Erector pili muscles are a)Voluntary, multiunitb)Involuntary, multiunitc)Involuntary, single unitd)Voluntary, single unitCorrect answer is option 'B'. Can you explain this answer?

Question

Erector pili muscles are  a)Voluntary, multiunitb)Involuntary, multiunitc)Involuntary, single unitd)Voluntary, single unitCorrect answer is option 'B'. Can you explain this answer?

Answer

Erector pili muscles are involuntary.
The arrector pili muscles are small muscles attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end. Each arrector pili is composed of a bundle of smooth muscle fibres, which attach to several follicles (a follicular unit) and is innervated by the sympathetic branch of the autonomic nervous system. The contraction of the muscle is, therefore, involuntary stresses such as cold, fear etc., may stimulate the sympathetic nervous system and thus, cause contraction, but the muscle is not under conscious control.

Answer

These muscles are either voluntary or involuntary. Skeletal muscles are voluntary, meaning they are controlled by the brain. ... A type of smooth muscle in the skin, known as the arrector pili, is responsible for forming goose bumps. Goose bumps are an uncontrollable reflex started by the sympathetic nervous system.

Multi-unit smooth cells can be found in the in the trachea, the large elastic arteries, the iris of the eye, in the lungs, erectile tissues of hair follicles ( Arrector pili of the dermis) and the vas deferens in the male genital tract.

Answer

Erector pili muscles:

The erector pili muscles are small muscles attached to hair follicles in mammals. These muscles are responsible for causing the hairs to stand up, resulting in 'goosebumps' or 'piloerection'. The erector pili muscles are found in various parts of the body, including the scalp, limbs, and trunk.

Classification of muscles:

Muscles can be classified based on their structure and function. They can be categorized as voluntary or involuntary, and as single unit or multiunit.

Voluntary vs involuntary muscles:

Voluntary muscles, also known as skeletal muscles, are under conscious control. They are responsible for movements of the body, such as walking, running, and lifting objects. These muscles are attached to bones via tendons and are controlled by the somatic nervous system.

Involuntary muscles, on the other hand, are not under conscious control. They regulate various bodily functions and are controlled by the autonomic nervous system. Involuntary muscles include smooth muscles and cardiac muscles.

Single unit vs multiunit muscles:

Single unit muscles, also known as visceral muscles, are composed of cells that are connected by gap junctions. These muscles contract as a single unit, meaning that when one cell is stimulated, the entire muscle contracts. Single unit muscles are found in the walls of hollow organs, such as the digestive tract, blood vessels, and uterus.

Multiunit muscles, on the other hand, are composed of individual muscle fibers that are not connected by gap junctions. Each muscle fiber functions independently and can be individually controlled. Multiunit muscles are found in structures such as the iris of the eye, the arrector pili muscles, and the muscles of the vas deferens.

Erector pili muscles classification:

The erector pili muscles are classified as involuntary, multiunit muscles. They are not under conscious control and function independently. Each erector pili muscle is attached to a hair follicle and can contract to cause the hair to stand up.

Conclusion:

In summary, the erector pili muscles are involuntary, multiunit muscles. They are responsible for causing hairs to stand up and are not under conscious control. Understanding the classification of muscles helps in understanding their functions and control mechanisms.

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