Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Keratoconus wikipedia , lookup
Contact lens wikipedia , lookup
Idiopathic intracranial hypertension wikipedia , lookup
Mitochondrial optic neuropathies wikipedia , lookup
Photoreceptor cell wikipedia , lookup
Eyeglass prescription wikipedia , lookup
Cataract surgery wikipedia , lookup
Chapter 11 Medical Terminology and Chapter 10 Body Structures: SPECIAL SENSES Functions of the Eyes – receive images and transmit to brain receptor organs of sight Optic: pertaining to eye or sight Ocular: pertaining to the eye Extraocular: outside the eyeball Intraocular: within the eyeball Structures of the Eye ADNEXA – accessory structures Orbit Eye Muscles Eyelids Eyelashes Conjunctiva Lacrimal Apparatus www.ipo.tue.nl/.../seminar-2%20human/ sld015.htm What structure contains and protects the eyeball and its associated muscles, blood vessels, and nerves ORBIT www.lau-verlag.de/anatom/ skeletal-system.htm Frontal Sphenoid Ethmoid Maxilla Zygoma Lacrimal Palatine Muscles of the Eye 6 Major muscles attached to each eye Superior/Inferior Rectus Superior/Inferior Oblique Lateral/Medial Rectus Binocular means both eyes working together. Eyelids: protect the eyeball from foreign matter, excessive light, and impact Canthus: angle where upper/lower eyelids meet Inner Canthus Outer Canthus Conjunctiva: lines the underside of each eyelid and provides protective covering over exposed surface of eyeball The Lacrimal Apparatus – structures that produce, store, and remove tears Lacrimal Glands: secrete lacrimal fluid to maintain moisture on the anterior surface of the eyeball Lacrimal Canaliculi: ducts at the inner canthus of each eye – collect tears and drain them into the lacrimal sac Lacrimal sac: an enlargement of the upper portion of the lacrimal duct Lacrimal duct: passageway that drains lacrimal fluid into the nose Eyebrows and Eyelashes Prevent foreign matter from reaching the eye Cilia – small hairs that are located along the edges of the eyelids (eyelashes) The Eyeball globe www.optelec.com/ lv_ref.php Made up of 3 layers Sclera Choroid Retina Interior of eye is divided into anterior/posterior segments The Sclera – the white of the eye Outer layer of eye Maintains shape of the eye and protects the delicate inner layers of tissue Cornea: transparent anterior portion of the sclera Provides most of the optical power of the eye The Uveal Tract The vascular layer of eye Choroid: opaque (light cannot pass through it) middle layer of the eyeball – provides blood supply for entire eye Iris: colored layer that surrounds pupil – it’s muscles control amount of light entering eye – decrease muscles contract making opening smaller (visa versa) Pupil: black circular opening in center of iris – permits light to enter eye Lens: focuses images on the retina – located behind iris and pupil Ciliary Body: located within the choroid, set of muscles and ligaments that adjust lens to refine the focus of light rays on the retina Near-by objects = thicker Distance objects = thinner Nerve layer located between the posterior chamber and the choroid layer at the back of the eye Contains light sensitive rods (black/white receptors) and cones (color receptors) Receive images and convert them into nerve impulses The Retina Optic disk: (blind spot) – contains no rods/cones – nerve endings of retina gather to form optic nerve which transmits nerve impulses from the retina to the brain The Anterior Segment – front 1/3 of eye Divided into anterior and posterior chambers Anterior chamber Posterior chamber behind the cornea in front of the iris Between the back of the iris and the front of the lens These chambers filled with aqueus humor (fluid) Nourishes intraocular structures Constantly filtered and drained which regulates intraocular pressure (IOP = btwn 12 & 21 mm Hg) The Posterior Segment – posterior 2/3 of eye Aids in maintaining the shape of the eye Contains vitreous humor Lined with retina and it’s related structures Normal Action of the Eye Accommodation: the eyes make adjustments for seeing at various distances Includes constriction or dilation of the pupil, movement of the eye, and changes in the shape of the lens Convergence: simultaneous inward movement of both eyes – in an effort to maintain single binocular vision as an object comes nearer Visual Acuity: the ability to distinguish object details and shape at a distance Normal vision = 20/20 Snellen Chart: used to measure visual acuity Glaucoma Glaucoma is the increase of the IOP (intra-ocular pressure) Macular Degeneration Loss of central vision over a period of time but, not total blindness Pathology of the Eyes EYELIDS Blepharoptosis (A) Ectropion (C) Entropion (B) Hordeolum: (D) A C B D Functions of the Ears Receive sound impulses and transmit them to the brain Inner also helps maintain balance Auditory: pertaining to the sense of hearing Acoustic: relating to sound or hearing Structures of the Ear The Outer Ear The Middle Ear The Auditory Ossicles The Eustachian Tubes The Inner Ear The Outer Ear Pinna: auricle – External portion Catches sound waves and transmits them into the external auditory canal (EAC) EAC: transmits sound waves from pinna to middle ear What is the name for the sticky yellow-brown substance that functions to prevent bacteria and dust from entering the middle ear?? CERUMEN (earwax) The Middle Ear Tympanic Membrane (eardrum) Transmits sound by vibrating Surrounded by hollow air spaces – mastoid cells (which can easily become involved in a middle ear infection) The Auditory Ossicles 3 small bones in the middle ear Transmit sound waves from the eardrum to the inner ear by vibration Named for their shape Malleus: hammer Incus: anvil Stapes: stirrup malleus stapes incus The Inner Ear- Contains sensory receptors for hearing and balance labyrinth Cochlea: spiral shaped passage that leads from the oval window Cochlear duct: filled with fluid that vibrates when sound waves strike it Organ of Corti: receptor site that receives vibrations and relays them to the auditory nerve fibers that transmit them to the auditory center of the cerebral cortex, where they are interpreted and heard Semicircular canals: helps maintain equilibrium Normal Action of the Ears Air conduction: sound waves enter the ear through the pinna, travel down the auditory canal, and strike the TM between the outer and middle ear Bone conduction: as the eardrum vibrates, it moves the auditory ossicles and these conduct sound waves through the middle ear Sensorineural conduction: sound vibrations reach the inner ear via the oval window where the structures of the inner ear receive the sound waves and relay them to the brain Pathology of the Ears Outer Ear Middle Ear Eustachitis: inflammation of the eustachian tube Mastoiditis Otosclerosis: ankylosing of the bones of the middle ear = hearing loss Otitis Media Inner Ear Otalgia: earache Otitis: inflammation of the ear Otomycosis: swimmer’s ear Meniere’s syndrome: vertigo, fluctuating hearing loss, tinnitus (ringing or buzzing in the ears) Hearing Loss Deafness Noise-Induced hearing loss Diagnostic Procedures of the Ears Audiometry: use of audiometer to measure hearing Speech audiometry: measures the threshold of speech reception and speech discrimination Monaural: testing involving one ear Binuaral: testing involving both ears audiometry Both ears - AU Right ear - AD Left ear - AS Treatment Procedures of the Ears Outer Ear Middle Ear Otoplasty: surgical repair of the pinna of the ear Mastoidectomy Tympanocentesis Tympanostomy tubes Inner Ear Fenestration Labyrinthectomy Labyrinthotomy otoplasty tympanostomy Mastoidectomy labyrinthectomy