Sensory Anatomy

Question 1

Skin size/weight?

Answer 1

21 square feet

3lbs

Question 2

Acne vulgaris

Answer 2

Blockage of hair follacle with dead skin or sebum (oil)

Question 3

Types of skin sensory receptors

Answer 3

Mechanoreceptors (deformation) - typically encapsulated

Thermoreceptors (heat/cold) & Nociceptors (pain) – free endings

Question 4

Receptive field

Answer 4

Area monitored by single neuron; cannot distinguish between stimuli within a single receptive field

Most of the body: 4cm diameter receptive fields

Fingertips: 1mm diameter receptive fields

Question 5

Pain

Answer 5

Damage to free endings of nociceptors

Nociceptors are most common in body (4M)

Question 6

2 types of pain meds

Answer 6

Prostaglandin blockers: reduce cellular signaling to peripheral nerves

Opiods: bind to receptors in the brain inhibiting pain signals

Question 7

How many olfactory receptors?

Answer 7

6M; can detect 3-10M odors

Dogs have 300M receptors

Question 8

Olfactory bulb

Answer 8

Buds off forebrain, connects to limbic system

Limbic system: strong emotions, memories

Question 9

Olfactory receptors

Answer 9

They are chemoreceptors, cilia directly exposed to environment; need replacement every 60 days

Chemicals are trapped in mucus and sensed by receptors

Question 10

Traumatic anosmia

Answer 10

Temporary/permanent loss of smell due to shearing of the olfactory nerve endings at the cribiform plate;

misaligned regeneration can result in olfactory confusion

Question 11

Purpose of external nose?

Answer 11

Moisture retention

Question 12

How do food particles get to the olfactory receptors?

Answer 12

They are aerated and pass through the CHOANA

Question 13

Tongue anatomy and innervation

Answer 13

Question 14

Word for taste buds? 2 types of taste buds?

Answer 14

Fungiform – dominate the body, small, few buds

Vallate – dominate the root, large, many buds

Question 15

Receptors within a tastebud?

Answer 15

60-100 chemoreceptors (gustatory cells) that react to certain molecules (salt, sugars, etc…)

Question 16

How does the eye develop?

Answer 16

Question 17

Answer 17

Question 18

Glaucoma

Answer 18

Blockage of the canals of Schlemm prevent drainage of aqueous humor, results in increased pressure in eye and loss of sight

Question 19

Intrinsic eye muscles

Answer 19

Constrictor and dilator pupillae

Ciliary muscle: Alters lense shape

Question 20

Cateracts?

Answer 20

Clumping and hardening of protein in the lens, leads to diffusion of light (hazy vision) and rigid lens (lack of clarity)

Question 21

Photoreceptors?

Answer 21

Rods (very sensitive– B&W) and cones (high resolution - color) located in the retina; high concentrations at the fovea

Question 22

Why is color vision evolutionarily important?

Answer 22

Identifying ripe fruit

Question 23

Color blindness?

Answer 23

Defect in certain cones

Question 24

Visual path of light?

Answer 24

Cornea -> Aqueous humor -> pupil -> lens -> vitreous humor -> retina(fovea) -> excitation of photoreceptors -> optic nerve

Question 25

Optic Chiasma

Answer 25

Question 26

Evolutionary benefit of binocular vision?

Answer 26

Question 27

Myopia and Hyperopia

Answer 27

Question 28

What's the mammalian equivalent of the fish branchial arches?

Answer 28

Pharyngeal arches

Question 29

Ear development

Answer 29

Question 30

Answer 30

Question 31

Answer 31

Question 32

How does the ear protect from loud noises? (2 muscles)

Answer 32

Question 33

Inner ear?

Answer 33

Fluid-filled space that contains organs of hearing and balance (cochlea and semicircular canals)

Question 34

How does the Cochlea work?

Answer 34

Sound waves along the cochlea, stimulating vibrations of the tectorial membrane in the Organ of Corti, stimulating hair cells

Question 35

How are volume and pitch detected?

Answer 35

Pitch – determined by the diameter of the tympanic duct, causing localized vibration of the tectorial membrane by wave frequency Volume – rate of stimulation, higher volumes = more rapid stimulation

Question 36

Hair cells (ear)

Answer 36

Mechanoreceptors; stimulated by vibrations of the tectorial membrane

Question 37

Answer 37

Question 38

Utricle & Saccule

Answer 38

Question 39

Otoliths

Answer 39

"Stones" - Embedded in the membrane above the hairs cells; mass of the “stones” amplifies gravity and accelerations

Question 40

Semicircular canals detect...?

Answer 40

Mechanoreceptors (hair cells) detect angular acceleration; 3 fluid-filled canals arranged orthogonally to each other, no otoliths

Question 41

Positional vertigo

Answer 41

Caused by dislodged otoliths entering a semicircular canal; dizziness, nausea; self resolves or is treated with series of motions

Question 42

Purpose of Auditory (Eustachian) tube?

Answer 42