General & Special Senses

2 classes of receptors:

1. general

2. special

list general senses

• temperature

• pain

• touch

• stretch

• pressure

list special sense

• gustation

• olfaction

• vision

• equilibrium

• hearing

where in the body are special senses located?

head

stimuli are detected by:

receptors

3 criteria used to describe receptors

1. stimulus origin

2. receptor distribution

3. modality of stimulus

3 types of receptors classified by stimulus origin

1. exteroceptors

2. interoceptors

3. proprioceptors

interoceptors

• aka visceroceptors

• stimuli come from internal environment/organs

**ex O2 levels

exteroceptors

• stimuli from external environment

• receptors located in skin

proprioceptors

• stimuli from joints

• determine joint position

list general sense receptors classified by receptor distribution

• somatic

• visceral

list receptor types classified by modality of stimulus

• chemoreceptors

• thermoreceptors

• photoreceptors

• mechanoreceptors

• baroreceptors

• nociceptors

most numerous type of receptor

tactile receptors

location of tactile receptors

cutaneous layer of skin

tactile receptors are ____________ receptors that react to touch, pressure, and vibration stimuli

mechano

2 types of tactile receptors

1. unencapsulated

2. encapsulated

unencapsulated tactile receptors

• free nerve endings

• root hair plexuses

• tactile discs

encapsulated tactile receptors

• Krause bulbs

• lamellated corpuscles

• ruffini corpuscles

• tactile corpuscles

what layer of the skin are the tactile receptors located in?

stratum basale

deeper tactile receptors require _________ stimulation to detect pressure

more

gustatory receptors are housed in _________ on the dorsal surface of the tongue

taste buds

papilla

CT elevations

• 4 types

• associated with taste buds/cells

what type of papilla has the most taste buds?

valiate

what papilla is the least numerus?

vallate

what papilla has a mushroom shape?

fungiform

which papilla has no tastebuds?

filiform

location of filiform papilla

medial, dorsal tongue

location of vallate papilla

form inverted V at base of tongue (proximal)

location of foliate papilla

edge of tongue

location of fungiform papilla

distal, dorsal tongue

life span of gustatory cells

7-10 days

what layer of the tongue are gustatory cells located under?

stratified squamous epithelium of tongue

5 basic taste sensations

1. salty

2. sweet

3. sour

4. bitter

5. umami

what causes the salty taste?

K+, Na+

what causes the sweet taste?

sugar

what causes the sour taste?

acid, H+

what causes the bitter taste?

alkaloid

what causes the umami taste?

amino acid

list 8 primary smells

1. champhor

2. fishy

3. minty

4. pungent

5. musky

6. sweaty

7. floral

8. putrid

bone of skull that olfactory bulb travels thru

cribriform plate of ethmoid bone

list accessory structures of the eye

• conjunctiva

• eyebrows

• eyelashes

• eyelids

• lacrimal glands

light first enters the eye thru the:

cornea

opening of the eye

pupil

what assists the dilation of the pupil?

iris

what focuses light?

lens

what refracts light?

cornea

components of fibrous tunic

• slcera

• cornea

list components of vascular tunic

• iris

• ciliary body

• choroid

list components of neural tunic

retina

list tunics from outer to inner

1. fibrous

2. vascular

3. neural

what is the white of the eye?

sclera

what structure do contacts sit on?

cornea

anterior cavity contains:

• anterior chamber

• posterior chamber

cavities of the eye are divided by:

lens

humor of anterior cavity

aqueous

ciliary body components

1. ciliary muscle

2. ciliary process

humor of posterior cavity/vitreous chamber

vitreous humor

• thick, gel-like

location of anterior cavity

cornea to lens

location of anterior chamber of anterior cavity

cornea to iris

location of posterior chamber of anterior cavity

iris to lens

what structure allows for binocular vision?

optic chiasm

what muscle is involved in near/far vision?

ciliary muscles

what divides the external and middle ear?

tympanic membrane/ear drum

list auditory ossicles from lateral to medial

1. malleus

2. incus

3. stapes

which inner ear structure is associated with hearing?

cochlea

which inner ear structure is associated with balance?

vestibule

the middle ear is known as the:

auditory tube

the auditory ossicles are housed in the:

tympanic cavity