U2 B2 2HVTTO

• Biologie
• Middelbare school
• havo, vwo
• Leerjaar 2

B2 The digestive system

• Take off your jacket
• Put your things on your desk

       Book, notebook, pencil case

• Bag on the floor
  
• Read pages 97-99

Lessongoals

• You can describe the functions of digestion, digestive juices and enzymes
• You can list parts of your dentition and their functions
• You can describe the function of peristalsis an how it works

Wheel of homework

Go to Lessonup.app and use this code

Reward

Penalty

Homework: 1-9, 4c, 8c, 10c pgs. 92-95

Which of these statements is FALSE

1. Fruit contains lots of vitamins
2. Vitamins can be used as building material for the body
3. Vitamins help protect your body
4. Vitamins can be used as reserves

Which of these statements is TRUE ?

1. Foodstuffs are in nutrients
2. Foodstuffs and nutrients are synonymous
3. Nutrients are in foodstuffs

Which of these statements is FALSE

1. All carbohydrates are sugars
2. Carbohydrates can be used as building materials
3. Carbohydrates can make people fat
4. Carbohydrates can be used as fuels

Too big to take in, needs digestion

• Proteins
• (most) carbohydrates
• Fats

No digestion needed:

• Glucose
• Minerals
• Vitamins
• Water

Intestines take up the nutrients inside food.

Not all nutrients can enter the body without digestion

Digestion

• Digestion = breaking nutrients into smaller substances (so they can enter the body)
• Mechanical and chemical digestion
• Chewing and digestive juices

Why chew?

Digestive juices need to digest nutrients

Chewing makes the surface area bigger

You've got a cube of 1x1x1 cm. What is the surface area of this cube??
...... cm2 (only the number)

The cube of 1x1x1 cm is cut in to 8 similar sized smaller cubes of 0,5x0,5x0,5 cm.
What is the surface area of one of these cubes?
..... cm2 (only the number)

How big is the surface area of the 8 cubes together?
....cm2 (only the number)

Why chew?

Chewing creates a bigger surface area.

bigger surface area = more surface where digestive juices can do their job = more and quicker digestion

surface area of 6 cm2

surface area of 1,5 cm2

together 12 cm2

Dentition (all teeth together)

Crown

Root

incisor             canine                        molar

cutting off parts of food

cutting off pieces of food

grabbing on to food (mainly used by predators when capturing their prey)

grinding food down into smaller pieces

Digestive juices

• Digestive glands: salivary gl, gastric gl, liver, pancreas, intestinal gl
• Nutrients > digestion products
• Often contain enzymes

Peristalsis

Food moves through lots of tubes : intestinal tract

• Oesophagus
• Duodenum
• Small and large intestines

peristalsis = muscle movements that push food through the intestinal tract

00:00

Darmperistaltiek

Eten gaat door allerlei 'buizen'

• Slokdarm
• Dunne darm
• Dikke darm

Darmperistaltiek = spierbewegingen die eten door de darmen heen duwen

00:06-00:16

Peristalsis of the large intestine

What nutrients is NOT digested?

1. Water
2. Fat
3. Carbohydrate
4. Protein

Chewing your food is part of
.... digestion

1. Mechanical
2. Motor
3. Chemical
4. Chew

What you should do:

• Read pages  97-100
• Do asgmt  1-8 4c, 9c, 10c pgs. 100-103

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zs = Working in Silence

• No asking questions
• Silent, don't disturb anyone
  
• Stay at your  desk

What you should do:

• Read pages 97-100
• Do asgmt 1-8 4c, 9c, 10c pgs. 100-103

Done with the above?

• Work on the next chapter(s)
• Learn for the test 
• Make other homework
• Read a book

Zw = Working with whispering

• Teacher is available for questions
• Only whisper with the student next to you
• Stay at your  desk

Tidy Duty

Today these people are on tidy duty

• Desks: empty and straight
• Chairs:  underneath the desks
• Floor: no rubbish