The human breathing system

HideShow resource information
  • Created by: zoolouise
  • Created on: 04-05-16 17:53
What are the lungs enclosed in?
An airtight compartment called the thorax.
1 of 21
What lines the thorax?
Pleural membranes line the thorax and cover each long. Fluid between the membranes prevents friction between the lungs and the chest cavity.
2 of 21
What shape is the diaphragm and what does it do?
The diaphragm is a dome-shaped sheet of muscle at the base of the thorax, it separates the thorax from the abdomen.
3 of 21
What surrounds the thorax?
The ribs, there's intercostal muscles between the rubs.
4 of 21
What is the trachaea and other features of the human breathing system?
The trachea is a flexible airway to bring air to the lungs, it has semi-circles of cartilage. Two bronchi, then bronchioles and then air sacs called alevoli are also features of the human breathing system.
5 of 21
How do mammals ventilate?
Negative pressure breathing. Air enters lungs as pressure inside lungs is lower than atmospheric pressure. Pressure wants to balance, so air will flow from an area of high pressure to an area of low pressure.
6 of 21
What is inspiration?
It's an active process as the muscle contraction requires energy in the form of ATP.
7 of 21
What's the process of inspiration?
1) External intercostal muscles contract, internal intercostal muscles relax. 2) Ribs are pulled upwards and outwards. 3) Diaphragm muscles contract, it flattens. 4) These actions increase volume of the thorax. 5) Reduces pressure in the lungs.
8 of 21
continued
6) Atmospheric pressure is greater than the pulmonary pressure and so air is forced into the lungs
9 of 21
What is expiration?
Expiration is a passive process as it does not require any energy.
10 of 21
What's the process of expiration?
1) External intercostal muscles relax, internal intercostla muscles contract. 2) Ribs are pulled downwards and inwards 3) Diaphragm muscles relax, returns to dome-shape. 4) Actions decrease the volume of the thorax. 5) Increases pressure in the lungs
11 of 21
continued
6) Pulmonary pressure is greater than atmospheric pressure, air is forced out of the lungs
12 of 21
What is the lung tissue?
It's elastic. They recoil and regain their original shape, the recoil action helps to expel air out of the lungs.
13 of 21
Where is pleural fluid found and what does it do?
It's found between the pleural membranes, it acts as a lubricant allowing friction-free movement against the inner wall of the thorax during ventilation.
14 of 21
What are the inside surfaces of the alveoli coated with?
They're coated with a surfactant, an anti-sticking mixture which is made of moist secretions containing phospholipid and protein.
15 of 21
What does the surfactant do?
Has a low surface tension, prevents alveoli from collapsing during exhalation when air pressure inside them is low. It allows gases to dissolve before they diffuse in or out.
16 of 21
Why is the alveolus very efficient at gas exchange?
They provide a large surface area relative to volume of body. Gases dissolve in the surfactant moisture lining the alveoli.
17 of 21
What are alveoli walls made of?
They're made of squamous epithelium, only one cell thick, diffusion pathway is short
18 of 21
What does the extensive capillary network surrounding the alveoli do?
It maintains diffusion gradients as carob dioxide is rapidly brought to the alveoli and oxygen is rapidly carried away
19 of 21
What are capillary walls?
One cell thick, contributing to the short diffusion patheway for gases.
20 of 21
What are capillary walls?
One cell thick, contributing to the short diffusion pathway for gases.
21 of 21

Other cards in this set

Card 2

Front

Pleural membranes line the thorax and cover each long. Fluid between the membranes prevents friction between the lungs and the chest cavity.

Back

What lines the thorax?

Card 3

Front

The diaphragm is a dome-shaped sheet of muscle at the base of the thorax, it separates the thorax from the abdomen.

Back

Preview of the back of card 3

Card 4

Front

The ribs, there's intercostal muscles between the rubs.

Back

Preview of the back of card 4

Card 5

Front

The trachea is a flexible airway to bring air to the lungs, it has semi-circles of cartilage. Two bronchi, then bronchioles and then air sacs called alevoli are also features of the human breathing system.

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Human, animal and plant behaviour resources »