Glandular Epithelium

How are glandular epithelia categorized?

based on the types of secretion, gland structure, and mechanism of secretion

Exocrine glands

glands that secrete onto the body surface or into a passageway connected to the exterior

Epithelilal ducts

a structure in which exocrine glands release their secretions

What are examples of exocrine secretions?

enzymes entering the digestive tract, perspiration on the skin, and milk produced by mammary glands

What are the types of exocrine glands?

Serous, mucous, and mixed exocrine

Serous glands

secretes a watery solution that contains enzymes

Mucous glands

secrete glycoproteins called mucins that absorb water to form mucus

Mixed exocrine glands

contain more than one type of gland cell and may produce both serous and mucous secretions

Endocrine glands

ductless glands that release their secretions by exocytosis directly into the interstitial fluid surrounding the cell

What are the types of unicellular glands?

mucous cells and goblet cells

Where are mucous cells found?

the stomach mucosa, the respiratory mucosa, and salivary glands

Where are goblet cells found?

in the mucous of the small and large intestines and the terminal bronchioles

What is the simplest multicellular exocrine gland?

The secretory sheet

What is the function of the secretory sheet that lines the stomach?

to protect the stomach from acid and enzymes

Secretory sheet

a structure in which glandular cells dominate the epithelium and release their secretions into an inner compartment

What are the epithelial components of multicellular glands?

a glandular portion that produces the secretion and a duct that carries the secretion to the epithelial surface

What characteristics describe the organization of a multicellular exocrine gland?

the shape of the secretory portion of the gland and the branching pattern of the duct

What are the methods of secretion?

eccrine, apocrine, and holocrine

Eccrine secretion

a method of secretion in which the secretory product is packaged into secretory vesicles and is released via exocytosis on the surface of the cell

Apocrine secretion

a method of secretion in which the secretory product is released during the shedding of the apical portion of the cell’s cytoplasm, which is packed with secretory vesicles

Holocene secretion

a method of secretion in which the entire cell becomes packed with secretory vesicles and bursts in order to release the product;