Biology Chapter 5 Quiz

Tissues

• Tissues are groups of cells with similar structure and function, along with extracellular substance (matrix).
• Histology is the study of tissues.
• The four primary types of tissue are epithelial, connective, muscular, and nervous tissues.

Extracellular Matrix (ECM)

• The ECM is a vital component of tissues.
• Functions:
  • Structural support for tissues.
  • Local communication between the ECM and cells via integrins.
• Components
  • Water: Essential for fluidity and transport within the ECM.
  • Proteins:
    • Collagen: Provides tensile strength.
    • Elastin: Enables stretching and recoiling.
  • Glycoproteins: Attach ECM components to cells, facilitating cell-ECM communication.

Epithelial Tissues

• Location: Cover body surfaces (internal and external).
• Examples: Skin, kidneys, trachea, and glands.
• Characteristics:
  • Closely packed cells (minimal extracellular matrix).
  • Primarily form glands.
  • Have free/apical and basal surfaces.
• Functions:
  • Protection (e.g., skin).
  • Barrier function (e.g., skin).
  • Diffusion and filtration (e.g., lungs, kidneys).
  • Secretion (e.g., glands).
  • Absorption (e.g., intestines).

Classification of Epithelial Tissues

• Classified by:
  • Number of cell layers (simple or stratified).
  • Cell shape (squamous, cuboidal, columnar, transitional).

Types of Simple Epithelial Tissues

• Simple Squamous: Single layer, flat cells; functions in diffusion and filtration (e.g., lungs, blood vessel lining).
• Simple Cuboidal: Single layer, cube-shaped cells; functions in secretion and absorption (e.g., glands, kidneys).
• Simple Columnar: Single layer, tall cells; functions in secretion and absorption (e.g., intestines, stomach).
• Pseudostratified Columnar: Appears stratified but is a single layer; secretes mucus and moves debris (e.g., respiratory tract).

Types of Stratified Epithelial Tissues

• Stratified Squamous: Multiple layers, flat cells; provides protection and barrier (e.g., skin, mouth).
• Transitional: Specialized, shape changes; accommodates stretching (e.g., urinary bladder).
• Stratified Cuboidal: Two to three layers, cube-shaped cells; protection and secretion (e.g., glands).
• Stratified Columnar: Top layer elongated; bottom layers cuboidal; protection and secretion (e.g., parts of pharynx, male urethra).

Free Cell Surfaces and Cell Connections

• Free Cell Surfaces:
  • Smooth surface: Reduces friction.
  • Microvilli: Increase surface area for absorption.
  • Cilia: Move materials across surfaces.
  • Goblet cells: Produce mucus
• Cell Connections:
  • Tight junctions: Form barriers.
  • Desmosomes: Mechanical links.
  • Hemidesmosomes: Connect cells to basement membrane.
  • Gap junctions: Channels for communication between cells.

Connective Tissue

• Characteristics:
  • Cells are spaced apart.
  • Large amounts of ECM.
  • Classified by ECM type and function.
• Major cells:
  • Fibroblasts: Produce fibers.
  • Macrophages: Phagocytic (remove foreign material).
  • Mast cells: Release histamine and heparin.
• Types of fibers:
  • Collagenous: Tensile strength.
  • Elastic: Stretch and recoil.
  • Reticular: Form supportive networks.
• Functions:
  • Enclose, separate, connect tissues.
  • Support movement (e.g., bones).
  • Storage (calcium, fat).
  • Cushion, insulate, transport, and protect.

Types of Connective Tissue

• Connective Tissue Proper:
  • Loose:
    • Areolar: Soft, pliable, contains all fiber types; supports and soaks up fluid.
    • Adipose: Fat storage, insulation, protection.
    • Reticular: Forms a supportive network.
  • Dense:
    • Regular: Fibers in one direction (e.g., tendons, ligaments).
    • Irregular: Fibers in multiple directions (e.g., dermis).
    • Elastic: Contains elastic fibers (e.g., arteries).
• Specialized Connective Tissue:
  • Cartilage:
    • Hyaline: Reduces friction (e.g., bone ends).
    • Fibrocartilage: Withstands compression (e.g., between vertebrae).
    • Elastic: Flexibility and recoil (e.g., ear).
  • Bone: Provides structural support and protection.
  • Blood: Transports oxygen, nutrients, and waste.

Muscular Tissue

• Responsible for movement, posture, and heat generation.
• Types:
  • Skeletal: Voluntary, striated, moves skeleton, peripheral nuclei.
  • Cardiac: Involuntary, striated, pumps blood, intercalated discs, central nuclei.
  • Smooth: Involuntary, non-striated, moves substances through hollow organs, central nuclei.

Nervous Tissue

• Controls and coordinates body functions via electrical impulses.
• Contains neurons and neuroglia.
• Neurons: Conduct electrical signals; have cell body, dendrites, and axon.
• Neuroglia: Support, nourish, and protect neurons.

Epithelial Membranes

• Composed of epithelial tissue and connective tissue.
• Types:
  • Serous: Reduces friction in body cavities.
  • Mucous: Lines tubes/organs opening to outside; secretes mucus.
  • Cutaneous: Protective covering (skin).
  • Synovial: Lines joint cavities; secretes synovial fluid.

Glands

• Specialized structures that secrete substances.
• Types:
  • Exocrine: Ducts carry secretions to targets (sweat, oil, salivary glands).
  • Endocrine: Ductless, release hormones directly into bloodstream (thyroid, pituitary).

Exocrine Glands

• Simple: No branches
• Compound: Many branches
• Merocrine: Release through exocytosis (most common).
• Apocrine: Portions of cells pinch off.
• Holocrine: Entire cells disintegrate.

Tissue Repair

• Process of replacing damaged or dead tissue.
• Types:
  • Regeneration: Same cell type, no scarring.
  • Replacement: Formation of scar tissue.
• Inflammation: Body's response to tissue damage.
  • Symptoms: Redness, heat, swelling, pain, loss of function.

Developmental Aspects of Tissues

• Primary germ layers: Ectoderm, mesoderm, endoderm.
• Tissue formation by end of second month.
• Aging effects: Reduced collagen production, elasticity, and repair.

Test your knowledge on the extracellular matrix and epithelial tissue with this quiz. Explore concepts like tensile strength, glycoproteins, absorption, and tissue repair. Ideal for students studying biology, this quiz will challenge your understanding of key histological principles.