Fetal Pig Dissection Day 4: Digestive System

Day 4:

Day 4 was all about the digestive system which includes the 

stomach, gallbladder, pancreas, small intestine, liver, rectum, anus, and large intestine.

Gallbladder

The gallbladder is that stores bile salts that are made in the liver. Bile salts emulsify fats in the duodenum which is the first part of the small intestine

Liver

The liver has a wide range of functions that help with many of the systems in the body including the digestive system. The liver is necessary for survival and is one of the only organs that can be surgically cut and it will regrow back and just like the lungs the liver contains lobes. The liver creates bile salts which in the digestive system helps emulsify fats that are located in the stomach the liver stores it's bile salts in the gallbladder like I had said above. 

  The stomach is a very main part of digestion because it secrets protein enzymes and the stomach has a pH of 2 so it contains very strong acids  that aid in the break down of foods. An enzyme that works well in such a low pH is pepsin which helps break down proteins into amino acids. Because the acids are so strong there are sphincters located at the top and at the bottom of the stomach so the acid does not burn the esophagus or the small intestine. The one located at the top is called the esophageal sphincter and the one located at the bottom is called the pyloric sphincter.

  

Small Intestine

This is where the last part of digestion and absorption happens because the small intestine has a pH of 8 the pancreas secrets bicarbonate ions that then buffers the chyme before it enters the small intestine. Most of digestion and absorption take place in the small intestines. Because of the intense fold and the villi(which are like small cilia and line the walls of the intestine) the villi increase the surface area of the small intestine which allows a lot more absorption.

   

The Large Intestine is the last portion that I got a picture of. The large intestines goal is to take the remaining waste and try to and get all the water absorbed out of it then pass the waste. Because the fetal pig does not eat for itself the waste in the colon(large intestine) is amniotic fluid. It them travels to the rectum where 

the waste is stored then excreted by the anus.

 This photo is of a cross section of the large intestine.