FINISHED General and Special Senses (Chapter 19)

made based off of review guide and clinical perspectives

receptors

the structure that converts sensory stimulus to nerve impulses

general senses

temperature, pain, touch, stretch, pressure

Special sensed

gustation, olfaction, vision, equilibrium, audition

tonic

receptors that slowly adapt to stimuli, EX: pain

phasic

receptors that rapidly adapt to stimuli, EX:smell

adaptation

decreased action potential firing following prolonged exposure to constant stimulus

exteroceptors

receptors near the surface of the body, receive stimuli from outdoor environment

interoceptors

aka visceroceptors or enteroceptors, detect stimuli inside the body on organs

proprioceptors

provide information about body position, located in muscles, tendons, and joins

chemoreceptors

sensory receptor that detects molecules in liquid

thermoreceptors

sensory receptor that detects temperature

photoreceptors

sensory receptor that detects changes in intensity, color, and position of light

mechanoreceptors

sensory receptor that detects touch, pressure, vibration, and stretch

Nocieptors

sensory receptor that detects pain

reffered pain

impulses from viscera perceived as from dermatome of skin, IE when you experience pain in your leg, but the issue is in your hip (relocation of pain)

tactile recpetors

most numerous type of sensory receptor

where tactile receptors are located

dermis and subcutaneous layer

unencapsulated tactile receptors

endings are not wrapped in connective tissue or glial cells

encapsulated tactile receptors

endings wrapped in connective tissue or glial cells

free nerve endings

a type of unencapsulated tactile receptor that perceives temperature and pain

root hair plexuses

a type of unencapsulated tactile receptor that perceives hair movement

Tactile discs

a type of unencapsulated tactile receptor that perceives light touch

End bulbs

a type of encapsulated tactile receptor that detects light pressure and low frequency vibration

lamellated corpuscles

a type of encapsulated tactile receptor that detects deep pressure and high frequency vibration

bulbous corpuscles

a type of encapsulated tactile receptor that detects continuous deep pressure

palpebrae

eyelid

sclera

whites of eye

iris

pigmented part of eye, acts as a diaphragm to control pupil size

pupil

opening in iris

conjunction

lines the sclera and eyelid, lubricates and moistens eye, contains blood vessels that supply the sclera

CN VII

innervates the lacrimals

lacrimal gland

produces tears

lacrimal puncta

little opening that drain tears

lacrimal caruncle

pink bump in corner of eye, produces gritty secretion (eye gunk)

nasolacrimal duct

drains tears into nasal cavity

suspensory ligaments

the part of the body that holds the lens in place

avascu.lar

does not have its own blood supply

vascular

has its own blood supply

Sclera

posterior 5/6 of eye, provides eye shape and protects delicate internal components

cornea

curved transparent structure in front of iris and pupil, anterior 1/6 of eye. acts as eyes outermost lens, refracts light rays

choroid

dark brown membrane, supplies nutrients and oxegen to retina, the melanin pigment (reason for dark brown color) absorbs extraneous light

ciliary body

ring of tissue that surrounds the lens, smooth muscle tissue, attatches to lens via suspensory ligaments, produces aqueous humor and changes shape of lens (lens accomadation)

iris

pigmented part of the eye, acts as a diaphragm to control pupil size

what is conjunctivitis

pink eye

what causes conjunctivitis

inflammation of the conjunctiva, sometimes due to infection or allergy

what is trachoma

an infectious eye disease

what bacterium causes trachoma

Chlamydia trachomatis

why is trachoma the leading cause of blindness in developing countries?

lack of sanitation and clean water, and lack of access to drugs to treat it

what are cataracts?

Cloudy areas that form on the lens of your eye. Caused by proteins breaking down and forming cloudy patches

what is otitis media

a middle ear infection

what are the symptoms of otitis media?

ear pain, loss of hearing, trouble sleeping

how is otitis media treated

antibiotics and ear drops, and in some extreme cases ear tube placement

because it is the location where the optic nerves exit, and has no photo receptors

why is the optic disc called the blind spot

nueral layer

layer that receives light info, and converts said info into nerve impulses that are sent via CNII, contains rods and cones

macula lutea

area lateral to blind spot, center of it is the fovea centralis, neural layer

fovea centralis

the highest concentration of cones, neural layer

pigmented layer

layer that reinforces light absorbing properties of the choroid. outer layer

anterior cavity

between cornea and lens, filled with aqueous humor, removes waste products

posterior cavity

between lens and retina, contains vitreous humor, helps maintain eye shape and transmits light to retina

cornea

where does light first enter the eye

optic nerve

where does light info (electrical signals) leave the eye

auricle

outer mass of tissue, protects entry into ear and directs sound waves into bony tube.part of the external ear

external auditory canal

between auricle and tympanic membrane, directs sound to tympanic membrane.part of the external ear

tympanic membrane

eardrum, vibrates and transmits sound to middle ear. part of the external ear

auditory ossicles

melleus, incus, stapes

lateral boundary of middle ear

tympanic membrane

medial boundaries of middle ear

oval window

the oval window

what does the stapes connect with

role of auditory ausicles

amplify sound waves and transmit to oval window

pharyngotympanic tube/eustachian tube

connects middle ear with nasopharynx, equalizes pressure between external and middle ear

vestibule

oval central portion of the bony labryinth

semicircular canals

three circular canals in bony labryinth

cochlea

spiral chamber in bony labryinth

utricle

part of membranous labryinth that detects horizontal motion

saccule

part of the membranous labyrinth that detects verticle movement

semicircular ducts

part of the membranous labyrinth, detects rotational and angular movements

cochlear duct

membranous tube inside cochlea, contains scala media, splits cochlea into 2 chambers,

structures responsible for interpreting equilibrium

saccule, utricle, semicircular ducts

CN VIII

what cranial nerve is equlibrium info transported through

scala vestibuli

area in cochlea above cochlear duct. connects to round window

scala tympani

area in cochlea below cochlear duct. connects to oval window

spiral organ/ organ of corti

rests in basilar membrane in cochlear duct, contains hair cells with sterocillia

when the basillar membrane moves

steroecilia of the hair cells touch the tectorial membrane, generating nerve impulses

nerve impulse is generated by

stereocillia bending against tectorial membrane

cochlear branch

what part of CN VIII are nerve impulses from tectorial membrane sent

via scala tympani and round window

where do remaining sound waves exit the inner ear?

via the basilar membrane

how does the cochlea detect different frequencies of sound

scala tympani and round window

where do sound waves leave the ear

auricle

where do sound waves enter the ear

CN VIII

what CN is associated with the path of sound through the ear?

CN VIII

what CN is associated with the path of equilibrium through the ear?

parts of bony labyrinth

vestibule, semicircular canal, cochlea

parts of membranous labyrinth

utricle, saccule, semicircular duct, cochlear duct, scala vestibuli, scala tympani

components of external ear

auricle, external auditory canal, tympanic membrane

components of middle ear

auditory ossicles, oval window, pharyngotympanic/eustachian tube

components of internal ear

vestibule, semicircular canals, cohclea, utricle, saccule, semicircular ducts, cochlear duct

superior rectus

elevates eye and moves medially, innervated by Cn III

inferior rectus

deppresses eye and moves medially, innervated by Cn III

medial rectus

moves eyemedially, innervated by Cn III

lateral rectus

moves eye lateraly, innervated by CN VI