Histology Study Guide: Epithelial and Connective Tissues

Introduction to Histology

Histology is the study of the microscopic structure of tissues. In Anatomy & Physiology, understanding tissue types is fundamental for recognizing how organs and systems function. This guide covers the major types of epithelial and connective tissues, with examples from human organs.

Epithelial Tissue

Epithelial tissues cover body surfaces, line cavities, and form glands. They are classified by cell shape and the number of layers.

Simple Squamous Epithelium

Simple squamous epithelium consists of a single layer of flat, scale-like cells. It is specialized for diffusion and filtration.

• Location: Found in the alveoli of the lungs, lining of blood vessels (endothelium), and serous membranes (mesothelium).

• Function: Facilitates rapid exchange of gases, nutrients, and waste.

• Example: Alveolar walls in the lung allow oxygen and carbon dioxide to diffuse between air and blood.

Simple Cuboidal Epithelium

Simple cuboidal epithelium is composed of a single layer of cube-shaped cells, often with centrally located nuclei.

• Location: Commonly found in kidney tubules, ducts of glands, and the thyroid gland.

• Function: Secretion and absorption.

• Example: Renal tubules in the kidney use cuboidal cells to reabsorb water and solutes from filtrate.

Key Terms and Concepts

• Epithelium: A tissue composed of one or more layers of cells that forms the covering of most internal and external surfaces of the body and its organs.

• Simple: Refers to a single layer of cells.

• Squamous: Flat, thin cells.

• Cuboidal: Cube-shaped cells, as tall as they are wide.

• Diffusion: The passive movement of molecules from an area of higher concentration to an area of lower concentration.

Comparison of Simple Squamous and Simple Cuboidal Epithelium

Feature	Simple Squamous	Simple Cuboidal
Cell Shape	Flat, scale-like	Cube-shaped
Number of Layers	One	One
Location	Alveoli, blood vessels	Kidney tubules, glands
Function	Diffusion, filtration	Secretion, absorption

Additional info: More epithelial types (such as columnar, stratified, and transitional) and connective tissues (such as adipose, cartilage, and bone) are commonly covered in histology labs. This guide focuses on the types shown in the provided materials.