Physiology of the eye Imagine your eyes as
- Slides: 45
Physiology of the eye
Imagine your eyes as a camera
Sagital View of the eye
1. Image Focusing Refractive media • • Cornea Humor akuos Crystallin Lens Vitreous Body
Refractive media CORNEA • Media refrakta yang terpenting • Barrier penting dari isi bola mata • Kekuatan refraksi ± 43 Dioptri • Indeks bias 1. 376
Cornea Physiology • sel epitel dpt hidup rata-rata 4 -8 hr • epitel dpt beregenerasi lengkap dlm 7 hr • epitel dan LAM permukaan optik halus • Pompa endotel mempertahankan kondisi dehidrasi relatif
Physiology cont’d • Innervated by N V. 1 corneal sensitivity • Tear film maintain the smooth corneal surface, and protection effect
Refractive Media Aquos Humor • Produced by the ciliary body • Refractive Media • Nutrition and O 2 supply for cornea, lens etc. • Maintain the ocular pressure • Refractive index 1. 336
Refractive Media The Lens • biconvex, avascular, and transparent • 66% water • Other Proteins • Protein Can be degenerated cataract Other function 1. Accommodations 2. UV absorption (protecting the retina)
Refractive Media Vitreous Body
• • • Struktur seperti gel 80% terdiri air Index bias 1. 334. Beratnya sekitar 4 g, volumenya 4 cc Ukuran sekitar 2/3 dari seluruh volume bola mata
Refractive Indices of Refractive Media Element Air Cornea Surface Thickness Radius (mm) Anterior Posterior 7. 7 6. 8 Aqueous Anterior lens Anterior cortex Posterior Lens core Posterior Anterior lens cortex Posterior Vitreous Retina 10. 0 0. 50 Refractive Index 1. 000 1. 376 Position (mm) 3. 10 0. 546 1. 336 1. 386 3. 60 2. 419 0. 635 1. 406 1. 386 4. 146 6. 565 0. 0 0. 50 7. 911 -5. 76 -6. 0 7. 20 16. 80 -12. 0 1. 336 24. 0
The receiver RETINA
• Transparant, • Histology 10 layers • Photoreseptor : rod & cones • Supporting : Glial cells, amacrine, Muller cells
Comparison of Rods and Cones Rods Cones Used for night vision Used for day vision Very light sensitive; sensitive to scattered At light (have more pigment than cones) sensitive; sensitive only to direct light Loss causes night blindness Loss causes legal blindness Low visual acuity High visual acuity; better spacial resolution Not present in fovea centralis Concentrated in fovea Slow response to light, stimuli added over Fast response to light, can perceive more time rapid change in stimuli Stacks of membrane-enclosed disks are Disks are attached to outer membrane least 1/10 th of the rods light unattached to cell membrane 20 times more rods than cones in the retina One type of photosensitive pigment Three types of photosensitive pigment in (monochrome vision) human (color vision) Confer achromatic vision Confer color vision
• Fovea central for visual acuity • Perifovea peripheral vision
The Conversion Phototransduction • Process of conversion from image in to neural impulse
The Pathway Retina into visual cortex § Start from the retinal photoreceptors , through the optic nerve, chiasma and optic tract into the LGN § Ends in the visual cortex (LGN) Striate Cortex
The Pathway Optic Nerve (C. N. II) • Merupakan Perpanjangan dari Otak • Terdiri dari 4 bagian • Intra ocular, intra orbita, intra canalicular, intra cranial
Cortex visual Visual Perception Area Visual Primer Area Visual Sekunder • Jalur Ventral / What stream V 1 -V 2 -V 4 -Lobus temporal informasi warna, bentuk&tekstur –mengenali benda • Jalur Dorsal / where stream V 1 -V 2 -V 3 -V 5/MT-lobus parietal. Informasi pergerakan, orientasi ruang dan lokasi
Optic Nerve field of vision
• Pembagian daerah visual field saat serabut saraf berjalan ke otak
Neural pathways 7 direct reflex
Neural pathways consensual reflex Note: Ada 2 tempat dimana information bersilangan - the optic chiasm - the pretectal nucleus. to the Edinger-Westphal nucleus 8
RELATIVE AFFERENT PUPILLARY DEFECT (RAPD) v. Menggambarkan adanya kelainan patologis pada jalur afferent refleks pupil v. Membandingkan refleks pupil 2 mata dengan melihat r. c. langsung dan tidak langsung kelainan harus unilateral v. Sederhana, mudah dan obyektif v. Dapat dievaluasi meskipun pasien dalam kondisi tidak sadar
BAGAIMANA RAPD TERJADI ? v. Penyinaran pada mata yang sakit penerimaan cahaya kurang pada mata sakit dan juga ke mata sehat otak akan menginterpretasikan adanya penurunan penerimaan cahaya otak merespon dengan pupil berdilatasi supaya cahaya lebih banyak masuk ke 2 mata, walau hanya 1 mata yang sakit.
KONDISI DGN PENURUNAN PENGLIHATAN ADA TIDAKNYA RAPD. . . : Neuritis optik Walau neuritis optik yang sedang dan kehilangan penglihatan yang ringan, memberi RAPD berat. Ischemic Optic Neuropathies Ada Glaucoma Akan muncul jika satu mata lebih berat dari yang lain Traumatic optic neuropathy Ada Optic Nerve Tumor Ada Optic Nerve Inflamation (sarcoidosis) Ada Ischemic Retinal Disease (CRVO, CRAO, etc) Ada Ischemic Ocular Disease Ada Chiasmal Disease Jarang Optic Tractus Disease Ada dan biasanya kontralateral dengan tempat lesi krn jumlah serabut yang bersilangan lebih banyak. Retinal Detachment Akan timbul jika makula ablasi atau dua kuadran retina ablasi Severe Macular Degeneration Timbul jika keadaan berat atau unilateral Retinal or Choroidal Tumor Timbul jika keadaan berat Amblyopia Timbul jika keadaan berat Refractif Error Tidak ada walau keadaan berat Cerebral disease Tidak ada
The Supporting structure of the Eye • Palpebra • Conjunctiva cover most exposed part of the eye • Sclera the sceleton of the eye • Uveal Tract Iris, Ciliary Body and Choroid Nutrition, circulation, immune system • Lacrimal Gland tear film production • Extra ocular muscles Ocular movement
The Extraocular Muscles • 7 extraoculer muscles • 6 Ocular Movement
Eye Movements I. Monocular eye movements (ductions) 1. Adduction is movement of the eye nasally. 2. Abduction is movement of the eye temporally 3. Elevation (supraduction) is an upward rotation of the eye. 4. Depression (infraduction) is a downward rotation of the eye. 5. Intorsion (incicloduction)is a nasal rotation of the superior portion of the vertical corneal meridian. 6. Extorsion (excycloduction) is a temporal rotation of the superior portion of the vertical cornea meridian Sherrington’s law Pada gerakkan monookular impuls syaraf akan dialirkan secara aktif untuk otot-otot sinergis sedangkan untuk otot -otot antagonis impuls syaraf akan dihambat. II. Binocular eye movements (versions) Innervasi yang seimbang dan simultan mengalir ke otot-otot yang berpasangan Hering’s law
Parese n. III
right cranial nerve VI palsy
Penutup • Mata merupakan satu kesatuan sistem optik • Jalur penglihatan meliputi pembiasan cahaya, reseptor, neurotransmisi dan persepsi • Keseluruhan struktur bola mata berfungsi untuk menunjang fungsi visual
Terima kasih
JALUR NEAR REFLEKS : AKOMODASI KONVERGENSI
- Story behind this picture
- Present continuous close
- Close your eyes and imagine story
- Open your eyes free your mind
- Anatomy and physiology of eye
- Brown eyes are dominant to blue eyes
- Genotypes punnett square
- Pf
- Punnet square eye color
- Hazel vs green eye color
- Hammurabi
- Bird's eye view vs worm's eye view
- Eye for an eye code
- Hammurabi's code activity
- An eye for an eye a tooth for a tooth sister act
- Explain the image
- An eye for an eye meaning
- Behold he is coming
- Imagine it's your birthday
- These are photos from your photo album
- Imagine that you are preparing a project with your friend
- Give us your hungry your tired your poor
- 當轉眼仰望耶穌turn your eyes upon jesus
- I _______ speak swedish, but maybe i'll learn it someday.
- Amazing grace how sweet the sound hillsong
- 當轉眼仰望耶穌turn your eyes upon jesus
- The eyes eats first
- I pray also that the eyes of your heart
- Through your child's eyes
- Love in your eyes
- Stuff your eyes with wonder
- Open your eyes the invisible argument
- Open your eyes lgbt
- You eat with your eyes first
- Oppression 1765 to 1835
- Close your eyes and go back
- Eyes on the prize ain't scared of your jails summary
- Open your eyes look within
- Tis midnight and on olive's brow
- Hình ảnh bộ gõ cơ thể búng tay
- Bổ thể
- Tỉ lệ cơ thể trẻ em
- Gấu đi như thế nào
- Chụp phim tư thế worms-breton
- Bài hát chúa yêu trần thế alleluia