BIOS251 Exam 2 Weeks 3-4 Outline-Review May 24

Week 3 Concepts

Principles of Cell Theory

  • Smallest structure capable of life processes.

  • All organisms are made of one or more cells.

  • Cells arise only from pre-existing cells.

    • Cell Organization:

      • Prokaryotic Cells: No organized nucleus.

      • Eukaryotic Cells: Organized and well-defined nucleus.

    • Common Structures in Most Cells:

      • Plasma Membrane: Separates internal and external environments.

      • DNA: Genetic material that dictates composition and replicates the cell.

      • Cytoplasm: Liquid portion (cytosol) and organelles.

      • Ribosomes: Site of protein synthesis.

      • Cytoskeleton: Provides intracellular support and aids in movement.

Gamete and Somatic Cells

  • Gamete Cells: Reproductive cells (sperm and ovum) replicate via meiosis.

  • Somatic Cells: All other body cells replicate via mitosis.

Cell Membranes and Functions

  • Functions of Cell Membrane:

    • Protective barrier, anchors cytoskeleton, shapes the cell, facilitates communication, and manages substance movement.

  • Structure:

    • Phospholipid Bilayer: Hydrophilic (water-loving) heads and hydrophobic (water-repelling) tails.

    • Molecules Embedded in Membrane:

      • Transmembrane Proteins: Cross entire membrane.

      • Peripheral Proteins: Found on one surface.

      • Cholesterol: Provides structure and fluidity.

      • Sugars: Glycolipids and glycoproteins for protection and signaling.

Plasma Membrane Proteins

  • Integral Proteins: Include ion channels, proton pumps.

  • Channel Proteins: Facilitate ion crossing.

  • Carrier Proteins: Transport specific substances.

  • Receptor Proteins: Bind to ligands.

  • Cell Identity Markers: Help immune system identify the cell.

  • Na+/K+ ATPase Pump: Maintains electrochemical gradient.

Week 4 Concepts

Introduction to Main Tissue Types

  • Histology: Study of tissues; structure, function, and microscopic organization.

  • Four Major Tissue Types:

    • Epithelial: Lines cavities, covers surfaces, forms glands.

    • Connective: Provides support and protection.

    • Muscle: Facilitates body movement.

    • Nervous: Conducts electrical impulses.

Epithelial Tissue

  • Avascular; relies on connective tissue for nutrients.

  • Protects organs, controls permeability, provides sensation.

  • Classification Criteria:

    • Number of Layers: Simple, Stratified, Pseudostratified, Transitional.

    • Cell Shape: Squamous, Cuboidal, Columnar.

Connective Tissue

  • Composed of sparse cells in an extracellular matrix (ground substance + protein fibers).

  • Types of Connective Tissues: Loose, Dense, Blood, Cartilage, Bone.

Muscle Tissue

  • Skeletal Muscle: Voluntary, striated, multinuclear.

  • Cardiac Muscle: Involuntary, striated, uninuclear.

  • Smooth Muscle: Involuntary, found in hollow organs.

Nervous Tissue

  • Focus on neuron structure: soma, dendrites, axon, and axon terminals.

Membranes

  • Types: Cutaneous, Mucous, Serous, Synovial.

  • Functions of Membranes: Provide barriers, protect organs, facilitate lubrications and absorption.

Cell Junctions

  • Tight Junctions: Nearly impermeable barriers.

  • Desmosomes: Provide structural strength.

  • Gap Junctions: Allow for rapid communication between cells.

Tissue Growth and Repair

  • Types of Tissue Changes: Atrophy, Necrosis, Apoptosis, Regeneration, Fibrosis, Hypertrophy, Hyperplasia, Metaplasia, Dysplasia.

  • Steps of Tissue Repair: Inflammation, Proliferation, Maturation.