Special senses

Question 1

Special senses

Answer 1

Separate cell structural classification of receptor

• smell
• taste
• hearing
• balance
• vision

Question 2

Sense of smell

Answer 2

• odor dissolves in mucus surrounding the olfactory cilia (in contact with epithelium in the nasal cavity)
• receptor potential is passed to the olfactory nerves in the olfactory bulb
• impulse passes through olfactory tract into the thalamus and olfactory centers of the brain

Question 3

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Answer 3

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Question 4

Sense of taste

Answer 4

• receptor potential in taste buds (from chemo receptors called gustatory cells)
• propagation of action potential
• transmits to the brain

Question 5

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Answer 5

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Question 6

Hearing and balance

Answer 6

• external, middle, and inner ear

Question 7

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Answer 7

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Question 8

External ear

Answer 8

1. Auricle or pinna: visible portion
2. External auditory canal: tube leading to the temporal bone and tympanic membrane
3. Tympanic membrane

Question 9

Middle ear

Answer 9

Tympanic cavity

• tiny epithelial lined cavity hollowed out of the temporal bone
• contains 3 auditory ossicles
  1. Malleus - hammer - attached to inner surface of tympanic membrane
  2. Incus - anvil - attached to malleus and stapes
  3. Stapes - stirrup - attached to the incus

Question 10

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Answer 10

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Question 11

Inner ear

Answer 11

Labyrinth

• consist of two main parts: a bony labyrinth and inside a membranous labyrinth
• the bony labyrinth consists of 3 parts
  1. Vestibule
  2. Cochlea
  3. Semicircular canals

Question 12

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Answer 12

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Question 13

Inner ear

Answer 13

Membranous labyrinth is inside the bony labyrinth and contains

• the utricle and saccule (inside vestibule)
• the cochlear duct inside cochlea
• the membranous semicircular ducts inside
• the bony semicircular canals

Question 14

Vestibule and semicircular canals

Answer 14

Involved with balance

Question 15

Cochlea

Answer 15

Involved in hearing

Question 16

Endolymph

Answer 16

Fluid filling the membranous labyrinth

Question 17

Perilymph

Answer 17

Fluid that suspends the membranous

Question 18

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Answer 18

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Question 19

Sense of hearing

Answer 19

Sound is created by vibration

• the ability to hear sound waves is depend on volume, pitch, and other acoustic properties
• to be hear, sound must travel though air, bone, and fluid

Question 20

Sense of balance

Answer 20

• the sense organs involved in the sense of balance, or equilibrium, are found in the vestibule and semicircular canals
• the sense organs located in the vestibule: utricle and saccule function in static equilibrium
• the sense organs associated with the semicircular ducts function in dynamic equilibrium

Question 21

Static equilibrium: otoliths organs

Answer 21

Utricle and saccule

• walls of both organs contain a small thickened region called the macula
• the tow macula are perpendicular to each other and provide information for static equilibrium
• 2 kinds of cells in the macula (hair and otolithic membrane)

Question 22

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Answer 22

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Question 23

Dynamic equilibrium: semicircular canals

Answer 23

Semicircular canals lie at right angles to one another in 3 planes

• 2 verticle ducts (anterior and posterior)
• 1 horizontal duct (lateral)
• sensory organ: crista. Located in ampulla and contains hair cells and supporting cellls

Question 24

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Answer 24

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Question 25

Sense of vision

Answer 25

Light converts stored photochemical energy into nervous impulses that are interpreted by the brain as sight - external structures include: eyebrows, eyelashes, eyelids, lacrimal apparatus, muscles (intrinsic and extrinsic)

Question 26

Layers of the eyeball

Answer 26

1. Fibrous layer - sclera - cornea 2. Vascular layer - choroid - iris - ciliary body 3. Inner layer - retina - optic nerve - retinal blood vessels

Question 27

Fibrous layer

Answer 27

Outer coat of eyeball - cornea: the transparent anterior portion of the fibrous layer - sclera: white opaque outer portion of the eye (white secondary to collagen and elastin bundles)

Question 28

Vascular layer

Answer 28

- choroid: highly pigmented area - ciliary body: formed by a thickening of the choroid and contains the ciliary muscle - iris: colored part of the eye that attaches to the ciliary body which controls the diameter of the pupil

Question 29

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Answer 29

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Question 30

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Answer 30

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Question 31

Inner layer

Answer 31

Retina - mostly made up of nervous tissue - 3 layers of neurons 1. Photoreceptors cells: rods and cones 2. Bipolar cells: receive impulses from rods and cones 3. Ganglio cells: receive info from rods, conoces, and bipolar cells and send the information to the optic nerve via the optic disk