Muscle Tissue 🏋‍♀️

Muscle tissue is one of the four types of tissue in the body, and it is unique in its ability to cause movement through contraction.

Characteristics of Muscle Tissue

• Allows for movement through contraction

• Enables the body to move and function

• Found in various parts of the body, including the esophagus, stomach, intestines, heart, and bones

Types of Muscle Fibers 🧬

There are three major categories of muscle fibers:

Skeletal Muscle Fibers 💪

• Also known as striated muscle fibers

• Have multiple nuclei

• Voluntary, meaning they can be controlled consciously

• Attached to bones and cause movement when contracted

"Voluntary" means that the muscle can be controlled consciously, allowing for intentional movement.

Characteristics of Skeletal Muscle Fibers

Structure of Skeletal Muscle Fibers 📦

A skeletal muscle fiber is composed of:

• Sarcolemma: The cell membrane that surrounds the muscle fiber

• Cytoplasm: The jelly-like substance inside the cell membrane

• Organelles: Small structures within the cell that perform specific functions

• Endomysium: A fine, protective sheath of connective tissue that surrounds each muscle fiber

Bundles of Muscle Fibers 📈

• A group of muscle fibers is called a fascicle

• Fascicles are organized into bundles, which make up the skeletal muscle tissue

Analogy: Skeletal Muscle Fiber Structure 🥤

A skeletal muscle fiber can be compared to a straw:

• The straw represents the muscle fiber

• The plastic wrapping around the straw represents the sarcolemma

• The paper wrapping around the straw represents the endomysium

• The bundles of straws represent the fascicles## 🏋‍♀️ Skeletal Muscle Structure

Muscle Bundles and Connective Tissue

A muscle is composed of multiple bundles of muscle fibers, each wrapped in a layer of connective tissue.

• Fascicle: a bundle of muscle fibers wrapped in a layer of connective tissue called paramycin.

• Paramycin: a strong, fibrous membrane that wraps around each fascicle.

• Epomycin: a thick, tough connective tissue that encloses all the fascicles in a muscle.

Muscle Fibers and Cell Membrane

• Muscle Fiber: a single muscle cell.

• Sarcolemma: the cell membrane of a muscle fiber.

Connective Tissue Layers

Tendons and Aponeurosis

• Tendon: a cord-like structure that connects muscle to bone.

• Aponeurosis: a flat, sheet-like structure that serves the same function as a tendon, but is flat rather than cord-like.

"Tendons connect muscle to bone, whereas ligaments connect bone to bone."

Key Terms

• Fascicle: a bundle of muscle fibers wrapped in a layer of connective tissue called paramycin.

• Paramycin: a strong, fibrous membrane that wraps around each fascicle.

• Epomycin: a thick, tough connective tissue that encloses all the fascicles in a muscle.

• Sarcolemma: the cell membrane of a muscle fiber.

• Tendon: a cord-like structure that connects muscle to bone.

• Aponeurosis: a flat, sheet-like structure that serves the same function as a tendon, but is flat rather than cord-like.