CH8 - Special Senses Flashcards
1
Q
Lacrimal glands
A
Makes tears (lubricates)
2
Q
Nasolacrimal duct
A
Excess tears drain into nasal cavity
3
Q
Sebaceous and sudoriferous glands (maintains moisture)
A
Eyelids
4
Q
Warn incoming objects
A
Eyelashes
5
Q
Membrane secretes mucus; prevents entrance of microbes
A
Conjunctiva
6
Q
White connective tissue layer
A
Sclera
7
Q
Allows light to enter the eye
A
Cornea
8
Q
Coloured part of eye; regulates light allowed to enter
A
Iris
9
Q
Hole through the iris where light passes through
A
Pupil
10
Q
Changes shape to focus on far/near objects
A
Lens
11
Q
Smooth muscle controls lens shape
A
Ciliary body
12
Q
Anterior segment
A
- Anterior to lens
- Contains aqueous humor
13
Q
Posterior segment
A
- Posterior to lens
- Contains vitreous humor
14
Q
Aqueous humor
A
- Provides nutrients for lens/cornea
- Maintain intraocular pressure
15
Q
Vitreous humor
A
- Prevents eye from collapsing
- Maintain intraocular pressure
16
Q
Blood vessels bring oxygen/nutrients
A
Choroid (Vascular layer)
17
Q
Absorbs light; contains photoreceptors
A
Retina
18
Q
Focus point for detailed central vision
A
Fovea centralis
19
Q
Blind spot; exit point for optic nerve
A
Optic disc
20
Q
Photoreceptors - Rods
A
- Grey tones
- Dim light
- Peripheral vision
21
Q
Photoreceptors - Cones
A
- Color
- Densest in center of retina
22
Q
Cone sensitivity
A
- 3 types of cones
- Different cones sensitive to different wavelengths
- Color blindness; result of lack of 1 cone type
23
Q
Pathway of Light Through the Eye
A
- 20 ft away for distance vision
- Less than 20 ft away for closer objects (accommodation)
24
Q
Real images
A
- Formed in retina
- Reversed from left to right
- Upside down
- Smaller than object
25
Carries signal to occipital lobe
Optic nerve
26
Internal muscles
Controlled by autonomic nervous system
27
Viewing close objects; eyes moving medially
Convergence
28
Special senses
- Smell
- Taste
- Sight
- Hearing
- Equilibrium
29
Ear senses
- Hearing
- Equilibrium
30
Ear is divided into 3 areas
- Outer ear
- Middle ear
- Inner ear
31
Curve of elastic cartilage; collects sounds waves
Auricle/Pinna
32
External Acoustic Meatus
- Narrow chamber in temporal bone
- Lined with ceruminous (wax) glands
33
Outer ear; Transfers sound waves vibrations deeper into ear
Tympanic Membrane
34
Pharyngotympanic Tube
- Connects middle ear with throat
- Equalizes pressure when yawning/swallowing
35
Auditory Ossicles
- Amplification of sound wave vibrations
- Malleus "hammer"
- Incus "anvil"
- Stapes "stirrup"
36
Vibrations move from air to fluid of inner ear through stapes action
Oval window
37
Allows fluid in cochlea to pass vibrations down to entire length
Round window
38
Inner ear
- Sense organs (hearing/balance)
- Filled with perilymph
- Bony chambers within temporal bone
39
Cochlea
- High pitched sounds vibrate hair cells near beginning
- Low pitches vibrate deeper in spiral organ
40
Vestibulocochlear Nerve
- Carries hearing signal to temporal lobe of brain, and balance/equilibrium to cerebellum
41
Hair Cells & Endo/Perilymph Fluid
- Cochlea, vestibule, semicircular canals
- All connected together
- Contain hair cells surrounded by fluid
- Hair cells bend when fluid is moved
42
Equilibrium receptors of the inner ear are called
Vestibular apparatus
43
Vestibular apparatus functions
- Static equilibrium
- Dynamic equilibrium
44
Vestibule detects
Linear acceleration/Static equilibrium (horizontal/vertical movement)
45
Semicircular Canals detect
Angular acceleration/Dynamic equilibrium (yaw, pitch, roll)
46
Receptors in vestibule
Maculae
47
Anatomy of Maculae
- Hair cells are embedded in the otolithic membrane
- Otoliths (tiny stones) float in gel around hair cells
- Movements cause otoliths to bend hair cells
48
Dynamic Equilibrium
- Respond to angular/rotary movements
- Located in semicircular canals
49
Organ of Corti (Hearing)
- Located in cochlea
- Receptors = hair cells on basilar membrane
- Gel like tectorial membrane can bend hair cells
- Cochlear nerve attached to hair cells transmits nerve impulses to auditory cortex on temporal lobe
50
Mechanism of Hearing
- Vibrations from sound waves move to tectorial membrane
- Hair cells are bent by membrane
51
Action potential starts in
Cochlear nerve (Impulse travels to temporal lobe)
52
Receptor cells close to oval window are stimulates
High-pitched sounds
53
Specific hair cells further along cochlea are affected
Low-pitched sounds
54
Olfaction (Sense of Smell)
- Olfactory receptors are in roof of nasal cavity
- Impulses are transmitted via olfactory nerve
- Interpretation of smells is made in cortex
55
Sense of Taste
Taste buds house receptor organs
56
Location of Taste Buds
- Most are on the tongue
- Soft palate
- Cheeks
57
The Tongue & Taste
- Covered with projections called papillae
- Taste buds found on sides of papillae
- Gustatory cells are the receptors
58
Filiform Papillae
Sharp with no taste buds
59
Rounded with taste buds
Fungiform Papillae
60
Large papillae with taste buds
Circumvallate Papillae
61
Sweet Receptors
- Saccharine
- Some amino acids
62
Sour Receptors
Acids
63
Bitter Receptors
Alkaloids
64
Salty Receptors
Metal ions
65
Chemical Senses: Taste & Smell
- Both sense use chemoreceptors
- Each gustatory cell responds to only 1 taste
- Both senses complement each other; respond to same stimuli
