week 2 LSB421 lecture 5

Muscle Tissue

• Muscle tissue allows movement and force production at command.

• Muscle cells use actin and myosin proteins to form intracellular filaments for force generation.

• ATP is the fuel necessary for muscle contraction.

Types of Muscle Tissue

• Skeletal Muscle:

  • Most common type of muscle tissue.

  • Responsible for moving bones.

  • Cells are elongated, slender, and contain multiple nuclei from merged embryonic cells.

  • Striations are visible and run perpendicular to the long axis of the cell.

• Cardiac Muscle:

  • Found exclusively in the heart.

  • Identical to skeletal muscle in appearance but with shorter cells.

  • Requires continuous ATP generation due to constant functioning, hence contains many mitochondria.

• Smooth Muscle:

  • Located in the walls of hollow organs (e.g., blood vessels, GI tract, urinary bladder, uterus).

  • Cytoplasm appears uniform and lacks striations when observed under a microscope.

Nerve Tissue

• Unique tissue that uses electrical signals for information conveyance.

• Mostly found in the brain and spinal cord (central nervous system).

• Peripheral nervous system is formed by nerves extending throughout the body.

  • Contains nerve fibers that issue motor commands to muscles and glands as well as receive sensory signals from the body.

• Composed of glial cells (support) and neurons (signal transmission).

Neurons

• Comprised of a compact cell body and extensions for signaling to targets and receiving input from other neurons.

Key Points from the Lecture

• Plasma Membrane: Controls the movement of substances in and out of the cell.

• Transport Methods: Active and passive transport enable substance movement across membranes.

• Cytoskeleton: A protein network defining cell shape, strength, and mobility.

• Mitochondria: Produce ATP, the cell's energy source.

• Golgi Apparatus: Modifies and packages proteins into functional forms and cellular products.

• Ribosomes: Bind amino acids to create new proteins.

• Endoplasmic Reticulum: Essential for protein synthesis and transport of cellular products.

• Nucleus: Houses genetic material, controlling cell functions.

• Epithelial Tissues: Form the skin and linings, protect internal cavities, and are involved in secretion.

• Connector Tissues: Protect, support, and give structure to the body; these are necessary for muscle functioning.

• Muscle Tissue: Generates force for body movement.

• Nerve Tissue: Conducts electrical signals, conveying body information.