Stages of Digestion. Four Stages of Digestion Ingesting Digesting Absorbing Eliminating.
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Transcript of Stages of Digestion. Four Stages of Digestion Ingesting Digesting Absorbing Eliminating.
Stages of Digestion
Four Stages of Digestion
• Ingesting• Digesting • Absorbing• Eliminating
Stage 1:Ingesting
• The starting point of the digestion process.
Stage 2: Digesting• Mouth: Mechanical and Chemical digestion begins.• Mechanical digestion is the chewing and breaking food
down into smaller pieces• Each small piece of food is a bolus• Saliva lubricates the food, and contains an enzyme, called
amylase. • Chemical digestion occurs when amylase begins to break
down complex carbohydrates.
• Esophagus: as food passes through the pharynx, the epiglottis covers the airway tube.
• The food moves on to the esophagus.
• The esophagus is a tube that connects the pharynx and the stomach.
• The esophagus is long and muscular
• The bolus is pushed through the esophagus in a process called peristalsis.
Stomach
• Your stomach is like a stretchable muscular bag.
• Inside the stomach is gastric juice, which is very acidic.
• The stomach walls are lined with mucus, that protects the tissue.
• Pepsin is an enzyme which breaks down protein, and needs an acidic environment.
• The bolus breaks down into a liquid called chyme.
Small Intestine
• Once the chyme leaves the stomach, it empties into the small intestine.
• The first metre is called the duodenum. Digestion is complete after foods leaves.
• Within the first 30 cm are ducts that connect to other organs.
• Pancreas: produces enzymes
• Liver: produces bile.