Anatomy and Physiology Lecture 3

Study Notes

Histology Overview

Simple cuboidal epithelium has nearly equal cell sides; located in ovary lining and kidney tubules.
Simple columnar epithelium features greater height than width; primarily found in the stomach and intestines, serving a filtration function.
Variations of columnar epithelium include:
- Ciliated Columnar: Cilia aid in removing mucus and dust.
- Columnar with Striated Border: Contains microvilli for absorption and protection, located in intestines.
- Pseudo-stratified Columnar: Appears layered but consists of single-layer cells with cilia, found in the trachea, where basal cells undergo mitosis and goblet cells produce mucus.

Embryonic Development of Epithelial Tissues

Ectoderm: Forms skin epithelium and parts of the nervous system.
Endoderm: Develops into digestive and respiratory tubes.
Mesoderm: Gives rise to connective tissues, bones, and muscles.

General Characteristics of Epithelium

Epithelial tissues cover surfaces and line cavities; one surface is free while the opposite is attached via:
- Basement Membrane: Supports the epithelium and connects it to the underlying tissue.
- Tunica Propria: Connective tissue that nourishes epithelium through blood vessel projections.
Epithelia are avascular, obtaining nutrients via osmosis and diffusion.
Most epithelial tissues are moist, except for skin epithelium, which is dry.

Classification of Epithelium

Simple Epithelium: Single layer of cells.
- Simple Squamous Epithelium: Flattened cells; includes:
  - Endothelium: Lines heart cavity and blood vessels.
  - Mesothelium: Lines internal organs.
Stratified Epithelium: Multiple layers of cells.
- Examples include non-keratinizing and keratinizing stratified squamous epithelium found in various bodily linings.
- Transitional Epithelium: Located in the urinary bladder; cells change shape when stretched.

Glands

Glands form from epithelial cells growing inward into connective tissue, producing secretory units tailored to physiological needs.
Exocrine Glands: Have ducts to secrete substances outside the body.
Endocrine Glands: Ductless, releasing hormones directly into the bloodstream to activate target organs.

Classification of Exocrine Glands

Glands can be classified by the shape of their secretory units, adapting their functions to the body's requirements.

Description

This quiz covers the histology of epithelial tissues, specifically focusing on simple cuboidal epithelium. It explores the structural characteristics of these cells and their locations in the body, such as in the ovary lining and kidney tubules. Ideal for first-year nursing students studying anatomy and physiology.