Which structures are part of the retina? Select all that apply.

The macula is indeed one of the key structures found in the retina, making it a correct choice. This area is crucial for high-acuity vision and is where the highest concentration of photoreceptors, specifically cone cells, are located. Within the macula is the fovea, which is responsible for our sharpest vision because it contains a high density of cones and no overlying blood vessels, allowing for clear and bright images to be formed.

While the fovea is also part of the retina, it seems it was not acknowledged in the selected choice. Rods, another type of photoreceptor that is sensitive to low light and helps in night vision, are further evidence of the retinal structures. Meanwhile, the zonule, which connects the ciliary body to the lens, is not part of the retina itself but belongs to the eye's supporting structures.

Hence, to fully encompass the structures associated with the retina, both the macula and the fovea should be highlighted, along with rods. This understanding contributes to recognizing the components essential for vision and how they function collectively within the retina.