somatic

rods & cones for vision

Photoreceptor

Light entering the eye will go through which part of the eye first

cornea

Temperature

Thermoreceptor

Which of the following is a proprioceptor?

muscle spindle

Waves inside the cochlea are amplified due what structure pushing directly into the oval window?

stapes

Physical stimuli / sound / balance- pressure/ vibration

Mechanoreceptor

Pain- chemical released from tissue damage – not found in brain

• Nociceptor

Solute concentrations- maintain fluid electrolyte balance

Osmoreceptors

chemical stimuli

Chemoreceptor

what are sensory receptors based on

structure, location, function

3 structural sensory receptors

Free nerve endings

Encapsulated endings

Specialized Receptor cell

Pain and temperature- has dendrites- receive stimulus axon- travel down, soma-process

Free nerve endings

enhance sensitivity  
Pressure and touch- Pacinian and Meisner in dermis 

Encapsulated endings (capsule over dendrite)

distinct component for specilaized stimulkus  
ex- Photoreceptors in eyes

Specialized Receptor cell-

3 location sensory receptors

Exteroceptor

Interceptor

Proprioceptor

Located near stimulus- in external environment ex – eyes, dermis, tongue (taste pain, temp touch) stimulus from outside

Exteroceptor

located internally 
Internal organs- chemoreceptors, baroreceptor

Interoceptor

Near moving body part –- ex muscle spindle Golgi tendon

Proprioceptor

6 functional sensory receptor

chemoreceptor

osmoreceptor

nociceptor

mechanoreceptor

thermoreceptor

photoreceptor

Each sensory info travels through ___

modality 

Specific organ dedicated to it

Special sense

- Modality

Refers to how information is 
encoded

 Distributed throughout body 

• General sense 

gustation

taste

Taste happens because of

receptor cells that cause change in chemical concentration  

Dissolved glucose 
G protein-coupled receptors

sweet

Perception of Sodium in saliva

salty

Hydrogen ion perception

sour

Presence of alkaloids – depolarization and hyperpolarization- leads to gag reflex – helps avoid poison  
G protein- coupled receptors 
Depolarize or hyperpolarize

bitter

Sense of fat 
G protein-coupled receptors 
L-glutamate (amino acids)

 umami-sour

exist Within papillae 
• have (taste) Gustatory receptor cells- have hair microvilli- help grab chemical and travel

taste bud

50 to 100 epithelial cells on tongue

taste bud

• Supporting cells, Basal Cells- makes sure taste molecule dissolve and travel to sensory nerve

taste bud

sensory info that reaches sensory nerve can activate after tasting something

Facial nerve 
• Glossopharyngeal nerve 
• Vagus nerve

How do u smell

odorant molecules (in a gas form) have to make it to olfactory epithelium

when smelling something odorant nerves have to make it here

Olfactory epithelium

odarant molecules have to be in

gas form

Bind to proteins in mucus 
• Transported to dendrites- olfactory cilia

olfactory

how does olfactory molecules move

graded potential- high to low concentration

bipolar neurons exist in

olfactory epithelium

only neuron that is consistently replaced in our body

olfactory neuron

axon extend from

From basal surface to brain 
• Connect to olfactory bulb 
• Axons then split

Inferior and medial area of 
temporal lobe

olfactory cortex

Long term memory / Emotion associated with smell

Hypothalamus and Limbic 
system

Have most amount of sensory info coming in

eyes

produce tears

lacrimal gland

lacrimal gland connects to

lacrimal duct leads to the eye and 
conjunctiva.

what is conjunctiva

lashline

Four straight muscles in eye superior, inferior, lateral, rectus

do what?

helps eye move up down left right

two oblique extrinsic muscles
superior and inferior

do what?

allows rotation of eye

what are for protection of eye

• Eyelids, eyebrows, and eye lashes

tissue layer of eye

tunic

most external layer of eye

Fibrous tunic

what is sclera

white of eye- extrinsic muscle attach

most anterior clear portion of eye lets light in

cornea

what does fibrous tunic include

the sclera and cornea

middle layer of eye tissue

vascular tunic

what is vascular tunic also known as what does it have

uvea

veins

has choroid, ciliary body, iris

vascular tunic

layer of tissue that helps nourish retina

choroid

has muscles that act on lens to help open and close eye

produces aques humer- nourish cell

ciliary body

pigmented part of eye

control pupil size

iris

most inner eye layer

neural area (sensory)

has retina- pigmented epithelium

optic nerves

neural tunic

where we find rods and cones

retina

attached to optic disc (blind spot)

has orra serrata

retina

pushed against choroid by vitreous body

retina

is the central region of the retina where visual acuity is highest due to a high density of cones.

Bobia centralis

biconvex, flexible structure to help focus light on the 
retina, held by suspensory ligaments which attach to ciliary 
muscles 

lens

is there more rods or cones

rods

130 million rods

6.5 million cones

concentrated area of cones

fovea centralis

cylindrical stacks covered in proteins, they react to light,

rods

more rods when  ___

further from the fovea centralis

sense color (blue, green, and red) and are concentrated in the fovea centralis

cones

eyeball structure is short, light focuses after the retina (farsightedness)

hyperopia

– eyeball structure is long, light focuses before retina (nearsightedness)

myopia

eyes don’t focus on same spot (double vision

diplopia

how does our eyes process image

our eyes processes images upside down

locates objects in space 
and guides movements in response, uses 
parietal lobe structures and interacts with 
somatosensory cortical areas 

dorsal stream

recognizes an objects 
significance, uses temporal lobe structures

The ventral stream

3 part of ear

outer, middle, inner

includes auricle, external auditory meatus, external auditory canal with 
ceruminous glands, and tympanic membrane (ear drum) 

outer ear components

begins at tympanic membrane,

houses 3 ossicles (malleus, incus, and stapes), 
and ends at oval window.

with air unless there is an ear 
infection. 

has eustachian tube

The middle ear

 

• starts with oval window

• creates passages in the temporal bone.

• include Vestibule, cochlea (audition), and 3 
  semicircular ducts (equilibrium).

inner ear structures

Connects middle ear to the 
pharynx

Allows air to enter or leave to 
equalize pressure 
• Fluid can drain through tube 
during infections

Eustachian tube

• surrounds the membranous labyrinth 
  and endolymph fills the membranous labyrinth

perilymph

Has 3 ducts – scala vestibule (attached to oval window), scala media (organ of 
Corti), and scala tympani (attached to round window). 

Cochlea

Vestibular and tympanic canals are filled with

perilymph

Scala media is filled with ——and is where sensory function occur

endolymph, allowing for sound transduction.

each duct in cochlea is seperated by

membrane

in the scala media

attaches to the basilar membrane, has hair cells with stereocillia, 
and hairs are anchored to a tectorial membrane 

organ of corti

specialized hair like structure used for sound

stereocillia

Sound waves cause tympanic membrane to vibrate,
move,

perilymph moves basilar membrane which bends the hairs, and now channels can open for depolarization. 
• Nerve signal can now be conducted through the vestibulocochlear nerve (CN VIII) to the brain 
• Ossicles amplify the sound waves

how sound works

vibrations make  

amplify dound waves

ossicles

Audition is sensation

physical/mechanical

what type of sound is found at the base (start) of the cochlea 

high frequency sounds

what type of sound is found at the apex () of the cochlea 

low frequency sounds

amplifies the sound if the system isn’t working well enough, but 
won’t do anything if hairs are compromised 

hearing aid

should conduct sound to nerve and used if hairs are no 
longer working 

cochlear implant

more hair cells move because of louder sounds

intensity –