special senses: summary

Question 1

GUSTATION

Answer 1

involves distinguishing five tastes: bitter, sour, salty, sweet and umami.

Question 2

TASTE BUDS

Answer 2

Receptors for taste in them. Each consists of supporting cells, basal cells, and gustatory receptor cells w/ a gustatory hair projecting from cell through taste pore to surface.
WHERE: vallate, fungiform, foliate and filiform papillae.

Question 3

TASTANTS

Answer 3

Dissolve in saliva and bind to gustatory hairs, stimulating R Cells to have R potential that releases neurotransmitter- action potentials in 1st order neurons.

Question 4

GUSTATION PROPAGATION

Answer 4

3 cranial nerves - medulla - limbic system - hypo - thalamus - cc

Question 5

ACCESSORY EYE STRUCTURES

Answer 5

Eyelids, eyelashes, eyebrows, lacrimal apparatus and extrinsic eye muscles.

Question 6

EYELIDS

Answer 6

Shade, protect and spread lubricants. Contain: orbicularis oculi, meibomian glands and conjuntiva.

Question 7

LACRIMAL APPARATUS

Answer 7

Includes: lacrimal glands, ducts, puncta, canals, sac and nasolacrimal duct. Together drain lacrimal fluid.

Question 8

EXTRINSIC EYE MUSCLES

Answer 8

Superior rectus, inf rectus, lat rectus, med rectus, sup and inf oblique.

Question 9

FIBROUS TUNIC, VASULAR TUNIC & RETINA

Answer 9

FT: post; sclera, ant cornea. Sclera venous sinus at juntion of 2 layers and drains aqueous humour.
VT: choroid supplies nutrients to retina and absorbs scattered light rays. Ciliary body (processes and muslce) shape of lens & iris (pupil) and aqueous humour.
R: Neural layer; photoreceptors, bipolar cels and ganglion cells. Rods- low light Cones- colour.

Question 10

VISUAL PATHWAY

Answer 10

Refraction - fovea centralis - Photoreceptors - bipolar cells - ganglion cells (axons) - -optic disc - optic nerve - primary visual cortex

Question 11

FOVEA CENTRALIS

Answer 11

Area of highest visual acuity (central post of retina).

Question 12

LENS

Answer 12

Contains proteins called crystallins (focuses). Divides eyeball into ant (filled w/ aqueous humor) and vitreous chambers (vitreous body).

Question 13

EXTERNAL EAR

Answer 13

Collects and channels sound waves inward. 3 structures; auricle collects, external auditory canal carries waves from aur to tympanic membrane, tympanic membrane seperates EAC from middle ear.

Question 14

MIDDLE EAR

Answer 14

Conveys sound vibrations to oval window. Consists of: auditory ossicles, oval window, round window, and auditory tube (equalizes atmospheric pressure).

Question 15

INTERNAL EAR

Answer 15

Has receptors for for hearing and equilibrium. Bony labyrinth and membranous labyrinth. B LAB divided into semicircular canals and the vestibule, both contain receptors fro equilibrium &the cochlea which has receptors for hearing.

Question 16

VESTIBULE

Answer 16

Contains 2 sacs; utricle and saccule. 3 bony semicircular canals project from the vestibule and contain the semicircular ducts that com w/ the urticle. The vest and semi canals transmit impulses to the vest branch of vestibulocochlear nerve.

Question 17

COCHLEA

Answer 17

3 interior channels; scala vestibuli, scala tympani and cochlear duct. The spiral organ contains hair cells, the receptors for hearing, the basal ends of hair cells synapse w/ sensory neurons from the cochlear branch of the vestibulocochlear nerve.

Question 18

SOUND PATHWAY

Answer 18

External auditory canal - tympanic membrane - ossicles - oval window - perilymph - vestibular membrane - scala tympani - endolymph - basilar membrane - cochlea (hair bend convert mechanical vibrations to receptor potentials) - vestibulocochlear nerve - medulla - thalamus - primary auditory cortex

Question 19

STATIC EQUILIBRIUM

Answer 19

Orientation of the body to relative to the pull of gravity. The maculae of the utricle and saccule are the sense organs for this. Stimulated by tilting head fwd and bwd and linear acc/dec.

Question 20

DYNAMIC EQUILIBRIUM

Answer 20

The maintenance of body position in response to rotational movements. The cristae in the 3 semicircular ducts are the main organs in this.