Digestive System Organs of the Digestive System mouth

Digestive System

Organs of the Digestive System • • • mouth esophagus stomach small intestine large intestine rectum anus pancreas gall bladder liver

Functions of the Digestive System • Your cells need a lot of energy. They get energy from the food we eat. • But, your digestive system has to break down the food we eat into microscopic nutrients before our cells can use it.

Functions of the Digestive System • Digests food into molecules the body can use (physical or chemical change). • Absorbs nutrient molecules and carries them around the body (physical change). • Eliminates waste material from unused nutrients.

mechanical digestion vocabulary word! • mechanical digestion - food is physically broken down into smaller pieces by breaking, crushing and mashing. • increases the surface area of the food • begins in the mouth – teeth chewing/tearing – movement of smooth muscles

vocabulary word! chemical digestion • chemical digestion - chemicals (enzymes)produced by the body break foods into their smaller nutrients. – mouth – stomach

vocabulary word! absorption • absorption - process by which nutrient molecules pass through the wall of your digestive system into your blood. – The lining of the small intestine is covered in villi that aid in absorption

vocabulary word! elimination • elimination – removal of waste material left over after food is digested to prevent illness.

mouth • Digestion begins in the mouth – mechanical – teeth – chemical - saliva

vocabulary word! salivary gland • salivary gland – gland that produces enzymes that help to break down food chemically.

vocabulary word! esophagus • esophagus - muscular tube that connects your mouth to your stomach. – moves food down into your stomach using involuntary muscle contractions (peristalsis). – Lined with mucus that allows food to slide down.

vocabulary word! stomach • stomach – a muscular bag that crushed food and contains acids and enzymes for breaking down food. • Most mechanical digestion takes place in the stomach because it is made of thick smooth muscle. • Chemical digestions also takes place • Mucus keeps the acids from burning a hole in your stomach.

Stomach

vocabulary word! small intestine • small intestine – muscular tube where most of the chemical digestion takes place and most nutrients are absorbed. • Covered in villi which enlarge the surface area

small intestine The villi increase the surface area that can absorb nutrients.

vocabulary word! liver • liver – large organ that produces bile and breaks down medicines and other chemicals. • The gall bladder stores bile

vocabulary word! pancreas • pancreas - secretes insulin to carry glucose around the body and makes enzymes that help digest food. • Causes diabetes when it does not make insulin.

vocabulary word! large intestine • large intestine – muscular tube where vitamins B and K are made and water is removed from food waste. • Food spends 18 -24 hours here

rectum and anus • rectum – end of the large intestine, forms the solid waste – elimination • anus – muscular opening at the end of the rectum – elimination

The digestive system interacts with: • muscular system (smooth muscle) to move and digest food. • respiratory system to provide oxygen. • circulatory system to move nutrients.

These cell parts are like the digestive system: Which one makes energy? mitochondria Which one allows materials to pass in and out? cell membrane Which one helps get rid of waste? lysosomes