Epithelial Tissue

Front

Tissues Noun

---

[tish-oos]

Back

Tissues

---

A cluster of specialized cells that are grouped together to perform a common function in an organism.

---

Example: This image displays four types of epithelial tissue, showing how cells group together in different shapes (cubed, flat, column-like) and layers to cover surfaces.

Front

Epithelium Noun

---

[ep-i-thee-lee-um]

Back

Epithelium

---

A type of animal tissue that covers body surfaces, lines body cavities and hollow organs, and also forms glands.

---

Example: This diagram shows that epithelial tissue, which covers body surfaces, is a category that includes different types based on cell shape and layers.

Front

Homeostasis Noun

---

[hoh-mee-oh-stay-sis]

Back

Homeostasis

---

The ability of an organism or cell to maintain a stable internal environment despite changes in external conditions.

---

Example: This diagram shows red blood cells delivering a constant supply of oxygen to body cells, a key process for maintaining the body's stable internal environment (homeostasis).

Front

Cellularity Noun

---

[sel-yoo-lar-i-tee]

Back

Cellularity

---

A characteristic of tissue describing the state of being composed of cells that are tightly packed with little intercellular space.

---

Example: This diagram shows epithelial tissue, which is defined by its high cellularity, meaning it is made of many cells packed very closely together.

Front

Polarity Noun

---

[poh-lar-i-tee]

Back

Polarity

---

The characteristic of epithelial cells having distinct structural and functional sides, known as an apical and a basal surface.

---

Example: This diagram shows an epithelial cell has a distinct top (apical membrane) and bottom (basal membrane), which is a feature called polarity.

Front

Avascularity Noun

---

[ay-vas-kyoo-lar-i-tee]

Back

Avascularity

---

The characteristic of a tissue lacking blood vessels, requiring it to receive nutrients through diffusion from adjacent tissues.

---

Example: This image illustrates four components of alternative education; it does not explain avascularity, which is the lack of blood vessels in a tissue.

Front

Regeneration Noun

---

[ri-jen-uh-rey-shuhn]

Back

Regeneration

---

The natural process of replacing or restoring damaged or missing cells and tissues to restore their full function.

---

Example: This image shows how a lost limb can regrow in stages, starting with wound healing, which involves epithelial tissue covering the injury.

Front

Apical Surface Noun

---

[ey-pi-kuhl sur-fis]

Back

Apical Surface

---

The surface of an epithelial cell that is exposed to the external environment or an open internal space (lumen).

---

Example: This diagram shows that the apical surface is the top layer of epithelial cells, which faces an open space or cavity called the lumen.

Front

Basal Surface Noun

---

[bey-suhl sur-fis]

Back

Basal Surface

---

The surface of an epithelial cell that is anchored to the underlying connective tissue via a basement membrane.

---

Example: This diagram shows that the basal surface of epithelial cells is the 'bottom' layer that attaches to the underlying basement membrane.

Front

Simple Epithelium Noun

---

[sim-puhl ep-i-thee-lee-um]

Back

Simple Epithelium

---

Epithelial tissue that is composed of a single layer of cells, typically involved in absorption, secretion, or filtration.

---

Example: This image shows a single layer of cube-shaped cells, called simple cuboidal epithelium, which line tiny tubes inside an organ like the kidney.