Epithelial Tissue: Types and Functions - Anatomy and Physiology
- Which epithelium lines most of the trachea?
- Pseudostratified ciliated columnar epithelium with goblet cells; mucus traps particles and cilia sweep it upward.
- Which epithelium lines the urinary bladder and allows it to stretch?
- Transitional epithelium (urothelium). Its surface cells change from rounded to flattened as the bladder fills.
- What two layers make up the basement membrane beneath an epithelium?
- The basal lamina, secreted by the epithelial cells, and the reticular lamina, secreted by the underlying connective tissue.
- Why does pseudostratified epithelium look layered even though it is a simple epithelium?
- Every cell touches the basement membrane, but the cells differ in height, so their nuclei sit at different levels.
- Which apical surface modification increases the absorptive surface area of small intestine epithelial cells?
- Microvilli, which form the brush border.
- Which epithelium forms the epidermis of the skin?
- Keratinized stratified squamous epithelium, which resists abrasion and water loss.
- Which epithelium lines the mouth, esophagus, and vagina?
- Nonkeratinized stratified squamous epithelium, which resists abrasion while staying moist.
- Which epithelium lines the kidney tubules and small gland ducts?
- Simple cuboidal epithelium, specialized for secretion and absorption.
- Epithelium is avascular. How do its cells receive nutrients?
- By diffusion from blood vessels in the underlying connective tissue, across the basement membrane.
- Which epithelium lines the alveoli of the lungs and the inner surface of blood vessels?
- Simple squamous epithelium. Its thin cells allow rapid diffusion and filtration.
- Which two criteria are used to name epithelial tissues?
- The number of cell layers (simple or stratified) and the cell shape (squamous, cuboidal, or columnar); a stratified epithelium is named for its apical layer.
- Which epithelium lines the stomach and the intestines?
- Simple columnar epithelium, specialized for secretion and absorption.