Lecture Notes: Muscle Tissue

Overview of Muscle Tissue

• Muscle tissue is also known as muscular tissue.
• Functionality:
  • Contractile properties.
  • Provides movement (voluntary or involuntary).
  • Helps maintain posture and control heat (e.g., shivering).
• Location:
  • Around bones (e.g., biceps, quads, hamstrings).
  • Surrounding blood vessels and the GI tract.
  • Other areas in the body.

Types of Muscle Tissue

There are three main types of muscle tissue:

1. Skeletal Muscle

• Function: Moves the body, attached to bones.
• Characteristics:
  • Voluntary control (conscious control of movement).
  • Striated (striped appearance).
  • Multinucleate (multiple nuclei per muscle fiber).
• Example: Diaphragm, which is essential for breathing.

2. Cardiac Muscle

• Location: Found only in the heart.
• Characteristics:
  • Involuntary control (not under conscious control).
  • Striated (striped appearance like skeletal muscle).
  • Branched fibers, allowing for unique structure.
  • Contains intercalated discs with gap junctions:
    • These discs are dark lines visible between cells.
    • Gap junctions function as tunnels for rapid ion passage.
    • Ensures synchronous contraction of heart muscle cells.

3. Smooth Muscle

• Location: Found in blood vessels, GI tract, and various other parts of the body.
• Characteristics:
  • Involuntary control (not under conscious control).
  • Not striated (unlike skeletal and cardiac muscles).
  • Unique cell shape allows for greater size change upon contraction compared to skeletal or cardiac muscle.

Summary

• Muscular tissue is a crucial component that facilitates movement and various involuntary bodily functions.
• Understanding the differences between skeletal, cardiac, and smooth muscle helps clarify their unique roles and characteristics in the body.