Simple Cuboidal and Simple Columnar Epithelial Tissues
Simple Cuboidal Epithelium
Description:
- Consists of a single layer of cubelike cells.
- Cells contain large, spherical central nuclei.
Function:
- Secretion.
- Absorption.
Location:
- Kidney tubules.
- Ducts and secretory portions of small glands.
- Ovary surface.
Histological Details:
- Specimen: Simple cuboidal epithelium in kidney tubules.
- Magnification:
- Key Labeled Structural Features:
- Simple cuboidal epithelial cells: Monolayer of cube-shaped cells forming tubular boundaries.
- Nucleus: Centrally located, prominent spherical nucleus in each cell.
- Basement membrane: Underlying basal membrane anchoring the epithelial cells.
- Connective tissue: Surrounding supportive tissue adjacent to the basement membrane.
Simple Columnar Epithelium
Description:
- Consists of a single layer of tall cells.
- Cells contain round to oval nuclei.
- Surface and cellular specializations:
- Many cells bear microvilli.
- Some cells bear cilia.
- The epithelial layer may contain mucus-secreting unicellular glands (goblet cells).
Function:
- Absorption.
- Secretion of mucus, enzymes, and other substances.
- Ciliated type propels mucus (or reproductive cells) by ciliary action.
Location:
- Nonciliated Type:
- Lines most of the digestive tract (stomach to rectum).
- Lines the gallbladder.
- Lines excretory ducts of some glands.
- Ciliated Variety:
- Lines small bronchi.
- Lines uterine tubes.
- Lines some regions of the uterus.
Histological Details:
- Specimen: Simple columnar epithelium of the small intestine mucosa.
- Magnification:
- Key Labeled Structural Features:
- Cavity inside intestine: The internal lumen space bounded by the apical border of the epithelium.
- Microvilli (on apical surfaces): Microscopic cellular membrane protrusions on the apical surface of epithelial cells.
- Simple columnar epithelial cells: Tall, closely packed columnar cells.
- Mucus of goblet cell: Mucus product stored and secreted by specialized unicellular goblet cells.