Science: Process in the Digestive System

• Nutrition - the intake of food are being processed and converted into energy that is used by the human body.
• Holozoic Nutrition is the mode of feeding found in animals and humans
• Digestive System is important for the processing of food for nutrients and other important molecules needed by the body.
• Ingestion is the intake of food in the mouth either by eating or drinking.
• The tongue receives stimuli to determine the taste of the food.
• The saliva in the mouth lubricates the food.
• Digestion is the breaking down of the food into soluble molecules.
• Two types of Digestion: Mechanical and Chemical
• Mechanical Digestion happens only in the mouth with the aid of the teeth.
• Chemical Digestion starts to happen in the mouth.
• The saliva in the mouth contains enzymes such as amylase which digests sugar molecules.
• The tongue and the throat will push the food into the esophagus.
• In the esophagus, the food moves to the stomach through peristalsis.
• Gastric Juice breaks down proteins into amino acids.
• Hydrochloric acid kills bacteria and other microbes.
• Several Enzymes also digest food into different molecules.
• The food is now converted into a semi-liquid state called chyme
• The chyme now is moved into the small intestine for the last phase of digestion.
• several enzymes break down:

  1. fats into fatty acids and smaller molecules
  2. carbohydrates into simple sugars
  3. proteins into amino acids
• Absorption is the passing of soluble molecules or nutrients into the circulatory system via the capillaries.
• Absorption happens in the internal folds of the small intestine known as the villi.
• Villi are folds that allow to maximize the absorption of nutrients into the body.
• Aside from the nutrients, the water is also absorbed by the body in the large intestine.
• The large intestine also contains bacteria that digests left-overs in the chyme to maximize the intake of nutrients in the body.
• What happen to the nutrients absorbed by the cells?

  How do they help in overall function of digestive system?

  • They provide fuel for energy.
  • Nutrients are also used as raw material for biosynthesis of other organic molecules. The process of transport and use of absorbed nutrients is known as assimilation.
• Assimilation is the process by which molecules move into the cells for different cellular processes.
• Assimilation's process is carried out by the circulatory system.
• Excretion is also called as defecation.
• Defecation removes undigested materials from the large intestine.
• The feces is excreted through the anus.
• Five main processes in the digestive system: Ingestion, Digestion, Absorption, Assimilation and Excretion.
• Mouth - where mechanical digestion happen in the digestive system
• It is the intake of food to the mouth from different sources

  • Ingestion
• It pertains to the intake of nutrients into the circulatory system for assimilation.

  • Absorption
• Large Intestine - where the absorption of water of the chyme happen.
• Excretion - removal of undigested materials in the body.