Respiration Mechanics

Question 1

what is tissue respiration?

Answer 1

the aerobic metabolism in cells

Question 2

what is breathing?

Answer 2

gas exchange and the associated processes

Question 3

what is respiration mechanics?

Answer 3

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

Question 4

what is the lungs job?

Answer 4

to bring in fresh air rich in oxygen needed to fuel the body and to expel the waste (CO2) produced from cells in the body

Question 5

why is respiratory mechanics important?

Answer 5

to understand how lungs work normally and in disease states, almost all lung disease affect mechanical properties of the lung and death from lung disease is usually due to the inability to overcome changes in lung and/or chest mechanics

Question 6

what is the resting PO2?

Answer 6

100 +/- 2mmHg

Question 7

what is the resting PCO2?

Answer 7

40 +/- 2mmHg

Question 8

what is the exchange of O2 to CO2 at rest?

Answer 8

250ml O2/min and 200ml CO2/min

Question 9

what is the exchange of O2 and CO2 when breathing regulation is continuous?

Answer 9

800ml O2/min and 750ml CO2/min

Question 10

what is the exchange of CO2 and O2 when you are undertaking severe exercise?

Answer 10

5000ml O2/min and 6000ml CO2/min

Question 11

what is the function of the nasal cavities and paranasal sinuses?

Answer 11

filter, warm, humidify air, detect smells

Question 12

what is the function of the pharynx?

Answer 12

conducts air to larynx, a chamber shared with the digestive tract

Question 13

what is the function of the larynx?

Answer 13

protects opening to trachea and contains vocal cords

Question 14

what is the function of the bronchi and trachea?

Answer 14

filters air, traps, particles in mucus and has cartilages to keep airway open

Question 15

what is the function of the lungs?

Answer 15

responsible for air movement through volume changes during movements of ribs and diaphragm; include airways and alveoli

Question 16

what is the function of the alveoli?

Answer 16

act as sites of gas exchange between air and blood

Question 17

what are the major functions of the upper airway?

Answer 17

humidify (saturate with water), warm (to body temp) and filter

Question 18

what is the epithelium of the upper airways?

Answer 18

pseudo-stratified ciliated columnar epithelium

Question 19

what is the ventilation at rest?

Answer 19

about 6L/min, about 12 breaths of 500ml

Question 20

what is the max ventilation?

Answer 20

160L/min, about 40 breaths of 4L

Question 21

what is the cardiac output at rest?

Answer 21

5L/min, 70bpm, 70ml/beat

Question 22

what is the max cardiac output?

Answer 22

25L/min, 200bpm, 125ml/beat

Question 23

what is inspiration when practising quiet breathing?

Answer 23

active

Question 24

explain the mechanism of inspiration in quiet breathing

Answer 24

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

Question 25

what is expiration when practising quiet breathing?

Answer 25

passive

Question 26

explain the mechanism of expiration in quiet breathing

Answer 26

elastic recoil

Question 27

what is inspiration when practising strenuous breathing?

Answer 27

active

Question 28

explain the mechanism of inspiration when strenuous breathing

Answer 28

greater contraction of diaphragm (1cm quiet breathing up to 10cm during strenuous breathing) and external intercostals. Inspiratory accessory muscles e.g. sternocleidomastoid, alae nasi and genioglossus

Question 29

what is expiration when practising strenuous breathing?

Answer 29

active

Question 30

explain the mechanism of expiration in strenuous breathing

Answer 30

abdominal muscles used (rectus abdominus, internal oblique, external oblique and transversus abdominus), internal intercostal muscles oppose external intercostals by pushing ribs down and inwards

Question 31

what is Pa?

Answer 31

alveolar pressure

Question 32

why does the Pa = 0 at the beginning of inspiration?

Answer 32

because there is no flow

Question 33

what is Ppl?

Answer 33

pleural pressure

Question 34

what is Pel?

Answer 34

plastic recoil pressure

Question 35

what is Pl?

Answer 35

transpulmonary pressure

Question 36

what is Pb?

Answer 36

barometric pressure

Question 37

in healthy lungs how efficient is low level breathing?

Answer 37

very efficient because there is a small muscle effort

Question 38

in healthy lungs how efficient is higher intensity breathing and why?

Answer 38

less efficient because gas flow is more turbulent and it uses more muscles. The accessory muscles can fatigue easily to limit exercise

Question 39

what is the functional residual capacitu?

Answer 39

the volume of air in the lung at the end of expiration during quiet breathing

Question 40

what do the elastic recoil forces of the lung do?

Answer 40

act to decrease lung volume

Question 41

what does the outward recoil of chest wall do?

Answer 41

acts to increase lung volume

Question 42

at functional residual capacity what is the elastic recoil ad the outward recoil like?

Answer 42

opposite and equal and muscles are relaxed

Question 43

what happens to the FRC when chest wall muscles are weak?

Answer 43

it decreases

Question 44

what is FVC?

Answer 44

forces viral capacity

Question 45

what is FEV?

Answer 45

forced expiratory volume in 1 second

Question 46

in a healthy individual what is the FEV/FVC ratio and what does this mean?

Answer 46

it is greater than 70% meaning that 70% of the lung volume is expired in 1 second

Question 47

in patients with obstructive lung disease what is the FEV/FVC ratio and what does this mean?

Answer 47

it is less than 70% meaning that less than 70% of the lung volume is expired in 1 second

Question 48

in patients with restrictive lung disease e.g. pulmonary disease what is the FEV/FVC ratio?

Answer 48

greater then 70% because the lung volume (FVC) is smaller