Sense organs: แบบฝึกหัด

Which part of the human eye contains the highest concentration of cone cells and gives the sharpest vision?

A student looks up from reading a book at a whiteboard at the front of the classroom.
What changes occur in the ciliary muscles, suspensory ligaments, and lens shape during this adjustment?

A person is walking outdoors on a sunny day and suddenly steps into a very dark cave. Why is the person initially unable to see clearly, and what adaptation allows them to see better after a few minutes?

In the human eye, which structure is responsible for focusing light rays specifically onto the retina?

When a person moves from a dimly lit room into bright sunlight, which changes occur in the eye to protect the retina from damage?

State the main function of rod cells in the human retina.

Explain how the distribution of rod and cone cells across the retina allows for sharp, high-resolution colour vision at the centre of the visual field.

Explain why astronomical observers often look slightly to the side of a faint star (averted vision) rather than directly at it to see it more clearly.

(a) Define what is meant by a sense organ.
(b) Complete the table to match each eye structure with its correct description or function:
- Cornea
- Lens
- Ciliary muscle
(c) State whether the pupil reflex is a voluntary or involuntary response.

The graph shows the relative density of rods and cones across the retina from the nasal side to the temporal side of the eye.
(a) Using the graph, identify the region labeled P and explain why cone density peaks at this point.
(b) Identify the region labeled Q where the density of both rods and cones is zero, and explain why vision is not possible at Q.
(c) Compare the overall distribution and abundance of rod cells with cone cells across the peripheral areas of the retina.