Lesson 9: Respiratory system

Question 1

Where does air enter our lungs from?

Answer 1

Air enters from nose/ mouth.

Question 2

What does it mean if an object has a large surface area to volume ratio?

Answer 2

• This means a large surface area is folded into a small volume.

Question 3

How does a bacterial cell get oxygen into it?

Answer 3

By diffusion, it is small and so has a large surface area to do so.

Question 4

What is the function of cartliage rings in the trachea?

Answer 4

• To keep the trachea open.

- Allow it to move during breathing.

Question 5

What does the trachea have that stops dirt from entering the lungs?

Answer 5

• Mucus catches dirt and bacteria

- Cilia (on ciliated epithelial cells) waft mucus up to swallow.

Question 6

What is diffusion?

Answer 6

Diffusion is the movement of particles from an area of high to low concentration down a concentration gradient.
passive process that doesn’t require energy

Question 7

Where does oxygen diffuse into the blood?

Answer 7

• Oxygen diffuses into the blood at the alveoli.

* This is where gas exchange occurs.*

Question 8

What is gas exchange?

Answer 8

• Gas exchange is the delivery of oxygen from alveoli to blood and removal of carbon dioxide from blood to alveoli.

Question 9

What are alveoli?

Answer 9

Alveoli are tiny air sacs in the lungs, where gas exchange occurs.

Question 10

What are the adaptations of the alveoli?

Answer 10

2. ) Thin lining -> short diffusion pathway-> increased rate of diffusion.
3. ) Large surface area (folded membranes/many alveoli) -> more contact with carbon dioxide and blood -> increased rate of diffusion.
4. ) Good blood supply -> mantains steep concentration gradient between alveoli and blood -> increased rate of diffusion (more efficient.)

Question 11

What is the function of the red blood cell?

Answer 11

• Carry oxygen from lungs to tissues and cells around the body.

Question 12

What is aerobic respiration?

Answer 12

• Aerobic respiration is a chemical reaction that releases energy using oxygen and glucose.

Question 13

What do we need energy for?

Answer 13

• Growth
• Building larger molecules
• Matain internal body temperature
• Cell division
• Muscle contraction

Question 14

What is the symbol equation for aerobic respiration?

Answer 14

60₂+C₆H₁₂0₆ —>6C0₂ +6H₂0

Question 15

Where does aerobic respiration take place?

Answer 15

• Aerobic respiration takes place in the mitochondria.

Question 16

How can a low red blood cell count lead to tiredness?

Answer 16

• Red blood cells transport oxygen around the body to release energy.
• If less oxygen is transported, less enegy is released.
• This is why a low red blood cell count can lead to tiredness.

Question 17

What happens to diaphragm when you inhale and exhale?

Answer 17

Inhale: contracts, flattens.
Exhale: relaxes, returns to dome- like shape.

Question 18

What happens to the intercostal muscles when you inhale and exhale?

Answer 18

Inhale: Contracts
Exhale: Relax

Question 19

What happens to the ribcage when you inhale and exhale?

Answer 19

Inhale: Upwards and outwards
Exhale: Downwards and inwards

Question 20

What happens to the volume in the thorax when you inhale and exhale?

Answer 20

Inhale: Increase
Exhale: Decrease

Question 21

What happens to the pressure in the lungs when you inhale and exhale?

Answer 21

Inhale: Decrease (air rushes in)
Exhale: Increase (air rushes out)

Question 22

Where does air move in terms of pressure?

Answer 22

Air moves from an area of high to low pressure.

Question 23

What is lung volume?

Answer 23

Lung volume: Volume of air that can be held in lungs

Question 24

What affects lung volume?

Answer 24

• Age
• Fitness levels
• Smoking
• Biological sex
• Diseases eg. asthma.

Question 25

What is the issue for people with asthma?

Answer 25

• Airways are narrowed and inflamed.

- Makes breathing difficult.

Question 26

What happens in an asthma attack?

Answer 26

• Contraction occur –> make airways more narrow

Question 27

What do inhalers do?

Answer 27

• Inhalers will relax muscle -> widen airways -> more air can be inhaled.

Question 28

Does the percentage of nitrogen change when exhaled?

Answer 28

• No. The percentage of nitrogen stays the same as it is not used in respiration.

Question 29

Does the percentage of argon change when exhaled?

Answer 29

• No. The percentage of argon stays the same as it is not used in respiration.

Question 30

Does the percentage of carbon dioxide change when exhaled?

Answer 30

• Yes. The percentage increases as it is released by respiration.

Question 31

Does the percentage of oxygen change when exhaled?

Answer 31

• Yes. The percentage of oxygen decreases as it is used up in respiration.

Question 32

How are the lungs adapted for gas exchange?

Answer 32

• Alveoli have good blood supply: mantains concentration gradient.
• Alveoli are thin: short diffusion pathway.
• Alveoli = large surface area. Increases rate of diffusion. (more diffusion spots.)
• Lungs are ventilated to mantain concentration gradient.

Question 33

Why does the trachea have cartliage rings on it?

Answer 33

• These prevent the trachea from collapsing in inhalation.