Digestive System

Catalyst Sarah is concerned because she is getting sick all the time. What body system may not be working properly?

Describe gas exchange. (What is it? Where does it occur?)

Explain how the respiratory system maintains homeostasis.

Work on the Warm-Up Activity at the top of your worksheet.

Agenda

Catalyst review Warm-up activity Predictions! The Digestive System! NOM NOM NOM! Flow of Food Exit Question

HW: Patient Diagnosis – GERD (AKA Acid Reflux)

What’s in the digestive system?

Stomach Large Intestine

Teeth Liver

Small intestine

Mouth Anus Esophagus

Is there a “rule” for organs in the digestive system?

Get Out Your Notes

Expectations: You will be looking at the picture on the board and writing. ONLY WRITING.

This is a silent activity.

1. Why do you think the digestive system is shaped like this?

2. Predict the function of each part.

3. Describe how this system maintains homeostasis.

4 Minutes to write. It is OK if you are wrong, just THINK!

What’s the point?

Key Point #1: The digestive system breaks down food into carbohydrates, protein, and fats.

The body uses these three molecules for different functions.Carbohydrates = quick energyProtein = build muscleFat = long term energy storage

One long tube…

Key Point #2: The digestive system is one long tube that changes structure along the way.

Each part has a specific purpose in digesting food…

What’s the first stop?

In yo’ mouth!

Teeth crush food into smaller pieces

Saliva begins to digest carbohydrates into sugars

Swallowing causes a flap of skin – epiglottis – to cover your trachea (windpipe) so food goes down right “pipe”.

Next Step

Have you ever tried to swallow food upside down? Why is it possible?

Esophagus: tube that connects mouth and stomach

Peristalsis is the contraction of muscle as the food moves down

In the tummy

Stomach: churns to break up food Contains hydrochloric acid (HCl)

Very acidic

Digestion All-Star

Small Intestine:Finishes digesting and ABSORBS nutrients

Very long (16-20 ft!)

Almost all nutrients are absorbed into the blood through the walls of the small intestine WHY?? What does the blood do?

Helpers: Liver & Pancreas The liver aids in digestion by producing bile Bile helps to break down fat

The pancreas aids in digestion by producing many different enzymes to break down food.

Large Intestine???

Large Intestine: Absorbs water

~ 5 ft

Solidifies waste

Rectum/Anus

Excretes unused food/waste

Practice – Graphic Organizer!DIRECTIONSWithout using your notes…

Left side: Describe what the part does

Right side: Predict what would happen if that part of the digestive system was not working

EXPECTATIONS Be creative! THINK! Whispers only. Stay in your seat.

Key Point Wrap-Up

Key Point #1: The digestive system breaks down food into carbohydrates, protein, and fats.

Key Point #2: The digestive system is one long tube that changes structure along the way.

Exit Question

Choose two of the three macronutrients (carbohydrates, protein, fat) and describe what they are used for.

What would happen to a person if they suffered damage to their small intestine? (Explain how/why they would not be able to maintain homeostasis.)