Chapter 17

Question 1

Photopigments in rods

Answer 1

Rhodopsin

Question 2

Rods and cones contain photopigments that absorb light which initiates the events that lead to this

Answer 2

Nerve impulse

Question 3

Refraction

Answer 3

Bending

Question 4

Know compartments of eye

Answer 4

Know compartments of eye

Question 5

Tarsal plate

Answer 5

Fold of connective tissue that gives form to eyelids

Question 6

Extrinsic eye muscles

Answer 6

Controls movement of eyeball itself

Question 7

Palpebral muscles

Answer 7

Control eyelid movement (opening and closing eyes)

Question 8

Two types of photoreceptors in retina

Answer 8

• Rods: see in dim light
• Cones: produce color vision

Axons of these exit at the optic (II) nerve

Question 9

Fovea centralis

Answer 9

Area of highest visual acuity

Question 10

Macula lutea

Answer 10

Exact center of retina

Question 11

Optic disc

Answer 11

Point at which optic nerve exits the eyes (aka blind spot)

Question 12

3 layers of eye

Answer 12

• Fibrous tunic
  » Cornea: admits/refracts (bends) light
  » Sclera: provides shape/protects inner parts
• Vascular tunic
  » Choroid: provides blood supply and absorbs scattered light
  » Ciliary body: secretes aqueous humor/alters shape of lens for near or far vision
  » Iris: regulates amount of light entering eye
• Retina
  » Pigmented layer
  » Neural layer

Question 13

Pathway for tears

Answer 13

• Lacrimal gland secretes tears into
• Excretory lacrimal ducts (distribute tears over surface of eye)
• Superior/inferior lacrimal caniliculi drains tears to
• Lacrimal sac, then drains tears into
• Nasolacrimal duct then drains tears into
• Nasal cavity

Question 14

Function of lacrimal apparatus

Answer 14

Produces and drains tears

Question 15

Keeps eyelids from sticking to ea. other

Answer 15

Row of sebaceous glands (tarsa;/Meibomian glands)

Question 16

Keeps eyelids from sticking to ea. other

Answer 16

Row of sebaceous glands (tarsal/Meibomian glands)

Question 17

Conjuctiva

Answer 17

Thin, protective mucous membrane that lines eyelids/covers sclera

Question 18

Accessory structures of eyes

Answer 18

• Eyelids
• Eyelashes
• Eyebrows
• Lacrimal apparatus
• Extrinsic eye muscles

Question 19

3 cranial nerves that carry impulses in the gustatory pathway

Answer 19

1. Facial (VII): carries taste info from anterior 2/3 of tongue
2. Glossopharyngeal (IX): carries taste info from the posterior 1/3 of tongue
3. Vagus (V): carries taste info from taste buds on epiglottis and in the throat

Question 20

Types of papillae

Answer 20

• Vallate
  » Around 12
  » 100-300 taste buds
• Fungiform
  » Scattered on tongue
  » Around 5 tastebuds ea.
• Follate
  » In lateral trenches of tongue w/ taste buds
  » Most degenerate in childhood
• Filiform
  » Have tactile receptors
  » No tastebuds
  » Incr. friction to make it easier for tongue to move food in mouth

Question 21

Papillae

Answer 21

Elevations where taste buds on tongue are located

Question 22

Three kinds of epithelial cells located in taste buds

Answer 22

1. Supporting cells
2. Gustatory receptor cells
3. Basal stem cells

Question 23

Where taste buds are located

Answer 23

• Tongue of YA
• Soft palate
• Pharynx
• Epiglottis

Question 24

5 primary tastes

Answer 24

1. Sour
2. Sweet
3. Bitter
4. Salt
5. Umami

Question 25

Olfactory transduction

Answer 25

Binding of odorant molecule to an olfactory receptor protein

Question 26

Lobe of cerebral cortex that contains the primary olfactory area

Answer 26

Cerebral cortex/cerebellum

Question 27

Know pathway of nerve impulses from receptors to the primary olfactory area of cerebral cortex

Answer 27

Know pathway of nerve impulses from receptors to the primary olfactory area of cerebral cortex

Question 28

Three types/functions of cells in olfactory epithelium

Answer 28

1. Olfactory receptor cell: produce mucus used to dissolve odor molecules so transduction can occur 2. Supporting cells: physical support, nourishment, and electrical insulation for olfactory receptor cells 3. Basal cells: undergo mitosis to replace olfactory receptor cells

Question 29

Location of olfactory epithelium

Answer 29

Inferior surface of cribriform plate (of ethmoid bone of skull) and extends along superior nasal concha

Question 30

Where receptors are for general senses

Answer 30

Widespread in body (pain receptors, pressure receptors, etc.)

Question 31

3 types of sensory receptors

Answer 31

1. Free nerve endings of 1st order sensory neurons 2. Encapsulated nerve endings of the 1st order sensory neuron 3. Separate cells that synapse w/ first order sensory neurons

Question 32

4 events in the process of sensation

Answer 32

1. Stimulation of sensory receptor 2. Transduction of stimulus: conversion of stimulus energy to neural energy 3. Generation of nerve impulses: energy levels build up to where graded potential has propagated an action potential toward CNS 4. Integration of sensory input: brain interprets input in cerebral cortex in CNS