Digestive System — Science 8

• Ingestion – is the process of putting something into our mouth.
• Digestion – is the mechanical chemical break down of food into small organic fragments.
• Abrorption – The simple products of digestion is small enough to be absorbed by the epithelial cells of the intestinal vlli
• Assilmilation – in the movement of digested food molecules into the cells of the body where they are used.
• Excretion – By the time chymes passes the ilem into the largo intertine, it is essentially indgertible food reside (mainly plant Fibers like cellulose).
• Enzymes – They are the catalyst which speed up the break down of complex simple and food into soluable products.
• Digestive system - is like a big juicer of food that processes important materials needed for the function of the body
• • Mechanical Digestion – is the process in which food is broken down by means of chewing biting, and grinding to make it into smaller partiales.
• Chemical digestion – Is the process of digesting food with the use of enzymes to make food soluble for it to be absorbed by the body and be transferred through the circulatory system
• Four stages of food processing.

  1. Ingestion- taking in tood that starts in the mouth.
• Parts of the Alimentary Canal

  1. Mouth

  • Saliva

  – contains ptayalin, a.k.a salivary anıylase

  – soften and converst as the starch in the food we eat into a simple sugar called maltose while chewing
• Pharynx – found at the region of the neck
• Bolus (to the erophgas) – Function is a passageway at the ball of fodd mixed with saliva
• 3 main divisions of pharynx

  •Nasopharynx – near in nasal activity.

  • Oropharynx – area of oral activity.

  • Hyphopharynx – lowest part of the gherynx near the esophagus
• Esophagus – a long, muscular tube Functions: passageway of food from the pharynx to the stomach with the use of peristalsis.
• Peristalsis – a wave of muscular contractions the masticatd food (bolus) down towards that push push the stomach
• Stomach – Is a J shaped muscular bag where the food goes to be chemically digested.
• Cardiac sphincter - is an opening in the stomach that allows the food to get inside the amphagus and closes to prevent back flow of food and digestive enzymes.
• Chyme – semisolid form of digestive tood The Chyme now goes to the pyloric sphincter, then goes to the first region of the small intestine called duodenum
• Small intestine – 20-30 teet long mall intestine. after in duodenum, it will go to the longest & part of the small intestine called jejenum. villi-nutrients are mainly absorbed with the tiny hair lik projections in the interstire wall.
• LargeIntestine – 1.5 meter long large intestine is divided into: 1. Cecum

  2. Descending colon

  3. Transwerke colon

  4. Descending colon

  5. Sigmoid color
• Mucus – Is also present in the large intestine to lubricate the food as it goes to the rectum and to the anus.
• Rectum and anus • the waste product or feces from the large intestine is then temporarily stored to the rectum before it will be expelled by the anus. • The rectum expands untit it becomes full which then ont with the rectum- tells the brain to release it of the nervous reves in the •This is called bowel movement
• Accessory Organs

  1. Salivary Gland – othese are glands that produce saliva used for softening ints the food and breaking down carbohydrates into simpler sugar.
• 2. Liver – found below the right ride of the ribs.

  Main functions: produce bile, which breaks down or emulsitytat during digestion.

  Also detoxifies the blood as it circulates the body such as alcohol.
• 3. Gall Bladder – Is a small sac located under the liver .

  Oston bile - main purpose.
• 4. Pancreas – Is a bumpy, leaf -rhaped organ located below the stomach. • it contains pancreatic chuct a tube that is located at the duodemum of the small inteatine.
• 2. Digestion - breaking down of food into smaller particles in order to use its nutrients
• 4. Egestion– removing any leftovers wastes after the digestion process.
• 3. Absorption – taking the nutrients from the digested. food to be used by the body for different life processes aut