Respiratory System

Breathing

Breathing

What do you know?

Take a minute to breath in and breathe out.

With a partner near you, explain the physical difference between breathing in and out.

Discuss what makes this happen.

Breathing is the process your respiratory system uses to move air in and out of your lungs.

Share your answers!

Differences in:

Breathing in:

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Breathing out:

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What do you think makes these happen?

Lung Model (PEOE)

Predict what will happen when the diaphragm moves downwards. Explain!

Predict what will happen when the diaphragm moves upwards. Explain!

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Lung Model (PEOE)

Let’s see what happens!

Observe, keep track of what you see and explain why you thought it happened.

Lung Model

Has the lung model made you change your mind about breathing?

The Diaphragm

https://www.youtube.com/watch?v=hp-gCvW8PRY

Key ideas:

• Diaphragm:
• Primary muscle of respiration
• a thin dome shaped layer of muscle and tendon
• Flattens during inhalation
• Ribs expand to make room for the expansion of lungs

Movements of Inhalation and Exhalation

Inhalation:

• When we breathe in air, our diaphragm moves downwards ↓ and ribs move upwards ↑ and outwards

Exhalation:

• When we breathe out air, our diaphragm moves upwards ↑ and ribs move downwards ↓ and inwards

Breathing occurs because of your rib (intercostal) and diaphragm muscles.

Process of breathing - Inhalation

Inhale: Breathe in air

When we inhale, it lowers ↓ the pressure in the lungs as the space inside the lungs increase ↑

Due to the airtight seal in the chest cavity, the diaphragm and intercostal muscles are able to contract, and this expands the lungs and ribcage and air rushes in as a result

Process of breathing - Exhalation

Exhale: Breathe out air

When we exhale, the lung pressure increases ↑ and this decreases ↓ the space in the chest cavity.

The intercostal muscles and diaphragm relax, the rib cage returns to its normal position and air moves out.

Airtight seal

What would happen if the diaphragm was punturced?

Since there no longer is an airtight seal, the diaphragm will no longer contract properly. This means that the diaphragm will not have the ability to create or release pressure in the lungs and the person will not be able to inhale or exhale.

Variations of Breathing - Yawning

• A yawn is an involuntary reflex where the mouth is opened wide, and the lungs take in a lot of air (Extended inhalation).
• The air is then exhaled slowly.
• Yawning is usually triggered by sleepiness or fatigue.

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Variations of Breathing - Hiccups

• Hiccups are involuntary contractions of the diaphragm
• if something irritates your diaphragm, it can spasm, forcing you to suddenly suck air into your throat, where it hits your voice box. That makes your vocal cords suddenly close, creating the distinct “hic!” sound

Brainstorm

A person's respiratory/breathing rate is the number of breaths you take per minute.

Why do breathing rates change when we are resting vs. when we are exercising?

• When you exercise and your muscles work harder, your body uses more oxygen and produces more carbon dioxide.
• Your respiratory rate during exercise increases to allow more oxygen to reach your muscles and to expel the carbon dioxide waste

Brainstorm

What is the difference between voluntary and involuntary breathing?

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Identify which activity requires voluntary vs. involuntary breathing:

• Normal breathing
• Sleeping
• Singing
• Speaking
• Holding your breath
• Swimming
• Playing instruments

• Voluntary: any type of respiration that is under conscious control
• Involuntary: any form of respiratory control that is not under direct, conscious control (Automatic)

Brainstorm

What is the difference between voluntary and involuntary breathing?

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Identify which activity requires voluntary vs. involuntary breathing:

• Normal breathing - Involuntary
• Sleeping - Involuntary
• Singing - Voluntary
• Speaking - Voluntary
• Holding your breath - Voluntary
• Swimming - Voluntary
• Playing instruments - Voluntary

• Voluntary: any type of respiration that is under conscious control
• Involuntary: any form of respiratory control that is not under direct, conscious control (Automatic)

Videos

What is the Diaphragm? https://youtu.be/0PyDEna7qs0

What Holding Your Breath Does To Your Body https://youtu.be/phpbZqlPHXk