Physiology Flashcards
1
Q
What is external respiration?
A
Exchange of oxygen and carbon dioxide between body cells and the external environment
2
Q
What is internal respiration?
A
The intracellular mechanisms that consume oxygen and produce carbon dioxide.
3
Q
Which 4 body systems are involved in external respiration?
A
- Respiratory system 2. Cardiovascular system 3. Haematology system 4. Nervous system
4
Q
In terms of respiration what does the term “ventilation” refer to?
A
The mechanical process of moving air between the alveoli and the atmosphere
5
Q
What is Boyle’s Law?
A
At any constant temperature the pressure exerted by a gas varies inversely with the volume of the gas ( gas will move from area of high pressure to area of low pressure at constant temperature )
6
Q
Using Boyle’s Law, describe why the lungs must expand to allow air to enter them during inhalation.
A
As the volume of the lungs (and thoracic cavity) increase, the pressure decreases. This means atmospheric pressure is high than intrathoracic pressure. Gas (air) flows down the pressure gradient into the lungs
7
Q
Which two forces hold the thoracic walls and the lungs in close contact?
A
- The intrapleural fluid cohesiveness (fluid tension)
- The negative intrapleural pressure
8
Q
A transmural pressure gradient exists between lung walls. What is this?
A
A difference in pressure between any separtation
The transmural pressure gradient refers to the difference in pressure between the inside of the airways and the outside of the lung tissue (pleural space).
9
Q
What causes the increase in thoracic volume during inspiration? (2)
A
- Contraction of the diaphragm 2. External intercostal muscle contraction
10
Q
During expiration, which two factors contribute to the recoil of the lungs?
A
- Elastic properties of the involved muscles 2. Alveolar surface tension
11
Q
What sort of situation would result in a lung collapse?
A
Any situation involving pleural pressure equalising with or exceeding atmospheric pressure e.g. a puncturing wound
12
Q
What is alveolar surface tension?
A
The attraction between water molecules at the liquid air interface of the alveoli - water molecules pull towards each other
13
Q
What does alveolar surface tension allow for?
A
A resistance to lung stretching - the water molecules are attracted together so oppose stretching forces
14
Q
What does the law of LaPlace state?
A
Smaller alveoli have a higher tendency to collapse due to the increased proximity of the water molecules
15
Q
What is pulmonary surfactant and where is it produced?
A
Pulmonary surfactant is a complex mixture of lipids and proteins. It is produced by type II alveoli
16
Q
What is the effect of pulmonary surfactant?
A
It reduces surface tension by “diluting” the effect the water molecules have by interspersing them ( one head attaches to water molecule the other pulls upward )
17
Q
Why do some infants suffer from respiratory distress syndrome?
A
Foetal lungs cannot synthesise surfactant meaning premature babies do not have enough surfactant in their lungs. Breathing will them become strenuous as the babies must overcome the high surface tension (of the water droplets) to inflate the lungs
18
Q
Describe alveolar interdependence
A
Alveolar interdependence describes the fact that adjacent alveoli protect each other from collapse. If one alveoli begins to collapse, others around it will compensate and stretch. As volume increases in the surrounding alveoli, pressure decreases meaning air flows to the collapsed alveoli to reinflate it. This is due to the pressure gradient.
19
Q
What are the three types of muscles involved in respiration?
A
- Accessory muscles (scalenus, sternocleidomastoid) 2. Major muscles (diaphragm, external intercostal muscles) 3. Muscles of active expiration (abdominal muscles, internal intercostal muscles)
20
Q
What is the tidal volume?
A
The volume of air entering or leaving the lungs in a normal breath (around 500ml)
21
Q
What is the inspiratory reserve volume?
A
This is the extra volume of air that can be breathed in over and above the tidal volume (around 3000ml)
22
Q
What is the inspiratory capacity?
A
The maximum volume of air that can be breathed in (inspiratory reserve volume + tidal volume)
23
Q
What is the expiratory reserve volume?
A
This is the extra volume of air that can be breathed out over and above the tidal volume (around 1000ml)
24
Q
What is the residual volume?
A
This is the minimum volume of air remaining in the lungs even after a maximal expiration - it is always present
25
What is functional residual capacity and how is it calculated?
Resting lung volume (Expiratory reserve volume + residual volume)
26
What is vital capacity and how is it calculated?
The maximum volume of air that can be expired in a single breath following maximum inspiration (inspiratory reserve volume + tidal volume + expiratory reserve volume)
27
What is total lung capacity and how is it calculated?
This is the total volume of air the lungs can hold (vital capacity + residual volume) Around 5.7 litres
28
Why is total lung capacity hard to measure in real life?
Residual volume must be known and this cannot be measured
29
What could lead residual volume to increase?
Reduction in elastic recoil of the lungs - as in emphysema
30
Which two measurements can be plotted on volume/time curve, and what are they?
Forced Vital Capacity (FVC) ; The volume a person can forcefully inspire and expire
o It is the highest point in the curve
Forced Expiratory Volume - FEV (1 sec)
o The volume of air that can be forcefully expired in the
first second
31
For normal healthy patients, FEV1/FVC x 100 should equal what?
80%
32
What does a low FEV1/FVC ratio indicate?
Obstructive lung disease
33
What type of results do individuals with restrictive lung disease give for a FEV1/FVC ratio test?
Normal, if not slightly elevated. They can instead be diagnosed by an initially low FVC
34
What is the primary determinant of airway resistance?
The radius of the conducting airway
35
How does the autonomic nervous system affect the resistance to airflow?
Sympathetic - decreases resistance (bronchodilation) Parasympathetic - increases resistance (bronchoconstriction)
36
Why are sufferers from obstructive lung conditions likely to suffer from collapsing airways?
he collapse of the airway in obstructive lung conditions can be caused by multiple factors, including the narrowing of the bronchi due to the loss of recoil, the loss of elastic recoil in the alveoli seen in emphysema, and the buildup of mucus in the airways, which can all contribute to increased resistance to airflow and decreased ventilation. As a result, this can cause a decrease in air pressure within the airways during exhalation, leading to the collapse of the airway walls and obstruction of airflow
37
How is peak flow rate measured?
Using a peak flow meter
38
Describe how to use a peak flow meter
A short sharp block is given into the meter The score on the scale at the side is taken 3 attempts are given to allow for poor initial technique The best value is recorded This test can highlight obstructive lung disease
39
What is pulmonary compliance?
This is a measure of the effort required to stretch or distend the lungs
40
What are the two methods to measure pulmonary compliance clinically?
1. Static - the change in volume for any given pressure is measured (measures elastic resistance only)
2. Dynamic - change in volume for any given pressure during the movement of air (measure both elastic resistance and airway resistance)
41
The less compliant the lungs are the _____ work must be done to inflate them
More
42
List 3 factors that decrease pulmonary compliance
This refers to the ability of the lungs to stretch and expand in response to changes in pressure. During increased work of breathing
Pulmonary fibrosis
Pulmonary oedema
Lung collapse due to Pneumonia or Absence of surfactant
43
How may a patient present clinically if they have less complaint lungs
low long compliance may indicate fibrosis however patients can still experience *Breathless and Low exercise tolerance*
becauses Lung fibrosis can make it more difficult for the lungs to expand and *contract* during breathing.
44
When would pulmonary compliance increase?
When elastic recoil is lost
45
Describe a condition in which pulmonary compliance is increased
Emphysema Hyperinflation (air trapping in the lungs) occurs causing increased difficulty during exhalation
Age also increases compliance
46
List 3 factors which will increased the required work done by the lungs
* Decreased pulmonary compliance
* Increased pulmonary compliance
* Increased airway resistance (potentially when bronchoconstricted)
* Decreased elastic recoil
* Increased elastic recoil
* Need for increased ventilation (low O2)
47
What is airway physiological "dead space"?
This is the area within the airway (anatomical) and alveoli that is unsuitable for diffusion to occur
48
How is alveolar ventilation calculated?
Dead space volume must be subtracted from the tidal volume
49
What is the difference between pulmonary and alveolar ventilation?
Pulmonary - volume of air breathed in and out per minute (includes dead space) Alveolar - volume of air exchanged between atmosphere and alveoli (excludes dead space)
50
How can pulmonary ventilation be increased?
Increasing depth and rate of breathing
51
Why is pulmonary ventilation increase advantageous?
Amount of inhaled air increases but dead space does not - this causes relative increases in alveolar ventilation
52
What is ventilation?
Rate at which gas passes through the lungs
53
What is perfusion?
Rate at which blood passes through the lungs
54
What is the ventilation perfusion match?
This ensures ventilation of gas can match the blood flow for optimised gas transfer - local controls can ensure this can happen
55
What will happen when perfusion is greater than ventilation?
CO2 build up in alveoli Airway resistance is reduced in these situations as well as contraction of arteriolar smooth muscle to reduce blood flow to match the airflow
56
What will happen when the ventilation is greater than perfusion?
Increased alveolar oxygen concentration Pulmonary vasodilation will occur to incease blood flow to match the ventilation Constriction of airways also increases resistance to reduce ventilation
57
Which four factors can influence alveolar gas exchange?
1. Partial pressure gradient (of O2 and CO2) 2. Diffusion coefficient (of O2 and CO2) 3. Surface area of alveolar membrane 4. Thickness of alveolar membrane
58
What is Dalton's law of partial pressure?
The total pressure of a gaseous mixture of a sum of all the partial pressure of individual gases
59
What is the partial pressure of a gas?
The pressure one gas would exert if it were the only gas making up the full volume
60
How is partial pressure of oxygen calculated?
PaO2 = PiO2 - [PaCO2/0.8] 0.8 = respiratory exchange ratio (ratio of CO2 produced/O2 consumed)
61
How is mmHg easily converted to KPa?
Divide by 7.5
62
Why is partial pressure for carbon dioxide much lower than oxygen?
CO2 is much more soluble than O2
63
What is the diffusion coefficient?
This is the solubility of a gas in a membrane
64
Why is there always a small pressure gradient between oxygen in the alveoli and the arteries?
Ventilation and perfusion matching is always slightly out of sync
65
What could be the cause of a large oxygen partial pressure difference in alveoli and arteries? (2)
1. Significant gas exchange problems in the lungs 2. Left to right heart shunt
66
What is Fick's law?
The amount of gas that moves across a sheet of tissue in unit time is proportional to the area of the sheet but inversely proportional to its thickness
67
What does Henry's law state?
The amount of given gas dissolved in a given type and volume of liquid at a constant temperature is proportional to the partial pressure of the gas in equilibrium with the liquid
68
In which two forms is oxygen found in the blood?
1. Bound to haemoglobin 2. Physically dissolved
69
What is the primary factor determining the percentage saturation of haemoglobin with oxygen?
Partial pressure of oxygen
70
Which factors can impair oxygen delivery to tissues?
1. Decreased PiO2 2. Respiratory disease 3. Anaemia 4. Heart failure
71
What term is used to describe the increased affinity Hb has for O2 with each subsequent oxygen molecule bound?
Cooperativity (sigmoid curve is shown)
72
Why is the sigmoidal curve of oxygen cooperativity significant? (2)
1. Moderate alveolar PO2 fall does not greatly impact O2 loading 2. Small drop in capillary PO2 means oxygen affinity is hugely decreased greatly reducing oxygen load
73
What is the Bohr effect?
O2 dissociation curve shifts to the right Factors reduce oxygen affinity and aid offload
74
Give examples of factors that will reduce oxygen affinity of haemoglobin
1. Increase PCO2 2. Increase H+ 3. Increase temperature 4. Increase 2,3-biphosphoglycerate (allosteric haemoglobin inhibitor)
75
Why does foetal haemoglobin have increased affinity for oxygen?
Interacts less with 2,3-biphosphoglycerate O2 dissociation curve is shifted to left Allowing for O2 transfer from mother even in low PaO2
76
What is myoglobin?
Present in voluntary muscle and provides storage of oxygen Oxygen is released at low partial pressures Presence indicates muscle damage
77
What are the three ways carbon dioxide is transported in the blood?
1. Solution (10%) 2. Bicarbonate (60%) 3. Carbamino compounds (30%)
78
How is bicarbonate formed in the blood?
CO2 + H2O ⇌ H2CO3 ⇌ H+ + HCO-3
79
In relation to the two reactions which produce bicarbonate, which catalyst acts on the first reaction?
Carbonic anhydrase
80
In the two equilibria used to form bicarbonate, why is it that they always run in the forward direction? (2)
1. Haemoglobin buffers hydrogen ions and produces HbH 2. Chloride shift allows Cl- to enter the red blood cells as bicarbonate leaves into the plasma
81
How are carbamino compounds formed?
When CO2 combines with the terminal amine groups in blood proteins
82
How is HbCO2 formed? does it require enzymes
Haemoglobin is provided by the breakdown of oxyhaemoglobin into O2 and Hb.
Hb combines with CO2 forming HbCO2.
This process is rapid and does not require an enzyme
83
What is the Bohr effect? (2)
The Bohr effect states that the affinity of haemoglobin for oxygen decreases inversely with increasing acidity and carbon dioxide concentration. The oxygen-haemoglobin curve shifts to the right
84
For the oxygen-dissociation curve what are the axis labels?
85
Which factors would cause a right shift in the oxygen-haemoglobin curve?
86
Which factors would cause a left shift in the oxygen-haemoglobin curve?
87
Describe the Haldane effect
Removing O2 from Hb increases the ability of Hb to pick-up CO2 and CO2 generated H+
(and vice versa)
88
How does the presence of oxygen (at the lungs) affect the oxygen-haemoglobin curve?
It will shift it to the left causing increased CO2 (and H+) offload from haemoglobin
(Haldane effect)
89
How is oxygen released at a tissue cell?
Due to the Bohr effect
Increased CO2 and H+ reduces haemoglobin's affinity for oxygen causing it to ofload
90
During gas exchnage at tissues, why is choliride shift important?
It ensures the equilibria for bicarbonate remain producing products in the forward direction.
By removind the end product (HCO3) and replace it for chloride ions, the reaction will continue to run in the forward direction
91
During gas exchnage at tissues, which haemoglin associated compound is broken down, and which two are synthesised?
Oxyhaemoglobin (HbO2) - broken down
HbH - synthesised
HbCO2 - synthesised
92
During gas exchange at the alveolus, which haemoglobin associated compounds are broken down and which one is resyntheised?
HbH - broken down - H+ released (used for HCO3- equilibria)
HbCO2 - CO2 released (diffuses into alveoli)
HbO2 - resynthesised (O2 diffuses from alveoli)
93
Carbon dioxide diffuses into the alveolus from whcih three sources?
1. Plasma
2. HbCO2 breakdown
3. HCO3- equilibrium
(HCO3- + H+ (from HbH breakdown) → H2CO3 → H2O + CO2)
94
What controls the rhythm of respiration?
Medulla oblongata
95
What is the pre-Botzinger complex?
A complex of neurones responsible for the rhythm of breathing in the medulla
96
How does the pre-Botzinger complex function?
1. Pre-Botzinger complex excites dorsal respiratory group neurones (inspiratory)
2. Firing leads to contraction of inspiratory muscles → inspiration
3. When firing stops → passive expiration
97
Active expiration involves increased firing rate of which neurones?
Usually dorsal which activate respiratory neurones subsqequently activating intercoastal, abdominal and other neurones.
98
What is the role of the pons?
The pins is an area of the medulla that modifies the produced rhythm of breathing
99
When dorsal respiratory neurones fire which area within the pons is inhabited ?
When dorsal respiratory neurons fire, the pneumotaxic center is inhibited, allowing for a prolonged inspiratory phase and deeper breathing.
100
What is the function of the pneumotaxic centre in the pons?
It will cause termination of inspiration
Without it apneustic breathing wil occur - a prolonged inspiration with insufficient short expiration
101
What is a function of the apneustic centre? (situation)
Influences breathing rhythm, by prolonging inspiration
102
What is the Hering-Breuer reflex?
A reflex which prevents over stretching of the lungs, due to the activation of stretch receptors.
Inspiration will be inhibited by activation of these receptors
103
What are joint receptors?
J receptors pick up impulses from moving muscles and adjust breathing according to intensity of movement
104
What is the function of the cough reflex?
To clear dust, dirt, excess mucous etc out of the respiratory tract
105
What does a cough relfex stimulate? (5)
1. Short intake of breath
2. Closure of larynx
3. Contraction of abdominal muscles
4. Opening of larynx
5. Expulsion of air
106
What can chemoreceptors do in relation to the respiratory system?
Sense and control values of blood gas tensions
107
Where are chemoreceptors found in relation to the respiratory system? (2)
1. The CNS (central) - at surface of medulla
2. The rest of the body (peripheral)
108
What can peripheral chemoreceptors do?
Sense O2 and CO2 tensions as well as H+ concentration
109
What can central chemoreceptors detect?
Concentrations of H+ in cerebrospinal fluid
110
Of the three substances listed below, which are able to permeate the blood brain barrier?
1. CO2
2. H+
3. HCO3-
Only CO2 is permeable
111
How are H+ and HCO3- produced in cerebrospinal fluid if they cannot pass the blood brain barrier?
CO2 dissociates across the BBB forming carbonic cid which can dissociate to form both H+ and HCO3-
(CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3-)
112
What effect on ventilation do central chemoreceptors have?
By sensing high H+ concentrations in cerebrospinal fluid, they can increase ventilation
113
What is hypercapnia?
When there is excess CO2 in the blood
114
What is hypoxia?
When abnormally low amounts of O2 is present in tissues
115
What is the effect of decreasing partial pressure of oxygen on ventilation?
It will increase rapidly up until a point where neural action becomes depressed (due to low oxygen) and ventilation then rapidly decreases
116
What happens at high altitudes?
Partial pressure of oxygen is very low
Hyperventilation and increased cardiac output will occur to attempt prevention of hypoxia.
117
What is the H+ drive of respiration?
Increased H+(mediated by peripheral chemoreceptors) in the blood (along with increased PaCO2) causes increased ventilation
As CO2 produces H+ and is eliminated, H+ load is decreased.
118
The transthoracic pressure is equal to ninja nerd
Pip - Patm
119
What does affect the negativity of intrapleural pressure? ninja
Elasticity of the lungs
Surface tension
Elasticity of the chest wall
(Gravity)
120
The Surface tension increases thoracic cavity volume True / False ninja nerd
Tends to collapse the alveoli → tends to collapse the lungs → ↑Thoracic cavity volume
121
some of the features of pleural fluid ninja nerd
a. located within the pleural cavity
b. it prevents inflammation
c. it allows the parietal and the visceral pleura to be tightly adherent to one another
122
At rest the transpulmonary pressure is equal to ninja nerd
+4
this mean that visceral pleura is trying to expand (inflate) outward at rest
123
At rest the pulmonary pressure is equal to ninja nerd
The atmospheric pressure
124
some of the features of the e diaphragm ninja nerd
a. It is an inspiratory muscle
b. It’s innervated by the **phrenic nerve**
c. It depresses when it contracts
125
what happen when the external intercostals contract ninja nerd
pull up the ribs
push the sternum outwards and upwards
the aim is to increase the thoracic cavity increasing the pressure
126
During the inspiration process the Pip is -4 mmHg TRUE /FlASE ninja nerd
False this because Intrapleural pressure (Pip) need to get lower to increase the thoracic space thus plureal cavity get longer for more air to come in .
126
During the inspiration process the Pip is -4 mmHg TRUE /FlASE ninja nerd
False this because Intrapleural pressure (Pip) need to get lower to increase the thoracic space thus plureal cavity get longer for more air to come in .
127
During the inspiration process the TP is ninja nerd
+5mmHg
128
what happen during inspiration? ninja nerd
1. ↑Thoracic cavity volume
2. ↑Transpulmonary pressure (TP)
3. ↓Intrapulmonary pressure (Ppul)
4. ↓Intrapleural pressure (Pip)
129
During forced inspiration the intrapleural pressure is equal to ninja nerd
-4mmH
130
During forced expiration the pulmonary pressure is equal to ninja nerd
+1mmHg
131
During quiet expiration the transrespiratory pressure is equal to ninja nerd
2mmHg
132
Which muscles involved in forced expiration? ninja nerd
**_abdominal_**
walls Transverse abdominus
Rectus abdominus
Internal oblique
External oblique
**_Internal intercostals_**
133
Stretch receptors send inhibitory signals to the VRG in the medulla. true / false ninja nerd
true
134
Internal intercostals increase thoracic cavity volume.
a. True
b. False ninja nerd
b. False
135
Quiet expiration depends upon the elasticity of the
lungs.
a. True
b. False ninja
True
136
Stimulations of the parasympathetic postganglionic fibers inverting bronchial and bronchiolar smooth muscle true false ninja nerd
True
137
Some of the features of alveolar pressure ninja nerd
Alveolar pressure is greater than atmospheric pressure during force expiration Alveolar pressure is equal to the supination of intrapleural pressure plus electric recoil pressure Alveolar pressure I’d equal atmospheric pressure at the end of normal tidal expiration
138
some of small airways features ? ninja nerd
a. The total resistance to airflow increases with
successive generations of airways because there are increasing numbers of units arranged in parallel.
b. The linear velocity of airflow decreases as the airways
increases in size because their total cross-sectional
area increases.
c. Alveolar elastic recoil plays an important role in
determining the resistance to airflow in small airways
because alveolar septal traction helps to increase
dynamic compression.
139
describe the mechanism of
flow affection? ninja NERD
Pressure is directly proportional to gas flow with
consideration the resistance remains constant
140
Which part of the airways has greatest airway
resistance? ninja nerd
a. Larger airways
141
WHAT ARE following factors can greatly
influence airway resistance? NINJA NERD
a. Radius
b. Length
c. The lung volume
142
The bronchioles smooth muscle is responsible for
contraction and relaxation of bronchi True / False ninja nerd
true
143
Surface tension is caused by ninja nerd
Cohesive intermolecular interaction between water molecules
144
Which structures that produces surfactant? ninja nerd
Type II alveolar epithelial cells
145
What happens if we increase the radius of the alveoli
according to LaPlace’s law of sphere? ninja nerd
Decreased collapsing pressure of the alveoli
146
What cause decrease in
alveoli radius? ninja nerd
Occlusion of the airway due to mucus
147
Pores of Kohn ninja nerd
the structure that connects two alveoli for gas
flow?
148
Which structure of the surfactant that binds to water
molecules? ninja nerd
Phosphatidylcholine group
149
What is the function of SP-A and SP-D in surfactant? ninja nerd
Opsonization
150
8) How does type II alveolar cells store surfactant? ninja nerd
Packs them inside of lamellar bodies
151
What’s the correlation between surfactant distribution
and radius of alveoli?
ninja nerd
a. ↓ radius → surfactant distribution is denser
152
A prematurely born baby (29th week of gestation) with
unremarkable medical and family history was reported to
have difficulty of breathing that causes cyanosis. The baby
is immediately put into ventilator and treated in ICU. No
signs of bacteremia from blood culture result.
Abnormalities found in CXR including diffuse opacities of
the lung. No cardiomegaly was found. What is the probable
cause and diagnosis for this case? ninja nerd
Cause: Not enough surfactant production in baby due to
prematurely born
Diagnosis: Infant respiratory distress syndrome
153
Some of states decrease lung
compliance? ninja nerd 4
a. Lung fibrosis
b. Increased pulmonary venous pressure
c. Long period of time where the lung is
unventilated
d. Alveolar oedema
154
When producing a pressure-volume loop for the measurement of static lung compliance ninja nerd
measurements of volume and intrapleural
pressure are taken as the subject holds his
breath because then alveolar pressure is zero
155
Surfactant Function ninja nerd
more effective at lowering the surface tension as the alveoli and airways get smaller in expiration
156
ow static lung compliance ninja nerd
a. Can often be deduced from measurements of lung volumes and from forced expiratory spirograms, without a formal measurement of lung compliance
157
Some of the features regarding
Pulmonary Resistance? N.N
a. Increase in pulmonary arterial pressure generally
cause a fall in pulmonary resistance
b. Pulmonary resistance is only 1/10 of systemic
circulation resistance
c. Increase of lung volume results in decrease of
resistance in extra alveolar vessels
d. Acetylcholine has a good bronchiole smooth
muscle relaxation effect
e. Resistance in pulmonary capillaries increases at
large lung volumes
158
conditions are reasonable
explanations for a patient's decreased static
pulmonary compliance (the pressure-volume
curve for the lungs shifted to the right)? N.N
a. Decreased functional pulmonary surfactant
b. Fibrosis of the lungs
c. Surgical removal of one lobe
d. Pulmonary vascular congestion
159
Regarding compliance N.N
compliance
a. functional residual capacity is the equilibrium
volume when elastic recoil of lung is balanced by
normal tendency for chest wall to spring out
b. hysteresis is due to frictional resistance to air
movement
c. compliance is greater in expiration than in
inspiration
d. compliance is increased in emphysema
e. Compliance It is a measure of stretchability/distensibility
o. Depends on the change in volume over the change in pressure
160
emphysema It's increases lung compliance
chest wall recoil its naturally prefers inward recoils
True /False N.N
True
161
Regarding the elastic properties of the lung: N.N
surface tension is the force acting across an imaginary line in the surface of the liquid
**During deflation, lung volume at any given pressure is slightly greater than it is during inflation**
Volume-pressure (VP) curves, referred to as ***lung compliance***
162
What is pulmonary function capacity? N.N
INSPIRATORY CAPACITY (IC)
EXPIRATORY CAPACITY (EC)
FUNCTIONAL RESIDUAL CAPACITY (FRC
VITAL CAPACITY (VC
TOTAL LUNG CAPACITY (TLC)
163
What does it mean by tidal volume? N.N
Total volume of air inspired and inspired during normal quiet breathing
164
A patient suffers from an acute asthma attack. The patient has no history of COPD. What changes of the respiratory parameters is associate with his asthma attack? N.N
FEV1 is decreased???
165
Force of respiratory muscles is dependent on lung volume. At which lung volume have the expiratory muscles their greatest force? N.N
RV
166
The airway resistance of a healthy person has to be determined. Close to which lung volume do you expect to measure his highest resistance to expiratory airflow? N.N
. 60 % of VC
167
You refer your patient with pulmonary fibrosis to the pulmonary function lab. Which of the following values can be measured using direct spirometry N.N
Total lung capacity
168
By a routine examination of respiratory functions, a spirometer is used to measure lung volumes. Which lung volume or lung capacity cannot be determined by this method? N.N
. Total lung capacity (TLC)
169
obstructive pulmonary disorder include ? N.N
Emphysema o Chronic bronchitis o Asthma
170
In TB, the FVC (L) is decreased true false ?N.N
True
& The PFT is \>80%
171
Force vital capacity is ? N.N
Volume of air a person can forcefully expire and inspire
172
**In pulmonary fibrosis ? N.N**
Increased in lung elasticity leads to decreased in compliance
173
Emphysema is
Obstructive disorder with increased compliance
174
. Increase in lung elasticity equals to increase in lung compliance True False N.N
Flase
175
A patient has PFT \< 80%, what can you suspect from
him? N.N
His lung elasticity is high
176
A patient comes to you with a history of chronic
bronchitis, what can you expect to see from his PFT? N.N
PFT \< 80%
177
what are the components of the alveolar ventilation rate? N.N
Tidal volume
Dead space
Dead space
178
what is the direct component that can affect perfusion? N.N
Cardiac output
𝐶O= 𝐻R 𝑥𝑥 𝑆V
179
How does oxygen can indirectly cause vasodilation of blood vessel in pulmonary circulation ? N.N
Oxygen induces endothelial cell to produce nitric oxide
180
What mechanism that occurs when we have increased ventilation during exercise to maintain V/Q ratio? N.N
a) Vasodilation
181
What happens when there’s low oxygen level in blood in systemic circulation and pulmonary circulation? N.N
Systemic circulation: vasodilation; pulmonary circulation:
vasoconstriction
182
6) What does carbon dioxide do when the concentration
is high enough to bronchiole smooth muscles?
b) It causes bronchiole smooth muscles to relax
183
t and mentioned changes below that is true when bronchiole dilates N.N
Increase flow
184
Why does the top of the lung have the lowest perfusion? N.N
Because of the gravity pulls down the blood thus it will have high ventilation
185
Regarding the respiratory membrane made of ? N.N
There are two types of alveolar cells lining the alveoli
186
The normal thickness of respiratory membrane is ? N.N
Around 0.5 -1 micrometers
187
3) Thick respiratory membrane may cause ? N.N
Alteration of gas exchange process be more specific
188
3) Thick respiratory membrane may cause ? N.N
Alteration of gas exchange process be more specific
189
4) Regarding dyspnea, caused by left sided heart failure true/ False ? N.N
True
190
5) In pneumonia the respiratory membrane becomes thinner true / false N.N
False
191
The surface area Is inversely proportional to the gas exchange true false N.N
False
192
Elastase function is N.N
Breaks down elastic fibers caused mostly in smokers due to Deficiency of alpha 1 antitrypsin may cause
193
d. Increase in degradation of anti 1 antitrypsin protease caused by smoking true /False N.N
False
194
Regarding the partial pressure of gases in the alveoli, ? N.N
a) The pO2 in the alveoli is 40 mmHg
195
2) In external respiration what happen to oxygen ? N.N
Oxygen moves from high concentration to low
concentration
196
Regarding partial pressure of oxygen? N.N
It is 104 mmHg in alveoli
197
features of the hemoglobin? N.N
a) It contains 2 alpha chains
b) There are 4 oxygen binding sites
d) The iron is in the ferrous state
198
5) In the deoxygenated blood T state N.N
The hemoglobin has low affinity for oxygen
199
6) Regarding the carbon dioxide distribution, ? N.N
70% of the carbon dioxide is in the form of bicarbonate
b)2% of the carbon dioxide is dissolved in the blood
plasma
c) The carbon dioxide bound to amino acids of the globin chain is known as carbamino hemoglobin
200
7) In the oxygenated blood haemoglobin in which state N.N
d) The hemoglobin has a high affinity for oxygen
201
Regarding Haldane effect
c. The hemoglobin which has low affinity for oxygen becomes
high
202
9) Regarding nitrogen N.N
It is one of the most abundant atoms in the alveoli
203
10) In deoxy hemoglobin N.N
a) The carbon dioxide is bound to amino acids of the
globin chains
b) The protons are bound to negatively charged amino
acids
c) The 2,3-biphosphoglycerate is bound to positively
charged pocket
204
) Binding of carbon dioxide to the hemoglobin helps in the release of oxygen into the tissues True /False N.N
True
205
Pulmonary ventilation is part of the circulatory
system? True /False N.N
False
pulmonary ventilation happen in the alveolar not between the alevolar and pulmonary veins
b) External respiration
c) Transport
d) Internal respiration
206
The most important factor that determines how much
oxygen combines with hemoglobin is N.N
Oxygen
207
Hemoglobin has a tendency to release oxygen where N.N
pH is more acidic
208
Most of the carbon dioxide transported by the blood is N.N
converted to bicarbonate ions and transported in plasma /
209
6) Approximately 20% of carbon dioxide is transported in the blood as N.N
b. carbaminohemoglobin
210
In the alveoli, the partial pressure of oxygen is N,N
d. about 104 mm Hg
211
8) In the internal respiration
Oxygen moves from the blood into the tissues
212
9) Regarding the Bohr effect N.N
The hemoglobin affinity to oxygen decreases
213
10) Breaking of the iron and oxygen bond is caused by N.N
Binding of carbon dioxide to the hemoglobin
214
) Which is an early signs of hypoxia? N.N
RATT
Restlessness and certain agitation Anxiety Tachycardia o Heart rate greater than 100 beats per minute Tachypnea o Accelerated respiration o Not to be mistaken with: Hyperventilation • Excessive increase in pulmonary ventilation that exceeds the metabolic demands of the body and can change the blood chemistry (respiratory alkalosis) Hyperpnea • Increase in the depth of the respirations (usually after exercise or painful stimuli) that does not change the blood chemistry
215
(B) LATE SIGNS of hypoxia N.N
BEDC
Bradycardia
o Heart rate less than 60 beats per minute Extreme restlessness Dyspnea o Gasping to bring the air in Cyanosis o A bluish cast of the skin
216
types of hypoxia ?N.N
1. Hypoxemic hypoxia
2. Ischemic (stagnant) hypoxia
3. Anemic hypoxia
4. Hystotoxic hypoxia
217
cytotoxic hypoxia is type of hypoxia but not stagnant hypoxia True /False
False Stagnant hypoxia is type of hypoxia but not cytotoxic hypoxia
218
5) What is the term for lymph in the pleural cavity? N.N
Chylothorax
a) Pneumothorax
b) Hemothorax
d) Pyothorax
219
Which drugs is used to treat ischemic hypoxia? N.N
a) Tissue plasminogen activator
b) Warfarin
c) Aspirin
220
Which conditions do result in abnormal hemoglobin?
a) Folic acid deficiency
c) Thalassemia
d) Sickle cell anemia
221
8) How many oxygen molecules can one RBC bind? N.N
d) 1 billion
222
Which organelle is affected by histotoxic hypoxia? N.N
b) Mitochondria
223
Which hypoxia is NOT treated with supplemental oxygen? N.N
a) Histotoxic
as the tissue are unable to use the oxygen that is being delivered to them
224
The Bohr effect is driven by an increase in what factors? N.N
Mnemonic – “CADET” face right -
any increase to the CADET components will cause a shift the curve to the right
o C – CO2 increase
o A – Acidic (Increase in protons)
o D – 2,3 DPG (alternate name to 2,3 BPG) increase
o E – Exercise increase
o T – Temperature increase
● All will give an increased O2 dissociation (therefore a decreased affinity for O2.)
● Therefore, the **Bohr effect** will assist the body to compensate for energy use.
225
) If a person were to be febrile with temperature, would you expect the percentage of hemoglobin saturation to do what? N.N
increase ?
shift the graph to the left
226
If a person were under hypoventilation conditions, would you expect the percentage of hemoglobin saturation to do what? N.N
Decreases
227
What is the expected percentage of saturation of hemoglobin in the lungs in a healthy person under normal conditions? N.N
98%
228
The blood in the artery travelling to the peripheral tissue has/is what? N.N
. More saturated that the venous blood supply ?
229
What center controls prolonged breathing ? N.N
Apneustic Centre
* prolonged inspiration called **_apneustic breathing_**
230
An increase in action potential travelling via the phrenic nerves to the diaphragm cause what action N.N
The diaphragm to lower
231
. What nuclei in the VRG have leaky cation channels, allowing cations to flow into the neuron, causing spontaneous depolarization, sending action potentials to the external intercostals and diaphragm
in other words what's the pacemaker neurons ? N.N
o Pre-Botzinger Complex
232
.What is the normal respiratory rate set at (eupnea)? N.N
The normal respiratory rate (Eupnea)is set by this complex is between 12-16 breaths per minute.
233
5.The Pneumotaxic Centre and Apneustic Centers are both located in the pons? true /false N.N
true
The Pneumotaxic Centre is the upper aspect
and Apneustic Centers lower aspect of the Pons
234
Chemoreceptors
Cells that respond to chemical compounds to give an impulse to a sensory nerve.
o There are two sets of chemoreceptors.
o O2 receptors which are in the peripheral nervous system.
o CO2 receptors which are found both peripherally and centrally.
235
Stretch receptors
o Cells that respond to the stretching of muscles by giving impulses to the central nervous system.
o These receptors are a pivotal part of the proprioception system which coordinates muscle activity.
236
Proprioceptors
o Cells that monitor body changes brought about by muscular movement to give an impulse to the central nervous system to co-ordinate movement.
237
Juxtacapillary receptors (J-receptors or pulmonary c-fiber receptors)
o Cells that cause an increase in breathing rate as reflex response.
o Thought to be involved in the sensation of dyspnea
238
Nociceptors
o Cells that respond to a pain stimulus by giving impulses to the central nervous system.
239
o VRG and DRG both have inspiratory neurons which move downwards and give off fibers into the anterior or ventral grey horn. These specialized cell bodies are somatic motor neurons what happen when they get excited ? N.N
* If exiting through C3-C5, via the phrenic nerve, the signals carry to the cervical plexus and diaphragm
* If exiting through T1-T11, via the intercostal nerves, they will carry to the external intercostals. Stimulating inspiration
240
Without the dopamine being released, the cranial
nerves will not be stimulated. What are the overall
effects of this? N.N
a) decrease ventilation
b) increase carbonic acid
c) increase blood pCO2
241
The peripheral chemoreceptors are stimulated by N.N
Increase in protons
242
The peripheral chemoreceptors are inhibited by N.N
d. Decrease in protons
243
4) Regarding pCO2, 70% affect the central chemoreceptors true/ False ?N.N
70% affect the central chemoreceptors
244
Regarding carotid bodies of the peripheral
chemoreceptors, a. Send impulses through the 9th cranial nerve true/ False ? N.N
True
245
6) In hypercapnia, The CO2 can cross the blood brain barrier true/ False ? N.N
ttrue
246
7) Stimulation of central chemoreceptors cause ? N.N
Stimulation of DRG and pneumotaxic centre
247
8) features Regarding central chemoreceptors, N.N
a) Can be found in CSF
b) It is stimulated by high blood pCO2
d) It is inhibited by low blood pCO2
248
features Regarding oxygen,N.N
a) Stimulation of the chemoreceptors occur when the
level is \< 60 mmHg
249
In hypocapnia, there is N.N
a) There is decrease in carbonic acid
b) The pH level is high
c) The protons level is low
250
Regarding the hypothalamus, what are some of the features N.N
Stimulated by stimulation of thermoreceptors causing …….
Its associated with the limbic nuclei
251
Receptors found in the lung include N.N
a) Irritant receptors
b) Stretch receptors
d) Juxta capillary receptors
252
3) Features Regarding stretch receptors, N.N
Located in two locations
o Within visceral pleura
o Smooth muscle of bronchi and bronchioles
* **_Associated with Herring Breuer reflex_**
Stimulated when the tidal volume \> 800 ml sends signals to the cranial nerve X (vagus nerve)
+ inhibit DRG o Will also inhibit VRG inhibition of inspiratory neurons & stimulation of the expiratory neurons → causing expiration
253
Features of irritant receptors, N.N
b) Located under the epithelial layer of the mucosa
c) Sends impulse through the 10th cranial nerve (vagal nerve )
d) Stimulation cause cough reflex
254
J fibers of juxta capillary receptors N.N
a. They have two fibers: o J fibers o C fibers
b. Are located within the interstitial fluids
c. The lung parenchyma
The alveoli and respiratory bronchioles
Sites of gas exchange
d. They respond to fluid accumulation which include
o Pulmonary edema
o Pneumonia
255
what happen during Pulmonary edema N.N
a) Cause stimulation of the juxta capillary receptor
b) May be caused by left sided heart failure
c) Causes thickening of the respiratory membrane
256
7) Fluid accumulation causes N.N
Rapid and shallow breathing
Dyspnea → shortness of breath (gasping of air)
as result of
257
What is hyperpnea,N.N
a) It is caused by the stimulation of proprioceptors of the skeletal muscles
b) It is normal during exercise
d) It the increase in respiration rate and depth
258
9) Impulse from the cerebral cortex can N.N
Can bypass the respiratory centers
259
what stimulate the limbic nuclei N.N
emotions
260
Which metabolic disorder is caused in high altitudes? n.n
Metabolic Alkalosis
261
Hypoxia causes what in the lung? N.N
Vasoconstriction
262
Stimulation of neural respiratory center cause N.N
) Hyperventilation and Hypoventilation periodically
263
two main respiratory centres in the brain N.N
Medullary Respiratory Centers
(i) DRG- Dorsal Respiratory Group of Neurons (ii) VRG- Ventral Respiratory Group of Neurons (iii) CCR- Central Chemoreceptors
(2) Pontine Respiratory Centers
(i) Apneustic center (c1-C (ii) Pneumotaxic center (T1-T11)
264
HYPOXIA Decreased PO2 which mechanism will compensate in this situation N.N
* EFFECT OF HYPOXIA ON PERIPHERAL CHEMORECEPTORS
* EFFECT OF HYPOXIA ON RESPIRATORY CENTERS
265
DECREASED PCO2 which mechanism will compensate in this situation N.N
A) **_CENTRAL_** CHEMORECEPTORS
B) EFFECT OF ↓ CO2 ON RESPIRATORY CENTERS
(C) RESPIRATORY ALKALOSIS
266
ACCLIMATIZATION which mechanism will compensate in this situation N.N
(A) KIDNEY
(B) V/Q COUPLING
(C) ENDOTHELIAL CELLS OF BLOOD VESSELS
VEGF and (PDGF)
(D) BABIES BORN AT HIGH ALTITUDES Strong Ventricles
267
the nervous control of
respiration during exercise n.n
Respiratory centers
o Ventral and dorsal respiratory group (VRG and DRG) Located in the medulla
o Central chemoreceptors (CCR) Located posterior to the DRG
o Pneumotaxic and apneustic center Located in the pons
268
What happen during exercise ?N.N
Arterial PO2 and PCO2 **DONT CHANGEA** during exercise
b. Hyperpnea is defined as increased alveolar ventilation
without any change in blood gas chemistry
c. The primary somatosensory cortex receives
proprioceptive information from the spinothalamic tract
269
The carotid and aortic bodies send impulses to [what
cranial nerve] and [what cranial nerve], respectively. n.n
CN IX, CN X
270
ACUTE MOUNTAIN SICKNESS which would it lead to and how to treat it
a)Cerebral Edema
which treated with
Acetazolamide (ii) Supplemental oxygen (iii) Mannitol (iv) Dexamethasone
b) Pulmonary Edema
271
The myoglobin dissociation curve
A hyperbolic curve
272
The Bohr effect on the haemoglobin dissociation curve.
A sigmoid curve, shifted right
273
Chronic adaptations to hypoxia (e.g mountain sickness)
- Increased RBC production
- Increased 2,3 BPG produced within RBC - O2 offloaded more easily into tissues
- Increased number of capillaries
- Increased number of mitochondria - O2 used more efficiently
- Kidneys conserve acid - decrease arterial pH
274
Acute mountain sickness symptoms
Fatigue, headache, tachycardia, dizziness and shortness of breath, slipping into unconsciousness.
275
These chemoreceptors, when stimulated, can compensate for metabolic acidosis by triggering increased elimination of CO2.
Peripheral chemoreceptors
276
hyperinflated lungs think
emphysema
277
**Causes also cause shortness of breath on exertion**, a restrictive defect on spirometry and reduced pulmonary compliance but no sign of infection.
Pulmonary Fibrosis
278
he maximum total volume of air that can be inspired at the end of a normal, quiet respiration.
Inspiratory capacity
279
1. The volume of air in the lungs after a maximal expiration.
2. The volume of air in the lungs at the end of a normal, passive expiration.
1. Residual volume
2. Functional residual capacity (include some air from expiration)
280
right horizontal fissure is displaced indicate
Right Upper lung collapse
281
Lingular pneumonia
infection of the lingual lobe (small angle extended from lung tissue)
this can be CXR as the left heart border is obscured.
282
veil-like opacity.
is siang indicating Left upper lobe collapse
