Overview
This presentation introduces glandular tissue, its connection to epithelial cells, and distinguishes between exocrine and endocrine glands.
Glandular Tissue Basics
- Glandular tissue is any tissue that produces secretions.
- Common misunderstanding: "swollen glands" in layman's terms usually refer to lymph nodes, not true glands.
- Glandular tissue ranges from single cells (e.g., goblet cells) to complex organs (e.g., thyroid gland).
Epithelial Cells and Glands
- Epithelial cells are the only tissue type capable of producing secretions.
- Glandular epithelium is usually buried deeper in the body than typical epithelial linings.
- Secretory epithelial cells are simple (single-layered), typically cuboidal or columnar in shape.
- Squamous epithelial cells do not typically produce secretions.
Types of Glands
- Exocrine glands: Have ducts that carry secretions to a body surface or cavity (e.g., salivary glands).
- Endocrine glands: Ductless; release secretions (hormones) directly into the bloodstream (e.g., adrenal glands).
- Exocrine secretions act locally; endocrine secretions (hormones) can affect the entire body.
Key Terms & Definitions
- Glandular tissue — Tissue whose main function is to produce and release substances (secretions).
- Goblet cell — A single, mucus-producing epithelial cell.
- Exocrine gland — Gland that uses ducts to secrete substances onto surfaces or into cavities.
- Endocrine gland — Gland that releases hormones directly into the blood without ducts.
- Hormone — Chemical messenger released by endocrine glands to regulate body functions.
- Simple epithelium — Single layer of epithelial cells, often cuboidal or columnar, involved in secretion.
Action Items / Next Steps
- Review examples of exocrine and endocrine glands.
- Read about mucous membranes and their secretory cells for the next session.