Basics of Functional and Clinical Histology

Basics of Functional and Clinical Histology

• This book covers the fundamentals of histology, focusing on the functional and clinical aspects.
• The book is authored by Ayman Ghallab.

Cell Structure (Page 2, 3)

• Diagrams show the internal components of a protein-synthesizing cell.
• Key Structures:
  • Cell membrane
  • Secretory vesicles
  • Golgi apparatus
  • Nucleus
  • Nucleolus
  • Rough endoplasmic reticulum
  • Ribosomes
  • Mitochondria

Epithelial Tissue (Page 4)

• Epithelial tissue forms continuous sheets of cells, often with minimal intercellular substance.
• It lines body surfaces and cavities.
• It rests on a basement membrane.
• Blood vessels and lymphatics are typically absent in the tissue itself.
• Nutrients reach epithelial cells through diffusion from surrounding connective tissues.
• It performs various functions:
  • Protection (skin)
  • Secretion (hormones, enzymes, mucus)
  • Excretion (urine, sweat)
  • Absorption (digestive tract)
  • Contraction (specific cells)
  • Sensory reception (taste, smell, hearing)
  • Reproduction (ovaries, testes)

Types of Epithelial Tissue (Page 5, 6, 7)

• Epithelial tissue types are classified by the shape of cells and layers.

  • Simple epithelium: Single layer
  • Stratified epithelium: Multiple layers
    • Simple squamous epithelium is a single layer of thin, flat cells lining blood vessels, heart, lymphatic vessels, and body cavities; facilitating diffusion and filtration.
    • Simple cuboidal epithelium is a single layer of cube-shaped cells, found in kidney tubules and glands; involved in secretion and absorption.
    • Simple columnar epithelium is a single layer of long, column-shaped cells, found in the digestive tract and kidney tubules; key for absorption and secretion. -Can be categorized further by presence of cilia, brush border, or goblet cells. -Ciliated simple columnar epithelium with brush border lines the intestines and proximal convoluted tubules of the kidneys, and has microvilli for absorption. -Simple columnar secretory epithelium lines glands and the stomach -Goblet cells are specialized columnar cells in the digestive and respiratory tracts that produce mucus. -Pseudostratified columnar epithelium appears layered but all cells contact the basement membrane; found in the respiratory tract and has cilia. The cells’ different heights give a layered appearance.

• Stratified epithelium categories:

  • Stratified squamous epithelium, which includes both keratinized (skin) and non-keratinized types lining body openings; essential for protection.
  • Stratified cuboidal epithelium lines large glands and has protective function.
  • Stratified columnar epithelium lines larger ducts and has protective function.
  • Transitional epithelium lines the urinary system and its layers change depending on whether stretched or relaxed.

Glandular Epithelium (Page 14)

• Endocrine glands release hormones directly into the bloodstream without ducts.
• Exocrine glands release secretions through ducts onto surfaces or into cavities.

Cell Structure at EM Level (Page 15)

• Diagrams illustrate simple columnar absorptive epithelium at electron microscope (EM) level, showing cell coat, microvilli, lateral inter-digitation, mitochondria, nucleus, rough endoplasmic reticulum (RER), and hemidesmosomes, as well as terminal web and cell junction complexes, and Golgi apparatus.

This quiz explores the fundamentals of histology, highlighting key concepts in cellular structure and epithelial tissue. It covers vital cellular components like the Golgi apparatus, nucleus, and various functions of epithelial tissue. Suitable for students studying histology in a clinical context.