Question

the part of the eye that regulates the size of the pupil is the:
o extrinsic muscle
o iris
o ciliary muscle
o suspensory ligaments

question 2
1 pts
detect light touch of skin
o mechanoreceptors
o photoreceptors
o pain receptors
o chemoreceptors
skill: knowledge

Explanation:

• For the first question: The iris is a muscular structure in the eye. It has smooth muscle fibers (sphincter pupillae and dilator pupillae). The sphincter pupillae constricts the pupil (in bright light, for example), and the dilator pupillae dilates the pupil (in dim light). Extrinsic muscles move the eye ball; the ciliary muscle is involved in accommodation (changing the shape of the lens for focusing); suspensory ligaments hold the lens in place.
• For the second question: Mechanoreceptors are sensory receptors that respond to mechanical stimuli such as pressure, vibration, and light touch. Photoreceptors respond to light (in the eye); pain receptors respond to potentially damaging stimuli (pain); chemoreceptors respond to chemical stimuli (e.g., in taste and smell).

Answer:

1. iris
2. mechanoreceptors