Question

a)identify a and b
b)what is the function of b?
this is an eyeball, sagittal section, showing parts of the eye with arrow a pointing to a thickened ring of tissue and arrow b pointing to a white channel structure that encircles the eye.
a) iris a,ciliary body b b) control the shape of the lens
a) iris a,ciliary body b b) control the shape of the lens
a) scleral venous sinusa,irisb b) control the diameter of the pupil
a) scleral venous sinus a,ciliary body b b) control the shape of the lens

Explanation:

• Part A:
• The ciliary body (A) is a thickened ring of tissue. The scleral venous sinus is not a thickened ring of tissue like the ciliary body. The iris is a different structure (colored part of the eye that controls pupil diameter).
• Part B:
• The ciliary body has ciliary muscles. When these muscles contract or relax, they change the shape of the lens (accommodation). For example, when looking at a near object, the ciliary muscles contract, making the lens more convex.

Answer:

A) Ciliary body [A], ciliary body [B] (assuming there was a typo in options and it should be A) Ciliary body [A], ciliary body [B] as per the description of A being a thickened ring of tissue which is the ciliary body). B) Control the shape of the lens.