Digestive System Speech

Hi! Today we’ll be talking about the Digestive System. The Digestive System is a team of organs that help break down, and absorb nutrients from the food we eat. Allow me to show you how.

Part 1 – THE MOUTH

It begins in the mouth, where your teeth and tongue help eachother to physically break the food into smaller pieces by chewing the food. This is known as mechanical digestion (Mechanical & Chemical Digestion). The salivary glands excrete amylase, an enzyme that helps break down starch. The process of using chemicals to break food down is known as chemical digestion. The product that leaves the mouth is known as bolus (The Structure and Function of the Digestive System) Let me explain why the two together are important. Mechanical digestion,

It recieves food from the mouth, and moves it to the stomach through a series of muscular contractions know as peristalsis (Human Digestive System). At the same time, our soft palates block the upper pharynx (The Structure and Function of the Digestive System). Why? To prevent food away from our nasal airway, so that the bolus does not block our air passages, allowing us to breath normally.

Part 3 – THE STOMACH

Now comes the extremely important stomach. Like the mouth, within the stomach both mechanical and chemical digestion take place. The stomach has the ability to expand due to folds in the stomach wall known as rugae (Stomach). Why have this ability? To allow for more food to be contained!

The mixing action within the stomach further breaks down the the bolus, and mixes it with stomach secretions – mainly gastric juices to form chyme (Stomach). These gastric juices contain mucus, hydrocholoric acid to kill bacteria, pepsinogen and other digestive enzymes that chemically digest the bolus (Human Digestive System). Enzymes are catalysts in a digestive reaction, they break down the food into less complex parts, and prepare it for absorbtion in the intestine (Human Digestive System)

Because of the fact that our stomach lining is covered by mucus, our stomach is protected from the corrosive nature of acidic substances (Stomach)

Part 4 – The

The enzymes assist in chemical digestion in the duodenem, while the bicarbonate help neutralize the acidity of the chyme that flows from the stomach to the small intestine (Pancreas Function). Why are the bicarbonates important? Because they prevent any damage from corrosion.

Part 6 – The Small Intestine

The small intestine is what absorbs nutrients from the chyme received from the stomach. The duodenem releases hormones that allow for the secretion of bile and pancreatic juice – which chemically digest the food one more time before nutrients are absorbed by the Jejunum (Jejunum | Anatomy).

The Jejunum is covered by villi, “small finger like projections”, which have their own microvilli. The villi are what absorb the nutrients that have been chemically digested before, and transport them around the body through capillaries which are embedded within the villi The structure of the villi increase the surface area availible. (VIlli: Function, Definition & Structure). How? The entire structure is ribbon. When it’s folded up, the same area is packed into a smaller space as when it would be when it’s flat out. This in turn increases the rate of diffusion (the rate at which the food is absorbed), and makes the entire process more efficient (How Do Villi Affect the Absorption of