Anatomy Chapter 13

middle ear (tympanic cavity)

Air filled cavity in the temporal bone, encloses and protects the auditory ossicles, contains the auditory or eustachian tube, permits equal pressure on each side of the tympanic membrane (ears popping ), connected to the nasopharynx can allow microorganisms to enter causing the otitis media or er infection, normally flat or closed but swallowing or yawning opens it u to equalize pressure in the ear with atmospheric pressure.

Equilibrium

Anterior, posterior, and lateral semicircular ducts are continuous with the utricle (provide sensations of gravity and linear acceleration) Each duct contains an ampulla with receptor regions called crista containing hair cells and attached to the gelatinous cupula. Hair cells monitored by the dendrites of sensory neurons. The surface has steriocillia, when pressure is applied it alters the rate of release of chemical transmitter providing information about direction and strength of stimuli. Provides information about movement one way distorts receptor process and movement in opposite direction inhibits them, each of the three ducts responds to one of these rotational movements

foeva centralis

Area of most acute vision responsible for sharp vision when reading watching driving etc

internal eye muscles

Autonomic nervous system (not a lot of control) Ciliary body (muscles that alter the lens curvature) Radial and circular muscles of the eye (Control Pupil Size)

acessory structures of the eye

Eyelids (palpebrae), eyelashes, tarsal glands, lacrimal caruncle, conjunctiva , lacrimal apparatus, cornea, iris, photopupillary/accomidation reflex, pupil, lens

lacrimal apparatus

Gland above the lateral end of the eye in the fronta bone, secretions from the acrimal gland contain lysozoem antibodies to kill bacteria, release dillute salt through tears and through several small ducts, tears form in the lacrimal glands, wash across the eye and collect in the lacrimal lake, pass through the lacrimal punctae, lacrimal canniliculi, lacrimal sac and nasolacrimal duct, emotional tears is not understood.

taste receptors

Gustation or taste clustered in taste buds adult has 3000, kids have 10,000 (why they hate veggies) replaced every two weeks; contain basal/stem cells, gustatory cells extend taste hairs through a narrow taste pore, taste buds are monitored by cranial nerves, synapse within the solitary nucleus of the medulla oblongata, then on thalamus and primary sensory cortex

Glaucoma

Increased pressure due to backup of aqueous humor fluid, causes blindness over time

Cornea

Protective transparent anterior part of the eye (fibrous tunic) anterior most part of the sclera.

lacrimal caruncle

Soft tissues with glands that produce gritty or thick secretion after sleep. (Sleepdust)

convergence

Squinting your eyes to view close objects

conduction deafness (leaving a concert)

Temporary, damage of mechanical factors, caused by a buildup of earwax, fusion of ossicles, otitis media. Treatment: Hearing aid/implant

Tympanic Membrane or Eardrum

Thin semitransparent sheet, amplifies sound vibrations and transmits them to the three ossicles of the middle of the ear (malleus, incus, stapes), converts sound waves into mechanical movements

Eyelids (palpebrae)

Top and bottom separated by palpebral tissue, fxn to protect eye

astigmatism

Unequal curvature of one or more refractive lenses of the eye, usually the cornea, fixable with glasses

cilliary body

Where lens is attached

The anterior cavity of the eye is further divided...

anterior chamber in front of the eye, posterior chamber between the iris and the lens

outer fibrous tunic

cornea and sclera, limbus (between sclerra and cornea), attacthment site for extrinsic eye muscles, center is transparent containing optic nerve endings, can be transplanted without rejection since it is avascular.

night blindness

deterioration of the neural retina, vitamin A deficiency

hyperopia

farsightedness; light focused behind the retina instead of on it, inability to see objects clearly caused by shortened eyeball correction: Convex lens also called farsightedness hypermetropia, or misshapen lens

eyelashes prevent

foreign matter from getting into the eye

Rods

function best under low light conditions and are responsible for peripheral/night vision

outer ear

pinna, auditory canal, tympanic membrane

filiform papillae

provide friction to move your mouth

accomodation pupillary reflex

reflex constriction of the pupils when viewing close objects

photopupillary reflex

reflex-constriction of pupils when they are exposed to bright light

tarsal glands

secretors of an oily substance; located in the eyelids, prevent them from sticking together

taste sensations

stages of a relationship: starts out sweet, then it gets salty, then its sour, then its bitter when you break up

umami

taste for monosodium glutamate, like msg or beef, chicken broth etc, circumvallate papillae,

taste and age

taste sensitivity shows the number of taste buds you have, the number of taste buds you have declines with age

pupil

the adjustable opening in the center of the eye through which light enters (like a camera)

Retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

auditory ossicles

three small bones linked together that connect the eardrum to the inner ear, malleus, incus, stapes, tensor tympani, stapedius muscle, malleus receives vibration from tympanic membrane and passes it to the incus which is attached to the stapes. Stapes is bound to the oval window and the vestibule

blind spot (optic disc)

where the optic nerve leaves the eye; there are no photoreceptor cells (cones) here, the overlap of the visual fields and inputs from both eyes to each optic cortex for depth perception

Sclera

white of the eye; maintains the shape of the eye and protects the delicate inner layers of tissue

The Eye

Composed of three layers: Outer fibrous tunic, Middle vascular tunic, and retina

retina (sensory tunic)

Contains photoreceptor cells (rods and cones)

Primary taste sensations

SWEET (OH; glucose), salty (alkaloids; NACL), sour (H+; acids like lemon), bitter (metal ions; ie calcium in veggies) and umami

Pinna

Shell Shaped outer ear provides directional sensitivity, like hands over your ears.

External acoustic canal

Short Chamber Contains Ceremonious glands which secrete cerumen or ear wax, keeps foreign objects away from the tympanic membrane, earwax slows the growth of microorganisms to reduce infection

Eye disorders

Cojuctivitis, night blindness, color blindness, cateracts, glaucoma, myopia, hyperopia, astigmatism

anterior eye chamber

- Contains clear watery aqueus humor -provides nutrients to lens and cornea -drains through the canal of schlemn to vascular system to maintain proper eye pressure

Posterior eye chamber

- Has vitreous humor reinforce the eyeball gel like not recycled and permanent

Nasal Olfactory Organs

- Olfactory epithelium has olfactory receptors, supporting cells, basal cells --Olfactory receptors are modified neurons cover the interior surface of the cribriform plate, superior perpendicular plate, and superior nasal conchae, contains olfactory glands or bowman's glands which are covered by a thick pigmented mucus, olfactory reception involves detecting dissolved chemicals as they interact with odorant binding proteins.

Sound Transmission (Go over three times)

1. Sound waves enters the ear canal and reaches the tympanic membrane which vibrates, 2. Auditory ossicles conduct vibration into the inner ear, -tensor tympani and stapedius muscles contract to reduce the amount of movement when loud sounds arrive. 3 Movement at the oval window applies pressure to the perilymph of the cochlear duct, perilymph fluid in the cochlea vibrates, 4. Membranous labyrinth suspended in perilymph containing endolymph fuid vibrates, pressure waves distort basilar membrane. 5. Hair cells of the organ corti are pushed against the tactoral membrane 6. Impulse is transmitted through the auditory nerves and to the brain, intensity is the energy content of a sound measured in decibels.

How does vision work? (Read through the steps three times)

1. Vision from the field of view transfers from one side to another while in transit 2. Depth perception is only obtained by comparing the relative positions of objects 3. Light from object is refracted, inverted and reduced in size, by the cornea and lens. 4. Image will be sent to the retinal surface and makes nerve impulses 5. The cornea lens system produces an image of an object on the retinal surfaces, process known as accommodation 6. Vision is dependent on context/lighting situation 7. Finally, the reduction in size allows it all to "fit" on our retina 8. The brain flips the image and superimposes it onto our eyes.

the difference between 20/20 vision and a worse vision, like 20/500 (difference in sight)

20/20: You can see what is 20 feet away perfectly, at 20/500 you see what is 500 feet away like what most people would see at 20 feet.

sensorineural deafness

A permanent lack of hearing caused by a lesion or damage of an auditory nerve (cochlear nerve, hair cells in the organ of corti), caused by a blood clot in the auditory complex of the brain listening to a loud noise.

osseous

Bony and membranous labyrinth with two conduction fluids that regulate electrochemical impulses of hair cells. -Perilymph is fluid resembling cerebrospinal fluid -Endolymph is fluid with electrolyte concentrations

cilliary body

Ciliary muscles ad ciliary processes which attach to suspensory ligaments of the lens

Bony Chamber

Cochlea (hearing), Vestibule (linear movement), Semicircular canals (Balance/ angular movement)

color blindness

Lack of all three cones, sex inked predominantly in males, most common lack of red or green receptors

Cateracts

Lens hard and opaque as we age treatment is removal of lens and lens transplant, laser it off

How does the lens focus?

Light is refracted to it as it passes through the lens, accomidation is the process b which the lens adjusts to focus images or to light the retina, shape changed by cilliary muscles, normal vision is 20/20

lens

Major refractory structure, posterior to the cornea and forms anterior boundary of posterior cavity, posterior cavity contains a gel-like vitreous humor, helps to focus

round window

Membrane covered opening in the inner wall of the middle ear that compensates for changes in cochlear pressure, separates the perilymph from the air spaces.

Cones

Mostly concentrated in the macula, in the foeva centralis (eyes central vision), perceive color, sensitive pigments to the three wave lengths (RGB), need a bright light to see color (ie why in the day color is more visible than at night, because you are using different muscles) (all three channels = white, none = black)

conjunctiva

Mucous membrane covered by stratified squamous epithelium, covers most of the exposed surface of your eye (inner and outer surface), secretes mucus to lubricate the eye. (the stuff underneath your eyelids)

olfactory sensing (nose)

Occurs on the surface of the olfactory cillia which is sent to the olfactory bulb, odorants are small chemicals that stimulate olfactory receptors small organic molecules (strongest ones are soluble in water and liquid) Number of receptors decline with age (Read pg 551 in ur book)

pupil

Opening to allow light reach the lens size adjusts with light, more light = smaller pupil less light= larger pupil

Inner Ear: Osseous Labyrinth

Osseous, Bony Chmaber (Cochlea, Vestibule, Semicircular canals)

retinal pathway

Photoreceptors to bipolar cells to ganglion cells to the brain via the optic nerve, axons of ganglion cells, horizontal and amacrine cells modify the signal passed along the retinal neurons

Iris

Pigmented diaphragm opening in eye, contains muscles to open and close the pupil

semicircular canals

Receptors are stimulated by the rotation of the head for equilibrium, helps with balance and angular acceleration

External eye muscles

Rectus and oblique muscles that control the eye movements; convergence

Cornea

The clear tissue that covers the front of the eye

lingual papillae

bumps and projections on the tongue that are the sites of the taste buds, also on larynx and pharynx 3 types, filiform papillae, fungiform papillae, circumvallate papillae

hearing loss

conduction deafness, sensorineural deafness

fungiform papillae

contain 5 different taste buds

circumvallate papillae

contain taste pores form a v near posterior margin of the tongue

cochlea

contains mechanoreceptors for hearing, organ of corti which contains sensory hair cells, that measure pressure

vestibule

contains utricle and saccule, responsible for static equilibrium, sensations of gravity and linear acceleration (Think of Space Mountain at Disneyland)

Conjunctivitis

inflammation of the conjunctiva, caused by bacteria or virus, makes your eyes red (pink eye)

otitis media

inflammation of the middle ear in children, eardrum bulges, puss pressure, treatment: Myringotomy

eye reflexes

internal and external muscles

middle vascular tunic

iris, ciliary body, choroid; provides route for blood vessels and lymphatics. Control shape of the lens

vitreous humor

jellylike substance found behind the lens in the posterior cavity of the eye that maintains its shape

myopia

nearsightedness; distant objects appear blurred images are focused in front of the retina rather than on it. Correction: Concve lens, also called short sight or nearsightedness.

tensor tympani

origin on walls of Eustachian (auditory) tube and temporal bone; insertion on malleus, contract and stiffen the tympanic membrane

stapedius muscle

originates from the posterior wall of the middle ear and inserts on the stapes controls movement and shape at the oval window