Chapter 17 - Special Senses Flashcards Preview

somatic & visceral 

smell, taste, vision, hearing & equilibrium 

sense of smell

olfactory epithelium consists of olfactory receptors, supporting & basal cells

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

2) supporting cells-  support & nourishment

3) basal cells - replace olfactory receptors

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 

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

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. 

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

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

1) fibrous tunic 

2) vascular tunic

retina 

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