Physiology

Question 1

define internal respiration

Answer 1

intracellular mechanism involving oxygen and carbon dioxide between body tissues and the blood

Question 2

define external expiration

Answer 2

external exchange of oxygen and carbon dioxide between external environment and cells of the body

Question 3

define the 4 steps of external respiration

Answer 3

ventilation
gas exchange between alveoli and blood
gas transport
gas exchange between blood and tissues

Question 4

describe the process of ventilation

Answer 4

mechanical process of moving air between atmosphere and lungs (both in and out)

Question 5

air flows down a pressure gradient from ___ to ___ pressure?

Answer 5

high, low

Question 6

during inspiration is intra-alveolar pressure lower or higher than atmospheric pressure?

Answer 6

lower

Question 7

define Boyles law

Answer 7

as the volume of a gas increases, the pressure exerted by the gas decreases.

Question 8

what two factors link the lungs to the thorax

Answer 8

intrapleural fluid cohesiveness and negative intrapleural pressure

Question 9

what are the three pressures involved in ventilation

Answer 9

atmospheric, intra-alveolar, intrapleural

Question 10

are inspiration and expiration active or passive processes

Answer 10

inspiration is active relying on muscle contraction whereas expiration is passive

Question 11

what nerves supply the diaphragm

Answer 11

phrenic nerve which is via C3, 4, 5

Question 12

what is a pneumothorax

Answer 12

air within the pleural space

Question 13

what can cause a pneumothorax

Answer 13

trauma, iatrogenic, spontaneous

Question 14

symptoms of pneumothorax

Answer 14

shortness of breath and chest pain

Question 15

physical signs of pneumothorax

Answer 15

hyper-resonant percussion sounds and decreased or absent breath sounds

Question 16

what gives the lungs their elastic behaviour

Answer 16

elastic connective tissue and alveolar surface tension

Question 17

what creates the alveolar surface tension

Answer 17

attraction between water molecules at air liquid interface

Question 18

what reduces surface tension in the lungs

Answer 18

pulmonary surfactant

Question 19

what is surfactant made up of

Answer 19

lipids and proteins

Question 20

two forces that keep the lungs open

Answer 20

transmural pressure gradient and surfactant

Question 21

two forces promoting collapse of the lungs

Answer 21

elasticity of lung connective tissue and alveolar surface tension

Question 22

what are the main inspiratory muscles

Answer 22

diaphragm and external intercostals

Question 23

what cells secrete surfactant

Answer 23

type II alveolar cells

Question 24

parasympathetic nerve fibres promote

Answer 24

bronchoconstriction

Question 25

sympathetic nerve fibres promote

Answer 25

bronchodilatation

Question 26

what is peak flow rate

Answer 26

a test to measure someones maximum speed of expiration

Question 27

what is emphysema

Answer 27

air within the alveoli | results in them becoming enlarged and damaged

Question 28

lung are kept open by

Answer 28

surfactant | transmural pressure gradient

Question 29

lungs can be closed by

Answer 29

alveolar surface tension | connective tissue in lungs

Question 30

smaller alveoli are more likely to collapse true/false

Answer 30

true

Question 31

two main muscles used for inspiration

Answer 31

diaphragm | external intercostals

Question 32

two muscles used for active expiration

Answer 32

abdominals | external intercostals

Question 33

what is tidal volume

Answer 33

volume of air entering or leaving the lungs in one breath

Question 34

inspiratory reserve volume is

Answer 34

extra volume that can be inspired above the tidal volume

Question 35

expiratory reserve volume is

Answer 35

extra volume of air that can be expired above the tidal volume

Question 36

residual volume is

Answer 36

volume of air remaining in lungs after expiration

Question 37

total lung volume is

Answer 37

vital capacity + residual volume

Question 38

vital capacity is

Answer 38

max volume of air that can be expired after normal inspiration

Question 39

total lung volume can be measured by spirometry true/false

Answer 39

false because residual volume cannot be measured with spirometry

Question 40

what is spirometry

Answer 40

a test used to measure dynamic lung volumes and assess lung function

Question 41

what is FVC

Answer 41

forced vital capacity | maximum volume of air that can be forcefully expelled from the lungs following maximum inspiration

Question 42

what is FEV1

Answer 42

forced expiratory volume in 1 second | maximum volume of air that can be expired in the first second of an FVC determination

Question 43

FEV1/FVC ratio is ___ in normal people

Answer 43

>70%

Question 44

obstructive diseases affects __ example is __

Answer 44

the airway | example asthma and COPD

Question 45

restrictive disease affects __ example is __

Answer 45

the lungs | example is sarcoidosis

Question 46

in an obstructive disease, FEV1 is ___ FVC is ___ and ratio is ___

Answer 46

FEV1 - reduced FVC - normal ratio - reduced

Question 47

in a restrictive disease FEV1 is ___ FVC is ___ and ratio is ___

Answer 47

FEV1 - reduced FVC - reduced ratio - normal

Question 48

alveolar ventilation is less than pulmonary ventilation true/false

Answer 48

true

Question 49

why is alveolar ventilation less than pulmonary ventilation

Answer 49

due to alveolar dead space

Question 50

what 4 factors affect the rate of gas exchange

Answer 50

partial pressure of CO2 and O2 diffusion co-efficient of CO2 and O2 surface area of alveolar membrane thickness of alveolar membrane

Question 51

define partial pressure

Answer 51

total pressure a gas would exert if it occupied the total volume of the mixture

Question 52

adult haemoglobin is made up of ___ | this is the same/different as foetal haemoglobin

Answer 52

2 alpha and 2 beta subunits | different to foetal haemoglobin

Question 53

name three things oxygen delivery to tissues is impaired by

Answer 53

respiratory disease anaemia heart failure

Question 54

saturation of oxygen increases as partial pressure of oxygen __

Answer 54

increases

Question 55

what is the Bohr effect

Answer 55

shift in the standard oxygen curve to the right, due to release of oxygen at tissues increased by pCO2, increased [H+] and 2,3 - biphosphoglycerate

Question 56

name three ways carbon dioxide is transported in the blood

Answer 56

bicarbonate (60%) carbamino compounds (30%) solution (10%)

Question 57

CO2 is more/less soluble than O2

Answer 57

more, this is why its transported mainly as bicarbonate

Question 58

describe the Haldane effects

Answer 58

removing O2 from Hb increases affinity for Hb to pick up CO2

Question 59

specifically where is the respiratory rhythm generator in the medulla

Answer 59

pre-botzinger complex

Question 60

during inspiration, pre-botzinger complex activates which neurones to initiate contraction of inspiratory muscles?

Answer 60

dorsal group neurones

Question 61

what steps occur during active expiration

Answer 61

increased firing of dorsal neurones - excites ventral neurones which excites intercostals and abdominal muscles - forceful expiration

Question 62

where is the pneumotaxic centre and what does it do to inspiration

Answer 62

located in pons | terminates inspiration allowing passive expiration

Question 63

in normal breathing ventral neurones are excited true/false

Answer 63

false | only in forceful expiration

Question 64

what does the apneustic centre do to inspiration

Answer 64

prolongs inspiration

Question 65

what are the chemoreceptors responsible for

Answer 65

sensing value of gas tensions

Question 66

where are peripheral chemoreceptors located

Answer 66

aortic and carotid bodies

Question 67

where are the central chemoreceptors located

Answer 67

near the medulla

Question 68

hypoxia at high altitudes is caused by

Answer 68

decreased partial pressure of inspired oxygen | hyperventilation

Question 69

adaptation for high altitude hypoxia are

Answer 69

increased RBCs increased capillary numbers increase 2, 3-biphosphoglycerate so oxygen moves through tissues more easily

Question 70

what factors shift the oxygen dissociation curve to the right

Answer 70

``` CADET CO2 Acid 2,3-Diphosphoglycerate Exercise Temperature ```

Question 71

respiratory alkalosis can be caused by

Answer 71

``` hyperventilation increased intracranial pressure PE pregnancy altitude ```

Question 72

respiratory acidosis can be caused by

Answer 72

COPD, life threatening asthma, pneumonia, choking, opiates overdose

Question 73

metabolic acidosis can be caused by

Answer 73

diabetic ketoacidosis, impaired H+ excretion

Question 74

metabolic alkalosis can be caused by

Answer 74

potassium, deficiency, extreme vomiting, alkali indigestion