Flashcards in Chapter 2 - Lesson 3 Deck (20):
Name the 2 kinds of digestion.
What happens during mechanical digestion?
Food is physically broken down into smaller pieces such as biting into a sandwich and chewing the food into smaller pieces before you swallow.
What happens during chemical digestion?
Chemicals produced by the body break foods into smaller chemical building blocks - such as starch in bread turned into individual sugar molecules
What is absorption?
The process by which nutrient molecules pass through the wall of the digestive system into your blood.
What is the process of elimination?
When materials not absorbed such as fiber are eliminated from the body as waste.
What are the 3 main functions of the Digestive System?
1. Breaks down food into molecules the body can use.
2. Molecules are absorbed into the blood and carried throughout the body.
3. Wastes are eliminated from the body.
What is saliva?
The fluid released when your mouth waters. Saliva plays important part in both kinds of digestion.
Name the 4 types of teeth in mechanical digestion and their roles
1. Incisors (Center teeth) cuts the food into bite size pieces
2. Canines (teeth on either side of Incisors) which are sharp and pointy cuts the food into smaller pieces.
3. Premolars and molars behind the canines crush and grind the food as saliva moistens the pieces.
What is an enzyme?
The chemical in saliva that digests starch
What is the epiglottis?
The flap of tissue that prevents food from entering wind pipe
What is the esophagus?
A muscular tube that connects the mouth to the stomach
What is mucus?
A thick, slippery substance produced by the body and lines the esophagus to make swallowing food easier.
What is peristalsis?
Involuntary contractions of smooth muscle that pushes food towards the stomach from the esophagus. It also occurs further down the digestive system and keeps food moving in one direction.
What is the stomach?
A J shaped muscular pouch located in the abdomen
How does mechanical digestion work in the stomach?
3 strong layers of smooth muscles contract to produce churning motion and mixes food with fluids
How does chemical digestion work in the stomach?
It happens as churning food makes contact with digestive juice, a fluid produced by cells in the lining of the stomach.
What is Pepsin?
Is contained in digestive juice and chemically digests the proteins in food, breaking them down into short chains of aminos
What is hydrochloric acid?
This is also contained in digestive juice. Pepsin works best in this strong acid and the acid kills many bacteria you swallow with food.
Why doesn't hydrochloric acid burn a hole in your stomach?
Because stomach produces a thick coating of mucus and the cells that line the stomach are quickly replaced as they are damaged or worn out