The Dynamic Gastric Model ( Dgm )

The stomach is an organ that is part of the digestive system. The stomach is located in the upper left part of the abdominal cavity, below the diaphragm and next to the liver (Stomach, 2013). The inner walls of the stomach contain small pores called gastric pits. The gastric pits contain cells that secrete chemicals that aid in the digestion of food (Nguyen, 2015). In this essay, I will discuss the different cell types of the stomach, how they work together to provide the overall function of the stomach, why each organ requires different cell types, why the stomach can’t be comprised of just one cell type, and the advantage of having different types of cells.

The control of gastric secretions happens when the secretion of the gastric juice by the stomach is stimulated by both of the nerves and the hormones. There are three phases in which this happens;

The body digests food by breaking down large complex organic molecules with the assistance of enzymes. As a result, these large molecules, now transformed as small molecules, can pass through a selectively permeable membrane. This process of moving the molecules from a high concentration to a low concentration is called diffusion. In this experiment, the process of diffusion will be tested using dialysis tubing to represent how consuming carbohydrates such as starch are broken and how enzymes, in this case being amylase, help digest food to allow it to diffuse across a membrane. As a result, the experiment will provide data as to whether starch, after being broken down into glucose, can move across the membrane. as well as supporting

Once again my mini-sub and I will be miniaturized (8 microns long) and witnessing another ‘Fantastic Voyage’ in a human body. This time I will be swallowed by George, a 55 years old man, while he is eating his meal consisting of a hamburger, French fries and a soda. I will pilot my mini-sub through George’s GI (gastrointestinal tract), which is the tube that starts with the mouth and proceeds to the esophagus, stomach, duodenum, small intestine, large intestine (or colon), rectum and, finally, the anus (Pansky, 2007). Along this pathway I will describe the digestion of George’s meal and the major structures that I will encounter. Arrived to the distal

Immediately after entering the stomach, water and the unusable plasma of the ingested blood are absorbed by the lining of the stomach (Breidenstein, 1982). The majority of the dry matter in blood is mainly proteins, so the digestive system of the Arctic vampire lizard goes to work on breaking these proteins down (Breidenstein, 1982). Beginning in the stomach, the enzyme pepcin begins breaking some of the peptide bonds of the proteins (Silk et al. 1985). The contents of the stomach are then quickly transported to the small intestine, where pancreatic enzymes continue to hydrolyze the polypeptides, breaking them into individual amino acids (Silk et al. 1985). In the small intestine, the amino acids are diffused through the intestinal lining into the tangent blood vessels to be delivered through the body through the circulatory system (Silk et al. 1985). The liver can then convert amino acids like alanine to glucose through a process called gluconeogenesis (Yoon et al. 2001). The glucose is then made into ATP through aerobic respiration, producing water and carbon dioxide (Yoon et al.

Purpose: The purpose of this lab is to understand the process of digestion. In addition, to investigate what chemicals and enzymes are needed for carbohydrate, protein, and lipid digestion.

In this lab, I will study how digestion of carbohydrates, proteins, and fats occurs. I will define Key Terms that describe what will occur in the experiments; I will conduct an experiment for each Activity and provide all resulting Data as well as answer Questions from each Activity. I will then provide a short Summary for what I learned in each Activity.

In this experiment, the glucose and starch molecules accurately reflected the expected results of the biological simulation. Animal’s starch molecule can’t cross the plasma membrane to leave the intestine, similarity in our experiment, the starch solution were not able to permeate through the intestine (Dialysis tubing), thus a

Stomach acid is produced by parietal cells that line the stomach wall. Hypersecretion on stomach acid cause hyperacidity. Hyperacidity occur when these cells have proton pumps which will move more hydrogen ions from the inside the parietal cell into the stomach lumen against a concentration gradient. These pumps secrete acid in response to three neurohumoral signals: (i) acetylcholine, a neurotransmitter that is released by the vagal nerve endings, (ii) gastrin, a local hormone produced by G cells in the antrum, and (iii) histamine, a biologically active chemical produced by ECL-cells in the stomach wall. Thus, gastrin stimulates the parietal and pepsin cells, which increases gastric mucosal blood flow, and has a trophic effect on the gastric,

The stomach is an expandable muscular sac that is capable of holding 2-4 liters of food and liquids and breaks them down with the use of pepsinogen, an inactive form pepsin, a protein-digesting enzyme. If the stomach was damaged or dysfunctional, then it would be harder to gradually release food into the small intestine at a rate suitable for proper digestion and absorption and to digest the food because it is not as small or digested because the stomach also assists in the mechanical and chemical breakdown of the food as well as the killing of harmful bacteria due to the high acidic environment due to the hydrochloric acid. (Audesirk, T., & Audesirk, G. (1999). Retrieved November 21, 2015 from Chapter 29: Nutrition and Digestion. In Biology:

Digestion in the colon consists of two main mechanisms, the first one is mechanical digestion in which digestion starts when the chyme passes through ileocecal sphincter; the characteristic movement of the colon is haustral churning in which colon walls contract and squeeze contents into the second haustrum. The final digestion mechanism is chemical digestion in which microorganisms that inhabit the lumen of large intestine digest and ferment colon contents and release gases as carbon dioxide, two mechanisms are challanging drug absorption from the colon. [11]

In the process of diffusion, the net movement of molecules is from an area of high concentration to an area of low concentration. These molecules continue to move until they are distributed uniformly in the solution. The plasma membrane that surrounds the outside of the outside of the cell is selectively permeable, meaning that it allows the passage of certain compounds and molecules through the membrane and into or out of the cell. This experiment was meant to model the process of digestion in a caterpillar by testing to see if starch digested with -amylase would diffuse out of dialysis tubing and into the surrounding liquid. This process was to be tested using Lugol’s reagent by seeing the color change in the beaker and the dialysis tube due to the fact that Lugol’s reagent turns blue-black in the presence of starch. It was hypothesized that, after an hour, the digested starch in the dialysis tube would diffuse out in the surrounding liquid in order to follow the process of passive diffusion due to the lower concentration of solutes in the surrounding liquid. The null hypothesis would

The cell membrane was simulated by dialysis tubing. The tubing was folded, wetted and tied to allow it to look like a cell. It was then filled ⅔ by starch solution, tied shut and wetted from the outside. It was then placed into a beaker with ½ water and enough iodine to give the water a yellow-type colour. Observations of the tubing were recorded at the initial stage, after 15 minutes and after a 48 hour period.

over variable periods of time and at different pH values. At the acidity of the human stomach

The purpose of this lab was to understand how different solutions played a role in the digestion protein. By looking at different variables, such as temperature, and pH we’re capable of understanding just how certain substances functioned and when they didn’t. The data for all labs are clear and concise and give a clear understanding of what solutions work best. All three labs were placed in a warm water bath set at 37’C to stimulate the reaction as if it were taking place within the human body. This gives us a more accurate reading on how they would react at that set temperature. We concluded why certain tubes changed to the color they did and further explained it. This lab focuses primarily on two crucial