Muscle Groups Quiz Part 2

Muscle Groups Overview

• Three main types of muscle groups: Striated (Skeletal), Non-Striated (Smooth/Visceral), and Cardiac.

Striated (Skeletal) Muscle

• Responsible for voluntary movements, contracting to move limbs and maintain posture.
• Both ends of skeletal muscles connect to the skeleton via tendons.
• Composed of cylindrical muscle fibers, with a diameter ranging from 0.02 to 0.08 mm.
• Muscle fiber lengths can vary significantly, from 40 mm to 35 cm.
• Contains blood vessels and nerves for function and support.

Non-Striated (Smooth/Visceral) Muscle

• Found in walls of organs requiring movement of soft tissue, such as blood vessels and the alimentary canal.
• Muscle cells are spindle-shaped, with a central nucleus, and measure between 0.005 to 0.01 mm in diameter and 0.03 to 0.2 mm in length.
• Operates under the autonomic nervous system; contraction can occur for extended periods but relaxes for short durations.

Cardiac Muscle

• Exclusively located in the heart and responsible for its rhythmic contractions.
• Cardiac muscle fibers have a rectangular shape and feature intercalated discs for connectivity.
• Functions under the autonomic nervous system and possesses an intrinsic pacemaker to regulate heartbeat.

Comparison of Muscle Types

• Differences in shape, structure, and function among the three muscle types can be observed at the microscopic level.
• Skeletal muscle is distinct for its voluntary control, smooth muscle operates involuntarily, and cardiac muscle aids in the heart’s autonomous functioning.