Vision - Kashan University of Medical Sciences

Vision - Kashan University of Medical Sciences

Vision Surface Anatomy of the Eye Eyebrows divert sweat from the eyes and contribute to facial expressions Eyelids (palpebrae) blink to protect the eye from foreign

objects and lubricate their surface Eyelashes detect and prevent foreign objects Conjunctiva A mucous membrane lining the inside of the eyelids and the anterior surface of the eyes

Conjunctivitis (pinkeye): inflammation of the conjunctival sac Latin con = with, and junctus = joined (cf. junction) The Lacrimal Apparatus

Lacrimal Apparatus: lacrimal gland lacrimal sac nasolacrimal duct Rinses and lubricates the conjunctival sac

Drains to the nasal cavity where excess moisture is evaporated Extrinsic Eye Muscles Lateral, medial, superior, and inferior rectus muscles (recall, rectus = straight); superior and inferior oblique muscles

Eye Movments Cranial nerves & eye CN II - Optic nerve, vision CN III - Oculomotor, 5 muscles, Autonomic to pupil CN IV - Trochlear, superior oblique

CN V - Trigeminal, ocular sensation CN VI - Abducens, lateral rectus CN VII - Facial, obicularis oculi Autonomic Regulation of the Iris Autonomic Regulation of the Iris

Pupil Constricts Pupil Dilates Internal Anatomy of the Eye Anterior Segment contains

the Aqueous Humor Iris

Ciliary Body Suspensory Ligament Lens Posterior Segment contains the Vitreous Humor Latin humor = liquid

Circulation of the Aqueous Humor Ciliary process at the base of the iris produces aqueous humor Scleral venous sinus returns aqueous humor to the blood stream

Positive pressure from aqueous humor, generally above 6 mm Hg, is needed to keep the retina attached to the back of the eye and to nourish the cornea and lens

which have no blood vessels. But if the fluid cannot drain!? Glaucoma any disturbance that increases aqueous humor volume and pressure which causes pain ultimately the vitreous humor crushes the retina causing blindness

15 Internal Anatomy of the Eye--Tunics Fibrous tunic: sclera & cornea Vascular tunic: choroid layer Sensory tunic: retina

The Two Layers of the Retina Outer pigmented layer absorbs light to prevent light scattering inside Inner neural layer has the photosensory cells and various

kinds of rneurons in three layers Neural layer Organization in the Retina Photoreceptors: rods (for dim light) and cones (3

colors: blue, green and red, for bright light) Bipolar cells are connecting interneurons Ganglion cells axons become the Optic Nerve

The Optic Disc Axons of ganglion cells exit to form the optic nerve Blood vessels enter to serve the retina by running on top of the neural layer The location of the blind

spot in our vision blind spot vertebrate octopus

20

Recently Viewed Presentations

  • Introduction  la proprit intellectuelle (PI) Avant de commencer

    Introduction la proprit intellectuelle (PI) Avant de commencer

    Avant Vous découvrirez les cinq principaux types de propriété intellectuelle administrés par l'Office de la propriété intellectuelle du Canada (OPIC). L'OPIC joue un rôle essentiel pour favoriser l'innovation et la productivité du Canada en délivrant et en offrant une protection...
  • In which one of the following is the oxidation number of the ...

    In which one of the following is the oxidation number of the ...

    In which one of the following is the oxidation number of the transition metal incorrect? Complex Species / Oxidation Number of Transition Metal [Co(en)(NH3)2(OH)2]Cl / +3 ... tetradentate 6 - hexadentate Which ligand formula is incorrectly matched with its name...
  • The Orbit

    The Orbit

    Orbital Diseases. Orbital diseases may be vascular, thyroid-related (Graves' disease), infectious, inflammatory, or neoplastic.. Despite the number of different tissues present in the orbit, the expression of disease due to different pathologies is often similar.
  • Invertebrates - mrsbahe.weebly.com

    Invertebrates - mrsbahe.weebly.com

    Phylum: Cnidaria—includes jellyfishes, sea fans, sea anemones, hydras, and corals. Cnidarians are aquatic, soft-bodied, carnivorous, radially symmetrical animals with stinging tentacles arranged in circles around their mouths.
  • Undergraduate Research in the UK: One Perspective Alan

    Undergraduate Research in the UK: One Perspective Alan

    Alan Jenkins, Mick Healey and Ruth L Healey Oxford Brookes University, University of Gloucestershire, University of Chester [email protected] ; [email protected] ; [email protected] "We need to encourage universities and colleges to explore new models of curriculum. … There are several models...
  • Process Costing Systems - Pearson

    Process Costing Systems - Pearson

    Chapter 17 Process Costing Process Costing Systems Process costing is a costing system in which the product or service cost is obtained by assigning costs to masses of like units Conversion costs are costs that are applied uniformly in a...
  • National Wrestling Coaches Association - NWCA

    National Wrestling Coaches Association - NWCA

    Women's Intercollegiate Wrestling Prepared by the National Wrestling Coaches Association Quick Facts of Wrestling Wrestling prides itself on the fact that virtually anyone can participate regardless of gender, size, weight, socioeconomic background, and even most disabilities.
  • Job 23:1-9; 16-17 God nooi ons uit  en

    Job 23:1-9; 16-17 God nooi ons uit en

    Ek glo in God wat Sy Seun Jesus vir ons gestuur het; ek glo in die vergifnis van sonde en ek glo in die Heilige Gees. * God praat met ons en ons luister Epiklese Genadige God, ek is so...