What is the fibrous tunic of the eye composed of?
What is the function of the cornea?
To bend light
What is the vascular tunic of the eye composed of?
- Choroid-Areolar CT
- Ciliary body (ciliary muscle-Smooth MT. Ciliary process)
what is the function of the ciliary muscle?
- When relaxed, it pulls on the suspensory ligaments=flat lens
- When it contracts, it releases tension on ligaments=lens is round
what is the function of the ciliary process?
Secretes aqueous humor
what is the function of the iris?
Controls diameter of pupil
What is the nervous (sensory) tunic composed of?
- Macula lutea with fovea centralis
- Optic disc (blind spot)
- Optic nerve
What is the retina composed of?
- Pigmental layer
- Photoreceptor layer which contains:
- Rods-dim light, no colors
- Cones-see colors but need bright light
what is special about the fovea centralis?
Has greater number of cones anywhere on your retina but no rods
what is the function of the canal of schlemm?
- "Scleral venous sinus"
- Drains aqueous humor back to blood
What is part of the external ear?
- External auditory canal with cerumen
- Tympanic membrane
What is the posterior cavity of the eye filled with?
What does the conjunctiva contain?
Free nerve endings and blood vessels
what prevents something getting into the back of your eye?
what holds the lens in place?
what CN works with lateral rectus eye muscles?
CNN 6 Abducens
What CN works with the superior oblique muscles of the eye?
What does CNN 3 control?
Medial rectus, superior rectus, inferior rectus, and inferior oblique
What are the different extrinsic eye muscles?
- Lateral, medial, inferior and superior rectus
- Inferior and superior oblique
explain what happens when you cry?
Lacrimal glands secrete tears which drain into the lacrimal puncta which then drains into the nasal cavity
What type of fluid does the anterior cavity of the eye contain?
What is the posterior cavity filled with?
what is part of the middle ear?
- 3 ossicles
- Opening to Eustachian tube->nasopharynx
what makes up the ossicles?
Malleus, stapes, incus
What makes up the internal ear?
- In petrous portion of temporal bone
- Semicurcular canals-anterior, posterior and lateral
- Semicircular ducts
What is the structure of the semicircular canals?
- Contain semicircular ducts
- Each one has an ampulla which contains crista ampullaris which is a bump with hair cells covered with a cupula (huge with no otoliths)
- Cupula moves by moving endolymph
What is the function of the semicircular canals?
Detect rotational acceleration
What is the structure of the cochlea?
- Contains a cochlear duct
- Roof of duct is vestibular membrane
- The floor is the basilar membrane
- The roof separates it from scala vestibuli and the floor separates it from scala tympani-these contain perilymph and meet at the helicotrema
Describe the bony labyrinth of the inner ear
- Filled with perilymph
- 3 Semicircular canals (anterior, posterior and lateral)
describe the membranous labyrinth of the inner ear
- Filled with endolymph
- Cochlear duct
- Utricle and saccule
- 3 Semicircular ducts
what does the vestibule contain?
utricle and saccule
what is the function of the cochlear duct
what structure(s) is responsible for equilibrium?
vetibule and semicircular canals
what is the structure of the organ of corti?
- Contains hair cells with stereocilia (stiff microvilli)
- If microvilli are bent, the cell fires!
- Tectorial membrane (gelatinous)
- When cell fires, it communicates signal to sensory neurons. Cell bodies are in spiral ganglion
what does the stapes do?
Causes vibration of oval window
what structure absorbs pressure of the sound waves?
Describe the structures that deal with equilibrium
- Utricle and saccule (goes into cochlea) and each contains a macula (patch of hair cells)
- Macula is covered by otolithic membrane (gelatinous) which contains otoliths of CaCO3
WHat is the function of the vestibule?
Determine static head position and linear acceleration
what is the function of the utricle?
Horizontal acceleration (like in the car)
what is the function of the saccule?
Detects vertical acceleration (Saccule-Sky (up))
Describe the structure of parotid glands
- Serous acini only
- Looks uniform
- Parotid duct opens at 2nd upper molar
- Parotid gland is near the ear and extends down to the jaw
Describe the structure of the submandibular gland
- Mostly serous acini
- See nice serous acini surrounded by mucous acini
describe the structure of sublingual glands
- Mostly mucous acini
- serous cells don't form clumps
- Open into multiple tiny ducts under the tongue
what are the extrinsic salivary glands?
Parotid, submandibular, sublingual
what are the intrinsic salivary glands?
Intrinsic mucous and intrinsic serous glands
where will you find intrinsic salivary glands?
- Microscopic, buried in walls of the oral cavity
- Also buried deep to papillae of the tongue
- Acini are randomly scattered
Where will you find serous glands of von Ebner?
drain into the crypts of vallate papillae