The human body has four types of tissues. What part of the eye uses muscle tissue for opening and closing movements?
Cornea
Iris
Sclera
Retina
The part of the eye that uses muscle tissue for opening and closing movements is the iris.
The part of the eye that uses muscle tissue for opening and closing movements is the iris.
The part of the eye that uses muscle tissue for opening and closing movements is the iris.
To arrive at this answer, we need to understand the different types of tissues in the human body and their functions, specifically related to the eye.
The human body consists of four primary types of tissues: epithelial, connective, muscle, and nervous tissues. Each type of tissue has specific characteristics and functions.
In the case of the eye, we can rule out the cornea, sclera, and retina as options because they do not involve muscle tissue for opening and closing movements.
The cornea is the transparent outer layer of the eye, responsible for refracting light into the eye. It is made up of epithelial tissue, not muscle tissue.
The sclera is the white and tough protective layer surrounding most of the eye. It consists of connective tissue, not muscle tissue.
The retina is a layer of cells at the back of the eye that is sensitive to light and is responsible for transmitting visual information to the brain. It contains nervous tissue, not muscle tissue.
Therefore, the iris is the correct answer. The iris is the colored part of the eye. It contains circular and radial muscles that contract and relax, causing the pupil (the central black hole in the center of the iris) to change in size, thereby regulating the amount of light entering the eye. This muscular action enables the opening and closing movements of the iris.