respiration mechanics

Question 1

what is tissue respiration?

Answer 1

the aerobic metabolism in cells

Question 2

what is respiration (breathing)?

Answer 2

gas exchange and the associated processes

Question 3

what is respiratory mechanics?

Answer 3

study of mechanical properties of lung and chest wall- process by which air enters and leaves lungs

Question 4

what is breathing?

Answer 4

the job of lungs to bring fresh air with O2 needed to fuel body and to expel the CO2 waste gas- therefore must be coupled to respiration

Question 5

what is the peripheral/systemic circulation?

Answer 5

transport of blood between lungs and the rest of the body

Question 6

what is the pulmonary circulation?

Answer 6

transport of blood between heart and lungs

Question 7

what systems work together to maintain O2 and CO2 levels?

Answer 7

pulmonary and peripheral circulation

Question 8

why are respiratory mechanics important?

Answer 8

• To understand how lung works normally and in disease states.
• Almost all lung diseases affect mechanical properties of lung.
• Death from lung disease usually due to inability to overcome changes in lung and/or chest mechanics

Question 9

what maintains blood gas homeostasis (O2 CO2 pH)?

Answer 9

breathing

Question 10

what happens to breathing during strenuous exercise?

Answer 10

CO2 released > O2 consumed

Question 11

what are the functions of the upper airways?

Answer 11

conduct air to the lungs
- humidify
- warm
- filter

Question 12

describe air filtering

Answer 12

upper airways are lined by pseudo stratified ciliated columnar epithelium, so inhaled particles stick to mucus which is moved towards the mouth by cilia

Question 13

what do goblet cells release?

Answer 13

mucus

Question 14

what is ventilation at rest?

Answer 14

6-7 litres (12-15 breaths) per minute

Question 15

why is it important to recognise normal ventilation?

Answer 15

different anaesthesia react differently

Question 16

what happens during active inspiration?

Answer 16

• diaphragm contracts downwards pushing abdominal contents outwards
• external intercostals pull ribs outwards and upwards

Question 17

what are the states of inspiration and expiration during quiet breathing?

Answer 17

inspiration= active
expiration= passive

Question 18

why is inspiration active during quiet breathing?

Answer 18

as muscles are required to contract

Question 19

why is expiration passive during quiet breathing?

Answer 19

elastic recoil of lungs and diaphragm

Question 20

what are the states of inspiration and expiration during strenuous breathing?

Answer 20

inspiration= active
expiration= active

Question 21

what happens during active expiration?

Answer 21

abdominal muscles contract to decrease the volume of the thoracic cavity

Question 22

in a respiratory disorder patient what is different during quiet breathing?

Answer 22

active expiration

Question 23

what is the pleural space of the lungs?

Answer 23

space between the outer surface of the lungs and inner thoracic wall

Question 24

pressure in lung during inhalation- intrapulmonary

Answer 24

negative (lungs increase in size so pressure decreases)

Question 25

pressure in lung during exhalation- intrapulmonary

Answer 25

positive (lungs decrease in size so pressure increases)

Question 26

intrapleural pressure during inhalation

Answer 26

drops to a lower negative value (thoracic cavity increases in size so pleural cavity has more space, decreasing pressure)

Question 27

intrapleural pressure during exhalation

Answer 27

becomes less negative (thoracic cavity decreases in size so pleural cavity has less space, increasing pressure)

Question 28

what is always true for the value of intrapleural pressure?

Answer 28

negative

Question 29

intra-plueral and alveolar are interchangeable

Answer 29

.

Question 30

what is transpulmonary pressure?

Answer 30

difference in pressure between pleural and intra-pleural

Question 31

what is always true about pleural pressure?

Answer 31

always negative

Question 32

when does flow stop?

Answer 32

when atmospheric and alveolar pressure are equal (glottis closes)

Question 33

what is the pressure at the beginning of inspiration?

Answer 33

0

Question 34

what does the contraction of the diaphragm increase?

Answer 34

the thoracic volume

Question 35

describe the sequence of pressure and volume changes in the lungs

Answer 35

• Beginning of inspiration, no flow: PA=0 PB=0.
• Inspiratory muscles contract – inc. thoracic volume.
• Pleural pressure becomes more negative (decreases).
• Increase in transpulmonary pressure.
• Lungs expand and alveolar volume increases.
• PA becomes negative (below PB).
• Air flows into alveoli (from higher to lower pressure).
• End inspiration - Muscles stop contracting, thorax and alveoli stop expanding, PA = PB (no flow).
• Beginning expiration: Thoracic volume decreases. .
• Ppl & PL return to pre-inspiration values.
• Thorax and lungs recoil (elastic recoil pressure).
• Air in alveoli compressed.
• PA becomes greater than PB.
• Air flows out of lungs

Question 36

what is barometric pressure?

Answer 36

the pressure outside the lungs

Question 37

what is functional residual capacity?

Answer 37

the volume of air in the lung at the end of expiration during quiet breathing
- elastic recoil and outward recoil are opposite and equal and muscles are relaxed

Question 38

what does elastic recoil forces of the lung do?

Answer 38

act to decrease lung volume

Question 39

what does outward recoil of the chest wall do?

Answer 39

act to increase lung volume

Question 40

what happens to the chest wall muscles during neuromuscular disease?

Answer 40

they weaken, so functional residual capacity decreases

Question 41

what is residual volume?

Answer 41

volume of air remaining in lungs after expiration