Anatomy of Chest Wall and Mechanics of Breathing Flashcards Preview

Respiratory Physiology > Anatomy of Chest Wall and Mechanics of Breathing > Flashcards

Flashcards in Anatomy of Chest Wall and Mechanics of Breathing Deck (36):
1

Which gas law is breathing based on?

Boyle's Law

2

What does Boyle's Law state?

The pressure exerted by a gas is inversely proportional to its volume

3

What is the top of the lung called?

Apex

4

What is the first lobe below the apex called in both lungs

Superior lobe

5

What is different in the superior lobe of the left lung compared to the right

- Much bigger - Curved lower border

6

What are the lungs and interior of the thorax covered in?

Pleural sac

7

What is the pleural membrane made of?

An extremely thin layer of intrapleural fluid

8

What does the visceral pleural membrane coat?

Outer surface of the lungs

9

What does the parietal pleural membrane coat?

Inner surface of the ribs 

10

What does the interaction between the pleural membranes mean for the lungs and the ribs?

The lungs are effectively stuck to the ribs 

11

What is pleurisy?

Inflammation of the pleura 

12

Why does breathing occur?

Thoracic cavity changes volume

13

Why do the lungs need to be "stuck" to the ribs?

- The lungs are trying to move in the way and would collapse

- The ribs are moving against this force to maintain the shape of the cavity

14

Where do the two pleural membranes overlap?

The hilux of the lung

15

What is the overlapping membrane known as?

Visceralparietal membrane

16

What volume of fluid is there in the pleural cavity?

3ml

17

What does the pleural fluid allow the membranes to do?

- Slide over eachother

- Stick to eachother strongly (imagine 2 microscope slides with water between them

18

What symptoms, to do with the pleural membranes, can you get when you have pleurisy?

Pain and discomfort as they can't slide over each other 

19

What is the average negative pressure of the lungs due to the interaction with the ribs?

-3mm Hg

20

What is the name given to the force that the lungs and the ribs exert on each other due to the pleural membranes?

Elastic recoil

21

What is pneumothorax?

A collapse of the lung due to loss of pleural membrane interaction

22

What happens to the ribcage as the diaphragm is relaxed?

It rises

23

What effect does the rising of the ribcage have on the thoracic cavity and what does this cause?

- Lowers the pressure

- Air from the atmosphere moves into the lungs 

24

What happens to the thoracic pressure when the air moves in?

- Increases above atmospheric pressure (PATM)

25

What happens to the alveoli when air moves into them?

- They expand

- Elastic fibres stretch

26

How does air move back out of the alveoli?

Under elastic recoil from the elastic fibres surrounding the alveolar sacs

27

What two groups of muscles can be recruited to aid in expiration during exercise?

- Intercostal muscles 

- Abdominal muscles

28

How do the intercostal muscles aid in expiration?

- Innervating alpha motor neurone is switched off and they relax

29

How do the abdominal muscles increase expiration?

- Contraction of them increases thoracic pressure by decreasing thoracic volume

30

What shape is the diaphragm when it contracts?

- Flat

31

What does the shape change to a flat shape of the diaphragm do to thoracic pressure?

- Increases volume so decreases pressure 

32

How does intercostal muscle contraction increase anterior posterior thoracic volume?

Similar to a pump handle

33

How does intercostal muscle contracting increase lateral thoracic volume?

Similar to a bucket handle shape

34

How does inspiration follow Boyle's Law?

Air moves in from the atmosphere from high pressure to low pressure because the volume of the container (lungs) is increased.

35

How does expiration follow Boyle's Law?

Pressure of the thoracic cavity excedes atmospheric pressure as the volume is reduced by elastic recoil, rib cage decending and diaphragm rising

36

List reasons why intrapleural pressure is always lower than alveolar pressure

- Alveoli have residual volume in them ALL THE TIME

- Intrapleural space contains fluid

- Intrapleural pressure is always negative compared to atmospheric pressure, whereas alveolar pressure is sometimes above

- If intrapleural pressure equals alveolar pressure then a pneumothorax will form