 Here, everybody, Dr. O. In this video, we're going to talk about the three types of secretion with your exocrine glands. So first, remember that glands are a specialized type of epithelio tissue. Secondly, we have two types of glands. Exocrine glands are the ones that are going to dump their products onto surfaces. So think about the stuff that goes on your skin, the lining of your GI tract, endocrine glands. We usually think of hormones. Endocrine glands are going to dump their secretions into your body fluids. So we'll cover that way more in AMP2. For now, I just want to talk about the three types of secretions. So you see marocrine secretion, apocrine secretion, and holocrine secretion. So let's go ahead and take a look. So first, we see marocrine secretion, and in this type of secretion, there's no damage to the cell. The cell is producing a product, it's putting them in vesicles, and then dumping them onto the surface. That's a process called exocytosis that we covered, excuse me, in the last chapter. So the best example of marocrine secretion is going to be what are called your marocrine sweat glands. They're also called the acrine sweat glands. Let me go ahead and show you one. Here you see the acrine sweat glands. I call them marocrine sweat glands, and so the name actually tells you what kind of secretion. So no damage to that cell, it's just producing a product and dumping it into its environment. So that is marocrine secretion. Next we have apocrine, so apo should make you think apical or the top. So with apocrine secretion, all the secretory products are moved to the top of the cell, and just the apical or top portion of the cell breaks off and releases the cell content. So instead of dumping it out of the cell, it stores it in the part of the cell and then breaks off that whole part of the cell, releasing its product into the environment. Now this cell is not damaged, this cell will not die. Notice the nucleus, the Golgi, the rough and smoothy are, they're all good. This cell is not going to die. It will actually produce another apical portion and then dump it into the environment. So that is apocrine secretion. The example here are going to be your apocrine sweat glands, which are found armpits around the nipples in the genital area. So apocrine sweat glands produce a thicker, cloudier, stickier type of sweat than our watery, marocrine sweat glands, we'll cover glands in a little while. But this thick, sticky, cloudy sweat that's made by these apocrine glands is food for bacteria. So this is going to be where body odor comes from. It's actually the microbes living on you metabolize this kind of sweat and that's where the body odor comes from. So your body odor is really bacterial farts if you want to look at it that way. So that's going to be apocrine secretion and the key example there, your apocrine sweat glands. But here we have holocrine secretion. So holo, think whole, or entire cell. In this case, the cell fills with whatever its secretory product is and the cell dies and bursts and releases its contents out into the environment. So the key difference here is this cell is done. This entire cell will have to be replaced by another cell making whatever product we're looking at here. So the best example of holocrine secretion is going to be your sebaceous glands. So your sebaceous glands, there's a sebaceous gland that produces sebum that's with every hair follicle. And then we also have sebaceous glands that's all over our skin. These are going to be the oil glands that produce the oil that protects your skin and your hair. All right. So marocrine secretion. It's actually the cells that are harmed at all. It just dumps its products into the environment through exocytosis. Marocrine or acryne sweat glands are the key example there. Apocrine secretion. The typical portion, the top portion of the cell, breaks off releasing its contents and the apocrine sweat glands are the key example there. And then holocrine secretion, the whole or entire cell fills with products, ruptures releasing them into the environment. And the key example there is a sebaceous gland. So those are the three types of secretion that our exocrine glands use. I hope this helps. Have a wonderful day. Be blessed.