The Digestive System Organs
AIM: How do the organs of the
Digestive System aid in the
maintenance of homeostasis?
Do Now: 1. How are Hydrolysis and
Digestion similar?
2. What are Hydrolytic Enzymes?
Hydrolysis and Digestion
• Both are processes involved in breaking down
substances.
• Hydrolysis: addition of water to break
substances down
• Digestion: Breakdown food into nutrients
That are small enough to pass into our cells.
Hydrolytic Enzymes
•
•
•
•
Enzymes involved in the process of hydrolysis
Enzymes that speed up the rate of hydrolysis
Enzymes that break things down
ALL DIGESTIVE ENZYMES ARE HYDROLYTIC
Organs of the Digestive System
1. The MOUTH/ ORAL CAVITY
Teeth Chew – Increases Surface
Area – Mechanical Digestion.
Salivary glands: produce
Saliva that contains
amylASE (enzyme)–
starts the chemical
digestion of Starch
(carbs)
Pharynx, Trachea, and Epiglottis
Pharynx: Throat
Trachea: Windpipe for air only
Epiglottis: flap of tissue that protects trachea
from food or liquids.
Esophagus : Food/ Liquid Tube
• Connects the pharynx to the stomach.
• Food is pushed through the esophagus by
Peristalsis.
Peristalsis: wavelike muscular contractions of
the smooth muscle that lines the digestive
system that push food through the esophagus
and intestines.
Peristalsis Diagram
Stomach
J-shaped organ that
contains Gastric Juice.
Temporary holding tank for
food to mix
Churning: Mechanical Digestion
Gastric Juice: Contains Hydrochloric Acid
and Proteases which begins the chemical
digestion of proteins.
Material is now
called CHYME
ACCESSORY ORGANS: Liver, Gall
Bladder and Pancreas
Liver: Makes a substance called BILE.
Gall Bladder: Stores a substance called BILE.
So – What is Bile?
BILE
Bile contains bile acids, which are critical for
digestion and absorption of fats
Bile does
not contain
enzymes:
Mechanical
Digestion
All Bile does is EMULSIFICATION: Breaks large fat
globules into smaller fat droplets
PANCREAS
Makes Pancreatic Juice:
Contains many ENZYMES
that will chemically
breakdown Carbohydrates,
Lipids, and Proteins.
This juice gets secreted into
the first part of the small
Intestine through the
pancreatic duct.
SMALL INTESTINE
First Part of the Small Intestine is called the
DUODENUM: This is where most chemical
digestion occurs. WHY?
The duodenum is the first part of the small
intestine. It is located between the stomach and
the middle part of the small intestine, or jejunum.
After foods mix with stomach acid, they move into
the duodenum, where they mix with bile from the
gallbladder and digestive juices from the pancreas.
These CONTAIN ENZYMES!!!!!!!!!!!
This is where most chemical digestion
occurs: the Chemical digestion of proteins
fats and carbs occurs here
AFTER THE DUODENUM ALL
DIGESTION ENDS AND
ABSORPTION OF MATERIALS
BEGINS!!!!!!!!
Second part of the Small Intestine
This is where
absorption of
nutrients occurs.
HOW?
Through
Structures called
Villi
VILLI
• Increase the absorptive surface of the Small
Intestine for maximum absorption of material.
• Contain Capillaries so material can diffuse into
the bloodstream.
• Contain Lacteals for the absorption of fats.
(Capillaries are blood vessels that are
microscopic where diffusion of materials
occurs)
Large Intestine
• Reabsorption of water occurs and the
formation of feces (solid waste: material not
completely broken down or absorbed.