Chapter 17 - Special Senses

Question 1

General senses

Answer 1

somatic & visceral

Question 2

Special senses

Answer 2

smell, taste, vision, hearing & equilibrium

Question 3

Olfaction

Answer 3

sense of smell

**olfactory epithelium **consists of olfactory receptors, supporting & basal cells

Question 4

Olfaction

**(3) cells in **olfactory epithelium

Answer 4

**1) olfactory receptor - **bipolar neuron with cilia **(olfactory hairs) **that respond to odorants

**2) supporting cells- ** support & nourishment

**3) basal cells - **replace olfactory receptors

Question 5

Physiology of Olfaction

Answer 5

Odorant binds to receptor of olfactory hair→ G-protein activation→
activation of adenylate cyclase→ production of cAMP→ opening of Na+ channels→ inflow of Na+ →generator potential→ nerve impulse through olfactory nerves → bulbs →tract →primary olfactory area

Question 6

Gustation

Answer 6

taste buds -found in **papillae - **(vallate, fungiform, foliate)

**- ** made up of (3) cells: *supporting, basal cells, gustatory receptor cells *(50 per taste bud)

each gustatory receptor cell has a **gustatory hair **that projects through taste pore

Question 7

Physiology of gustation

Answer 7

5 types of taste: **sour, sweet, bitter, salty & umami

Tastant dissolves in saliva → PM of gustatory hair→ receptor potential→ nerve impulse via cranial nerves VII, IX & X→ medulla→ thalamus→ primary gustatory area of cerebral cortex.

Question 8

Lacrimal Apparatus of Eye

Answer 8

group of structures that produces & drains lacrimal fluid (tears)

Question 9

Lacrimal Apparatus

production & pathway of tears

Answer 9

Tears from the lacrimal apparatus- lacrimal glands→ excretory lacrimal ducts→ lacrimal puncta→ lacrimal canals→ nasolacrimal sac→ nasolacrimal duct

Question 10

Wall of eyeball

(3) layers

Answer 10

**1) fibrous tunic **

2) vascular tunic

**retina **

Question 11

(3) layers of wall of eyeball

**1) fibrous tunic **

**2) vascular tunic (uvea) **

**retina **

Answer 11

1) OUTER

**sclera **- white of eye

**cornea - **transparent coat covering iris

2) **choroid - **lines internal surface of sclera

becomes **ciliary body **consists of **ciliary processes **& **ciliary muscle **

**Iris **

**3) Optic Disk - **blind spot, where optic (II) nerve exits

**Macula lutea - **fovea centralis: area of highest visual acuity