Case 1 Flashcards
1
Q
how does air flow?
A
region of high pressure to a region of low pressure
2
Q
what kind of process is inhalation
A
an active process
3
Q
what muscles are used in quiet inhalation
A
diaphragm, external intercostal muscles and potentially scalene muscles
4
Q
how much of the air movement does diaphragmatic movement count for in quiet inhalation
A
75%
5
Q
accessory muscles in forced inhalation
A
sternocleidomastoid, scalene, serratus anterior and pectoralis minor
6
Q
why is air drawn into the bronchial tree during inhalation
A
due to positive atmospheric pressure exerted through upper respiratory tract and the negative pressure on the outer surface of the lungs, brought about by increase capacity of thoracic cavity
7
Q
is quiet exhalation active or passive
A
largely passive - due to elastic recoilq
8
Q
how does surface tension affect quiet expiration
A
fluid that lines the alveoli. as water molecules pull together they also pull on the alveolar walls, causing the alveoli to recoil and become smaller
9
Q
what two factors prevent the lungs from collapsing
A
surfactant (reduces surface tension) and inter pleural pressure
10
Q
is forced expiration passive or active
A
active
11
Q
what are the muscles of forced expiration
A
external and internal oblique. transverses abdominis, rectus abdominis, transverses thoracis
12
Q
what muscle pulls down the twelfth rib during forced expiration
A
quadratus lumborum
13
Q
what are the respiratory centres
A
medulla oblongata and pons
14
Q
what are the respiratory centres in the medulla oblongata
A
DRG and VRG
15
Q
what does the DRG control
A
controls mostly inspiratory movements and their timing
16
Q
what nerve innervates the diaphragm
A
phrenic nerve
17
Q
what does VRG cause
A
forced expiration
18
Q
what does VRG inspiratory centre do during forced inspiration
A
aids the DRG
19
Q
how do the signals in the RAMP pathway occur
A
in action potential bursts
20
Q
what do the 3 seconds of no signals in the RAMP pathway do
A
allow elastic recoil of the lungs and the chest wall to cause expiration (passive exhalation)
21
Q
what is the advantage of the RAMP pathway
A
causes a steady increase in the volume of the chest during inspiration, rather than inspiratory gaps
22
Q
what are the respiratory centres in the pons
A
apneustic and pneumotaxic centres
23
Q
what are the stimuli for the respiratory centres in the pons
A
the vagus nerve and the glossopharyngeal nerves to the respiratory centres
24
Q
where is the apneustic centres located
A
lower pons
25
what does the apneustic centre do
provides continuous stimulation to the DRG, resulting in long deep inhalation
26
what happens after 2 seconds of inhalation to the apneustic centres
they are inhibited by the pneumotaxic centres
27
where are the pneumotaxic centres located
in the upper pons
28
what does the pneumotaxic centre control
the 'switch off' point of the ramp signal, thus limiting inspiration
29
chemoreceptors:
P(CO2), P(02), pH of the blood
30
baroreceptors
changes in blood pressure
31
stretch receptors:
respons to changes in volume of the lungs (Hering-Breuer Reflex)
32
where do excess carbon dioxide and hydrogen ions in the blood act on
act directly on the respiratory centre itself
33
where does oxygen act on
on peripheral chemoreceptors in the carotid and aortic bodies
34
where is the chemosensitive area located
located bilaterally, lying beneath the ventral surface of the medulla
35
why can cross the blood-brain barrier
carbon dioxide
36
which has an effect in stimulation the neurone in the chemosensitive area
hydrogen ions have a direct effect unlike carbon dioxide
37
how does carbon dioxide effect the chemosensitive area
it cross the brain-blood barrier, reacts with water of the tissues to form carbonic acid, then dissociates into hydrogen and bicarbonate ions; the hydrogen ions then have a direct stimulatory effect on the chemosenstive area in the brain
38
do the Pco2, pH and Po2 values change during strenuous exercise
no they remain normal
39
what happens at the onset of exercise to the arterial Pco2
there is no increase, as alveolar ventilation increases instantaneously without an initial increase in arterial Pco2
40
which nerve is the carotid body associated with
glossopharyngeal nerve and then to the DRG
41
which nerve is the aortic body associated with
the vagus nerve which goes to the DRG
42
where are stretch receptors located
located in the muscular portions of the walls of the bronchi and bronchioles throughout the lungs
43
where do stretch receptors transmit signals to
the vagus nerve into the DRG when the lungs become over stretched
44
what happens where the lungs become overly inflated
the stretch receptors activate an appropriate feedback response that 'switches off' the inspiratory ramp and thus stops further inspiration
45
what happens in normal tissues if it becomes more active
Po2 falls and Pco2 rises
46
what do rising Pco2 levels do
they relax smooth muscle in walls of arteries and capillaries, causing vasodilation and increasing blood flow
47
what is hypoxia
lack of oxygen
48
what are the effects of hypoxia on the body
drowsiness, lack of energy, mental and muscle fatigue, headache and nausea
49
what is cyanosis
blueness of the skin
50
how is cyanosis caused
result of excessive amounts of deoxygenated haemoglobin in the skin blood vessels
51
what is pleural pressure
the pressure of the fluid in the pleural cavity which is the space between the visceral and parietal pleura
52
is pleural pressure usually slightly negative or positive
usually slightly negative (-5)
53
what happens to the pleural pressure during inspiration
expansion of the chest cage pulls outward on the lungs with greater force and therefore creates more negative pressure (7.5)
54
what is alveolar pressure
pressure inside the alveoli
55
what happens to the alveolar pressure when there is no air flow
it is equal to the atmospheric pressure which is considered to zero
56
what has to happen to pressure in alveoli during inspiration
the pressure must fall to a value slightly below atmospheric pressure (below 0)
57
what happens to alveolar pressure during expiration
the alveolar pressure rises to about +1 and this forced 0.5 litres of inspirited air out of the lungs during the 2 or 3 seconds of expiration
58
what is transpulmonary pressure
this is the difference between the alveolar pressure and the pleural pressure
59
what is recoil pressure
measure of the elastic forces in the lungs that tend to collapse the lungs at each instant of respiration
60
what does the work of breathing depend on
the tidal volume - increased = more work done by lungs
| respiratory frequency
61
what is airflow
partial pressure / airways resistance
62
what is partial pressure
alveolar pressure - atmospheric pressure
63
what happens in the airway is long
greater airway resistance
64
what happens in airway is short and narrow
the greater the airway resistance
65
What is compliance
indication of the lung's expandability or how easily the lungs expand and contract
66
what happens when the compliance is low
the greater the force required to fill and empty the lungs
67
what happens when the compliance is great
the easier to fill and empty the lungs
68
what is surfactant
surface active agent in water, which means it greatly reduced the surface tension of water
69
what cells secrete surfactant
type II alveolar epithelial cells
70
what confirms a pneumothorax
chest X-ray
71
what does a collapsed lung look like on an X-ray
extra black space indicates the presence of air
72
what are the steps to do a chest X-ray
A - airways
| B - breathing and bones
73
what Is the order for chest X-ray
```
A - airways
B - breathing and bones
C - cardiac
D - diaphragm
E - everything else
```
74
what films are used for pneumothorax
standard erect posterior anterior are usually adequate although if too injured to stand used anterior posterior
75
what treatment is used for a complete primary
aspirate / chest drain
76
what treatment is used for a moderate primary
aspirate
77
what treatment is used for a small primary
observe
78
what treatment is used for a complete secondary
chest drain
79
what treatment is used for a moderate secondary
chest drain
80
what treatment is used for a small secondary
chest drain
81
what treatment is used fro a complete traumatic
chest drain
82
what treatment is used for a moderate traumatic
chest drain
83
what treatment is used for a small traumatic
observe / chest drain
84
what else is given during immediate manage of a pneumothorax
supplemental oxygen
85
where does aspiration take place
second intercostal space, mid-clavicular line
86
where is a chest drain inserted
inter pleural space between two ribs
87
what does a chest drain do
it allows air to escape from the inter pleural space so that the underlying lung can re-inflate
88
how is pneumothorax drained via a chest tube
as pressure in the inter pleural space becomes positive, due to coughing, air passes along the chest drain and out into the atmosphere through an underwater seal and the pneumothorax is drained
89
what is ATLS
advanced trauma life support
90
what is the principle of ATLS
treat the greatest threat to life first
91
is a definitive diagnosis necessary to treat patient initially under ATLS protocol
no
92
what is the primary survey of ATLS protocol
A - airway maintenance with cervical spine protection
93
what does ABCDE stand for in ATLS protocol
A - airway maintenance and cervical spine protection
B - breathing and ventilation
C - circulation with haemorrhage control
D - disability and neurologic status
E - exposure and environment
94
what Is the secondary survey of ATLS protocol
a head to toe evaluation of the trauma patient, including a complete history and physical examination including the reassessment of all the vital signs
95
what happens if at any point during secondary survey of ATLS protocol the patient deteriorates
another primary survey is carried out as a potential threat to life may be present
96
what type of fibres are acetylcholine
cholinergic
97
what type of fibres are norepinephrine
adrenergic
98
what fibre are all preganglionic neurons
cholinergic
99
what type of fibres are in postganglionic of sympathetic
adrenergic
100
what receptors do acetylcholine activate
nicotinic receptors and muscarinic resceptors
101
where are nicotinic receptors found
found in the autonomic ganglia at the synapses between the pre and post ganglionic neurones of both para and sympathetic systems
102
where are muscarinc receptors found
found on all effector cells that are stimulated by the postganglionic cholinergic neurones of the parasympathetic nervous system
103
where are alpha 1 receptors found
in walls of blood vessels and cause smooth muscle contraction
104
what do alpha 2 receptors do
inhibit adenylate cyclase - decreasing cAMP formation
| negative feedback for release of norepinephrine from presynaptic neurone
105
what do all beta receptors stimulate
adenylate cyclase
106
where are beta 1 receptors found
located in the heart, increase cardiac output
107
where are beta 2 receptors found
in the lungs - bronchodilator
108
where are beta 3 receptors found
in fat cells - lypolisis in adipose tissue
109
what type of receptors are alpha and betas
they are G protein coupled receptors (intracellular messengers)
110
how does noradrenaline stimulate receptors
stimulates alpha receptors more than beta receptors
111
how does adrenaline stimulate receptors
stimulates alpha and beta receptors equally
112
what are the three phases of the stress response
1. Alarm phase
2. resistance phase
3. exhaustion phase
113
what happens during alarm phase of the stress response
response is directed by the sympathetic nervous system and causes increased secretion of adrenaline
114
what happens in alarm phase pt.2
energy reserves are mobilised, mainly in the form of glucose
115
what happens in the resistance phase of the stress response
the dominant hormone is cortisol which is a glucocorticoid
116
what happens during exhaustion phase of stress response
homeostatic regulation breaks down and the exhaustion phase begins
the failure of one or more organ systems will prove fatal
117
what happens with mineral balance in the exhaustion phase of the stress response
the production of aldosterone throughout the resistance phase results in the conservation of Na at the expense of K, as body's K content declines, neurones and muscle fibres begin to malfunction
118
when does stress occur
when the perceived demands of a situation are appraised as exceeding a person's perceived resources and ability to cope
119
what is the role of appraisal
Lazarus argued that stress involved in a transaction between the individual and their external world, and that a stress response was elicited if the individual appraised a potentially stressful event as actually being stressful
120
what is primary appraisal
when the individual initially appraises the event itself
121
how can an event be appraised
1. irrelevant
2. benign and positive
3. harmful and a threat
4. harmful and a challenge
122
what is the secondary appraisal of stress
the individual evaluating the pros and cons of their different coping strategies
123
what happens during acute stress response according the Cannon
- increased sympathetic activation
- increased cognitive performance
- increased muscular priming
- increased immune functioning
124
what happens during chronic stress response according to Cannon
- decreased immune functioning
- decreased cognitive functioning
- this eventually leads to exhaustion
125
what are the three distinct functional states of sodium channels
resting, open, refractory
126
what class of drug is lidocaine
class Ib
127
what is PTSD
ir is a condition where exposure to an intense and frightening emotional experience leads to lasting changes in behaviour, mood and cognition
128
major symptoms of PTSD:
feeling numb to the world, reliving trauma repeatedly, sleep disturbances, over alertness
129
what is category A of PTSD
exposure to an event involving actual/threatened death or serious injury
130
what is category b of PTSD
1+ symptoms of reliving the trauma repeatedly
131
what is class C of PTSD
3+ symptoms of persistent avoidance of trauma stimuli or numbing of general responsiveness
132
what is category D of PTSD
2+ symptoms of persistent increased arousal
133
how is PTSD diagnosed
had symptoms for one or more months
134
how is prevention of PTSD better achieved
through the support offered by others who were also involved
135
what is the primary goal of CBT for PTSD
undergo some sustained emotional processing of the traumatic experiences
136
what is CBT
A structured therapy that focuses on clearly identified and achievable treatment goals
137
what is the aim of CBT for PTSD patients
to desensitise the patient to the traumatic event
138
other aim of CBT
to modify unhelpful and maladaptive beliefs and to generate more flexible rational and adaptive beliefs
139
what is the bystander effect
psychosocial phenomenon in which someone is less likely to help and intervene in an emergency situation when other people are present
140
what is pluralistic ignorance
everybody in the group misleads everybody else by defining the situation as a non-emergency
141
what causes a person to not react to a clear cut emergency
diffusion of responsibility
142
what is catamenial pneumothorax
pneumothorax caused by endometriosis of a woman at the time of menstruation
143
what does monoaimine oxidase do
breaks down norepinephrine molecules after they have been released in the sympathetic synapse
144
do you get a decrease of blood pressure as a result of PTSD
no
145
what is the alveolar pressure required to draw in 0.5L of air in normal inspiration
-1mmHg
146
how does adrenaline lower cAMP levels
acts on the alpha 2 adrenergic membrane receptors
147
what pulse rate suggests a tension pneumothorax
pulse over 135bpm
148
what is first line treatment for PTSD
eye movement desensitisation and reprocessing
149
the activation of what receptor leads to peripheral vasoconstriction
alpha receptors
150
where are chest drains placed
best paced between the 5th and 6th ribs, anterior axillary line
151
what channels does lidocaine block
sodium channels
152
what is the brand name for lidocaine
Xylocaine
153
mode of action of lidocaine
- stabilises the neuronal membrane by inhibiting the ionic fluxed required for the initiation and conduction of pulses, thereby effecting local anaesthetic action
154
mode of action of lidocaine pt2
at sodium channels, neutral uncharged lidocaine molecules diffuse through neural sheaths into the axoplasm where they are subsequently ionised by joining with hydrogen ions. the resultant lidocaine cations are then capable of reversibly binding the sodium channels from the inside and keeping them locked in an open state that prevents nerve depolarisation. as a result, the membrane of neurone will ultimately not depolarise and thus fail to transmit an action potential.
155
what neurone does not depolarise when lidocaine is used
postsynaptic
156
Hypothalamic Pituatary-Adrenal System
- the stressor activates the HPA
- the hypothalamus stimulates the pituitary gland
- the pituitary gland secretes adrenocorticotropic hormone (acth)
- ACTH stimulates the adrenal glands to produce the hormone corticosteroid
- cortisol enables the body to maintain steady supplies of blood sugar
- adequate and steady blood sugar levels help a person cope with a stressor
157
functions of cortisol
releases stored glucose from the liver, controls swelling after an injury and also surpasses the immune system
158
true or false: chronic stress is maladaptive
true
159
oxygen needs of the body
250ml/min at rest
160
carbon dioxide production:
200ml/min at rest
161
what is the functional residual capacity
when respiratory muscles are relaxed the lung volume at this point is the FRC
162
why does a lung collapse?
when the pleural pressure is equal to the atmospheric pressure there is no force to counter the elastic recoil force
163
what is airway resistance proportional to:
length/radius
164
what cells are in the trachea
ciliated epithelium
165
what cells are in the primary bronchus
basal cells
166
secondary and tertiary bronchus have what cells
goblet cells and club cells
167
what cells do smaller bronchi, bronchioles and terminal bronchioles have
serous cells, brush cells and club cell
168
what cells do respiratory bronchioles and alveolar sacs have
alveolar type I and II cells
169
how many alveolar sacs are there on average
150 million
170
lining cells:
ciliated, intermediate, brush, basal epithelium
171
contractile cells:
smooth muscle
172
secretory cells:
goblet, mucous, serious (glands)
173
connective tissue:
fibroblast, interstitial cell produce elastin, collagen, proteoglycans, cartilage
174
neuroendocrine:
nerves, ganglia, neuroepithelial cells
175
vascular cells:
endothelial, smooth muscle, pericyte
176
immune cells:
mast cell, dendritic cells, lymphocyte, eosinophil, macrophage, neutrophil
177
functions of airway macrophages
- induction of inflammation: pathogens
| - inhibition of inflammation: clearance of self cells and extracellular matrix turnover products
178
type I alveolar cells
simple squamous epithelium, non-ciliated and main site of gas exchange - covers 90% of alveolus
179
type II alveolar cells
produce surfactant to reduce surface tension preventing alveoli collapse and renew of type I cells
180
what are the four types of clinical studies
randomized controlled trials (RCTs), cohort studies, case-control studies and qualitative studies
181
what is a randomised control study
A randomized controlled trial is a form of scientific experiment used to control factors not under direct experimental control.
182
what is a cohort study
A cohort study is a particular form of longitudinal study that samples a cohort, performing a cross-section at intervals through time. It is a type of panel study where the individuals in the panel share a common
183
what is a case control study
case–control study is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribut
184
what is a qualitative study
Qualitative research investigates the why and how of decision making, not just what, where, and when. Therefore, the need is for smaller but focused samples rather than large random samples. Qualitative analysis involves categorizing data into patterns as the primary basis for organizing and reporting results.
185
what does the carotid body detect that the aortic body does not
pH
186
what valves does thematic fever effect
mitral and aortic valves
187
what us cause of rheumatic fever
group A beta-haemolytic streoptocci
188
what immunoglobulin is most likely to cause rheumatic feeer
IgM
