logging in or signing up TEARS amitchabria Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 844 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: February 14, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript TEARS: TEARS Protective layer Watery liquid-Bathes/Nourishes Three layers: Lipid, Aqueous and Mucin Tear – secreted by glands around the eyelid TEAR PRODUCTION: TEAR PRODUCTION Lipid layer – Meibomian glands & Glands of Zeis Aqueous layer – Lacrimal glands, Glands of Krause & Wolfring Mucin Layer Goblet cells PHYSICAL CHARACTERISTICS OF TEAR FILM: PHYSICAL CHARACTERISTICS OF TEAR FILM Surface tension :40-50 dynes/cm2 pH :6.9 -7.4 Osmolarity :290-310 mOsm/l Viscosity :1.9-2 centipoises FUNCTIONS OF TEAR FILM : FUNCTIONS OF TEAR FILM Lubricates and moistens eye surface Provides nutrients & oxygen to cornea Washes away foreign bodies Protects against bacteria and viruses (with help of enzyme Lysozyme)COMPOSITION OF TEAR FILM: COMPOSITION OF TEAR FILM Lipid layer Proteins (albumin, globulin) Lysozyme (antibacterial) Aqueous layer Nutrients (minerals,Vitamins, electrolytes) Mucin layer Glycoproteins make the corneal surface more hydrophilicFUNCTIONS OF THE TEAR FILM LAYERS: FUNCTIONS OF THE TEAR FILM LAYERS Lipid layer Prevents evaporation of aqueous layer. Aqueous layer Nourishes and moisturizes the cornea and sclera. Protects against micro-organisms Mucin layer Helps in the even spreading of the tear film over the ocular surfaceTEAR SECRETION : TEAR SECRETION Two types of secretors :- basic and reflex Basic secretors Supply tears at constant rate – gland of Krause and wolfring Reflex secretors Supply tears when there is a stimulus like foreign body, emotions, bright light.BLINKING: BLINKING Provides regular rewetting Ensures normal tear film function Tear Break Up Time (TBUT) – 10 seconds Compromised blinking – leads to SSS (Screen Stare Syndrome) TEAR DRAINAGE: TEAR DRAINAGE PUNCTA CANALICULI LACRIMAL SAC NASO LACRIMAL DUCT EVAPORATION You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
TEARS amitchabria Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 844 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (0) Added: February 14, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript TEARS: TEARS Protective layer Watery liquid-Bathes/Nourishes Three layers: Lipid, Aqueous and Mucin Tear – secreted by glands around the eyelid TEAR PRODUCTION: TEAR PRODUCTION Lipid layer – Meibomian glands & Glands of Zeis Aqueous layer – Lacrimal glands, Glands of Krause & Wolfring Mucin Layer Goblet cells PHYSICAL CHARACTERISTICS OF TEAR FILM: PHYSICAL CHARACTERISTICS OF TEAR FILM Surface tension :40-50 dynes/cm2 pH :6.9 -7.4 Osmolarity :290-310 mOsm/l Viscosity :1.9-2 centipoises FUNCTIONS OF TEAR FILM : FUNCTIONS OF TEAR FILM Lubricates and moistens eye surface Provides nutrients & oxygen to cornea Washes away foreign bodies Protects against bacteria and viruses (with help of enzyme Lysozyme)COMPOSITION OF TEAR FILM: COMPOSITION OF TEAR FILM Lipid layer Proteins (albumin, globulin) Lysozyme (antibacterial) Aqueous layer Nutrients (minerals,Vitamins, electrolytes) Mucin layer Glycoproteins make the corneal surface more hydrophilicFUNCTIONS OF THE TEAR FILM LAYERS: FUNCTIONS OF THE TEAR FILM LAYERS Lipid layer Prevents evaporation of aqueous layer. Aqueous layer Nourishes and moisturizes the cornea and sclera. Protects against micro-organisms Mucin layer Helps in the even spreading of the tear film over the ocular surfaceTEAR SECRETION : TEAR SECRETION Two types of secretors :- basic and reflex Basic secretors Supply tears at constant rate – gland of Krause and wolfring Reflex secretors Supply tears when there is a stimulus like foreign body, emotions, bright light.BLINKING: BLINKING Provides regular rewetting Ensures normal tear film function Tear Break Up Time (TBUT) – 10 seconds Compromised blinking – leads to SSS (Screen Stare Syndrome) TEAR DRAINAGE: TEAR DRAINAGE PUNCTA CANALICULI LACRIMAL SAC NASO LACRIMAL DUCT EVAPORATION