resp physiology

Question 1

what does internal respiration refer go

Answer 1

the intracellular mechanisms that consume oxygen and produce carbon dioxide

Question 2

what does external respiration refer to

Answer 2

the sequence of events which involves the exchange of oxygen and carbon dioxide between the external environment and the cells of the body

Question 3

4 steps of external respiration

Answer 3

ventilation
exchange of O2 and CO2
transport
exchange

Question 4

4 systems involved in external respiration

Answer 4

respiratory
cardiovascular
nervous system
haematology system

Question 5

boyles law

Answer 5

at constant temperature, the pressure exerted by a gas varies inversely with the volume of gas

Question 6

air flow direction

Answer 6

area of high pressure to low pressure

Question 7

2 forces that hold the thoracic wall and the lungs in close opposition

Answer 7

the intrapleural fluid cohesiveness

the negative intrapleural pressure

Question 8

atmospheric pressure at sea level

Answer 8

760 mmHg

Question 9

intra-alveolar pressure

Answer 9

pressure within the alveoli

Question 10

intra - pleural pressure

Answer 10

pressure exerted outside the lungs within the pleural cavity

Question 11

pneumothorax

Answer 11

air in the pleural space

Question 12

what is alveolar surface tension

Answer 12

attraction between water molecules at liquid air interface

Question 13

smaller alveoli have what

Answer 13

higher tendancy to collaps

Question 14

major inspiratory muscles

Answer 14

diaphragm + external intercostal muscles

Question 15

accessory muscles of inspiration

Answer 15

sternocleidomastoid, scalenus, pectoral

Question 16

muscles of active expiration

Answer 16

abdominal muscles and internal intercostal muscles

Question 17

when do accessory muscles of inspiration contract

Answer 17

during forceful inspiration

Question 18

tidal volume

Answer 18

volume of air entering or leaving the lungs in a single breath

Question 19

inspiratory reserve volume

Answer 19

extra volume of air that can be maximally inspired over and above the normal tidal volume

Question 20

expiratory reserve volume

Answer 20

extra volume of air that can be actively expired by maximal contraction beyond the normal volume of air after a resting tidal volume

Question 21

residual volume

Answer 21

minimal volume of air remaining in the lungs after maximal expiration

Question 22

total lung capacity

Answer 22

maximum volume of air the lungs can hold

Question 23

average total lung capacity value

Answer 23

5700ml

Question 24

is it possible to measure total lung volume by spirometry? and why?

Answer 24

no because residual volume cannot be measured by spirometry

Question 25

vital capacity

Answer 25

maximal volume of air that can be moved out during a single breath following a maximal inspiration

Question 26

when is residual volume increased

Answer 26

when the elastic recoil of the lungs is lost

Question 27

parasympathetic stimulation causes...

Answer 27

bronchoconstriction

Question 28

sympathetic stimulation causes...

Answer 28

bronchodilation

Question 29

is expiration or inspiration more difficult

Answer 29

expiration

Question 30

intrapleural pressure ____ during inspiration

Answer 30

falls

Question 31

intrapleural pressure ____ during expiration

Answer 31

rises

Question 32

what is dynamic airway compression

Answer 32

pressure applied to alveolus that helps push air out of lungs - completely normal

Question 33

what is compliance

Answer 33

the measure of effort that has to go into stretching or distending the lungs

Question 34

the less compliant the lungs are...

Answer 34

the more work is required

Question 35

anatomical dead space

Answer 35

some inspired air remains in the airway and is unavailable for gas exchange

Question 36

why is alveolar ventilation less than pulmonary ventilation

Answer 36

the presence of anatomical dead space

Question 37

pulmonary ventilation

Answer 37

is the volume of air breathed in and out per minute

Question 38

alveolar ventilation

Answer 38

is the volume of air exchanged between the atmosphere and alveoli per minute

Question 39

alveolar dead space

Answer 39

ventilated alveoli which are not adequately perfused with blood

Question 40

4 factors that influence the rate of gas exchange across alveolar membrane

Answer 40

partial pressure gradient of oxygen and carbon dioxide diffusion coefficient for oxygen and carbon dioxide surface area of alveolar membrane thickness of alveolar membrane

Question 41

the partial pressure of a gas is...

Answer 41

the pressure that one gas in a mixture of gases would exert if it were the only gas present in the whole volume occupied by the mixture at a given temperature

Question 42

Henry's law

Answer 42

the amount of gas dissolved in liquid at a constant temperature is proportional to the partial pressure of the gas in equilibrium

Question 43

how is most oxygen in the blood transported

Answer 43

bound to haemoglobin in the red blood cells

Question 44

1.5% of oxygen is transported how

Answer 44

physically dissolved

Question 45

how many haem groups does each Hb molecule contain

Answer 45

4

Question 46

each haem group reversibly binds to...

Answer 46

one oxygen molecule

Question 47

when is haemoglobin considered fully saturated

Answer 47

when all the Hb present is carrying its maximum oxygen load

Question 48

P02

Answer 48

the primary factor which determines the percent saturation of haemoglobin within oxygen

Question 49

oxygen delivery to the tissues is a function of...

Answer 49

oxygen content of arterial blood and the cardiac output

Question 50

cardiac index

Answer 50

the cardiac output to the body surface area. ie size of individuak

Question 51

what is the oxygen content of arterial blood determined by

Answer 51

haemoglobin concentration | saturation of Hb with O2

Question 52

the % of haemoglobin saturated by oxygen is determined by what

Answer 52

PO2

Question 53

partial pressure of inspired oxygen depends on...

Answer 53

total pressure | proportion of oxygen in gas mixture

Question 54

properties of foetal haemoglobin

Answer 54

2 alpha and 2 gamma subunits | higher affinity for oxygen

Question 55

what muscles is myoglobin present in

Answer 55

skeletal and cardiac muscles

Question 56

means of CO2 transport in the blood

Answer 56

solution as bicarbonate carbamino compounds

Question 57

what is more soluble... | carbon dioxide or oxygen

Answer 57

carbon dioxide - 20x

Question 58

what % of CO2 is carried in solution

Answer 58

10%

Question 59

most CO2 is transported in the blood as

Answer 59

bicarbonate

Question 60

how are carbamino compounds formed

Answer 60

combination of CO2 with terminal amine groups

Question 61

the Haldane effect

Answer 61

removing oxygen from haemoglobin increases the ability of Hb to pick up CO2 and H+

Question 62

the Bohr effect

Answer 62

facilitates the removal of oxygen from Hb at tissue level

Question 63

the rhythm

Answer 63

inspiration followed by expiration

Question 64

what is the major rhythm generator

Answer 64

medulla

Question 65

what is the breathing rhythm generated by

Answer 65

network of neurons called the Pre-botzinger complex

Question 66

what type of process is inspiration

Answer 66

active process

Question 67

how can the rhythm of the medulla be altered

Answer 67

neurons in the pons

Question 68

chemical control of respiration

Answer 68

is a negative feedback control system

Question 69

what are the controlled variables in the chemical control of respiration

Answer 69

blood gas tensions - especially CO2

Question 70

what is the function of chemoreceptors

Answer 70

sense the values of the gas tensions