{"id":154,"date":"2015-08-08T15:46:35","date_gmt":"2015-08-08T15:46:35","guid":{"rendered":"http:\/\/sites.msudenver.edu\/haysc\/?page_id=154"},"modified":"2025-09-29T17:21:27","modified_gmt":"2025-09-29T17:21:27","slug":"outline-4-bio-2310-special-senses","status":"publish","type":"page","link":"https:\/\/sites.msudenver.edu\/haysc\/biology-courses\/human-anatomy-physiology-homepage-bio-2310\/outline-4-bio-2310-special-senses\/","title":{"rendered":"Outline-4, BIO 2310, Special Senses"},"content":{"rendered":"

III.\u00a0SPECIAL SENSES<\/strong><\/h3>\n

OLFACTION<\/strong><\/p>\n

A. Receptors in upper nasal mucosa<\/p>\n

B. Olfactory nerve<\/p>\n

C. Olfactory bulb<\/p>\n

D. Olfactory tract<\/p>\n

E. Temporal lobe of cerebral cortex<\/p>\n

GUSTATION<\/strong><\/p>\n

A. Taste buds – receptors<\/p>\n

1. Taste pore<\/p>\n

2. Dissolved in liquid<\/p>\n

B. Sensory nerve fibers<\/p>\n

1. Facial [ant. 2\/3]\n

2. Glossopharyngeal [post.1\/3]\n

3. Vagus [pharynx]\n

C. Brain stem<\/p>\n

D. Thalamus<\/p>\n

E. Parietal lobe of cerebral cortex<\/p>\n

 <\/p>\n

VISION<\/strong><\/p>\n

A. Anatomy of eye<\/p>\n

1. Fibrous tunic– Outer layer<\/em><\/p>\n

a. Sclera<\/strong><\/p>\n

b. Cornea<\/strong><\/p>\n

2. Vascular tunic = uvea– Middle layer<\/em><\/p>\n

a. Choroid<\/strong><\/p>\n

b. Ciliary body<\/strong><\/p>\n

c. Iris; Pupil<\/strong><\/p>\n

3. Nervous tunic =Retina<\/strong>–\u00a0Inner layer<\/em><\/p>\n

a. Outer pigmented layer<\/p>\n

Pigment decreases reflection of light<\/em><\/p>\n

b. Nervous layer<\/p>\n

c. Photoreceptors [rods & cones]\n

1. Macula<\/p>\n

Yellow region on retina<\/em><\/p>\n

2. Fovea centralis<\/strong><\/p>\n

Depression in macula<\/em><\/p>\n

d. Optic nerve<\/strong><\/p>\n

1. Optic disc<\/p>\n

Where optic nerve leaves eye<\/em><\/p>\n

2. Blind spot<\/p>\n

No rods and cones here<\/em><\/p>\n

4. Misc.<\/p>\n

a. Lens<\/strong><\/p>\n

Changes shape to allow focusing<\/em><\/p>\n

b. Anterior cavity<\/strong>– aqueous humor<\/p>\n

c. Posterior cavity<\/strong>– vitreous humor<\/p>\n

5. Accessory eye structures<\/p>\n

a. Eyelids = palpebrae<\/strong><\/p>\n

1. Tarsal plate<\/p>\n

Dense connective tissue<\/em><\/p>\n

2. Meibomian glands<\/p>\n

Oil<\/em><\/p>\n

3. Palpebral fissure<\/p>\n

4. Lateral commissure<\/p>\n

5. Medial commissure<\/p>\n

6. Caruncle<\/p>\n

7. Sebaceous ciliary glands<\/p>\n

b. Conjunctiva<\/strong><\/p>\n

1. Palpebral<\/p>\n

2. Bulbar<\/p>\n

c. Lacrimal apparatus<\/strong><\/p>\n

1. Function<\/p>\n

Tears to lubricate, moisten eye, cleanse eye of foreign material<\/em><\/p>\n

2. Lacrimal gland<\/p>\n

Superior and lateral margin<\/em><\/p>\n

3. Lacrimal puncta<\/p>\n

4. Lacrimal canal<\/p>\n

5. Nasolacrimal duct<\/p>\n

B. \u00a0Vision<\/strong><\/p>\n

1. Light, Refraction<\/p>\n

Bending of light rays<\/em><\/p>\n

2. Emmetropia<\/p>\n

Normal vision, light rays come to focus on a single point behind the lens called the focal point<\/em><\/p>\n

3. Accommodation<\/p>\n

Focusing for close vision<\/em><\/p>\n

a. Pupils constrict<\/p>\n

b. Convergence of eyeballs<\/p>\n

c. Near point of vision<\/p>\n

Distance from eye to nearest point whose image can be clearly focused on the retina<\/em><\/p>\n

4. Eye movement controls<\/p>\n

a. Voluntary fixation movement – premotor\/frontal<\/p>\n

b. Involuntary fixation movement – occip. lobe<\/p>\n

5. Binocular vision<\/p>\n

Each eye views a part of the world that overlaps considerable with the view from the other eye. The disparity between eyes allows a person to judge distances and have depth perception.<\/em><\/p>\n

a. Diplopia<\/p>\n

Double vision<\/em><\/p>\n

b. Strabismus<\/p>\n

Eye movement is not coordinated.<\/em><\/p>\n

6. Photoreceptors<\/p>\n

a. Rods<\/strong><\/p>\n

1. Rhodopsin<\/p>\n

Photopigment<\/em><\/p>\n

2. 120 million<\/p>\n

Very sensitive to light, relative lack of color, peripheral in location, work well for night vision, poor detail, convergence<\/em><\/p>\n

b. Cones<\/strong><\/p>\n

1. 400 nm blue<\/p>\n

2. 500 nm green<\/p>\n

3. 600 nm red<\/p>\n

Operate in high levels of illumination, color, excellent precise detail, located mostly in center of retina, little convergence<\/em><\/p>\n

7. Neural components<\/p>\n

a. Bipolar neurons<\/p>\n

b. Ganglion neurons<\/p>\n

c. Lateral inhibition<\/p>\n

1. Horizontal cells<\/p>\n

2. Amacrine cells<\/p>\n

8. Visual acuity<\/p>\n

20\/20 Snellen eye chart<\/p>\n

9. Light\/Dark adaptation<\/p>\n

a. Photopigment concentration<\/p>\n

Even a small change in rhodopsin concentration in rods can greatly influence light sensitivity<\/em><\/p>\n

b. Pupillary light reflex<\/p>\n

1. PNS<\/p>\n

Constricts pupils<\/em><\/p>\n

2. Direct, Indirect<\/p>\n

Direct is ipsilateral, indirect is consensual or contralateral<\/em><\/p>\n

c. Neural adaptation<\/p>\n

{cones inhibit rods in brt.. lt.}<\/p>\n

10. Visual pathway<\/p>\n

a. Optic nerve<\/p>\n

b. Optic chiasma<\/p>\n

About 1\/2 of the axons cross<\/em><\/p>\n

c. Optic tracts<\/p>\n

d. Lateral geniculate body – thalamus<\/p>\n

e. Occipital lobe of cerebrum<\/p>\n

EAR<\/strong><\/p>\n

A.\u00a0<\/strong>Outer ear<\/strong><\/p>\n

1. Function<\/p>\n

Gathers and resonates sound<\/em><\/p>\n

2. Pinna<\/strong><\/p>\n

3. External auditory meatus [canal]<\/strong><\/p>\n

-ceruminous glands<\/p>\n

Wax<\/em><\/p>\n

4. Tympanic membrane<\/strong><\/p>\n

Eardrum<\/em><\/p>\n

B. Middle ear<\/strong><\/p>\n

1. Auditory = Eustachian tube<\/strong><\/p>\n

Equalizes air pressure in middle ear<\/em><\/p>\n

2. Malleus, incus, stapes<\/strong><\/p>\n

Ossicles<\/em><\/strong>\u00a0<\/em>– lateral to medial<\/em><\/p>\n

3. Oval window<\/strong><\/p>\n

Separates middle and inner ear, vibrated by stapes<\/em><\/p>\n

4. Round window<\/strong><\/p>\n

Separates middle and inner ear, can bulge back into middle ear to keep inner ear pressure stabilized<\/em><\/p>\n

C. Inner ear<\/strong><\/p>\n

1. Osseous labyrinth [perilymph]<\/strong><\/p>\n

2. Membranous labyrinth [endolymph]<\/strong><\/p>\n

3. Vestibule<\/strong><\/p>\n

a. Utricle<\/strong><\/p>\n

b. Saccule<\/strong><\/p>\n

4. Semicircular canals\/ducts<\/strong><\/p>\n

5. Cochlea<\/strong><\/p>\n

a. Vestibular membrane<\/p>\n

b. Basilar membrane<\/p>\n

c. Cochlear duct<\/strong>[endolymph]\n

d. Scala tympani [perilymph]\n

Outer cochlear tunnel<\/em><\/p>\n

e. Scala vestibuli [perilymph]\n

Inner cochlear tunnel<\/em><\/p>\n

f. Spiral organ = organ of Corti<\/strong><\/p>\n

Contains receptors for hearing, hair cells located on basilar membrane<\/em><\/p>\n

D. Hearing<\/strong><\/p>\n

1. Transmission of sound<\/p>\n

a. Tympanic reflex<\/p>\n

Muscles dampen ossicle vibrations in response to loud sounds<\/em><\/p>\n

2. High frequency [base]\n

At the base of the cochlea (near the windows) the hairs are short and thick and vibrate and higher frequencies<\/em><\/p>\n

3. Low frequency [apex]\n

At the apex of the cochlea the hairs are long and thin and vibrate at lower frequencies<\/em><\/p>\n

4. Auditory pathway<\/p>\n

Cranial nerve VIII<\/em><\/p>\n

5. Pitch determination[20-20000 cps; best 1000-4000]\n

6. Loudness determination [amp. 1-120db]\n

7. Localization of sound [time-loudness]\n

 <\/p>\n

E. Equilibrium<\/strong><\/p>\n

1. Utricle & Saccule<\/p>\n

a. Macula<\/p>\n

b. Otolith<\/p>\n

c. Linear acceleration,<\/p>\n

Linear deceleration,<\/p>\n

Head position.<\/p>\n

2. Semicircular ducts<\/p>\n

a. Crista<\/p>\n

Group of hair cells<\/em><\/p>\n

b. Cupula<\/p>\n

Gelatinous mass<\/em><\/p>\n

c Rotational acceleration\/deceleration<\/p>\n

d. Vestibular nystagmus<\/p>\n

Characteristic eye movement to allow eyes to stay fixed on object while moving<\/em><\/p>\n

3. Dynamic equilibrium<\/p>\n

Whole body equilibrium involves receptors in eyes, ears, skin, muscles, joints…<\/em><\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

III.\u00a0SPECIAL SENSES OLFACTION A. Receptors in upper nasal mucosa B. Olfactory nerve C. Olfactory bulb D. Olfactory tract E. Temporal lobe of cerebral cortex GUSTATION A. Taste buds – receptors 1. Taste pore 2. Dissolved in liquid B. Sensory nerve … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":270,"featured_media":0,"parent":42,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"class_list":["post-154","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/users\/270"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/comments?post=154"}],"version-history":[{"count":0,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/154\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/pages\/42"}],"wp:attachment":[{"href":"https:\/\/sites.msudenver.edu\/haysc\/wp-json\/wp\/v2\/media?parent=154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}