Chapter Three: The Senses Flashcards
What are the orbital cavities of the eye
-the roof
-the lateral wall
-the floor
-the medial wall
The roof of the orbit
-orbital plate of frontal bone
-lesser wing of sphenoid bone
The lateral wall of the orbit
-frontal process of zygomatic bone
-zygomatic process of frontal bone
-greater wing of sphenoid
The floor of the orbit
-maxilla
-palatine bone
-orbital plate of zygomatic bone
The medial wall of the orbit
-maxilla
-lacrimal bone
-ethmoid bone
-lesser wing of sphenoid
Supraorbital margin
-part of the frontal bone
-forms upper boundary of anterior base of orbit
Supraorbital foramen
-at junction of lateral 2/3 and medial 1/3 of the supraorbital margin
-where supraorbital nerve and vessels emerge
Infraorbital margin
-lower border of the base of the orbit
-formed by margin of maxilla and zygomatic bone
Infraorbital groove
-floor of the orbit
Infraorbital foramen
-lies below the orbital margin
Which nerve runs through infraorbital foramen
-infraorbital nerve
-which is a branch of the maxillary division of trigeminal nerve
Optic foramen
-opens at the nasal side of orbit
Which nerve and artery runs through the optic foramen
-optic nerve
-opthalamic artery
Superior orbital fissure
-lies between greater and lesser wings of the sphenoid bone
Structures passing through superior orbital fissure
-oculomotor nerve
-trochlear nerve
-branches of ophthalmic division of trigeminal nerve
-abducens nerve
-sympathetic roots of ciliary ganglion
Inferior orbital fissure
-lies on the floor of the orbit
-seperates greater wing of sphenoid from orbital surfaces of palatine, maxilla, and zygomatic bones
What nerve passes through inferior orbital fissure
-infraorbital nerve and vessels
Nasolacrimal fossa
-anterior end of medial orbital wall
What structures are in the nasolacrimal fossa
-lacrimal sac
3 layers of the eyeball
-fibrous layer
-vascular layer
-retina (inner layer)
Outer layer of the eyeball
-fibrous
Parts of the fibrous layer
-sclera
-cornea
Sclera
-white opaque connective tissue
-gives shape to the eyeball
-protects internal parts
-attachment site for eye muscles
Cornea
-transparent fibrous layer
-superficial to iris and allows light to enter interior of the eye
Scleral venous sinus
-at junction of cornea and sclera
-aids in drainage of aqueous fluid
Middle layer of the eyeball
-vascular layer (uvea)
Parts of the vascular layer (uvea)
-choroid
-ciliary body
-iris
Choroid
-posterior, dark brown, vascular portion
-absorbs stray light rays
Parts of the ciliary body
-ciliary processes
-ciliary muscles
Ciliary processes
-folds on the internal surface of the ciliary body which secrete aqueous humor
Ciliary muscles
-smooth muscle tissue which encircles the lens
-contracts and relaxes to alter shape of the lens in order to adapt the lens for near or far vision
Iris
-coloured portion of the eyeball
-located between cornea and lens
-surround the pupil
2 muscle layers of the iris
-sphincter pupillae muscle
-dilator pupillae muscles
Inner layer of the eyeball
-retina
Optic disc
-site of exit of the optic nerve
-blind spot
2 major portions of the retina
-outer pigmented layer
-inner neural layer
Outer pigmented layer of retina function
-contains melanin which helps absorb stray lights rays
Inner neural sensory layer of retina function
-contains photoreceptors
3 layers of the inner neural layer of retina
-photoreceptor cell layer (contains rods and cones)
-bipolar cell layer
-ganglion cell layer
Macula
-exact center of retina
-contains small depression called fovea centralis
Lens of the eyeball
-clear transparent disc structure located posterior to the iris and pupil
What changes the shape of the lens
-ciliary muscles
2 cavities of the inferior of the eyeball
-anterior segment
-posterior segment
Anterior segment of inferior of eyeball location
-located between cornea and lens
Posterior segment of inferior of eyeball location
-located between lens and retina
Anterior segment of inferior of eyeball structures
-anterior chamber
-posterior chamber (watery aqueous humor)
Posterior segment of inferior of eyeball structure
-jellylike vitreous body
-contributes intraocular pressure
How is aqueous humor produced and drained
-by ciliary processes
-drained into scleral venous sinuses
Hyaloid canal
-narrow channel that travels through vitreous body from the optic disc to the posterior aspect of the lens
Superior rectus action
-moves eyeballs superiorly and medially
Superior rectus innervation
-oculomotor nerve
Inferior rectus action
-moves eyeballs inferiorly and medially
Inferior rectus innervation
-oculomotor nerve
Lateral rectus action
-moves eyeballs laterally
Lateral rectus innervation
-abducens nerve
Medial rectus action
-moves eyeballs medially
Medial rectus innervation
-oculomotor nerve
Superior oblique action
-moves eyeballs inferiorly and laterally
Superior oblique innervation
-trochlear nerve
Inferior oblique action
-moves eyeballs superiorly and laterally
Inferior oblique innervation
-oculomotor nerve
Levator palpebrae superioris action
-elevates upper eyelids
Levator palpebrae superioris innervation
-oculomotor nerve
3 major regions of the ear
-external (outer) ear
-middle ear
-internal (inner) ear
Function of the external (outer) ear
-collects sound waves and channels them inward
Parts of the external (outer) ear
-auricle (pinna)
-external acoustic meatus
-tympanic membrane
Auricle (pinna)
-flap of elastic cartilage covered by skin
Parts of the auricle
-helix: rim
-lobule: inferior portion
External acoustic meatus
-ear canal
-curved tube that lies in temporal bone
-leads to tympanic membrane
Tympanic membrane
-eardrum
-thin wall of dense connective tissue between external acoustic meatus and middle ear
Ceruminous glands
-hairs located on external acoustic meatus
-secrete cerumen (earwax)
Middle ear
-small, air filled cavity in petrous portion of temporal bone
How is middle ear separated from external ear
-tympanic membrane
How is middle ear separated from internal ear
-vestibular window and cochlear window
3 auditory ossicles of the middle ear
-malleus
-incus
-stapes
2 skeletal muscles attached to ossicles
-prevent damage to ear
-tensor tympani muscle
-stapedius muscle
Tensor tympani muscle innervation
-mandibular division of trigeminal nerve
Stapedius muscle innervation
-innervated by facial nerve
Auditory tube
-opening of the anterior wall of tympanic cavity
-travels to the nasopharynx
Auditory tube function
-equalize air pressure on both sides of the tympanic membrane
Internal ear (labyrinth) divisions
-outer bony labyrinth
-inner membranous labyrinth
3 areas of the bony labyrinth
-semicircular canals
-vestibule
-cochlea
Membranous labyrinth
-series of interconnected sacs and tubes inside the bony labyrinth
Vestibule parts
-utricle and saccule
Parts of the semicircular canals
-anterior
-posterior
-lateral
Ampulla
-swelling at one end of each semicircular canal
Semicircular ducts function
-communicate with the utricle of the vestibule
2 channels of the cochlea
-scala vestibuli
-scala tympani
What structure separates the scala vestibuli and scala tympani
-cochlear duct
Scala vestibuli
-ends at the vestibular window
Scala tympani
-ends at the cochlear window
Vestibular membrane
-sepeartes cochlear duct from scala vestibuli
Basilar membrane
-separates the cochlear duct from the scala tympani
Spiral organ (organ of corti)
-coiled sheet of epithelial and supporting cells which contains inner and outer hair cells
What are hair cells
-mechanoreceptors that detect auditory stimuli
Tectorial membrane
-flexible gelatinous projection over hair cells
Which structure forms the lateral walls of the mouth
-cheeks
What are the labia of the mouth
-the lips
Labial frenulum
-mucous membrane that attaches each lip to the gum
Oral cavity
-space that extends from the lips and teeth to the fauces
2 components of the oral cavity
-oral vestibule
-oral cavity proper
Oral vestibule
-space between external cheeks and lips and the internal gums and teeth
Oral vestibule
-space between external cheeks and lips and the internal gums and teeth
Oral cavity proper
-space that extends from the gums and teeth to the fauces that connects the oral cavity to the oropharynx
2 parts of the palate
-hard palate
-soft palate
Hard palate
-forms anterior 2/3 of the roof of the mouth
-consists of palatine processes of maxilla and perpendicular plates of palatine bones