Download Digestive System Digestive System- a series of organs that work

Digestive System
Digestive System- a series of organs that work together to break down foods
into substances that your cells can use.
Digestion- The process which the body breaks food down into smaller
components that can be absorbed by the bloodstream and sent to each cell in
your body. Also, eliminates undigested food and waste products from the
body.
2 Types of digestion
1. Mechanical- the breakdown of food by the mouth and teeth. Prepares for
chemical digestion.
2. Chemical- enzymes are responsible for the breakdown of food into smaller
particles so that they can be absorbed.
The Process and Parts
1. Mouth and Teeth- Break down food into smaller pieces so they can be
swallowed.
2. Saliva- a digestive juice produced by the salivary glands in your mouth.
Contain enzymes which begin to break down food and make it easier to
swallow. (softer)
3. Esophagus- long tube that leads from mouth to stomach.
4. Epiglottis- small flap of tissue that closes the windpipe as food is
swallowed.
5. Stomach- a muscular organ that mixes and churns food with acid and
enzymes to further break down food. (Chyme)
6. Small Intestine- a coiled tube about 20 feet long, where most of the
digestive process takes place. Waste that is not digested moves on to
large intestine.
a. Villi- small fingerlike projections in the walls of the small intestine
increase surface area 600x so more digestion can take place.
7. Large Intestine (Colon)- 6 foot long tube that absorbs water and some
remaining nutrients.
8. Rectum- where waste is stored for elimination
9. Anus- where solid waste is removed as feces and digestion ends.
Helper Organs
1. Liver- Largest gland in the body. Produces bile(to help digest fat),
maintains blood sugar, stores glycogen, makes vitamin A.
2. Gallbladder- stores bile (yellowish-green fluid)
3. Pancreas- produces enzymes for digestion of fat, carbohydrates,
protein. Produces bicarbonate which reduces acid levels.
Excretory system
Functions of the Excretory System
1. Filters wastes from the circulatory system
2. Eliminates wastes from the body in the form of urine
Liquid Waste
1. Kidneys- filter liquid waste from the blood, maintains proper levels of
water and salts.
2. Ureters- two tubes that connect the kidneys with the bladder
3. Bladder- a storage pouch for urine
4. Urethra- where urine passes. A signal from the nervous system is sent
when bladder is full.