Chapter 12 - Exocrine Glands
Exocrine glands consist of cells that release their products into the lumen of a duct.
Salivary Glands
The salivary glands secrete saliva that aids mastication, effective swallowing, and digestion. These glands contain two types of cells:
- Serous cells - secrete a protein-rich fluid
- Mucous cells - secrete highly-glycosylated proteins called mucins (mucins bound by water are known as mucus)
Sweat Glands
Sweat glands release fluids onto the surface of skin.
- Eccrine Glands - produce sweat primarily made of water and salt. Primary function is to regulate body temperature by evaporative cooling.
- Sebaceous Glands - produce sebum, an oily substance composed of lipids. Sebum lubricates and waterproofs the skin and hair.
Exocrine Pancreas
Most of the pancreas is formed by serous acini that comprise the exocrine component. The acini synthesize and secrete a variety of digestive enzymes.
The digestive enzymes are secreted as inactive proenzymes, or zymogens, that require further processing to become an active enzyme. If these digestive enzymes were activated before their secretion, it would lead to digestion of the pancreas itself.
Pancreatic ducts transport digestive enzyme released by exocrine cells and secrete an alkaline, bicarbonate-rich fluid. This solution is released into the duodenum of the small intestine.
Centroacinar cells are the terminal duct cells from intercalated ducts that extend into pancreatic acini.
