The Special Senses

Question 1

Receptors for special senses located in complex sensory organs in head

Answer 1

Smell olfaction 
Taste Gustation 
Vision
Hearing
Equilibrium

Question 2

Primary senses

Answer 2

Sour
Produced by acids H+
Sweet
Elicited by many organic substances
Bitter 
Elicited by alkaloids and some nonalkaloid
Salty 
Produced by metal ions
Umami
Elicited by amino acids glutamate and aspartate

Question 3

Olfactory I

Answer 3

Superior area of nasal cavity

Olfactory receptor cells
First order bi polar neurons
Hairs respond to inhaled chemicals

Odorant binding proteínas of cells
Bind with dissolved odorant
Produced generator potential ( depolarized)
Leads to action potential if threshold

Question 4

Gustation

Answer 4

Receptor in gustatory hair
Bind with tastant dissolved in saliva
Produced receptor potential if threshold

Variable threshold depending on taste sweet or sour
Quick adaptation decrease sensitivity within minutes after continuous stimulation

Question 5

Eyelids

Answer 5

Shade protect
Spread lubricant over eyeball
Obricularis oculo closes 
Meibomian gland secrete fluid keeps eyelids from adhering to each other 
Conjunctive
Protective mucous membrane

Question 6

Eyelashes and eyebrows

Answer 6

Help protect the eyeballs from foreign objects

Perspiration and direct rays of the sun

Question 7

Lacrimal fluid

Answer 7

Tears
Dilute saline solution contain mucus antibodies and lysozyme
Blinking spreads tears toward medial commissure
Tears enter paired lacrimal canaliculi via lacrimal puncta
Then drain into lacrimal sacs and nasolacrimal duct

Question 8

Conjunctiva

Answer 8

Palpebral 
Lines eyelid
Bulbar
Covers white
Conjunctival sac
Between palpebral and bulbar
Where contacts lens rest

Question 9

Ciliary body

Answer 9

Ciliary processes secrete aqueous humor
Zonular fibers
Attach lens and hold position
Ciliary muscles control shape of lens

Question 10

Retina

Answer 10

Optic disc
Site where axons from neural layer form optic nerve and exits the eyeball
No photoreceptors so blind spot

Question 11

Retina nerves

Answer 11

Central retinal artery and vein
Bundled with optic nerve
Forvea centralis
Central posterior portion of retina with highest visual acuity and color vision

Question 12

Optic disc blind spot

Answer 12

Sure where optic nerve leaves eye
Lacks photoreceptors
Quarter billion
Ross and cones

Question 13

retina Rods

Answer 13

Allow night and dim light
Black and white shades of gray
Stimulated by even low light levels
Absents from fovea centralis

Question 14

Cones

Answer 14

Produce color vision
Three types
Blue green and red cones
Stimulated by bright lights

Question 15

Anterior chamber

Answer 15

Between cornea and iris

Question 16

Posterior chamber

Answer 16

Between iris and zonular fibers and lens

Question 17

Photoreceptors of the retina

Answer 17

A) the outer segments of rods and cones are embedded in the pigmented layer of the retina
B) rhodopsin
The visual pigment in rods is embedded in the membrane that forms discs in the outer segment

Question 18

Image formation

Answer 18

Refraction of light rays
Bending of light rays at each surface of the cornea and the convex lens
Focuses an inverted image in the forvea centralis of the retina

Question 19

Image formation accommodation

Answer 19

Increase in curvature of lens for near vision

Question 20

Image formation refraction abnormalities

Answer 20

Myopia nearsightedness
Hyperopia farsightedness
Astigmatism
Partial distorsión of image

Question 21

Myopia

Answer 21

Concave lenses that diverge the light before it entered eye or laser

Question 22

Hyperopia far

Answer 22

Convex corrective lenses to converge light more strongly for close vision

Question 23

Astigmatism

Answer 23

Unequal curvature in cornea

Special cylindrically ground lenses or laser procedures

Question 24

Pupil central opening

Answer 24

Close vision and bright left
Circular muscles contract pupils constrict
Distant vision and dim light
Dilator pupillae (radial muscles) contact pupils dilate sympathetic fibers
Changes in emotional state
Pupils dilate when subject matter is appealing or requires problem solving

Question 25

Photo Receptors responding to light

Answer 25

Bipolar cells
Ganglion cells
Optic nerve
Occipital cortex

Question 26

Processing of visual input

Answer 26

Single bi polar cell synapse with many rods increases light sensitivity but blurs image
Single bipolar cell synapsing with single cone has higher visual acuity

Question 27

Brain pathway

Answer 27

Ganglion cell axons in optic nerve pass through optic chism
Optic Tract carries input from both eyes to thalamus
Optic radiation axons project to primary visual area of occipital lobes in cerebral cortex

Question 28

Light and dark adaptation

Answer 28

Photoreceptors adjust to level of light
Light decreased sensitivity as increased amounts of photopigments are bleached. But cones regenerate quickly
Dark
Increased sensitivity as photopigments are regenerated mainly rodes active at lowest level

Question 29

Night blindness

Answer 29

Nyctalopia
Rod degeneration
Commonly caused by vitamin a deficiency
Caused by retinitis pigmentosa

Question 30

Color blindness

Answer 30

Inability to distinguish between red and green.

Affects more makes sex linked genetic

Question 31

Vitamin a

Answer 31

Helps protect surface of cornea

Beta carotene is converted to vitamin a