BHSC 102
Histology
The Study of Tissues
Basic Health Sciences (BHSC) Program
Academic Year 2024–2025
, 1. Introduction to Histology
Histology is the microscopic study of tissues. Tissues are groups of cells with similar
structure that work together to perform a specific function. There are four primary tissue
types in the human body.
2. The Four Primary Tissue Types
2.1 Epithelial Tissue
Epithelial tissue covers body surfaces, lines hollow organs, and forms glands.
Classification by Cell Layers:
• Simple epithelium: single layer of cells
• Stratified epithelium: multiple layers of cells
• Pseudostratified epithelium: appears multilayered but is single layer
Classification by Cell Shape:
• Squamous: flat, scale-like cells
• Cuboidal: cube-shaped cells
• Columnar: taller than wide, may have cilia or microvilli
Functions:
• Protection (skin epidermis)
• Absorption (small intestine)
• Secretion (glands)
• Filtration (kidney tubules)
• Sensory reception
Key Feature Epithelial tissue has NO blood vessels (avascular) but is innervated. It
receives nutrients by diffusion from underlying connective tissue.
2.2 Connective Tissue
Connective tissue is the most abundant and widely distributed tissue type. It supports,
connects, and protects other tissues and organs.
Histology
The Study of Tissues
Basic Health Sciences (BHSC) Program
Academic Year 2024–2025
, 1. Introduction to Histology
Histology is the microscopic study of tissues. Tissues are groups of cells with similar
structure that work together to perform a specific function. There are four primary tissue
types in the human body.
2. The Four Primary Tissue Types
2.1 Epithelial Tissue
Epithelial tissue covers body surfaces, lines hollow organs, and forms glands.
Classification by Cell Layers:
• Simple epithelium: single layer of cells
• Stratified epithelium: multiple layers of cells
• Pseudostratified epithelium: appears multilayered but is single layer
Classification by Cell Shape:
• Squamous: flat, scale-like cells
• Cuboidal: cube-shaped cells
• Columnar: taller than wide, may have cilia or microvilli
Functions:
• Protection (skin epidermis)
• Absorption (small intestine)
• Secretion (glands)
• Filtration (kidney tubules)
• Sensory reception
Key Feature Epithelial tissue has NO blood vessels (avascular) but is innervated. It
receives nutrients by diffusion from underlying connective tissue.
2.2 Connective Tissue
Connective tissue is the most abundant and widely distributed tissue type. It supports,
connects, and protects other tissues and organs.
