Muscle types

Definition of Muscle Tissue

A group of specialized cells that can contract (shorten) to produce movement.

Skeletal Muscle: Location

Attached to the skeleton (bones) by tendons.

Skeletal Muscle: Function

Responsible for voluntary movement, such as walking or lifting weights.

Skeletal Muscle: Structure

Striped (striated) appearance and multiple nuclei per cell; very long and cylindrical.

Smooth Muscle: Location

Found in the walls of internal organs like the stomach, intestines, and blood vessels.

Smooth Muscle: Function

Responsible for involuntary movements, such as moving food through the gut (peristalsis).

Smooth Muscle: Structure

Spindle-shaped cells with a single nucleus; they do not have a striped appearance.

Cardiac Muscle: Location

Found only in the walls of the heart.

Cardiac Muscle: Function

Pumps blood around the body by contracting rhythmically without getting tired.

Cardiac Muscle: Control

Involuntary (you do not have to think about making your heart beat).

Cardiac Muscle: Structure

Branching cells that are striated (striped) and joined by special junctions for synchronized beating.

Voluntary vs Involuntary

Voluntary: You control it (Skeletal). Involuntary: It happens automatically (Smooth and Cardiac).

Adaptation: Mitochondria

Muscle cells contain many mitochondria to provide the energy (ATP) needed for contraction via respiration.

Adaptation: Protein Filaments

Muscle cells contain filaments of protein that slide over each other to cause the cell to contract.

Adaptation: Glycogen

Muscle cells store glycogen, which can be broken down into glucose for respiration during exercise.