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