Simplified Explanation of Sebaceous Glands:
Sebaceous glands are specialized structures that are found in the skin of mammals, including humans. They are responsible for producing and secreting an oily substance called sebum. Sebum plays a crucial role in maintaining the health and integrity of the skin and hair.

Understanding the Structure:
Sebaceous glands are classified as "simple branched alveolar" glands. Let's break down what this means:

Simple:
- Simple glands have a single unbranched duct that connects the gland to the surface of the skin.
- In the case of sebaceous glands, they have a single duct that opens into a hair follicle.

Branched Alveolar:
- Branched glands have multiple ducts that branch off from the main duct.
- Alveolar glands have a grape-like cluster of secretory cells at the end of each duct.
- In the case of sebaceous glands, they have multiple small ducts that branch off from the main duct, and each duct ends in a cluster of secretory cells called alveoli.

Function of Sebaceous Glands:
Sebaceous glands produce and secrete sebum, which is an oily substance. Here are some important functions of sebum:

1. Lubrication: Sebum helps to lubricate the skin and hair, preventing them from becoming dry and brittle.

2. Moisturization: Sebum helps to moisturize the skin by preventing excessive water loss through the skin surface.

3. Protection: Sebum forms a protective barrier on the surface of the skin, which helps to prevent the entry of harmful microorganisms and chemicals.

4. Hair Conditioning: Sebum coats the hair shaft, providing it with a natural shine and preventing it from becoming dry and frizzy.

Conclusion:
Sebaceous glands are classified as simple branched alveolar glands. They play a vital role in maintaining the health and integrity of the skin and hair by producing and secreting sebum. The sebum produced by these glands helps in lubrication, moisturization, protection, and hair conditioning.