your cells need a lot of energy for daily activities. cells use nutrients, which are substances in...
TRANSCRIPT
The Human Digestive System
Your cells need a lot of energy for daily activities.
Cells use nutrients, which are substances in food, for energy, growth, maintenance, and repair.
The digestive system breaks down the food you eat into nutrients that can be used as building materials and that can provide energy for cells.
What is the digestive system?
Digestion is the process of breaking down food into a form that can pass from the digestive system into the bloodstream.
There are two types of digestion: mechanical and chemical.
What are the two types of digestion?
Mechanical Digestion Is the breaking, crushing, and mashing of
food. Ex: Chewing is a type of mechanical
digestion. Chewing creates small pieces of food that are easier to swallow and digest than large pieces are.
What are the two types of digestion?
Chemical Digestion Is the process in which large molecules of food
are broken down into smaller molecules so that they can pass into the bloodstream.
An enzyme is a chemical that the body uses to break down large molecules into smaller molecules.
Enzymes act like chemical scissors, they “cut up” large molecules into smaller pieces.
*Without mechanical digestion, chemical digestion would take days instead of hours*
What are the two types of digestion?
In your mouth, teeth grind food mechanical chemical
In the small intestine, most nutrients are broken down by enzymes
mechanical chemical
Decide if these are mechanical/chemical
In your mouth, teeth grind food mechanical chemical
In the small intestine, most nutrients are broken down by enzymes
mechanical chemical
Decide if these are mechanical/chemical
The Mouth The Esophagus Stomach Small Intestine Large Intestine
What are the parts of the digestive system?
What are the parts of the digestive system?
The Mouth Digestion begins in the mouth with both
mechanical and chemical digestion. Teeth, with the help of the jaw, break and
crush food. As you chew, food is moistened by saliva. Saliva contains many substances,
including an enzyme that begins the chemical digestion of starches in food.
What are the parts of the digestive system?
The Esophagus Once food has been chewed, it is swallowed
and moves through the throat and a long tube called the esophagus.
Waves of muscle contractions move food into the stomach.
Ex: muscle moves food along the same way you move toothpaste from the
bottom of the tube with your thumbs
What are the parts of the digestive system?
Stomach The stomach is a muscular
bag that crushes food and contains acids and enzymes for killing bacteria and breaking down protein.
The stomach wall contains layers of muscle so the stomach can churn and mix food.
This is the final step of mechanical digestion.
Food sits in the stomach for a few hours before moving to…..
What are the parts of the digestive system?
Small Intestine The small intestine is a muscular tube were
most chemical digestion takes place. Most nutrients are absorbed in the small
intestine as well. Food travels from the stomach into the
small intestine in the form of chyme. Chyme is food reduced to a soupy mixture
What are the parts of the digestive system?
Large Intestine After food moves through
the small intestine, it moves to the large intestine.
In the large intestine, water and nutrients are absorbed.
Most solid material that remains is waste
Waste is compacted and stored until the body eventually eliminates it.
What are the parts of the digestive system?
Where are nutrients absorbed?
Small Intestine Large Intestine
After nutrients are broken down, they are absorbed into the blood stream and used by cells
Removes water from mostly-digested foods, absorbs vitamins, and turns food waste into semi-solid waste.
Pancreas-makes fluids that break down every type of material found in foods
Ex: these include proteins, carbohydrates, fats, and nucleic acids Liver-makes and releases a mixture called
bile that is stored in the gall bladder◦ Bile breaks up large fat droplets into very small
fat droplets
Other organs that help digest nutrients
HOW LONG ARE YOUR INTESTINES? At least 25 feet in an adult. Be glad you're not a full-grown horse -- their coiled-up intestines are 89 feet long!
Chewing food takes from 5-30 seconds Swallowing takes about 10 seconds Food sloshing in the stomach can last 3-4
hours
Facts about the Digestive System
It takes 3 hours for food to move through the intestine
Food drying up and hanging out in the large intestine can last 18 hours to 2 days!
Americans eat about 700 million pounds of peanut butter.
Americans eat over 2 billion pounds of chocolate a year.
In your lifetime, your digestive system may handle about 50 tons!!
Facts about the Digestive System
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