# SKELETAL MUSCLE #

• The skeletal muscles have stripes or striations. Hence they are also called the striated muscles.

• These are voluntary muscles.

《IT MEANS- these muscles are controlled by us》

• The cells are long and cylindrical shaped.

• The cells are MULTINUCLEATED.

*EXAMPLES* ~ The skeletal muscles can be found in the muscles of the limbs, face, neck etc.

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# CARDIAC MUSCLES #

• Cardiac muscles have stripes or straiations.

• These are involuntary muscles.
《IT MEANS- these muscles are not controlled by us》

• The cells of this muscle tissue are branched and cylindrical.

• The cells are UNINUCLEATED.

*EXAMPLE* ~ These muscles are only found in the heart.

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The Skeletal and Cardiac Muscles

Skeletal Muscle:
Skeletal muscles are the muscles that attach to the bones of the skeleton, enabling voluntary movements. These muscles are responsible for locomotion, posture, and other bodily movements. Here are some key points about skeletal muscle:

1. Anatomy: Skeletal muscles are composed of long, cylindrical cells called muscle fibers. These fibers are multinucleated and have a striped appearance due to the arrangement of contractile proteins. Each muscle fiber is surrounded by connective tissue layers that provide support and organization.

2. Function: Skeletal muscles are under voluntary control, meaning they can be consciously controlled by the brain. They contract and relax to produce movement and generate force. Skeletal muscles work in pairs, with one muscle contracting while the other relaxes to allow movement in opposite directions.

3. Force Production: Skeletal muscles generate force through the sliding filament theory. Thin filaments made of actin slide past thick filaments composed of myosin, causing muscle contraction. The force produced depends on the number of muscle fibers recruited and the frequency of their contractions.

4. Structure: Skeletal muscles are organized into bundles called fascicles, which are surrounded by connective tissue called perimysium. Each fascicle consists of individual muscle fibers enclosed by endomysium. The epimysium covers the entire muscle, providing protection and facilitating muscle attachment.

Cardiac Muscle:
Cardiac muscle is a specialized type of muscle found only in the heart. It is responsible for the involuntary contractions that pump blood throughout the body. Here's a closer look at cardiac muscle:

1. Anatomy: Cardiac muscle cells, or cardiomyocytes, are branched and interconnected. They contain a single nucleus and have striations similar to skeletal muscle. Intercalated discs, specialized junctions between cells, allow for rapid transmission of electrical impulses.

2. Function: Cardiac muscle contracts rhythmically to pump blood. It functions involuntarily and does not require conscious control. The coordinated contractions of cardiac muscle cells ensure efficient blood circulation and maintain the heart's pumping action.

3. Intercalated Discs: Intercalated discs in cardiac muscle play a crucial role in synchronizing contractions. They contain gap junctions that allow ions to flow between cells, facilitating the rapid spread of electrical impulses. This ensures that the entire heart contracts as a coordinated unit.

4. Endurance and Fatigue Resistance: Cardiac muscle has a high endurance capacity and is resistant to fatigue. This is due to its rich blood supply, aerobic metabolism, and efficient energy production. These features enable the heart to continuously contract and relax without tiring.

In conclusion, skeletal and cardiac muscles have distinct anatomical and functional characteristics. Skeletal muscles are voluntary and responsible for body movements, while cardiac muscles are involuntary and crucial for heart function. Understanding their structure and function helps us appreciate the complexity and importance of these muscle types in maintaining our overall health and well-being.