TY  - CHAP
M1  - Book, Section
TI  - Lens
A1  - Harper, Richard A.
A2  - Riordan-Eva, Paul
A2  - Augsburger, James J.
PY  - 2017
T2  - Vaughan & Asbury's General Ophthalmology, 19e
AB  - The  (crystalline)  lens  contributes  to  focusing  of  images  on  the  retina.  It  is  positioned  just  posterior  to  the  iris  and  is  supported  by  zonular  fibers  arising  from  the  ciliary  body  and  inserting  onto  the  equatorial  region  of  the  lens  capsule  (see  Figure  1–12).  The  lens  capsule  is  a  basement  membrane  that  surrounds  the  lens  substance.  Epithelial  cells  near  the  lens  equator  divide  throughout  life  and  continually  differentiate  into  new  lens  fibers,  so  that  older  lens  fibers  are  compressed  into  a  central  nucleus;  younger,  less-compact  fibers  around  the  nucleus  make  up  the  cortex.  Because  the  lens  is  avascular  and  has  no  innervation,  it  must  derive  nutrients  from  the  aqueous  humor.  Lens  metabolism  is  primarily  anaerobic  owing  to  the  low  level  of  oxygen  dissolved  in  the  aqueous.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/23
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1144468147
ER  -