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Flashcards in Respiratory Physiology Deck (212)
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1
Q

Respiration controls…

A
  • CO2 supply
  • O2 supply
  • H+ ion concentration
2
Q

What is the outer form of respiration?

A
  • Gas exchange: outside world → Blood
    • Take-up + transmission of oxygen by cells
    • CO2 elimination
    • Gas exchange
3
Q

Inner form of respiration

A

Gas exchange: Blood → Cells

4
Q

99% of pulmonary blood supply comes from…

A

A. pulmonalis

5
Q

99% blood leaves the lung via…

A

Vv. pulmonales → Left atrium

6
Q

Which vessels represent the ‘dual blood supply’ of lung circulation?

A
  • A. pulmonalis (Functional)
  • A. bronchiales (Nutritive)
7
Q

1% of pulmonary blood supply comes from…

A

Aa. bronchiales (Oxygenated)

8
Q

Venous blood contaminates refreshed blood via

A

V. bronchiales

9
Q

What transfers deoxygenated blood from the right ventricle to the lung?

A

A. pulmonales

10
Q

From the aorta, …transfers oxygenated blood to the lungs

A

A. bronchiales

11
Q

Automatically decreased perfusion to certain areas of the lung leads to…

A

Redirection of blood to well-ventilated lung territories

12
Q

Describe the physiology of blood redirection in the lung

A

Hypoxia causes vasoconstriction

13
Q

A small portion of blood goes directly to the right atrium via…

A

V. azygos

14
Q

Where does venous blood contaminate oxygenated blood?

A
  • V. bronchiales
  • Coronary vessels
15
Q

Blood stays in the capillaries for…during 1 cardiac cycle

A

800 msec

16
Q

O2 and CO2 diffusion takes how long to occur?

A

250 msec

17
Q
A

pO2 (mmHg)

18
Q
A

pCO2​ (mmHg)

19
Q

Unit for airflow

A

Va/min

(Ventilation, litre air/ min)

20
Q

Airflow is proportional to…

A

Perfusion of blood

21
Q

Unit for perfusion of blood (Q)

A

litre/min

22
Q

Normally: Va/Q =

A

1

23
Q

In normal conditions, blood will flow away…

A

Arterialised (oxygenated)

24
Q

When the alveolus is plugged…

A
  • Va = 0
  • Va/Q = 0
  • Blood flows away deoxygenated
25
Q

Capillary plug

A

When blood flow stops

26
Q

In the incidence of capillary plug…

A
  • Q=0
  • Va/Q = ∞
  • Alveolar gas pressure = atmospheric pressure
27
Q

Degree of perfusion

A

Perfusion absent

28
Q

Degree of perfusion

A

Perfusion is sporadic

29
Q

Degree of perfusion

A

Perfusion is constant

30
Q

Describe the effects of gravity in zone 1 of the lung

A
  • Pressure in alveoli compresses blood vessels
  • Perfusion decreases
  • PA > Pa> Pv
31
Q

Describe the effects of gravity in zone 2 of the lung

A
  • Alveolar capillaries are open during systole
  • Closed during diastole
  • PA>Pa>PV
32
Q

Describe the effects of gravity in zone 3 of the lung

A
  • Gravity increases BP
  • Alveolar pressure can’t compress capillaries
  • During diastole and systole
  • PA>PV>Pa
33
Q

PA=

A

Alveolar pressure

34
Q

Pa=

A

Arterial pressure

35
Q

PV=

A

Venous pressure

36
Q

Which innervation causes pulmonary vessels to enlarge

A

Parasympathetic (n. vagus)

37
Q

Which innervation causes pulmonary vessels to constrict?

A

Sympathetic, noradrenergic fibres

(Through α-receptors)

38
Q

Effect of adrenalin on pulmonary circulation

A
  • Creates intensive alveolar dilation (through β-receptors)
  • Increased ventilation
  • Crucial for anaphylaxis counteraction
39
Q

Local hypoxia in the lungs causes…

A

Local stenosis → Blood redistribution

40
Q

The effect of BP increase on pulmonary circulation

A
  • Decreased vascular tone
  • Affects the ability to achieve extremely high minute volume
41
Q

How does the nasal ciliated cylindrical epithelium + blood vessels play a role in organism defence?

A
  • Mechanically:
    • Mucous motion
    • Coughing
  • Immunologically
    • IgA
42
Q

How does the nasal ciliated cylindrical epithelium + blood vessels play a role in air conditioning?

A
  • Saturates inspired air with water vapour
  • Warms up the air
43
Q

What is the defensive function of the pharynx?

A
  • Mucous layer
  • Lymphatic vessels + glands
44
Q

Lower respiratory tract

A
  • Trachea, its branching and the lungs
  • Function: Filtering and protection
45
Q

Epithelium found in the lower respiratory tract

A

Pseudostratified ciliated columnar epithelium

Contains goblet cells

46
Q

Goblet cells produce…

A

Mucine - IgA

47
Q

Cilia of the epithelium are moving in…

A

Sol phase

48
Q
A

Terminal bronchiolus

49
Q
A
  • Bronchiolus* respiratorius
  • Respiratory epithelium appears
50
Q

Give the layers (alveolar) between blood and atmospheric air

A
  1. Surfactant layer
  2. Alveolar layer
  3. Membrana basalis
  4. Capillary endothel
51
Q

The alveolar wall is built up of which pneumocytes?

A
  • Epithel → Provides gas exchange
  • T2 → Produce surfactant layer
52
Q

Muscles involved in inspiration

A
  • Diaphragm
  • External intercostal muscles
  • Abdominal muscles
53
Q

Function of mm. intercostales externi

A
  • Raise ribs, assist inspiration
  • Parietal region of the diaphragm can dilate easier
54
Q

The collapsing tendency of the lung is due to…

A
  • The surface tension of alveoli
  • Elastic elements of the lung
55
Q

Total collapse of the lung is prevented by…

A

Fluid-film between:

  • Visceral pleura
  • Parietal pleura
56
Q

Pause of respiration

A

The retractive force of lung balanced with the tension of muscles and joints of the chest (rest)

57
Q

Rate of respiration is dependent on…

A

Metabolic activity

58
Q

Inspiration or expiration?

A

Inspiration

59
Q

Inspiration or expiration?

A

Expiration

60
Q

What do the blue lines represent?

A

Tendon-lamella

61
Q

Collapsing tendency of the lungs reduces…

A

Lung volume during expiration

62
Q

Title the figure

A

The mouse-elephant curve

63
Q

Which air-flow types are observed in panting?

A
  • Parietal
  • Central
64
Q

What kind of gas exchange occurs during panting?

A

Physiological gas exchange

  • Slight change in gas pressure
65
Q

During panting, parietal gas exchange is…

A

Slow

66
Q

Central gas stream

A
  • Fast
  • Heat exchange
  • Stimulates water release in mouth
67
Q

Panting in species other than canines would cause…

A
  • Loss of CO2
  • Alkalosis
68
Q

The spirometer measures…

A

Volume changes and air fractions of breathing

69
Q

Ventilation

A
  • The quantity of air entering and leaving the lung
  • Per unit time
70
Q

In the spirometer, the height of the upper cylinder indicates…

A

The size of the given volume fraction

71
Q
A

Inspiratory Reserve Volume

(IRV)

72
Q
A

Tidal volume

(TV or VT)

73
Q
A

Expiratory Reserve Volume

(ERV)

74
Q
A

Residual Volume

(RV)

75
Q
A

Inspiratory Capacity

(IC)

76
Q
A

Functional Residual Capacity

(FRC)

77
Q
A

Vital Capacity

(VC)

78
Q
A

Total Lung Capacity

(TLC)

79
Q

VC =

A

VT + IRV + ERV

80
Q

The deepness of inspiration increases…

A
  • The proportion of fresh air : used air
  • Measured with Ventilation coefficient
81
Q

Ventilation coefficient

A

Vcoeff = fresh/used

82
Q

Volume dead

A
  • Anatomical + physiological dead-space
  • Doesn’t contribute to gas exchange
83
Q

What contributes to anatomical dead space?

A
  • Air fraction of:
    • Upper respiratory tracts
    • Lower respiratory tracts
84
Q

What contributes to the physiological dead space?

A
  • Occluded alveoli
  • Alveoli excluded from circulation
85
Q

Used air =

A

FRC + VD

86
Q

Fresh air =

A

VT - VD

87
Q

Pressure change in the pleural cavity

A

Intrapleural pressure

88
Q

Pressure change in the lung

A

Intrapulmonar pressure

89
Q

Intrapleural pressure is always…

A

Negative

90
Q

Why is the intrapleural pressure always negative?

A

Gases constantly being absorbed by tissue

91
Q

Formula for transpulmonary pressure

A

Ptp = Palv - Ppl

92
Q

During apnea, pulmonary pressure is equal to…

A

Atmospheric pressure

93
Q
A

Pulmonary pressure

94
Q
A

Intrapleural pressure

95
Q
A

Volume

96
Q
A

Apnea

97
Q
A

Inspiration

98
Q
A

Expiration

99
Q

Müller’s experiment

A
  • Deep inspiration with a closed epiglottis
  • Pulmonary and intrapleural pressure decreases
100
Q

Valsava experiment

A
  • Forced expiration with closed epiglottis
  • Pulmonary + Intrapleural pressure increase

Used to equalise pressure in the ear

101
Q

Pneumothorax

A
  • Loss of intrapleural negative pressure
  • Small: Escaped air can be reabsorbed from the pleural cavity
  • Large: Air needs to be drawn out of the pleural cavity
102
Q

Closed pneumothorax

A
  • Small hole in thoracic wall/lung
  • Air gradually absorbed, IP pressure returns
103
Q

Open pneumothorax

A
  • Large hole
  • IP is atmospheric
104
Q

Valvular/tension pneumothorax

A
  • Flap of tissue acts as a valve over the hole
  • Allows air entry during inspiration
  • Doesn’t allow escape during expiration
  • Lung severely collapses
105
Q

Emphysema

A
  • Septa between alveoli are damaged
  • Reduced respiratory surface
106
Q

Resistance forces which need to be overcome during inspiration

A
  • Friction
  • Non-elastic tissue resistance
  • Total elastic resistance
107
Q

Friction force effect on inspiration

A
  • Smallest force of resistance
  • Caused be turbulent air flow
108
Q

Non-elastic tissue resistance during respiration

A
  • Caused by:
    • Diaphragm
    • Chest
    • Abdominal structures
109
Q

Total elastic resistance of inspiration

A
  • Stretch of vertebral + costal joints
  • Retractive forces
    • Resistance of interstitial elastic elements
    • Surface tension in the alveoli (Strongest)
110
Q

Surface tension

A
  • Cohesive forces
  • Internal pressure
    • Causes liquid surfaces to contract to minimal area
111
Q

Forces causing the collapse of alveoli

A
  • Retractive tendency of elastic elements
  • Surface tension
112
Q

Forces acting against collapse of alveoli

A
  • Actual intrapulmonary pressure
  • Surface tension of neighbouring alveoli
  • Presence of surfactant
113
Q

The result of alveolar dilating and retracting forces…

A

Transpulmonary pressure

114
Q

The open state of alveoli can be maintained only by…

A

Materials reducing surface tension

115
Q

DPPC

A
  • Reduces surface tension
  • If not present:
    • Fatal alveolar collapse
    • Plasma filtrated into alveoli (Reduced diffusion)
116
Q

DPPC deficiency occurs genetically in…

A
  • Calves
  • Causes early postnatal death
117
Q

How does lack of DPPC cause death?

A
  • Intrapleural pressure higher (30mmHg)
  • Alveolus cannot stay open against larger wall tension
118
Q

delta V / delta P =

A

Compliance

119
Q

Compliance

A

The ability of a hollow organ to change its volume

120
Q

Figure showing compliance in the lungs

A
121
Q

Surfactant layer during inspiration

A
  • Thicker
  • Lower number of DPPC on air-liquid interface
  • Only molecules on the surface can display tension-reducing effect
122
Q

As the alveolus expands, DPPC…

A
  • Can act on a larger surface area
  • Surface tension gets smaller
123
Q

Smaller changes in pressure may result in…

A

High unit volume changes

124
Q
A

DPPC max

  • DPPC molecules used up
  • Further volume increase requires exponential pressure increase
125
Q
A

Amount of DPPC on the alveolar surface

126
Q

Changes in volume depend on…

A

DPPC availability in the alveoli

127
Q

Surfactant is produced by…

A

Type II alveolar cells

128
Q

Respiratory gas exchange is determined by…

A
  • Partial pressure
  • Diffusion conditions
  • Surface size
  • Metabolic activity (O2 consumption)
129
Q

Dalton’s law

A
  • Calculate partial pressure
  • P/Ptotal = V / VT
130
Q

Henry-Dalton’s law

A
  • Expresses how a gas is diluted in fluid
  • C = alpha x P
131
Q
  • STPD
  • BTPS
A
  • Standard temperature and pressure
    • 760mmHg
    • 0°C
    • Free of water vapour
  • Body temperature and pressure
    • 760mmHg
    • 37°C
    • Saturated with water vapour
132
Q

Partial pressure

A

Measure of how much gas is present

133
Q

Partial pressure of oxygen in the air

A

160 mmHg

134
Q

DCO2 =

A

20 x DO2

135
Q

What binds 70x less O2 than the blood?

A

Plasma

136
Q

Average O2 consumption of animals

A

300 mlO2/min/100kg

137
Q

O2 consumption rate during forced physical performance

A

6000 mlO2/min/100kg

138
Q

1 Hb binds … O2

A

4

139
Q

Speed of haemoglobin saturation

A

10 msec

140
Q

Factors affecting haemoglobin O2 affinity

A
  • Body temp
  • Partial pressure CO2
  • 2,3-DPG concentration
  • pH
  • CO
  • Myoglobin
141
Q

Oxygen saturation curve shape

A

Sigmoidal

142
Q

Why is O2 saturation curve sigmoidal?

A
  • The binding of the first O2 facilitates the next
  • By allosteric stimulation
143
Q

Normal arterial and venous blood saturation %

A

A: 95%

V: 75%

144
Q

A shift to the right of the O2 saturation curve can be caused by…

A
  • Increase pCO2
  • Increased pH
  • Increased Temperature
  • Increased 2,3-DPG
145
Q

What is shown in the figure?

A

Change of O2 affinity of hemoglobin by pCO2 change

146
Q

What is shown in the figure?

A

Change of O2 affinity of hemoglobin by pH change

147
Q

Bohr shift

A
  • Decreased CO2 → pH increase
  • Haemoglobin picks up more oxygen
148
Q

What is shown in the figure?

A

Change of O2 affinity of hemoglobin by temperature change

149
Q

What is shown in the figure?

A

Change of O2 affinity of hemoglobin by 2,3 DPG change

150
Q

Describe the effect of 2,3-DPG increase

A
  • By-product of 2,3-DPG displaces O2 from Hb
  • Saturation curve shifts to the right
  • More O2 is given to the tissues
151
Q

Embryonic haemoglobin is less capable of binding…

A

2,3 DPG

  • Affinity is higher than maternal blood
  • Embryo can easily get O2 from the mother’s blood
152
Q

CO binding is…

A

Irreversible

153
Q

Change of O2 affinity of hemoglobin by myoglobin change

A

Non-sigmoidal curve

  • Myoglobin takes O2 from Hb, storing it in the muscle
154
Q

The fate of CO2 when it enters the capillary

A
  • Converted to bicarbonate (with carbonic anhydrase)

or

  • CO2 present in the blood:
    • Physically dissolved
    • Protein-bound

All form an equilibrium

155
Q

H+ produced when CO2 enters the blood is bound by…

A

Deoxihemoglobin

156
Q

Water + CO2

A

H2O + CO2 → HCO3- + H+

157
Q

If haemoglobin is not deoxygenated by the tissues…

A

Removal of CO2 is damaged

158
Q

RBC membrane is impermeable to…

A

K+

159
Q

Describe the function of capnophorine transporter

A
  • Exchanges bicarbonate to chloride
  • Ensuring electroneutrality
160
Q

Significant increase in IC Cl- concentration caused by capnophorine leads to…

A

Hamburger shift

161
Q

Cl- transport into the RBC causes

A
  • Simultaneous intracellular H2O migration
  • Causes cell volume increase
162
Q

What provides the buffer-base effect of blood?

A
  • Deprotonated hemoglobin
  • Bicarbonate in the plasma
163
Q

Haemoglobin buffer (Tissue)

A

Deoxyhaemoglobin produced → H+ acceptor

164
Q

Haemoglobin buffer (Lung)

A
  • H+ released from deoxyhaemoglobin
  • Oxyhaemoglobin created at lung-level
165
Q

Carbamino haemoglobin (tissue)

A
  • From CO2 binding haemoglobin
  • H+ dissociates
166
Q

Carbamino haemaglobin (Lung)

A
  • CO2 released from carbamino haemoglobin
  • Deoxyhaemoglobin uptakes H +
167
Q

Title the figure

A

CO2 dissociation curve

  • Shows quantity of CO2 transported in the blood
  • As a function of pCO2
168
Q

The haldane effect

A
  • Increased pO<span>2</span> → Decreased chemically bound CO2
  • High oxygen tension stimulates CO2 release
169
Q

CO2 concentration in arterial blood

A

22.1 mmol/l

170
Q

CO2 concentration in venous blood

A

24.4 mmol/l

171
Q

What is detected during breathing regulation?

A

Gas tensions of blood

172
Q

Effect of severing: Above the pons

A
  • [1]
  • No effect
173
Q

Effect of severing: Middle of the pons

A
  • [2]
  • Deep inspirations
  • Inspiration-inhibiting centre cut
174
Q

Effect of severing: Border of pons and medulla oblongata

A
  • [3]
  • Deeper + Shallow breathing
  • Apneustic centre
    • Responsible for normal rhythm
175
Q

Effect of severing: Medulla above the exit point of n. phrenicus

A
  • [4]
  • Respiratory cycle stops
  • Autonomous respiratory group cut
    • DRG (Dorsal respiratory group)
    • VRG (Ventral respiratory group)
176
Q

Effect of severing: below the exit point of n. phrenicus

A
  • [5]
  • No change is respiration
  • Respiration regulating groups located above this point
177
Q

Effect of cutting n. vagus

A

Deep inspiration, sudden expiration

178
Q

Hering-breuer reflex

A
  • Inspiration inhibiting reflex
  • Stretch receptors detect stretching
  • DRG centres recieve afferentation via n. vagus
  • Stimulates VRG
179
Q

Which afferent nervous factors other than Hering-Breur influence respiration?

A
  • Emotional changes
  • Hyperventialtion
  • Pain
  • Sleeping
  • Baroreceptor-related circulatory/ respiratory reactions
180
Q

Efferent nervous respiratory signals run to the…

A

Respiratory muscles

181
Q

Efferent stimulation of inspiration

A
  • Stimulation of respiratory muscles
  • Expiratory muscles inhibited
  • N. phrenicus stimulated
182
Q

Efferent stimulation of expiration

A
  • Normally passive
  • Inspiratory muscles inhibited
  • Expiratory muscles stimulated
183
Q

Which is more important:

  • Peripheral reception
  • Cenral reception
A

Central reception

184
Q

Location of the highest sensitivity to

  • pCO2 of blood and CSF
  • pH
A
  • The bottom of the IVth ventricle
  • Influences the DRG (inspiratory)
185
Q

How does CO2 stimulate DRG activity?

A
  • CO2 → CSF
  • pH drop → DRG activity stimulated
186
Q

Receptors of peripheral reception are located…

A
  • Glomus caroticum (Carotid body)
  • Glomus aorticum (Aortic body)
187
Q

Glomus caroticum

A
  • Cluster of chemoreceptors
  • Found at bifurcation of the carotid artery
188
Q

Glomus aorticum

A
  • Chemoreceptors and baroreceptors
  • Located along the aortic arch
189
Q

Peripheral reception is sensitive to…

A

pO2

190
Q

Secondary protective mechanism

A
  • By peripheral reception
  • pO2 reception
  • Generates hyperventilation
191
Q

Breathing type

A

Normal

192
Q

Breathing type

A

Biot

  • Long apnea
193
Q

Breathing type

A

Cheyne-Stokes

  • Characteristic periodicity
194
Q

Breathing type

A

Kussmaul

  • Found in uremia and diabetic coma
195
Q

Normal breathing

A
  • Steady inspiration + Expiration
  • Uniform depth
196
Q

Dyspnea

A

Random breathing

197
Q

List the defensive respiratory reflexes

A
  • Sneezing
  • Coughing
  • Nociceptive apnea
  • Diving reflex
  • Combined swallowing reflex
198
Q

Sneezing

A
  • Mechanical/chemical irritation of upper respiratory tract
  • Speed: 300 m/s
199
Q

Coughing

A
  • Tracheo-bronchial irritation
  • Mechanism similar to sneezing
200
Q

Nociceptive apnea

A
  • Prevents inhilation of gases or fumes
  • Sudden apnea
  • Same may happen for pain or cooling sensation
201
Q

Diving reflex

A
  • Water in contact with the head
  • Breathing motions inhibited
  • Protection from inspiration of water
202
Q

Combined swallowing reflex

A
  • Foot touches pharyngeal wall
  • Apnea → prevents choking
203
Q

Birds ventilate their lungs by expanding…

A

Their air sacs

204
Q

The cranial group of air sacs contain…

A

Used air

205
Q

The caudal group of air sacs contain…

A

Fresh air

206
Q

Mechanism of air sacs

A
  • Inhalation 1: Caudal air sacs fill
  • Exhalation 1: Caudal air sacs empty, lungs fill
  • Inhalation 2: Cranial air sacs fill
  • Exhalation: Cranial air sacs empty
207
Q

Benefit of the avian breathing cycle

A
  • Continuous gas exchange
  • Continuous respiration
  • Allows higher energy level than mammals
208
Q

The finest branches of the avian bronchial system

A

Parabronchi

  • Allows air to flow through unlike mammalian alveoli
209
Q

Countercurrent flow in the lung

A
  • Allows gas exchange
  • Air and the blood flow to eachother
210
Q

The lower gas-exchange capacity of bovines is a predisposing factor for…

A

Broncho-alveolar hypoxia

211
Q

Broncho-alveolar hypoxia reduces…

A

Pulmonary clearance rate

212
Q

Relatively higher air-exchange activity increases the risk of…

A

Pulmonary infectinon