unit 5 the somatic nervous system

Structural sensory receptors

free nerve ending

encapsulated nerve ending

specialized receptor cell

what is the chemoreceptor functional type?

chemical signals

osmoreceptor

send solute concentrations

nociceptor

chemicals from tissue damage(pain)

Mechanoreceptor

physical stimuli, touch

Thermoreceptor

register temperature

where do our taste buds come from and contains receptors?

papillae

Smell sensory

info from nose goes directly to brain

Anosmia

loss of olfactory nerve and smell

Audition/Hearing external

Auricle: large fleshy structure on lateral aspect of head; directs sound waves towards auditory canal, which enters skull at auditory meatus

Tympanic membrane: ear drum; end of auditory canal and external ear

Middle ear parts

three ossicles: malleus, incus, and stapes

Inner ear

Eustachian tube connects to pharynx to equilibrate air pressure

houses the cochlea (hearing) and the vestibule (balance)

Three cranial nerves for vision

abduscens nerve- lateral rectus

trochlear nerve- superior oblique

oculomotor nerve- remaining nerve

Choroid

vascularized connective tissue for blood supply

Ciliary body

muscle that adjusts the lens, attached with zonule fibers

Iris

colored part of the eye; smooth muscle that controls pupil

pupil

hole at the center of iris that allows light to enter

aqueous humor

watery fluid between cornea and lens

vitreous humor

viscous fluid posterior to the lens to back of eye

retina

contains specialized cells, rods and cones, which release neurotransmitters to bipolar cells when stimulated.

Fovea of vision

exact center of retina, not occluded by vessels or nerves, and so area of highest visual acuity; peripheral to the fovea, acuity drops significantly.

Rods

contain rhodopsin that changes in light/dark

cones

contain opsins for red, green and blue

Retinal

undergoes a change in shape from resting(cis) shape to activated trans shape, activation phototransduction cascade

Phineas Gage

lost his ability to function with others because he damaged his prefrontal cortex, plasticity-retrain retooled other parts of the brain