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1. Mechanical digestion- the actual breaking down of food into very small pieces (example Chewing).
2. Chemical digestion- the breakdown of large particles into smaller ones by using ENZYMES.
ENZYMES are substances created by the body that speed up CHEMICAL DIGESTION.
PERISTALSIS is the wave like muscle squeezing that forces food down into the stomach.
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∙ 14y ago
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∙ 16y agoWhen the stomach churns and squeezes the food this is physical digestion. When the enzymes and hydrochloric acid are added, this is chemical change.
Wiki User
∙ 15y agoStomach acid serves to slightly sterilize the contents of the stomach. The fluid contents of the stomach serve to hydrate the consumed foods. The stomach's motions serves to break the food down physically into slightly smaller size.
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∙ 11y agoThe stomach and its role in digestion
The stomach is a muscular sac that lies between the esophagus and the small intestine in the upper abdomen. The stomach is not the only part of your digestive system that absorbs food but rather is a part of the digestive system and important for churning food into a consistency that is easier to digest for the rest of your intestines.
Function of the stomach
The stomach is J-shaped and it can expand to temporarily store food.
Partial digestion of the food takes place here. The churning action of the stomach muscles physically breaks down the food.
The stomach releases acids and enzymes for the chemical breakdown of food. The enzyme pepsin is responsible for protein breakdown.
The stomach releases food into the small intestine in a controlled and regulated manner.
Chewed food passes from the esophagus into the stomach; the flow is somewhat regulated by the esophageal sphincter but more importantly depends on how fast you eat and if you are eating both solids and liquids. The passage of food from the stomach to the small intestine is controlled by the pyloric sphincter. The crushed and mixed food is liquefied to form chyme and is pushed through the pyloric canal into the small intestine.
A network of blood vessels and nerves surrounds the stomach; this is responsible for the regulation of the secretion and the motion of stomach muscles that churns food.
Different parts of the stomach
The stomach can be divided into four distinct parts. These are the cardia, fundus, corpus, and pylorus.
The cardia is the first portion of the stomach and is where food content passes from the esophagus into the stomach. The acids and enzymes referred to as the gastric juices are manufactured in the cardia. The fundus stores undigested food and also the gases released from the chemical digestion of food. The body of the stomach or the corpus is the largest of the four parts that make up the stomach. And this is where the bulk of the partial digestion occurs. The pylorus is connected to the duodenum or the beginning of the small intestine. The contents of the stomach move into the small intestine via the pyloric canal.
The stomach wall
The walls of the stomach consist of four layers, similar to other parts of the gastrointestinal tract. These layers, starting from the innermost layer, are named mucosa, sub-mucosa, muscularis externa, and the serosa.
The mucosa consists mainly of the gastric glands that secrete the digestive juices. It is covered by a layer of columnar epithelial tissue. The sub-mucosa consists of dense connective tissue and has blood vessels, lymphatic vessels, and nerves running through it. The sub-mucosa supports the mucosa and allows it to move in a flexible manner during peristalsis.
Peristalsis is the contraction and relaxation of the stomach muscles to physically breakdown food and propel it forward. These contractions are created by the muscular wall of the stomach which consists of inner circular and outer longitudinal smooth muscle. The outermost layer of the stomach wall, the serosa consists of an epithelial layer and connective tissue which connects to the surrounding organs. The mucosa and the sub-mucosa are present as folds termed rugae. When the stomach is distended with food, the rugae are flattened out and appear smooth.
Cell types in the stomach that help with digestion
There are four main types of cells for stomach secretions spread all over the inner surface of the stomach:
Mucous cells secrete the alkaline mucous for shielding the epithelium from hydrochloric acid. These are found in the fundic, cardiac, and pyloric region.
Parietal cells, located in the fundic, cardiac, and pyloric region, secrete hydrochloric acid; the acid activates release of pepsin for protein digestion. The acid also kills micro-organisms swallowed with the food.
Chief cells secrete pepsin. These cells are located in the fundic region.
G cells are found in the fundic, pyloric, and gastric region. These secrete gastrin which stimulates the secretion of hydrochloric acid.
Healthy habits for a healthy stomach
Certain lifestyle habits can help you maintain stomach health and also counter abdominal obesity. If you notice that certain food types do not agree with you, try to keep away from them. Limit junk food. If you experience bouts of acidity, consider adding to your diet food items that are alkaline in nature. Take walks, it aids digestion, will help you shed calories, and prevent a condition like GERD from occurring. In fact, a sedentary lifestyle with little or no exercise contributes to stomach-related problems.
Some stomach conditions and diseases
The umbrella term for stomach disease is gastropathy. Some common stomach disorders include:
Dyspepsia: This is a condition characterized by a feeling of fullness; indigestion; and pain in the upper abdomen or lower chest. Other symptoms include nausea and vomiting. Dyspepsia can be a precursor to GERD and may also indicate angina.
GERD: Gastroesophageal reflux disease is a condition in which the stomach acids rise up the esophageal passage. Heartburn is a common symptom of the condition.
Peptic Ulcers - These can occur when the protective mucous lining of the stomach walls is damaged by the stomach acids. The bacterium, Helicobacter pylori is thought to be an important factor in the development of gastric and duodenal ulcers.
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∙ 12y agoWiki User
∙ 11y agoEnzymes (eg. pepsine) and acid (hydrochloric) help the breakdown of food stuffs
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∙ 12y agono, mechanical digestion
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∙ 12y agoyes
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Structural adaptation in physical digestion of the stomach?
Your stomach is coated with mucous coat. This is made of sugars and there is no peptide bond, there in mucous. So the stomach is protected from the killing action of pepsin enzyme on the stomach wall.
What body parts is not involved in mechanical digestion?
Chemical digestion takes place in the stomach, the intestines, (saliva or enzymes) these parts of your body also use mechanical digestion.
Is formation of chyme by the stomach an example of mechanical digestion?
No, it is chemical digestion.
Most mechanical digestion takes place where?
In the Mouth then the second is the Stomach
Which organ is most important in digestion?
The organ responsible for most of the chemical digestion in the human body is mainly the stomach.
How does physical activities affect digestion?
because when we move or doing some physical activitieis like cycling climbing etc...... it will make our stomach to scretes the bjuice which help in digestion
Where does most digestion take place in the human body?
Most of the physical digestion takes place in the stomach, but the completion and absorption is done in the small intestine.
Where does the protein digestion start?
the digestion of proteins begin in the stomach.
What is chime in digestion?
It's a form of physical digestion, I assume its the substance inside your stomach, i.e liquid in the central region.
What does the mouth and stomach do in mechanical digestion?
The mouth and stomach both play parts in the digestive system ;also in chemical and physical digestion.In chemical digestion, in the mouth the saliva is mixed with enzymes which breaks down food into bolus and in the stomach acids break down the food turning it into chyme.In Physical digestion in the mouth the teeth tears the food and the stomach churns it.
Does digestion begin in your stomach?
Correctly, physical digestion begins in the mouth, when foodstuffs are pulverised and mashed up into small pieces, and coated with saliva, to make swallowing easier and to increase it's surface area. This process is completed in the stomach, where food is liquified by strong hydrochloric acid secreted by the gastric glands to make it easy to assimilate. All these processes are classed as physical digestion, but not actual ABSORPTION- this takes place in the small intestines. The only substance absorbed by the stomach is alcohol.
What is food like after digestion in the stomach?
Food becomes semisolid after digestion in stomach.
Where does the most digestion in the stomach occur?
Most nutrient digestion occurs in the stomach
Is digest a physical change?
Digestion involves both physical and chemical changes. The teeth crush food into smaller particles, which is a physical change, whereas the saliva, stomach, gall bladder, and pancreas contain chemicals that break down food chemically in the mouth, stomach, and small intestines.
Structural adaptation in physical digestion of the stomach?
Your stomach is coated with mucous coat. This is made of sugars and there is no peptide bond, there in mucous. So the stomach is protected from the killing action of pepsin enzyme on the stomach wall.
Function of the stomach?
starts the digestion of the food Physical and chemical digestion Hydrochloric acid activates pepsin (protease)
What is the two organs where digestion take place?
two organs where digestion occur are stomach and small intestine
