Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology Topic 3A > Gas Exchange in Humans > Flashcards

Gas Exchange in Humans Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the role of the gas exchange system?

A

To supply your blood with oxygen, and remove carbon dioxide from your body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why do humans need oxygen in the blood?

A

To take it to respiring cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the structure of the human gas exchange system?

A
  • As you breathe in, air enters through the trachea.
  • The trachea splits into two bronchi, one bronchus leading to each lung.
  • Each bronchus then branches off into smaller tubes called bronchioles.
  • The bronchioles end in small ‘air sacs’ called alveoli.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where are gases exchanged in humans?

A

At the alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What work together to move air in and out of the gas exchange system?

A
  • Ribcage
  • Intercostal muscles
  • Diaphragm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where are the intercostal muscles located?

A

Between the ribs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two types of intercostal muscles?

A
  • Internal intercostal muscles

* External intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where are the internal intercostal muscles found?

A

On the inside of the external intercostal muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is ventilation?

A

It consists of inspiration (breathing in) and expiration (breathing out).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is ventilation controlled by?

A

The movements of the diaphragm, internal and external intercostal muscles and the ribcage.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the structure of the human gas exchange system look like?

A

image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens during inspiration?

A
  • The external intercostal muscles and diaphragm contract.
  • The ribcage moves upwards and outwards.
  • The diaphragm flattens.
  • Increasing the volume of thoracic cavity (the space where the lungs are).
  • As the volume of thoracic cavity increases, the lung pressure decreases to below atmospheric pressure.
  • Air flows down the trachea and into the lungs (as air always flows down the pressure gradient).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of process is inspiration?

A

Active (it requires energy).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does inspiration look like?

A

image

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What happens during expiration?

A
  • The external intercostal muscles and diaphragm relax.
  • The ribcage moves downwards and inwards.
  • The diaphragm curves upwards again (becoming dome shaped).
  • This decreases the volume of the thoracic cavity (the space where the lungs are).
  • This causes the lung pressure to increase above atmospheric pressure.
  • Air is forced down the pressure gradient and out of the lungs.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does expiration look like?

A

image

17
Q

What type of process is expiration?

A

Passive (it does not require energy).

18
Q

What is forced expiration?

A

e.g. if you blow out the candles on your birthday cake.

19
Q

What happens during forced expiration?

A
  • The external intercostal muscles relax.

* The internal intercostal muscles contract, pulling the ribcage further down and in.

20
Q

What is said about forced expiration?

A

That the movement of the two sets of intercostal muscles is said to be antagonistic (opposing).

21
Q

How many alveoli do lungs contain?

A

Millions of microscopic alveoli, where gas exchange takes place.

22
Q

What are the alveoli surrounded by?

A

A network of capillaries.

23
Q

What is the structure of the alveoli?

A

The wall of each alveolus is made from a single layer of thin, flat cells called alveolar epithelium.

24
Q

What do are the capillary walls that surround the alveoli made of?

A

Capillary endothelium.

25
Q

What do these alveoli walls contain?

A

A protein called elastin (which is elastic).

26
Q

What does elastin in the alveoli allow for?

A

It helps the alveoli return (recoil) to their normal shape after inhaling and exhaling air.

27
Q

What does the alveoli structure look like?

A

image

28
Q

How does oxygen move through the gas exchange system?

A

Air (containing oxygen) moves down the trachea, bronchi, bronchioles into the alveoli.

29
Q

What allows oxygen to move through the gas exchange system?

A

Because it moves down a pressure gradient.

30
Q

What happens to oxygen after it reaches the alveoli?

A

It moves into the blood, where it can be transported around the body.

31
Q

What allows oxygen to move around the body in blood?

A

Because it moves down a diffusion gradient.

32
Q

How does carbon dioxide move through the gas exchange system?

A

It moves down its own diffusion and pressure gradient, but in the opposite direction to oxygen, so that it can be breathed out.

33
Q

What gas exchange occurs in the alveoli?

A
  • Oxygen diffuses out of the alveoli, across the alveolar epithelium and the capillary endothelium, and into haemoglobin in the blood.
  • Carbon dioxide diffuses into the alveoli from the blood.
34
Q

What does alveolar gas exchange look like?

A

image

35
Q

Summarise how oxygen moves through the gas exchange system and into the blood

A

Trachea - Bronchi - Bronchioles - Alveoli
DOWN A PRESSURE GRADIENT
- Alveolar epithelium - Capillary endothelium - Blood
DOWN A DIFFUSION GRADIENT

36
Q

What do alveoli contain, which increase the rate of diffusion?

A
  • A thin exchange surface (one cell thick = short diffusion pathway).
  • A large surface area (millions of alveoli).
  • A steep concentration gradient of oxygen and carbon dioxide between the alveoli and the capillaries.
37
Q

How is the diffusion gradient of oxygen and carbon dioxide between the alveoli and the capillaries maintained?

A

By the flow of blood and ventilation.

38
Q

What does blood and ventilation maintaining the concentration gradient look like?

A

image

Biology Topic 3A (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions