Here's a breakdown:
What they do:
* Synthesis: They create specific substances, like hormones, enzymes, mucus, sweat, or milk.
* Storage: They store these substances until they are needed.
* Secretion: They release the substances in a controlled manner, often in response to specific signals.
Types of glands:
* Exocrine glands: Release substances into ducts, which carry them to a specific location, such as the surface of the skin or into a hollow organ. Examples include sweat glands, salivary glands, and mammary glands.
* Endocrine glands: Release substances directly into the bloodstream, where they travel to target cells throughout the body. Examples include the thyroid gland, pituitary gland, and pancreas.
Examples of glandular cells:
* Pancreatic cells produce insulin and glucagon, hormones that regulate blood sugar.
* Thyroid cells produce thyroid hormones, which control metabolism.
* Goblet cells in the lining of the intestines secrete mucus, which lubricates the digestive tract.
* Sweat glands produce sweat, which helps regulate body temperature.
Structure:
Glandular cells have unique structures based on the type of substance they produce and how they secrete it. Some common features include:
* Abundant endoplasmic reticulum (ER): Involved in protein synthesis.
* Well-developed Golgi apparatus: Processes and packages proteins and other substances.
* Secretory granules: Store and release the synthesized products.
Importance:
Glandular cells are essential for a wide range of bodily functions, including:
* Regulation of metabolism and growth
* Digestion and absorption of nutrients
* Protection against pathogens
* Communication between cells
* Reproduction
In summary: Glandular cells are specialized cells that play a vital role in the body by producing and releasing substances that are necessary for many vital functions.
