Glandular Epithelium

Glandular

aggrigation of epithelial cells

Endocrine glands

release hormones into the blood vascular system; ex. adrenal gland & adrenaline

Paracrine gland

Signaling molecules secreted by one cell, act on adjacent cells; ex. immune cells

Autocrine gland

Signaling molecules act on the same cell that is secreting them; ex. liver regulation in response to injury

Exocrine gland

Secretion released onto the surface epithelium, has a duct; ex. sublingual gland

How are glands classified?

Number of cells, duct type, secretory unit shape, mode of secretion, or nature of secretion

Number of cells

unicellular and multicellular

Duct types

Simple- unbranched duct

Compound- branched duct

Secretory unit shape

Acinar - grape like

Tubular - tube like

Mode of Secretion

Merocrine, apocrine or holocrine

Merocrine secretion

Only the secreted molecule is released; ex. goblet cells

Apocrine secretion

The secreted molecule and the cytoplasm is released; ex. mammary glands

Holocrine secretion

Full cell content release; due to cell degeneration; ex. sebaceous glands

Nature of Secretion

Mucus, serous, mixed

Mucus secretion

Sticky, high glucose concentration; ex. goblet cells

Serous secretion

Watery secretions; ex. enzymes

Mixed secretion

A combination of both mucus and serous secretions; ex. salivary gland

Most glands within the body are?

Compound tubloacinar, aside from the GI tract

What type of glands in the GI tract?

Simple tubular & simple branched tubular

How are acini cells classified?

Mixed; secretion includes enzymes and carbohydrates

Serous gland characteristics

round, basal nucleus

basophilic infra-nuclear cytoplasm (RER aggregation)

esosinophilic super-nuclear area (protein accumulation)

Mucus gland characteristics

flat, basal nucleus

pale, empty cytoplasm

rich in carbohydrates

Mixed gland charcteristics

Flat, peripheral nuclei

Eosinophilic, semilunar cytoplasm

Secrete both protein and carbohydrates