In this video, we're going to begin our lesson on the functions of epithelial tissue. Before we get started, it's important to note that the functions of epithelial tissue are quite diverse. Instead of making an exhaustive list of all of the different functions of epithelial tissue, in this video, we're going to provide a big picture view and talk more broadly about the functions of epithelial tissue. Epithelial tissue can be broadly categorized into 2 major functional groups, as indicated below in our image. These 2 major functional groups are:
- Covering and lining epithelium, found in the far left block of the image.
- Glandular epithelium, located in the far right block of the image.
The covering and lining epithelium, as its name implies, is essential for covering body surfaces and many organs, and lining internal body cavities and ducts. The functions of covering and lining epithelial tissue can be grouped into 3 major functions, outlined below in our image:
- Provide protection: Serving as tissue on a boundary, it acts as a physical barrier, functioning like a shield protecting against mechanical stresses, pressures, microorganisms such as bacteria, and extreme temperatures.
- Regulating transport: This epithelial tissue is selectively permeable, allowing control over the transport of substances across the boundary. It regulates transport both into the open space above and deeper into the tissue below.
- Allow sensations: In close connection with nervous tissue, this epithelial tissue is involved in detecting stimuli from the outside world and activating nervous tissue to process these stimuli. This includes detecting sensations such as touch.
The glandular epithelium, as the name suggests, is crucial for forming glands which are cellular structures specialized for producing secretions. These secretions are released into an open space, as depicted below. Examples of these secretions include sweat, saliva, milk, oil, enzymes, hormones, and mucus.
This concludes our brief introduction to the functions of epithelial tissue. As we progress, we will delve deeper into these topics and apply these concepts practically. I'll see you all in our next video.