boil 231 senses

Question 1

what are the five special senses?

Answer 1

olfaction
gustation
equilibrium
hearing
vision

Question 2

what are the characterisitics of the special senses?

Answer 2

Concentrated (to specific locations of the head)
Anatomically (distinct from other senses)

Question 3

What is the Odor threshold and adaptation of olfacation?

Answer 3

Low threshold
Rapidly adapting

Question 4

Olfactory pathway: What components are included? In what order?

Answer 4

1. Olfactory receptors within the olfactor epithelium are stimulated
2. Axon bundles of right and left olfactory nerves are depolarized and connect to the olfactory bulbs
3. Continues onto the olfactory tract
4. Projects to the primary olfactory area in the temporal lobe of the brain (conscious awareness of smell occurs here)

Question 5

Relationship between odor and taste with memories/emotions

Answer 5

Odors and taste can evoke strong emotions and memories (impulses from these 2 senses can spread to limbic system (part of brain that controls instinct and moood/emotions)).

Question 6

What are the 5 primary tastes?

Answer 6

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

Question 7

Gustatory pathway: Which nerves are involved? (3)

Answer 7

1. Vagus (X) nerve: taste from the epiglottis and throat
2. Glossopharyngeal (IX) nerve: taste from the posterior ⅓ of the tongue
3. Facial (VII) nerve: taste from the anterior ⅔ of the tongue

Question 8

Gustatory Pathway:

Answer 8

• Taste bud receptors send nerve impulses via 3 cranial nerves to the gustatory nucleus in the brainstem.
• Taste signals reach the thalamus, then the primary gustatory area for conscious taste perception and discrimination.

Question 9

Accessory structures of the eye?

Answer 9

Eyelids
Eyelashes
Eyebrows
Lacrimal apparatus (group of structures that produce tears)
Extrinsic eye muscles (6)

Question 10

Eyeball anatomy

Answer 10

1. Superficial layer: fibrous tunic (cornea and sclera)
2. Middle layer: vascular tunic (choroid, ciliary body, iris)
3. Deep layer: retina (beginning of pathway)

Question 11

Optic Nerve and optic disc

Answer 11

• Optic nerve: the end of the eyeball, looks like a tunnel, goes into brain
• Optic disc: the exit of the inner eye into the optic nerve (goes into optic nerve)

Question 12

Image formation within the eyeball: what processes must occur to be able to see an object? (3 total, be able to describe the structures involved and the process)

Answer 12

• Refraction (bending) of light: Light bends at the cornea and lens to focus images onto the retina. Abnormalities can cause farsightedness or nearsightedness.
• Accommodation: The lens changes curvature to focus clearly, involving the ciliary body and zonular fibers.
• Pupil constriction: The iris controls pupil size via autonomic reflexes. Constriction occurs with accommodation to prevent peripheral light from causing blurred vision.

Question 13

Visual pathway: what nerves are involved and where does the information go within the brain?

Answer 13

optic nerve to the optic chias to the optic tract then to the occipital lobe

Question 14

Ear anatomy: outer ear, middle ear, inner ear

Answer 14

• Auricle (pinna): captures sound
• External auditory canal: transmits sound to the ear drum
• Tympanic membrane (ear drum): thin wall to separate the external and middle that vibrates sound, causing the malleus to vibrate

Question 15

middle ear

Answer 15

• the tympanic membrane through these 3 bones to the oval window
• Auditory tube: extends from the middle ear into the nasopharynx to regulate air pressure in the middle ear

Question 16

inner ear

Answer 16

• Cochlea: translates vibrations into neural impulses that the brain can interpret as sound
• Vestibular apparatus: works with cerebellum for balance and equilibrium
• Semicircular ducts: detect rotational acceleration or deceleration
• Utricle: detects linear acceleration or deceleration that occurs in horizontal direction and head tilt
• Saccule: detects linear acceleration or deceleration that occurs in a vertical direction

Question 17

Physiology of Hearing (pathway): Describe the structures sound travels through?

Answer 17

• Sound waves enter through the auricle and external auditory canal.
• Tympanic membrane vibration causes auditory ossicle vibration.
• Pressure is placed on cochlear fluid, vibrating hair cells.
• Hair cell movement generates nerve impulses in cochlear nerve fibers.
• Impulses reach the primary auditory area in the temporal lobe.

Question 18

Vestibular apparatus: what is it? What does it contain?

Answer 18

Contains structures that detect different kinds of movement:
- Semicircular ducts/canals
- Utricle
- Saccule

Question 19

Linear vs Rotational Acceleration/Deceleration

Answer 19

• Linear: Gravity moves hair cells in the utricle and saccule (e.g., car speeding up, nodding head, elevator).
• Rotational:Gravity moves hair cells in semicircular canals, detecting rotation (e.g., shaking head no, athletic activities).

Question 20

What structures make up the vestibular apparatus? What information is detected by each?

Answer 20

• Vestibular apparatus: Saccule, utricle (otolithic organs) in the vestibule, semicircular ducts in semicircular canals
• Saccule and utricle: Detect linear movement
• Semicircular ducts: Detect rotational movement