Question

Differentiate between skeletal muscles, smooth muscle, and cardiac muscle (at least two points in each).

Answer 1

Hint: Differentiate between the structure (striated or unstriated muscles; types of cells that make the tissue), function (voluntary or involuntary movement; self-stimulating or not; help in fluid and blood flow), and locations (present in which organs, attached to which structures) of these muscles.

Complete answer:
Muscle tissues are one of the four fundamental tissues (epithelial, muscle, connective, and nervous) found in the body. They are the soft tissues that help in the movement and in maintaining the posture of the body. Muscle tissues can be differentiated into three forms: skeletal, smooth, and cardiac muscles based on the structure and functions of these muscles.

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Features	Skeletal muscles	Smooth muscles	Cardiac muscles
Movement	Voluntary	Involuntary	Involuntary
Location	Attached to skin and bones	The lining of walls of internal organs	Present in heart
Cells	Long, multinucleated, cylindrical cells	Uni-nucleated, single tapering cells	Straight uni-nucleated cells with branching chains.
Muscle type	Myofibrils are arranged orderly to form striated muscle	Varying lengths of myofibrils forms un-striated muscle	The ordered arrangement of myofibrils forms striated muscle.
Controlled by	Nervous system	Nervous and endocrine system and other chemicals and stretching	The central nervous system, endocrine system, and different chemicals
Stimulation	Non-self-stimulating, stimulated by motor neurons of the nervous system	Self-stimulating	Self-stimulating
Energy requirement	High	Low	Intermediate
Contraction speed	Fast, non-rhythmic contraction	Slow and rhythmic in some organs	Intermediate speed and rhythmic contraction
Fatigue creation	Fatigues easily	Does not fatigue	Does not fatigue
Strength	Increases with stretching	Stress-relaxation response	Increases with stretching
Function	Movement and locomotion	Maintain the flow of food and fluids through the internal organs	Helps in pumping blood flow into and out of the heart.

Additional Information:
-42% of an average adult male body mass is made up of skeletal muscles and in females, they make up 36% of body mass of an average adult female.
-Muscles not only help in movement and maintaining the posture of the body, but they also help in regulating different organs (like the heart), create heat to warm up the body, and helps in the movement of substances around the body (like the movement of blood from heart and food in the digestive system)
-The striated appearance of skeletal muscles is due to the formation of actin and myosin muscle fibers. Skeletal muscles are well supplied with blood vessels and nerves.
-Cardiac muscles are arranged in bundles of muscle fibers sheets and show involuntary movement as they are regulated by the autonomic part of the nervous system.
-Cardiac muscles are though mainly controlled by the central nervous system (CNS), they can also contract without signals from CNS due to pacemaker cells.

Note: Muscle fatigue is the decrease in the ability of the muscles to perform over time due to a decrease in the force behind the muscles. That overall affects the body by making it weaker. Skeletal muscles fatigue more easily than cardiac or smooth muscles because skeletal muscles are not essential in homeostasis and survival. Unlike cardiac or smooth muscle that may cause a threat to life.