Digestive System Parts and Functions
Human Health and Digestion Food is our primary source of fuel and building blocks for body growth, maintenance and energy requirements Food can be contaminated with bacteria and also with chemical pesticides etc. This contamination can lead to health problems if ingested.
How much do you know? http://www.tvdsb.on.ca/westmin/science/sbi3a1/digest/digdiag.htm
Types of Digestion Physical Biting and chewing to initially break down food for swallowing Wetting to ease swallowing and movement Peristalsis (rhythmic contractions) of smooth muscle around esophagus, stomach, intestines to move food through the alimentary canal (tube) Churning of smooth muscle in stomach to mix food with digestive acid and enzymes
Chemical Breaking down macronutrients into their smaller sub-units for absorption and transport around the body PROTEINS amino acids LIPIDS fatty acids, glycerol CARBOHYDRATES simple sugars
Parts and Functions Mouth Esophagus Teeth Tongue Salivary glands Epiglottis Esophagus
Parts and Functions con’t Stomach Cardiac sphincter Stomach Lining (Acid secretion) (Enzyme secretion) (Mucus secretion) Pyloric sphincter
Parts and Functions con’t Small Intestines Duodenum (Enzyme secretion) Ileum Jejunum Pancreas Liver Gall Bladder (Neutralization of acid and emulsification of fats)
Parts and Functions con’t Large Intestines Ascending Transverse Descending Rectum (Storageand compaction) Anus (removal)
Enzyme Action Enzymes are specialized proteins manufactured in the body to help chemical reactions take place Some enzymes are especially designed to BREAK down macronutrients into their components! PROTEINS amino acids LIPIDS fatty acids, glycerol CARBOHYDRATES simple sugars
Enzyme names end in “ase” There are many digestive enzymes in the body and each has a SPECIFIC function Enzymes act as “hands” that hold a molecule and allow a specific reaction to take place Having healthy functional proteins means that this system works efficiently!
MOUTH Physical Digestion: Chemical Digestion: Biting, chewing Wetting of food SALIVA from salivary gland Chemical Digestion: Starts in the mouth Especially for those components that are difficult to digest AMYLASE Enzyme found in saliva from salivary gland Breaks down starch into simple sugars
STOMACH Physical Digestion Chemical Digestion Peristalsis (from esophagus) Churning (to mix) Chemical Digestion enzymes HCl Acid which helps to break down protein
INTESTINES: chemical digestion Enzymes: breaks down proteins and complex sugars into simple sugar components
Other Organs: chemical digestion From Pancreas: pancreatic juice Breaks down proteins into polypeptides and amino acids Sodium bicarbonate: neutralize stomach acid From Liver: bile salts Manufactured in Liver, stored in Gall Bladder mixes fats with water to assist in digestion