April 2, 2014

• 1. DO NOT TOUCH Bob the skeleton OR Junior the Organ model.

• 2. What is the function of the Digestive System?

• 3. Can you name all the organs in the digestive system?

The Digestive System

Hey- chew on this! We’ve made it to the..

Functions

• Ingest food

• Break down food

• Move through digestive tract

• Absorb digested food and water

• Eliminates waste materials

There are 3 Macronutrients

• Carbohydrates (Carbs)

• Proteins (ex: meat)

• Lipids (fats)

Carbohydrate

Protein

Fat (aka: Lipids)

• Gastrointestinal System• Function-physical and

chemical breakdown of food

• Accessory organs: Salivary glands, tongue, teeth, liver, gallbladder, and pancreas

Mouth

• Mouth- physical and chemical breakdown.

• Physical Digestion: chewing

• Chemcial Digestion: Saliva contains enzyme amylase to break down carbohydrates

Mouth

• Breaks down food into small pieces

• Begins starch digestion (amylase)

• Saliva produces amylase and lubricates food

• Moves food into esophagus

• Epiglottis covers trachea

• Peristalsis moves food to stomach

• Pharynx- contains opening to trachea as well.

• Epiglottis covers opening of trachea.

• Esophagus- the tube you swallow food with.

• Uses peristalsis – wave-like motion to push food down.

Peristalsis

The wave-like squeezing action of muscles that is used to move food along

http://www.lionden.com/peristalsis.htm

Esophagus- transverse view

• Sphincter-a circular muscle sqeezes shut

• Food sits in stomach for 1-4 hours. Gastric (stomach) juices contain hydrochloric acid- activates pepsin, kills bacteria.

• Small intestine: not so small! 20ft x 1’’

• Small intestine has lots of enzymes called peptidases

• Digested food is absorbed into the bloodstream.

• Large intestine- 5 ft x 2’’.

• Final absorption of water, storage of indigestible material, absorption of vitamins B and K by bacteria.

• Colon connects to rectum- anal canal opens to the anus (final opening). This is where your poop sits before… you “sit” ;) .

But Wait! What about the accessory organs: Liver, gall bladder and pancreas • Liver- largest gland in

your body• Secretes bile- digests

fat.• Detoxifies blood

• Gall bladder- stores and concentrates bile (which digests fats)

• Pancreas- produces insulin. – Insulin regulates the

uptake of glucose by the cells