similar to the __________ and is made of _________________________ called ______________

cupula; calcium carbonate crystals; otoliths

When the head tilts or body moves non-linearly, the _________ membrane moves, bending ______ cells, causing ______________ release and AP that cause the brain to perceive ____________

otolithic; hair; neurotransmitter; movement

When the head moves, the inertia of the crystals bend the hair in opposite direction. When all hairs bend towards the tallest hair, ___________, the cell depolarizes, inducing increase in ____

kinocilium; AP

When the hair cells bend away from the kinocilium, _____________ occurs, reducing ____ frequency

hyperpolarization, AP

The afferent terminals from the axons on the semicircular canals and utricle and saccule form the _______________ which joins with the ______________ to form the _________________

vestibular nerve; cochlear nerve; vestibulocochlear nerve (8th cranial nerve)

The vestibulocochlear nerve takes info into the ____________ which then travels to the ___________, and is relayed to the _________ area in the __________

brainstem; thalamus; vestibular; cortex

What part of the vestibular system is used when head is nodding "Yes"?

utricle and saccule

What part of vestibular system is used when head is rotating "No"?

semicircular canals