What is the Difference Between Smooth Muscle and Cardiac Muscle?

Smooth muscle and cardiac muscle are two types of involuntary muscle tissues found in the human body. They have distinct differences in their structure, function, and location:

Smooth Muscle:

• Found in the walls of inner organs, such as blood vessels, gastrointestinal tract, bladder, and uterus.
• Involuntary and non-striated.
• Cells are spindle-shaped and have one central nucleus.
• Contraction is slow and rhythmic.
• Regulated by the autonomic nervous system.
• Functions include shortening and propelling various contents across the lumen of multiple organ systems.

Cardiac Muscle:

• Found only in the walls of the heart.
• Striated, similar to skeletal muscle.
• Cells are rectangular in shape and contain one central nucleus.
• Contraction is involuntary, strong, and rhythmical.
• Regulated by the autonomic nervous system.
• Functions include propelling blood throughout the body, ensuring proper oxygenation, and maintaining cell integrity.

In summary, smooth muscle is found in inner organs and has a spindle shape, while cardiac muscle is found only in the heart and has a striated, rectangular shape. Both muscle types are involuntary and regulated by the autonomic nervous system, but they serve different functions and have distinct structures.

Comparative Table: Smooth Muscle vs Cardiac Muscle

Here is a table comparing the differences between smooth muscle and cardiac muscle:

Smooth muscle is found in the walls of internal organs and is not striated, while cardiac muscle is found only in the walls of the heart and is striated. Both types of muscle are involuntary, meaning they are not under conscious control. Smooth muscle cells have a lower energy requirement compared to cardiac muscle cells, which have many mitochondria to produce ATP for energy. Cardiac muscle contracts with an intermediate speed, while smooth muscle contracts more slowly and can produce rhythmic contractions in some organs. Unlike cardiac muscle, smooth muscle does not fatigue easily and serves various functions in internal organs.