ch 16 special sense

Lateral rectus

Moves eye laterally, abducens nerve

Medial rectus

Moves eye medically, oculomotor nerve

Superior rectus

Elevated eye, turns it medially, oculomotor nerve

Inferior rectus

Depresses eye and turns it medially, oculomotor nerve

Superior oblique

Depresses eye and turns it laterally

Photoreceptors

Rods and cones

Rods

Dim the light, black/white vision, peripheral vision

Bipolar cells

Transmit signals from the photo receptors to the ganglion cells

Ganglion cells

Transmit information from other retinal neurons to the brain

Cones

Intense light, color vision

3 layers of eye

Fibrous tunic = tough outer layer (sclera, cornea)

Vascular tunic = middle layer (choroid, iris, ciliary bodies)

Nervous tunic = inner layer (retina)

Perilymph

Extra cellular fluid located within the inner ear

Endolymph

Fluid in the cochlear duct

Lens

Clear curved structure at the front of the eye behind pupil, focuses light rays that enter the eye through the pupil

Iris

Thin, ring shaped structure, controlling the diameter and size of the pupil

Sclera

Thin, ring shaped structure, controlling the diameter and size of the pupil

Sclera

White of the eye, strong tissue that wraps around eyeball, helps maintain your eye’s shape and protects it from injury

Choroid

Thin layer of tissue, middle layer of the wall of the eye, between sclera and the retina, filled with blood vessels that bring oxygen and nutrients to the eye

Sympathetic activation (lens)

Lens is flattened for distant vision, relaxes ciliary muscle, tightens the ciliary zonule

Parasympathetic activation

Lends bulges for close vision, contracts the ciliary muscle, loosening the ciliary zonule

Astigmatism

Blurred vision cause by a misshapen lens or cornea

Tectorial membrane

Essential extracellular matrix in the cochlear, integral to auditory processing by facilitating hair cell stimulation and sound transmission

Cochlea

snail shell in inner ear, receives sound in form of vibrations

Hair cells

Capture sound energy, also exhibit an active process whereby sound signals are amplified, tuned, scaled, outer is amplification,

Steriocilia

Inside semicircular canals

Utricle in vestibule

Upper space of the vestibule

Utricle in vestibule

Upper space of the vestibule

Saccule in vestibule

inferior part of vestibule

Utricle and saccule function

To detect the static position and the linear, horizontal and vertical movements of the head

Stereocilia

Found inside semicircular canals, sensory cells required for hearing and balance

Cranial nerves for taste buds

Facial 7, glossopharngyeal 9, vagnus 10