8.2 You breathe

• Biologie
• Middelbare school
• vwo
• Leerjaar 3

Today

- Quiz (knowledge test)

- Learning objectives

- Instruction respiration, cells

- Homework assignments

- End of class

8.2 You breathe

You will learn how you breathe and how oxygen ends up in your bloodstream.

You will learn why breathing through your nose is better, and how your breathing is regulated.

Consumed during respiration

Created during respiration

Is not consumed nor created during respiration

Glucose (sugar)

Oxygen

Energy

Water

Carbon dioxide

Nitrogen

Enzymes

Cell nucleus

Cell membrane

Mitochondrion

Cytoplasm

Tubular

Ribosome

Inhaling

The intercostal (tussenribspieren) and diaphragm (middenrifspieren) muscles contract.

The ribs tilt upwards and the diaphragm becomes flat.

The chest cavity and your lungs expand.

Exhaling

Intercostal (tussenribspieren) and diaphragm (middenrif) muscles relax.

The ribs lower down; the diaphragm becomes convex (bol).

The chest cavity and your lungs reduce in volume.

Let's zoom in on the alveoli (end of the bronchioles).

How does the gas exchange happen so fast? 

1. Many alveoli

2. Alveoli have thin walls

3. Many capillaries around the alveoli

4. Continuous supply of fresh air

How does the air get cleaned and humidified?

Nose hairs: filter out dust.

Mucus producing cells: make the air moist and catch pathogens and dust.

Cilia: sweep dust and pathhogens up to your pharynx.

Why do you have to breathe through your nose?

Blood vessels: warm up the air.

Nerves: detect unpleasant or dangerous smells

Breathing regulation

1. Carbon dioxide receptors in your blood send impulses to the respiratory centre in your brain. 
2. Your brain sends impulses to your intercostal muscles and diaphragm muscles. 

What?	Read: 8.2 Make: 3-6, 9-11, 15-17
How?	In your book. You may whisper if you want to discuss an assignment with your neighbour.
Help?	Try to answer the question together. Raise your hand if you can't figure it out together.
Time?	15 minutes
Finished?	Check your answers with the solutions in Teams. Make assignments 13 and 14.
Proceeds	You have finished your homework! Well done!

End of class

Don't pack your bags yet!