Which one of the following is correct pairing of a body part and muscl...
The iris contains involuntary smooth muscles. Heart wall consistsof cardiac muscles that are involuntary but striated. Abdominal wall contains connective muscles andbiceps of arm contain skeletal muscle fibres.
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Which one of the following is correct pairing of a body part and muscl...
Smooth muscles are called as involuntary muscles as action of these muscles is controlled by autonomic nervous system i.e. not under the control of animal's will. Iris of eyes consist of smooth involuntary muscles.
○Smooth muscles are plain, non-striated, involuntary or unstriped muscles due to the absence of striations. These occur in the walls of hollow internal organs, in capsules of lymph glands, spleen, etc., in iris and ciliary body of eyes, skin dermis, penis and other accessory genitalia,
Which one of the following is correct pairing of a body part and muscl...
Iris - Involuntary Smooth Muscle
The correct pairing of a body part and the muscle fiber that moves it is option 'C': Iris - involuntary smooth muscle.
The iris is a part of the eye that controls the size of the pupil. It is responsible for regulating the amount of light that enters the eye. The iris contains two sets of smooth muscles, the dilator pupillae and the sphincter pupillae, which work together to adjust the size of the pupil.
Smooth muscles are one of the three types of muscles in the body, along with skeletal muscles and cardiac muscles. Smooth muscles are called involuntary muscles because they are not under conscious control. They are found in the walls of hollow organs, such as the digestive system, blood vessels, and the iris of the eye.
In the case of the iris, the smooth muscles are responsible for controlling the size of the pupil. The dilator pupillae muscle, when it contracts, causes the pupil to dilate or open up, allowing more light to enter the eye. On the other hand, the sphincter pupillae muscle, when it contracts, causes the pupil to constrict or close, reducing the amount of light that enters the eye.
The contraction and relaxation of these smooth muscles in the iris are controlled by the autonomic nervous system, specifically the sympathetic and parasympathetic divisions. The sympathetic division stimulates the dilator pupillae muscle to contract, resulting in pupil dilation, whereas the parasympathetic division stimulates the sphincter pupillae muscle to contract, leading to pupil constriction.
In conclusion, the correct pairing of a body part and the muscle fiber that moves it is the iris and the involuntary smooth muscle. The smooth muscles in the iris regulate the size of the pupil, allowing for the control of the amount of light that enters the eye.
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