Ciliary Muscle Contraction

http://www.handwrittentutorials.com - An explanation of the confusing ciliary muscle contraction process. For more entirely FREE tutorials and accompanying PDFs visit http://www.handwrittentutorials.com

Category:

Science & Technology

Tags:

• Eye
• Ciliary
• ciliary muscle
• neuroanatomy
• neuroscience
• anatomy
• tutorial
• handwritten
• tutorials

[SoHoTandCool]

i thought you were going to talk about ciliary muscle contraction with respect to miosis and mydriasis. does it follow the same rule? but then how come you the pupil change in size?? a bit confused.

[harpinmartin]

@SoHoTandCool Miosis and Mydriasis are movements of the pupil. The pupil's size is not controlled by the Ciliary muscles but rather two muscles known as "Sphincter Pupillae" and "Dilator Pupillae". This has nothing to do with the ciliary muscles or the lens.

NB. You might be getting confused by the Ciliary Ganglion which is a parasympathetic nerve ganglion at the back of the eye which give nervous innervation to the Sphincter Pupillae and the Cillary muscles.

[eugenekhcha]

I still don't understand what causes the tension on the zonules. Clearly the ciliary muscles aren't providing the tension (pulling on the zonules) because other wise when the ciliary muscles are taut the zonules would be taut. So what are the zonules and ciliary muscles both pulling at?

[imsosly]

@eugenekhcha The way the ciliary muscle and eye drawn here is not entirely accurate. When we look in the distance, our ciliary muscle is relaxed. In this state, the ciliary body is actually laying posterior (back) to the lens, which connects to the ciliary body by zonules from the lens' capsule. This is WHY the zonules fibers is TAUT. When we look at something up close, we contract the ciliary muscle which actually moves it up more anterior, relaxing the zonules, which increase lens thickness.

[chanty67cd]

could someone please provide an answer to @eugenekhcha 's response? i'm having the same misunderstanding here.

[YourGamingTeam]

I can control it, is that something rare and/or is bad for me?

I can only blur my vision.

[MrJtterbug]

This was one of those questions that confused me but, I was too overwhelmed with so many other things that I didn't bother to ask. The textbook didn't cover it so, I knew it wasn't on the test. With the semester over I am able to look at things now that confused me before.  Thank you for reducing the confusion.

[urREADINGmyCOMMENT]

freaking thank you!!

the concept seems simple enough, but for some reason i was having trouble. this really cleared it up!

[gnagaraj87]

Thanks, well done!