(Ireland, 2012) Stated “Hydrochloric acid is one of the strongest acids used in laboratories and can be found in our stomach, as PH2. Mucus is what produces mucous cells which are often clustered into small glands located on the mucous membrane that lines the entire digestive tract (Stomach and its role in digestion). The Parietal cell know as oxyntic or delomorphous cells are located in the fundic, cardiac, and pyloric region. The epithelial cells that collects hydrochloric acid activates the release of pepsin for digestion (Stomach and its role in digestion). These cells are located in the gastric glands found in the fundus and in the body of the stomach.
What is not absorbed by the small intestine passes into the large intestine, which includes the colon and rectum. Here, peristalsis (the contractions of the muscles around the stomach and intestines that assist in moving food through the system) slows, allowing the growth of bacteria, which aids in the digestion of fiber and the absorption of some vitamins. The colon absorbs water, vitamins and minerals not absorbed by the small intestine. Anything that has not been absorbed by this point is then eliminated through the rectum and anus, thus completing the journey food takes through the
The bolus then moves down into the esophagus, which follows to the stomach. Once the bolus engages the stomach, it starts to mix with the acid secretions convert the bolus into chyme. Chyme is the semi-fluid mass of in some measure of digested food discharged from the stomach in to the duodenum. Relying on the size and type of meal consumed, chyme usually empties from the stomach in 2 to 6 hrs. The liver, gallbladder and the pancreas begin to bestow to the digestive process once the chyme reaches the small intestine.
These glands provide a major shell of protection for the stomach wall and contribute to lubrication of food transport. The mucus produced by these mucus-secreting cells is alkaline (thus the normal stomach wall is not exposed to the highly acidic and proteolytic stomach secretions directly). o Oxyntic/gastric glands: • Located on the inside surfaces of the body and fundus of the stomach • Constitute the proximal 80% of the stomach • A typical gland is composed of 3 types of cells: mucous neck cells which secrete mainly mucus; peptic/chief cells which secrete large quantities of pepsinogen; parietal/oxyntic cells which secrete hydrochloric acid (gastric acid) and intrinsic factor o Pyloric glands: • Are located in the antral portion of the stomach • Make up the distal 20% of the stomach • Secrete mainly mucus for protection of the pyloric mucosa from gastric acid; also secrete the hormone gastrin and a small amount of pepsinogen o Pepsinogen: • Secreted mainly by peptic cells of the oxyntic glands, but a small amount is also secreted from the mucous cells of the oxyntic glands and from the pyloric glands (function is the same) • Molecular weight = c. 42,500 Da • Is inactive when first secreted into the into the stomach • Is activated to form pepsin: during this process, pepsinogen is split into a 35,000 Da molecule (pepsin) HCl creates an acidic environment which allows pepsinogen to
The small intestine is the principal site of digestion and absorption. Enzymes from the pancreas, liver, gallbladder, and the small intestine itself combine to break down nutrients so that they can be absorbed. The pancreas supplies enzymes to digest proteins, fats and carbohydrates. The live produces bile required for emulsification of fat, and the gallbladder stores the bile until it is needed. The absorption of nutrients in the small intestine is facilitated by tiny projections called villi, which provide more surface area for absorption.
Cholesterol helps to form the bilayer membrane that surrounds each cell within the body. (Cooper, 2000) Cholesterol is made by the liver and acquired through diet, and consists of a waxy like substance. The body uses cholesterol in the production of some hormones, bile, Vitamin D and is found within cells and blood. Cholesterol is also used in the production of myelin sheaths, which are essential in the covering of the nerves. HDL’s (high density lipoprotein) is considered to be “good” cholesterol and assists in carrying LDL’s (low density lipoprotein) to the liver to be processed and exported out of the body.
Skeletal muscles are very important for such joints. • Circulation- Cardiac muscles provide the main force for circulation of blood throughout human body. The regular pumping of the heat keeps the blood in motion and nutrients are readily available to every tissue of human body. • Digestion -Only until the time the food reaches the throat it is voluntarily after which, the rest of movement of the food from throat to anus is involuntary and is performed by smooth muscles. The food is chewed in the mouth by the teeth using voluntary muscles but once it enters esophagus, it moves down the digestive tract through the process of peristalsis.
Many lipids can are able to cross the membrane on their own, the lipids that cannot move across on their own get help by permeation which is the diffusion through a barrier of a substance of solution. The body can synthesize most of the fats it needs from the diet. There are two essential fatty acids however, that cannot be synthesized and must be obtained from food. These acids are called linolenic and linoleic acid. These basic fatty acids are used to build specialized fats called omega 3 and omega 6.
It coats the chewed food and transforms it into what is called a bolus. An enzyme called amylase found in the saliva breaks down the carbohydrates in the bolus into simpler sugars. By breaking down the food, the bolus becomes mushy, slippery and easy to swallow. The tongue also plays a big role in helping digest food in the mouth. It helps taste, transport and swallow food.
The trachea is surrounded by 15-20 C-shaped rings of cartilage at the front and side which help protect the trachea and keep it open. They are not complete circles due to the position of the oesophagus immediately behind the trachea and the need for the trachea to partially collapse to allow the expansion of the oesophagus when swallowing large pieces of food. Bronchi: The trachea divides into two tubes called bronchi, one entering the left and one entering the right lung. The left bronchi is narrower, longer and more horizontal than the right. Irregular rings of cartilage surround the bronchi, whose walls also consist of smooth