Physiology - lecture 2

Question 1

What does Boyle’s law state?

Answer 1

The pressure exerted by gas is inversely proportional to its volume

Question 2

in what direction to gases move?

Answer 2

From areas of high pressure to low pressure

Question 3

Be able to describe the anatomy of the pleural cavity

Answer 3

a

Question 4

Understand the relationship between the parietal and visceral pleura and why this is important for inflation of the lung

Answer 4

a

Question 5

Be able to describe how the muscles of respiration act to increase and decrease thoracic volume

Answer 5

a

Question 6

Relate Boyle’s law to the mechanics of breathing, inspiration and expiration

Answer 6

a

Question 7

State the mechanical factors that affect respiratory minute volume.

Answer 7

a

Question 8

Explain why intrapleural pressure is always less than alveolar pressure.

Answer 8

a

Question 9

How many lungs are the right and left lobe divided into and what are there names?

Answer 9

right lobe - 3 which are called superior, medial and inferior
left - 2 lobes called superior and inferior

Question 10

what are the names of the 2 membranes that enclose the lungs? where are they located exactly?

Answer 10

the parietal pleura is attached to the ribcage and the visceral pleural is attached to the lung’s outer surface and goes into all the fissures.

Question 11

what is present between the two membranes surrounding the lungs? what is its job?

Answer 11

intra-pleural fluid which makes sure that there is no friction caused when the lungs rub against each other and it is a smooth process

Question 12

what is pleurisy?

Answer 12

inflammation of the pleura

Question 13

in which direction do the lungs and chest wall want to move? what causes them to want to do this? What force doesn’t allow them to do this?

Answer 13

the chest wall wants to move outwards and the lungs want to move inwards due to the elastic recoil.
???????

Question 14

why does breathing occur? (boyles law)

Answer 14

a

Question 15

what muscles are used in inspiration?

Answer 15

diaphragm, external intercostal muscles, sternocleidomastoid and scalene muscles

Question 16

what muscles are used in expiration?

Answer 16

expiration is normally a passive process and the energy generated by inspiration is used, but in forced expiration, the internal intercostals and the abdominal???

Question 17

what are the skeletal muscles involved in breathing activated by?

Answer 17

alpha motor neurones

Question 18

what happens to the diaphragm during inspiration?

Answer 18

contracts and increases the volume of the thoracic cavity

Question 19

what happens to the diaphragm during expiration?

Answer 19

relaxes and decreases the volume of the thoracic cavity

Question 20

what does the pump-handle motion of the vertebrae, rib and sternum do?

Answer 20

a

Question 21

what does the bucket handle motion of the vertebrae, rib and sternum do?

Answer 21

a

Question 22

what is asthma?

Answer 22

over-reactive ?????

Question 23

what is more difficult in someone who has asthma - inspiration or expiration? why?

Answer 23

expiration as ????

Question 24

what happens during a pneumothorax?

Answer 24

the pleural cavity is ruptured causing air to flow into the lungs. this destroys the relationship between the lung and chest wall causing the lung to shrivel up and recoil inwards. This means that the chest wall and lung are no longer connected.

Question 25

what is intra-thoracic (alveolar) pressure?

Answer 25

The pressure in alveoli of the lungs. this is either negative or positive

Question 26

what is intra-pleural pressure?

Answer 26

the pressure in-between the two pleura of the lung. This is always NEGATIVE in health - it gets more or less negative

Question 27

what is transpulmonary pressure?

Answer 27

the difference between the alveolar pressure and the intra-pleural pressure. This is always POSITIVE in health.

Question 28

what is the alveolar pressure inbetween breaths?

Answer 28

0

Question 29

what happens if alveolar pressure is greater than atmospheric pressure?

Answer 29

Air moves into the lungs as air travels from an area of high conc to an area of low conc

Question 30

what happens if atmospheric pressure is greater than alveolar pressure?

Answer 30

air flows out of the lungs

Question 31

what happens to alveolar pressure during inspiration and expiration?

Answer 31

a

Question 32

what happens to intra-pleural pressure during inspiration and expiration?

Answer 32

a

Question 33

what happens to volume of air moved during inspiration and expiration?

Answer 33

a

Question 34

what is the bulk flow of air between the atmosphere and alveoli proportional to?

Answer 34

the difference between the atmospheric and alveolar pressures

Question 35

what is the bulk flow of air between the atmosphere and alveoli inversley-proportional to?

Answer 35

ratio ?????

Question 36

what is the relationship between pressure in the atmosphere and pressure in the alveoli between breaths? what direction does this cause the air to flow?

Answer 36

pressure in atmosphere is the same as pressure in the alveoli. This means that air doesn’t flow at this point

Question 37

what causes the dimensions of the lungs and thoracic cage to be stable?

Answer 37

a

Question 38

what are the chest wall and lungs wanting to do? what does this create?

Answer 38

the chest wall want to recoil outwards whereas the lungs want to recoil inwards. This leads to a subatmospheric intra-pleural pressure

Question 39

what does the sub atmospheric pressure lead to?

Answer 39

changes the transpulmonary pressure?????

Question 40

what does air resistance determine?

Answer 40

a

Question 41

what is the major determinant of air resistance?

Answer 41

The radius

Question 42

what does the volume of the lungs depend on?

Answer 42

a