human body digestive system. functions 1.break down food (digest) 2.take in food (ingest) 3.absorb...
TRANSCRIPT
Human Body
Digestive System
Functions
1.Break down food (digest)
2.Take in food (ingest)
3.Absorb nutrients from food
4.Eliminate (get rid of) solid waste
DIGESTION• The process of breaking
down food into a form that the body can use
• Large molecules into smaller ones!
2 Types of digestion
Mechanical
and Chemical
Mechanical Digestion
Food is chewed, mixed and churned. Takes place in the mouth and stomach
Chemical DigestionChemical reactions that break down large molecules into smaller molecules that can be absorbed by cells Examples: saliva in mouth
acids & enzymes
ORGANSMajor Organs:
Mouth
Esophagus
Stomach
Small Intestine
Large Intestine
Rectum
Anus
Accessory Organs:
• Tongue
• Teeth
• Salivary Glands
• Liver
• Gallbladder
• Pancreas
Mouth1. Digestion begins
2. Mechanical (teeth and tongue) & Chemical (saliva) digestion
3. Saliva mixes with food to produce a soft mass called a Bolus
Esophagus
1. No digestion takes place
2. Peristalsis-muscle contractions (squeezing) that helps move food down the esophagus and through the digestive tract
Stomach
1. Mechanical (churning) and chemical digestion2. Produces HCl (hydrochloric acid)
and mucus
3. Becomes a substance
called chyme (kime),
A thin watery product
Small Intestine1. Major portion of all digestion
occurs in the duodenum
2. Digestive juices from the liver, gall bladder (bile) and pancreas are added
3. Villi-make the surface larger so there are more places for food and nutrients to be absorbed
VILLI
Real above
Scientific illustration right
Large Intestine
1. Absorbs water from the chyme
2. Chyme may stay in the large intestine for up to 3 days
Rectum and Anus
Chyme makes its way out of the body, usually as “solid” waste… compacted in the rectum and expelled from the anus.