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Warm-up. Pick up the Digestive System Notes and the System Review In your spiral – Describe Cellular Respiration, where does it occur, what are the reactants (pg. 166 – 167 Fusion) Continue to the Digestive System Reading (pg. 464 Fusion). Digestive System Parts and Function.
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Warm-up • Pick up the Digestive System Notes and the System Review • In your spiral – Describe Cellular Respiration, where does it occur, what are the reactants (pg. 166 – 167 Fusion) • Continue to the Digestive System Reading (pg. 464 Fusion)
Digestion involves: • Breaking down of food into smaller pieces • The mixing of food • Movement through the digestive tract • Chemical breakdown of the large molecules of food into smaller molecules.
Digestion Breaks down • Carbohydrates (starch and sugar) → single sugar molecules • Proteins → amino acids • Fats → fatty acids, glycerol
Enzymes • Proteins that break bonds • Chemical Breakdown of Food
The Digestive System • Is a long tube from the mouth to the anus
Peristalsis • Muscular contractions that move food along throughout Digestive System
Mechanical Digestion • Involves the physical breakdown of food • Occurs in the: • Mouth – teeth and tongue • Esophagus – peristalsis • Stomach – muscular churning • Small Intestine – Bile and peristalsis
Chemical Digestion • Food is converted into substances that can be absorbed by the body in the small intestine • Occurs in the mouth (saliva), stomach (acids), small intestines (enzymes)
Mouth • Mechanical digestion - Teeth bite off and chew food into a soft pulp that is easy to swallow. • Chemical digestion – saliva
Esophagus The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach. It moves food by waves of muscle contraction called peristalsis.
Stomach • The stomach has thick muscles in its wall. These contract to mash the food into a water soup called chyme. • The stomach lining produces strong digestive juices.
Small Intestine • The nutrients are broken down small enough to pass through the lining of the small intestine, and into the blood. • Nutrients are carried away to the liver and other body parts to be processed, stored and distributed.
Large Intestine • Water is absorbed. • Bacteria breaks down remaining foods with enzymes that we do not produce, releasing vitamins like Vitamin K • The remains are formed into brown, semi-solid feces, ready to be removed from the body
Rectum • Rectum’s job to receive stool from the colon, to let the person know that there is stool to be evacuated, and to hold the stool until evacuation happens.
Anus • Anus - lets you know whether the contents are liquid, gas, or solid. The anus is surrounded by sphincter muscles that control of movement of stool.
Liver • It stores some nutrients, and releases them into the blood according to the activities and needs of the body (helps the body maintain homeostasis)
Gall Bladder Bile (enzyme) flows from the gall bladder along the bile duct into the intestine to aid in chemical digestion.
Pancreas • Makes digestive juices called enzymes which help to digest food.