Respiratory Flashcards
1
Q
What are the functions of the nose?
A
Temperature of inspired air
Humidity (75-80%)
Filter function
Defence (Cilia take inhaled particulates
2
Q
Where do the anterior nares (nostrils) open into?
A
vestibule
3
Q
How is the surface area of the nose increased?
A
Turbinates (rounded shelves)
4
Q
What are the three types of meatus?
A
Superior
Middle
Inferior
5
Q
Describe the properties of the superior meatus
A
Has olfactory epithelium
Olfactory nerve penetrates through superior meatus via pores in the cribriform plate
Sphenoid sinus drains here
6
Q
Describe the properties oft the middle meatus
A
Sinuses drain here
7
Q
Describe the properties of the inferior meatus
A
Nasolacrimal duct drains here
8
Q
Define what the paranasal sinuses are?
A
Pneumatised areas (Bone that is hollow or contains air cells) of the frontal, ethmoid,. sphenoid and maxillary bones that are arranged in pairs
9
Q
Draw a diagram to show the location of the paranasal sinuses
A
See diagrams I should know
10
Q
Describe the location and the innervation of the frontal sinus
A
Located within in the frontal bone and lies above the orbit
Innervated by the ophthalmic division (V1) of the trigeminal nerve
11
Q
Describe the location of the maxillary sinus
A
Located within the body of the maxilla where the base is the lateral wall of the nose, roof is the floor of the orbit, apex is the zygomatic process of the maxilla and floor is the alveolar process (Pyramidal shape)
Opens into the middle meatus
12
Q
What is the innervation of the maxillary sinus
A
Maxillary division (V2) of the trigeminal nerve
13
Q
Describe the location and the innervation of the ethmoid sinus
A
Between the eyes and is a labyrinth of air cells
Semilunar hiatus of middle meatus
Innervation by the ophthalmic and maxillary branches of trigeminal nerve
14
Q
Describe the location of the sphenoid sinuses
A
Medial to the carvenous sinus (which contains internal carotid artery, oculomotor nerve, trochlear, trigeminal and abducens
Inferior to optic canal, dura and pituitary gland
Empties into sphenoethmoidal recess lateral to the attachment of the nasal septum
15
Q
What is the innervation of the sphenoid sinus
A
Ophthalmic division off the trigeminal nerve
16
Q
What epithelium lines the pharynx
A
Squamous and columnar ciliated epithelium with mucus glands
17
Q
Where does the pharynx extend from and what parts does it consist of?
A
Fibromuscular tube running from the skull base to C6 where it becomes continuous with the oesophagus
consists of nasopharynx, oropharynx and laryngopharynx
18
Q
What Is the function of the larynx?
A
Valvular function which prevents liquids and foods from entering the lung
19
Q
Describe the cartilaginous structure of the larynx
A
Consists of 9 cartilages 3 paired (Cuneiform, corniculate and arytenoid) 3 unpaired (Epiglottis, thyroid, cricoid
20
Q
What two larynx cartilages interact to change the vocal cords?
A
Arytenoid cartilages rotate on the cricoid cartilages
21
Q
Where would you carry out a tracheotomy?
A
Cricothyroid membrane
22
Q
Which nerves innervate the larynx
A
Vagus Nerve
23
Q
What does the the recurrent laryngeal nerve innervate
A
All the motor innervation for all laryngeal muscles except cricothyroid
24
Q
What does the superior laryngeal nerve innervate
A
Divides into internal (for sensation to larynx) and external (motor innervation to cricothyroid muscle)
25
Describe the pathway of the left recurrent laryngeal nerve
Runs laterally to the arch of the aorta, loops under the aortic arch then ascends between the trachea and the oesophagus
26
Describe the pathway of the right recurrent laryngeal nerve
Loops under the right subclavian artery and runs up in the plane between the trachea and the oesophagus
27
What symptom would ulcers/tumours on or near the pathway of the recurrent laryngeal nerve cause?
Hoarse voice
28
What is the function of the lower respiratory tract?
Gas exchange
29
Define and give an approximation of minute ventilation
Volume of air inhaled/exhaled in a minute (approx 5 litres)
30
Describe the structure of the trachea
From larynx to carina (C6-T5) - oval in cross section
Contains semi-circular (C-shaped)(absent posteriorly) hyaline cartilages connected by tracheal muscle that increases flexibility
31
What epithelium lines the trachea
Pseudo-stratified ciliated columnar epithelium with goblet cells
32
The carina lies at what spinal level?
T5
33
Describe the structure of the main bronchus
Left and right main bronchus divided by the carina
right main bronchus is more vertically disposed (1-2.5cm long (related to pulmonary artery)
Left main bronchus is longer (5cm) and less vertical (Related to aortic arch)
34
Which main bronchus is a peanut more likely to get stuck in
Right main bronchus because the right is more vertically disposed and shorter
35
What does the right lobar bronchi consist of
Upper lobe
Middle lobe
Lower lobe
36
What does the left lobar bronchi consist of?
Upper lobe and lingual
| Lower lobe
37
How many segmental branches on the right are there
10
38
How many segmental branches on the left are there
8
39
Describe the pathway of the trachea and the bronchioles
Trachea, L/R main bronchus, Lobar bronchia, segmental bronchia, terminal bronchioles, respiratory bronchioles, alveolar ducts and finally alveoli
40
What are interconnections between alveoli known as
Pores of Kohn
41
Define acinus
Tissue supplied with air by one terminal bronchiole
42
What are the constituents of alveoli
```
Type I pneumocytes
Type II Pneumocytes (Secrete surfactant)
Alveolar macrophage
Basement membrane
Interstitial tissue
capillary endothelial cells
```
43
Describe the innervation of the lungs
Pulmonary plexus lies behind each hilum - receives innervation from vagus nerves and T2-4 of sympathetic trunk
44
Sympathetic innervation of the lung results in
Bronchodilation
45
Parasympathetic innervation of the lung results in
Bronchoconstriction
46
Describe the pleura of the lungs
2 layers of mesodermal origin
Visceral-lung surface - only has autonomic innervation
Parietal - internal chest - has pain sensation via phrenic nerve
Small amount of fluid in between
47
Describe the blood supply of the lung
Bronchial and pulmonary
L/R pulmonary run to right ventricle and have 17 orders of branching
Bronchus and pulmonary arteries run together via the bronchovascular bundle
48
Define transpulmonary pressure
Difference in pressure between the inside and outside of the lung (Alveolar pressure - intrapleural pressure)
49
Define intrapleural pressure
Pressure inside the pleural space - intrathoracic pressure
50
Define alveolar pressure
Air pressure in pulmonary alveoli
51
What are the muscles of inspiration
Quiet breathing and diaphragm (C3/4/5)
| External intercostals
52
What are the muscles of expiration
Passive process due to quiet breathing
53
Describe the process of inspiration
External intercostal muscles and diaphragm due to phrenic nerve from C3/4/5.
1. Diaphragm contracts causing the dome to move downwards, thereby enlarging the thorax (Increased volume)
2. Simultaneously, activation of motor neurones in the intercostal nerves to the external intercostal muscles causes them to contract resulting in upward and outward movement of ribs further increasing volume
3. As thorax expands, intrapleural pressure is lowered and transpulmonary pressure becomes more positive resulting in lung expansion as force causing lung expansion is greater than elastic recoil
4. Lung expansion causes alveolar pressure to become more negative
5. Causes inward flow of air
54
Describe the process of expiration during quiet breathing
1. motor neurones to intercostal nerves and diaphragm decrease firing so muscles relax and diaphragm ascends thus decreasing thoracic volume
2. As they relax, lungs and chest walls collapse passively due to elastic recoil as intrapleural pressure increases causing transpulmonary presure to decrease below elastic recoil pressure
3. As lungs become smaller the air in the alveoli becomes compressed resulting in an increase in external intercostal pressure above atmospheric pressure so air flows outwards
55
Describe the process of forced expiration that occurs during exercise
1. On top of passive expiration the internal intercostal muscles and abdominal muscles (rectus abdominus and external abdominal obliques) contract
2. This causes the ribs to move downwards and inwards, actively decreasing thoracic volume. Abdominal muscle contraction causes further increase in intra-abdominal pressure forcing the diaphragm further into the thorax further decreasing thoracic volume
3. Results in greater than normal volume of air being expired
56
What is the airway of greatest resistance?
The trachea because it has a smaller surface area than all the bronchioles combined meaning it provides the greatest resistance
57
Define dead space
Volume of air not contributing to ventilation
58
What is the volume of the physiological dead space?
175mls in total in the lungs
| 150mls anatomically and 25mls in alveoli
59
Where does gas exchange occur?
Between the alveoli and the capillaries
60
How many layers must O2 diffuse through to cross from alveoli to the capillaries
7 layers
1. Alveolar epithelium
2. Tissue interstitium
3. Capillary endothelium
4. Plasma layer
5. Red cell membrane
6. Red cell cytoplasms
7. Hb binding
61
What is required for each alveolus to be as efficient as possible?
The correct proportion of alveolar air Flow (ventilation) and capillary blood flow (perfusion) - any mismatch is called ventilation perfusion inequality
62
What is the main effect of a ventilation perfusion mismatch?
Decreased partial pressure of O2 in the systemic blood
63
Describe ventilation perfusion inequality in healthy individuals
inequality enough to reduce the arterial Po2 by 5mmHg due to gravitational effects as in upright position there is increased filling of blood vessels at the bottom of the lung which contributes to differences in blood-flow distribution so on average PO2 in alveoli is 5mmHg higher than in partial blood
64
What consequences of disease can cause a ventilation perfusion mismatch?
Regional changes in compliance, airway resistance and vascular resistance
65
What are the two extremes of ventilation perfusion mismatch?
Ventilated alveoli with no blood supply due to blood clot or adequate blood flow through the lung but no ventilation due to collapsed alveoli
66
Describe what happens during local homeostatic hypoxic pulmonary constriction?
Decrease in ventilation in alveoli leads to decrease in alveolar PO2 and in surrounding blood vessels. This decrease in PO2 leads to vasoconstriction to deliver the blood away from poorly ventilated areas - unique to pulmonary arterial vessels
67
What is PaCO2
Arterial Co2
68
What is PACO2
Alveolar Co2
69
What is PaO2
Arterial O2
70
What is PAO2
Alveolar O2
71
What is PIO2
Pressure of inspired O2
72
What is VA
Alveolar ventilation
73
What is VCO2
CO2 production
74
What is the structure of the haemoglobin molecule?
Four subunits (globin) with each subunit containing a heme group which contains an Iron atom to which oxygen can bind
75
How many molecules of oxygen can a single Hb molecule bind?
4
76
What are the two forms that Hb can exist as?
Oxyhaemoglobin
| Deoxyhaemoglobin
77
What is the value of systemic arterial PO2
100mmHg
78
What is the value of systemic venous PO2
40mmHg
79
Describe the oxygen dissociation curve
As PO2 increases the HB saturation will increase rapidly so that Hb saturation is at 90% at PO2 of 60mmHg. After this point, increases in PO2 will cause a small increase in Hb saturation
80
How many lobes does the right lobar bronchi have?
3
81
What are the 3 lobes of the right lobar bronchi?
Upper
Middle
Lower
82
How many physical lobes does the right lung have?
3
83
How many lobes does the left lung have?
2
84
What 3 qualities are required for efficient gas exchange to occur?
Large surface area
Minimal diffusion distance
Adequate perfusion
85
Describe what happens during local bronchoconstriction
Decrease blood flow in region means less systemic CO2 which means reduced PCO2 so bronchoconstriction occurs to divert airflow to areas with better perfusion
86
What does a shift in the oxygen dissociation curve to the left mean?
Hb has more affinity for oxygen
87
What does a shift in the oxygen dissociation curve to the right mean?
Hb has less affinity for oxygen
88
An increase in temperature will shift the oxygen dissociation curve in what direction
To the right
89
A decease in pH will shift the oxygen dissociation curve in what direction?
To the right
90
What are the effects of carbon monoxide on the oxygen dissociation curve?
CO has 200x greater affinity for Hb than O2 does so reduces the amount of O2 that binds with Hb and reduces Hb affinity for O2. CO therefore shifts curve to the left, decreasing O2 unloading in tissues
91
What are the three ways that CO2 Is carried in the blood?
1. Bound to Hb as carbaminohaemoglobin
2. Dissolved in plasma
3. As bicarbonate
92
What percentage of Co2 is transported I the blood as carbaminhaemoglobin?
23%
93
What percentage of CO2 is transported in the blood dissolved in the plasma?
10%
94
What percentage of CO2 is transported in the blood as HCO3- ions?
60-65%
95
Why does CO2 diffuse from the blood into alveoli?
Because the blood PPCO2 is greater than the alveolar PPCO2
96
What is normal blood pH?
7.35-7.45
97
What are the three main buffering systems for acid/base?
Intra/extracellular buffers, lungs eliminating CO2
| Renal HCO3- reabsorption and H+ elimination
98
What is the equation for the bicarbonate buffer system?
CO2 + H20 --> H2CO3 --> HCO3- + H+
99
Describe how a respiratory acidosis occurs
When someone hyperventilates there is inadequate ventilation of the alveoli meaning CO2 is not excreted so their PCO2 increases resulting in more carbonic acid being produced which dissociates to increase the H+ concentration in the blood = respiratory acidosis
100
Describe how a respiratory alkalosis occurs?
Hyperventilation causes CO2 to be blown off quickly which reduces the arterial partial pressure of CO2, reducing the formation of H2CO3 and H+ formation leading to.a respiratory alkalosis
101
What is the equation for Henderson Hasselbalch
pH = 6.1 + Log ([HCO3-]/(0.03 * PCO2))
102
What is Dalton's law
Pressure exerted by each gas in a mixture is independent of the pressure exerted by other gases so the total pressure of the mixture is a sum of the individual pressures which are directly proportional to concentration
103
What is Boyle's Law?
The pressure of a fixed amount of gas is inversely proportional to the containers volume
104
What is Henry's Law?
Amount of gas dissolved in a liquid is proportional to the partial pressure of the gas with which the liquid is in equilibrium
105
What is the alveolar gas equation?
```
PAO2 = PiO2 - PaCO2/R
(R = respiration exchange ratio = ratio between amount of CO2 produced in metabolism and oxygen used)
```
106
What is the Law of Laplace?
Relationship between pressure (P), surface tension (T) and radius of an alveolus (R) = P=2T/r
107
What is lung compliance?
Change in lung volume caused by a given change in transpulmonary pressure ie. greater the lung compliance the more readily the lungs expand
108
What is surface tension
Attractive forces between water molecules at the air-water interface in alveoli
109
What forces do the lungs need to overcome to expand?
Surface tension of the water lining the alveoli
| Stretch the connective tissue
110
How do the lungs overcome the forces that resist expansion
Type II pneumocytes secrete surfactant which reduces the cohesive forces between water molecules which lowers surface tension and increases lung compliance making it easier for the lungs to expand
111
When does the level of surfactant decrease
When individuals take take small and constant breaths
112
Define Inspiratory reserve volume?
Amount of air in excess tidal inspiration that can be inhaled with maximum effort
113
Define Expiratory reserve volume?
Amount of air in excess tidal expiration that can be exhaled with maximum effort
114
Define residual volume
The amount of air remaining in the lungs after maximum expiration
115
Define vital capacity
The amount of air that can be exhaled with maximum effort after a maximum inspiration (ERV + TV + IRV)
116
Define functional residual capacity
Amount of air remaining in the lungs after a normal tidal expiration (RV+ ERV)
117
Define inspiration capacity (IC)
Maximum amount of air that can be inhaled after a tidal expiration (TV + IRV)
118
Define Total lung capacity
Maximum amount of air the lungs can contain (RV + VC)
119
Define tidal volume
Amount of air inhaled or exhaled in one breath
120
What is a normal tidal volume?
500ml
121
Define FEV1
Forced expiratory volume in 1 second
122
What is a normal FEV1 value for a healthy individual
80% of their vital capacity in one second
123
What does an FEV1 value of 80% or greater suggest
Lung health is normal
124
What does an FEV1 value of less than 80% of the predicted value suggest
Lung health is abnormal
125
What does a low FVC value suggest
Airway restriction
126
What does an FEV1/FVC ratio of below 0.7 suggest
Airway obstruction
127
What does a normal FEV1/FVC ratio but low FEV1 value suggest?
Airway restriction
128
What are of the brain is responsible for the control of breathing?
Medulla oblongata
129
What are the two main anatomical components of the medulla oblongata that are important for breathing
Dorsal respiratory group
| Ventral respiratory group
130
What are the two main anatomical components of the medulla oblongata that are important for breathing
Dorsal respiratory group
| Ventral respiratory group
131
When do the neurone s of the DRG primarily fire and what do they activate?
Fire during inspiration and activate the diaphragm and external intercostal muscles
132
Where is the respiratory rhythm generator located
In the pre-Botzinger complex in the upper part of the DRG
133
When do they neurones of the VRG fire and what do they activate
Expiratory neurones of the VRG activated when large increases in ventilation are required such as during strenuous exercise by causing expiratory muscles to contract
Also has some inspiratory neurones
134
When is the DRG active
inspiration
135
when is the VRG active
Inspiration and expiration
136
Which respiratory control neurones are found in the pons
Pneumotaxic centre
| Apneustic centre
137
What is the function of the Pneumotaxic centre?
Inhibits the apneustic centre and promotes expiration
| Increased output here = shallower more frequent breaths raising respiratory rate but reducing inspiratory volume
138
What is the function of the apneustic centre
Stimulates the DRG
| Increases the intensity of inhalation but is quickly inhibited by the pneumotaxic centre
139
What is the function of the DRG
Contains inspiratory neurones
Involved in quiet and forced breathing
Innervates the external intercostal muscles and diaphragm to cause inhalation
Passive exhalation occurs on signal cessation
140
What is the function of the VRG
Contains inspiratory and expiratory neurones
Forced breathing
Stimulated by DRG activating muscles of inhalation then the expiratory neurones of VRG stimulate the accessory muscles exhalation
141
Describe slowly adapting pulmonary stretch receptors?
Found in airway smooth muscle
Activated by lung distension
High activity inhibits further inspiration beginning expiration
142
Describe rapidly adapting stretch receptors
Found between airway epithelial cells
Activated by lung distension and irritants
Produce brief burst of activity
high activity causes bronchoconstriction - cough reflex
143
Describe C fibres and J receptors
Found in capillary walls and interstitium
Stimulated by an increase in lung interstitial pressure caused by collection of fluid in the interstitium
Activity causes rapid breathing, shallow breathing, bronchoconstriction, CV depression and dry cough
J receptors give sensations of pressure in chest and dyspnea
144
Where are the peripheral chemoreceptors located
Common carotid bodies - bifurcation of the common carotid artery
Aortic bodies - Arch of the aorta
145
What are the peripheral chemoreceptors sensitive to?
An increase in arterial H+ concentration
A decrease in PaO2
146
Which CN afferents take information from the common carotid bodies
Glossopharyngeal
147
Which cranial nerve afferents take information from the aortic bodies
Vagus Nerve
148
What are peripheral chemoreceptors not activated until PaO2 drops to 60mmHg
peripheral chemoreceptors not sensitive to small reductions in PaO2 because at 60mmHg Hb saturation is still 90% so it is not until below 60mmHg that oxygen transport of the blood falls thus increasing ventilation to add more O2 to the blood is pointless until that point is reached
149
Where are the central chemoreceptors located
In the medulla of the brainstem
150
What are the central chemoreceptors sensitive to?
Stimulated to increased H+ conc in CSF but BBB is impermeable to H+ so blood PCO2 which diffuses across the BBB influences pH CSF
Ventilatory drive is extremely sensitive to changes in arterial PCO2
151
Central chemoreceptors account for what percentage increase in ventilatory rate
70%
152
Define hypoxia
Deficiency of oxygen at tissue level
153
What is the most common type of hypoxia?
Hypoxemia = reduced PaO2
154
What are the four most common causes of hypoxia?
1. Hypoventilation causing increased PaCO2 and failure to adequately ventilate alveoli
2. Diffusion impairment resulting from thickening of alveolar membrane or decrease in surface area
3. Shunting - anatomical CVS abnormality that causes mixed venous blood to bypass the ventilated alveoli
4. ventilation perfusion mismatch which is caused by COPD where the PaCO2 may be normal or increase
155
Define hypercapnia
CO2 retention leading to an increased PaCO2
156
What is the main cause of hypercapnia
Hypoventilation
157
What happens to CO2 and O2 in Type 1 respiratory failure
PO2 is low
| PCO2 is low or normal
158
What is the main cause of Type 1 respiratory failure
pulmonary embolism
159
What happens to Co2 and O2 in type 2 respiratory failure
PO2 is low
| PCO2 is high
160
What is the main cause of type 2 respiratory failure
Hypoventilation
161
What are the two circulations to the lung
Pulmonary circulation
| Bronchial circulation
162
Parasympathetic nervous system innervates the lung via what nerve
vagus
163
What neurotransmitter does the parasympathetic nervous system supplying the lung use and to what receptor does it bind
ACh
| Muscarinic M3
164
The parasympathetic nervous system governs what property of the airways
Their intrinsic tone
165
What will too much parasympathetic innervation of the lung cause
BronchoCONSTRICTION
166
What are the effects of the sympathetic nervous system on the lung
Cause the release of noradrenaline which causes release of adrenaline from the adrenal gland which binds B2 adrenoreceptors causing bronchoDILATION
167
Describe the intracellular casacade when ACh binds to M3 receptors
Activates the Gq protein
Activates PLC
PLC breaks down PM phospholipid into DAG and IPC
DAG acts s second messenger to activate PKC
IP3 binds ligand gated Ca2+ channels on endoplasmic recticumulum causing them to open, releasing Ca2+ which stimulates bronchoCONSTRICTION
168
Describe the intracellular cascade when adrenaline or noradrenaline binds to Beta 2 receptors
Activates Gs protein
Activates Adenyl cyclase which converts ATP to cAMP which acts as a second messenger to decrease calcium concentrations and activate PKA causing BRONCHODILATION
169
What types of drugs are given to alleviate asthma and COPD
Bronchodilators
Muscarinic antagonists
beta-2 agonists
170
Name 2 short acting beta-2-agonists
Salbutamol and terbutaline
171
Name 2 long acting beta-2-agonists
Salmeterol and formoterol
172
Name a short acting muscarinic antagonists
Ipratropium
173
Name a long acting muscarininc antagonis t
Tiotropium
174
How does the ciliated pseudo stratified columnar epithelium of the lung provide protection
Moistens and protects airways
Barrier to pathogens
Mucociliary escalator
Mucus secreted is sticky so particles adhere to it and are phagocytosis by macrophages
175
Define a cough
Explosive expiration that provides a normal protective mechanism for clearing tracheobrachial secretion and foreign material
either initiated voluntarily or reflexively
176
Where are the receptors for the cough reflex located
Larynx
trachea
bronchi
177
Which immune cells are phagocytes?
Neutrophils and phagocytes
178
Name the 4 chemical epithelial barriers
Antiproteinases
Anti-fungal peptides
Anti-microbial peptides
Surfactant A and D
179
Why can damage to the airway epithelium following an infection be resolved?
because the epithelium demonstrates functional plasticity but when this goes wrong a pulmonary disease might occur
180
What is the pathophysiology of COPD
Unresolving neutrophilic inflammation release proteases that cause breakdown of the lung walls reducing alveolar function
181
What are the 6 functions of neutrophils?
1. Identify threat receptors (Bacterial structures, host mediators, host opsonins)
2. Activation
3. Adhesion
4. Migration
5. Phagocytosis
6. Bacterial killing
182
How does the lung defend itself against pathogens
Innate mechanisms
| Adaptive mechanisms
183
What are the external defences of the innate immunity
Skin
Mucous membranes
Secretions
184
What are the internal defences of the innate immunity
Phagocytic cells
Antimicrobial proteins
Inflammatory response
natural killer cells
185
What are the acquired immunity defences
```
Humoral response (Antibodies)
Cell mediated response (Cytotoxic lymphocytes)
```
186
Which cells act as antigen present cells
Alveolar macrophages and dendritic cells
187
What are the two types of lymphocyte
```
T cells (Cytotoxic T cells and T helper cells)
B cells = produce antibodies
```
188
What is an antigen
A molecule capable of inducing an adaptive immune response
189
What are the 3 key properties of the adaptive immune system
Diversity
Self tolerance
immunological memory
190
Define humeral immunity
```
things that are in the blood but not cells
- immunoglobulins
Complement
Surfactant proteins
Cytokines
```
191
Define the innate immunity
Immediate response to foreign pathogen that does not require previous exposure and mainly involves the phagocytosis of Bacteria and rapid responses to viruses
192
How do alveolar macrophages respond to pathogens or tissues?
Recognise PAMPs (Pathogen associated molecular patterns)
Recognise DAMPS
(Damage associated molecular patterns)
193
How do alveolar macrophages recognise new pathogens
Pattern recognition receptors - part of innate immunity that recognise common antigens on bacteria such as Toll like receptors
194
What do the primary granules of neutrophils contain
Myeloperoxidase
Elastate - breaks down elastin in lungs to enable neutrophil to migrate through to get to pathogen
Capthesin and defensin (Antibacterial proteins)
195
What do the secondary granules of neutrophils contain?
Lysozyme - breaks down bacteria cell walls
| Collagenase - breaks down collagen allowing neutrophils to penetrate hard to reach collagenised areas
196
What happens in necrosis
Cells swell, lyse and ROS are released which causes damage to surrounding tissues resulting in inflammation and phagocytosis of necroses cell
197
What happens in apoptosis
More controlled process in which the cell is turned off and packaged to be phagocytksed by neutrophils with no surrounding tissue damage
198
Where are lymphocytes produced?
In the bone marrow but they mature in the thymus
199
Which immune cells express class II MHC proteins
Macrophages, B cells and dendrite cells
200
What are the 5 types of antibody
IgA, IgD, IgE, IgG (most abundant) and IgM
201
What do antibodies recognise
Specific epitopes
202
How does antigen presentation activate Cytotoxic T cells
1. antigen presenting cell ingest bug
2. Bug antigen is displayed on the antigen presenting cell surface with MHC II molecule
3. both must be recognised
4. Cytotoxic CD8 T cells become activated which bind to the infected cell
5. They use perforin to make hles in infected cell membrane causing cell to lyse
203
How does antigen presenting cells activate T helps cells
1. Antigen presenting cell ingests bug
2. Bug antigen is displayed of APC surface with MHC II - both must be recognised
3. Interactions with T cell receptor releases cytokines
4. CD4 cells differentiate into T-helper cells
204
What is secreted by immature plasma cells
IgM
205
What is a type 1 reaction
IgE - allergic, acute
| Immunological memory to something causes an allergic reaction
206
Give examples of type 1 immune reactions
Acute anaphylaxis and hay fever
207
What is a type 2 reaction
IgG and IgM bind to cell surface antigens
208
Give examples of type 2 reactions
Transfusion and autoimmune disease
209
What is a type 3 reaction
Immune complexes, activation of complement IgG
210
What are type 4 reactions
T cell mediated delayed type hypersensitivity
211
give examples of a type 4 reaction
Tuberculosis
| Contact dermatitis
212
What is PaCo2 directly proportional to?
1/alveolar ventilation
213
Write an equation to determine PAO2
PiO2 - PaCO2/R
214
What is PiO2 and can it change
Pressure of inspired oxygen and yes it can change
215
What is FiO2 and can it change?
Fraction of inspired oxygen and no it can't change (Fixed at 0.21)
216
What is PaO2 at sea level?
10.5-13.5 KPa
217
What is PaCO2 at sea level?
4.5-6.0KPa
218
As altitude rises, what happens to pressure?
It decreases in a non linear fashion
219
What is the effect of altitude on the lungs?
Hypoxia leads to hyperventilation which increases the minute ventilation, lowers PaCO2 and leads to alkalosis and tachycardia which is compensated for by renal bicarbonate excretion
