Chapter 16- Special Senses

Question 1

Sense of Taste

Answer 1

Gustation
Utilize taste receptors on surface of the tongue

Question 2

Basic Qualities of Taste

Answer 2

Sweet
Salty
Bitter
Sour
Umami

Question 3

Taste Buds

Answer 3

Collection of 50-100 epithelial receptor cells
Found in tongue papillae

Question 4

Gustation Pathway

Answer 4

Facial nerve- Anterior 2/3 of tongue
Glossopharyngeal nerve- Post. 1/3
Vagus nerve- Epiglottis and lower pharynx
Pathway:
Solitary nucleus in medulla
Thalamus (Ventral posteromedial nucleus)
Parietal cortex

Question 5

Sense of Smell

Answer 5

Olfaction
Bipolar receptor cells bind to chemicals to illicit response and synapse with olfactory bulb
Travel through cribriform plate of ethmoid bone

Question 6

Olfactory Pathway

Answer 6

Bipolar receptor cell
Olfactory bulb
Mitral cell
Olfactory tract

Question 7

Functions of the Eye

Answer 7

Protect and support photoreceptors
Gather, focus, and process light

Question 8

Fibrous tunic

Answer 8

Most external layer of the eye
Cornea and Sclera

Question 9

Cornea

Answer 9

Fibrous tunic anterior 1/6th of eye
Transparent layer that bends light
Avascular and very sensitive

Question 10

Conjunctiva

Answer 10

Anterior end of cornea

Question 11

Sclera

Answer 11

Fibrous tunic posterior 5/6th of eye
White, opaque region
Provides shape and attachment point for muscles

Question 12

Vascular tunic

Answer 12

Middle layer of the eye
Choroid, ciliary body, and iris

Question 13

Choroid

Answer 13

Vascular tunic posterior 5/6th of eye
Vascular, darkly pigmented membrane
Reduce scattering light
Provides support

Question 14

Ciliary body

Answer 14

Vascular tunic anterior 1/6th
Thickened ring of tissue surrounding lens
Contains ciliary muscles
Produce Aqueous humor

Question 15

Ciliary Muscles

Answer 15

Manipulate the shape of the lens to focus light on the retina
Contracting muscles relaxes lens

Question 16

Iris

Answer 16

Visible colored part of the eye
Attached to ciliary body
Composed of smooth muscles that control pupil size

Question 17

Iris muscles

Answer 17

Sphincter pupillae muscle- Limit light
Dilator pupillae muscle- Increase light

Question 18

Sensory Tunic

Answer 18

Deepest layer of the eye
Retina

Question 19

Retina

Answer 19

Sensory tunic
Houses photoreceptors
Notable locations:
Macula lutea and fovea centralis- High photoreceptor density

Question 20

Anterior Segment of Eye

Answer 20

Anterior 1/6th
Anterior and Posterior Chambers:
In front of and behind iris
Filled with aqueous humor

Question 21

Path of aqueous humor

Answer 21

Produced by ciliary bodies in posterior chamber
Circulate through anterior segment
Return to blood by scleral venous sinus in anterior chamber

Question 22

Aqueous humor

Answer 22

Blood filtrate that supplies nutrients to lens and cornea

Question 23

Posterior segment

Answer 23

Posterior 5/6th of eye
Filled wit vitreous humor- Thick substance that transmits light and maintains intraocular pressure

Question 24

Rods

Answer 24

Photoreceptors more sensitive to light
Provides black and white vision in dim light

Question 25

Cones

Answer 25

Photoreceptors that work best in bright light Provide clear, color vision 3 types- red, blue, and green

Question 26

Lens

Answer 26

Biconcave disc that changes shape to focus light on retina

Question 27

Cataracts

Answer 27

Clouding of lens due to inadequate nutrition

Question 28

Myopia

Answer 28

Nearsightedness Caused by eyeball being too long

Question 29

Hyperopia

Answer 29

Farsightedness Caused by eyeball being too short

Question 30

Optic nerve

Answer 30

Connects eye to optic chiasm

Question 31

Optic chiasm

Answer 31

Site of crossing over of visual pathways

Question 32

Optic tract

Answer 32

Connects optic chiasm to thalamus

Question 33

Lateral Geniculate Nucleus

Answer 33

Nucleus in thalamus responsible for transmitting visual information

Question 34

Optic radiation

Answer 34

Fibers that transmit information from thalamus to visual cortex

Question 35

External ear

Answer 35

Auricle External acoustic meatus Tympanic membrane

Question 36

Middle Ear

Answer 36

Tympanic cavity Ossicles Pharyngotympanic tube

Question 37

Inner ear

Answer 37

Semicircular canals Vestibule Cochlea

Question 38

Auricle (pinna)

Answer 38

Visible, external portion of the ear that directs sound

Question 39

Tympanic membrane

Answer 39

Membrane that forms the border between the external and middle ears Transmits sound to ossicles

Question 40

Tympanic cavity

Answer 40

Hollow space in petrous portion of temporal bone

Question 41

Ossicles

Answer 41

Bones in middle ear that amplify sound waves Malleus (hammer) Incus (anvil) Stapes (Stirrup)

Question 42

Pharyngotympanic tube

Answer 42

"Eustachian" or "Auditory" tube Connect middle ear and pharynx to regulate pressure

Question 43

Semicircular canals

Answer 43

Contain semicircular ducts Responsible for detecting rotational acceleration

Question 44

Vestibule

Answer 44

Contain utricle and saccule Responsible for detecting head position and linear acceleration

Question 45

Perilymph

Answer 45

Fluid continuous with cerebrospinal fluid that fills the bony labyrinth in inner ear

Question 46

Endolymph

Answer 46

Fluid in membranous labyrinth that assists detection of hearing or equilibrium

Question 47

Macula

Answer 47

Site of sensory epithelium within the utricle and saccule Contains hair cells Covered with otolithic membrane and otoliths that move with the force of gravity and bend hair cells

Question 48

Crista ampullaris

Answer 48

Site of sensory reception within semicircular canals Contain cupula surrounding hair cells When rotating, endolymph flows and distorts cupula, stimulating hair cells

Question 49

Parts of the Cochlea

Answer 49

Scala vestibuli- Connected to oval window Cochlear duct (scala media) Scala tympani- Connected to round window

Question 50

Cochlear duct

Answer 50

Houses organ of corti- Site of hair cells Basement membrane under organ of corti moves with vibration and pushes hair cells into tectorial membrane

Question 51

Pathway of sound through ear

Answer 51

Tympanic membrane Ossicles Oval window Scala vestibuli Cochlear duct Scala tympani Round window

Question 52

Equilibrium pathway

Answer 52

Vestibular branch of Cranial Nerve VIII Transmits information of head position and movement Goes to lower brain centers and reflex centers

Question 53

Ascending Auditory Pathway

Answer 53

Cochlear Branch of Cranial Nerve VIII Bipolar neurons -Superior olivary nucleus in medulla -Lateral lemniscus to inferior colliculi -Medial geniculate nucleus in thalamus -Primary Auditory Cortex (temporal lobe)