Based on the visual analysis of the eye diagram and standard anatomical knowledge, here is the solution to both parts of the question.
Part 1: Labeling the Parts of the Eye
By examining the diagram and matching the structures to their anatomical names, the labels can be assigned as follows:
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Top Left (from top to bottom):
- The transparent outer layer at the very front:
Cornea
- The colored part of the eye:
Iris
- The black opening in the center of the iris:
Pupil
- The structure behind the iris that focuses light:
Lens
-
Bottom Left (from top to bottom):
- The white, tough outer coat of the eyeball:
Sclera
- The innermost layer at the back of the eye containing photoreceptors:
Retina
-
Right Side (from top to bottom):
- The nerve that carries visual information to the brain:
Optic nerve
- The blood vessels visible on the surface of the retina:
Retinal blood vessels
- The central area of the retina responsible for sharp vision:
Macula
- The gel-like substance filling the main cavity of the eye:
Vitreous body
- The thin membrane covering the front of the eye and the inside of the eyelids:
Conjunctiva
*(Note: The words "Ciliary muscle" and "Conjunctiva" are in the box but not explicitly labeled in this diagram. The Ciliary muscle is located around the lens, and the Conjunctiva is the membrane covering the sclera and inner eyelids.)*
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Part 2: Which part of the eye controls the size of the pupil?
The correct answer is
b) Iris.
Explanation:
The iris is the colored, circular muscle that surrounds the pupil. It contains two sets of muscles: the sphincter pupillae (which contract to make the pupil smaller) and the dilator pupillae (which contract to make the pupil larger). By contracting or relaxing these muscles, the iris adjusts the diameter of the pupil in response to the amount of light entering the eye. In bright light, the iris constricts the pupil to reduce light intake, and in dim light, it dilates the pupil to allow more light in. Therefore, the iris is the part of the eye that directly controls the size of the pupil.
Parent Tip: Review the logic above to help your child master the concept of human eye worksheet answers.
