Lungs and respiratory system Flashcards
Valsalva manoeuvre is
forced expiration against a closed glottis
4 phases of valsalva manoeuvre
initial pressure rise, reduced venous return and compensation, pressure release, return of cardiac output
3 types of cycles for ventilators
pressure cycled, time cycled, volume cycled
ventilators can be invasive or
non-invasive
2 types of pressure ventilator
positive or negative pressure ventilators
main mechanism of action of positive pressure ventilators
increased pressure within airways - air pushed into trachea
two types of positive pressure ventilators
flow generator, pressure generator
flow generator usually used on
adults
pressure generator usually used on (2)
children, adults when control of peak airway pressure is important
flow generator produces known pattern of gas flow during
inspiration
in flow generator, lungs fill at rate entirely controlled by
ventilator
pressure generator produces preset pressure in airway and rate of lung inflation depends on pressure generated by ventilator and on
respiratory resistance and compliance
negative pressure ventilation reduces …….. which sucks air into …….
ambient pressure around thorax….. lungs
negative pressure ventilation uses rigid chamber which encloses thorax or whole body below neck - pressure in tank is
reduced cyclically
negative pressure ventilation is used for
long term respiratory support or for overnight use on patients with respiratory muscle weakness
intermittent positive pressure ventilation is used during
surgical procedures that require muscle relaxation
intermittent positive pressure ventilation used in ICU when patient is …………. or …………..
sedated or paralysed, unable to make any respiratory movement
intermittent mandatory ventilation allows patient to
breath spontaneously
synchronised intermittent mandatory ventilation avoids
stacking of ventilator - delivering mandatory breath during period of spontaneous breath
mandatory minute ventilation monitors ……….. in order to top up …..
exhaled volumes, patient’s respiratory efforts
inspiratory pressure support = patient initiates breath and ventilator
raises airway pressure to a preset value
in inspiratory pressure support, at end of inspiration, positive airway pressure is removed to allow
unimpeded expiration
positive end expiratory pressure is particularly useful in patients who are ……… or ……….. because there is a reduced ………. which leads to underventilation and a ………
anaesthetised or comatose; functional residual capacity; mismatched ventilation-perfusion balance
46000 non-smokers die from … each year due to second hand smoke
CHD
second hand smoke causes more than ….. premature deaths per year
600 000
PULMONARY OEDEMA: excessive collection of watery fluid in lungs > collects in ….. > difficulty breathing
alveoli
PULMONARY OEDEMA: most common cause =
heart failure
PULMONARY OEDEMA: can be caused by
conditions affecting heart
PULMONARY OEDEMA: 7 causes
heart failure (increased pressure in pulmonary vessels), damage to lung capillaries, failure of lung lymphatics, kidney failure, lung damage, major injury, high altitude
PULMONARY OEDEMA: reduction in cardiac output > fall in effective circulating volume and arterial filling > activation of …..-……-….. system, non-osmotic release of …, increased activity of renal sympathetic nerves > increased renal and ….. arteriolar resistance > water and …. retention > extracellular volume expansion and increased …. pressure > oedema
renin-angiotensin-aldosterone; ADH; peripheral; sodium ion; venous
8 respiratory system functions
O2/CO2 exchange, speech and vocalisation, pH and H+ control, smell, control of BP (angiotensin), pressure gradients promoting flow of venous blood and lymph, filtering of small blood clots, breath holding (expelling abdominal contents - Valalva Manoeuvre)
6 principal organs of respiratory system
nose, pharynx, larynx, trachea, bronchi, alveoli
Conducting division of respiratory system = from …. to ….. Only involved in … not gas exchange
nostrils; bronchioles; airflow
respiratory division of respiratory system involved in airflow and … …../ components = …. and other gas exchange regions of distal airway
gas exchange; alveoli
upper respiratory tract = nostril > …
pharynx
lower respiratory tract = ….. > alveoli
larynx
3 parts of pharynx
nasopharynx, oropharynx, laryngoparynx
trachea and bronchi have what type of epithelium
pseudostratified columnar
trachea pseudostratified columnar epithelium mainly made up of which 3 cell types
goblet cells, ciliated cells, short basal stem cells
2 types of gland in connective tissue beneath tracheal epithelium
mucous glands, serous glands
bronchioles have what type of epithelium
ciliated columnar
alveolar ducts and smaller divisions have what type of epithelium
non-ciliated squamous
2 types of alveolar cell
squamous (type I) alveolar cells, cuboidal great (type II) alveolar cells
which type of alveolar cell are larger (thin and broad) and cover more surface area (~95%)
squamous (type I) alveolar cells
which type of alveolar cell are more numerous but smaller and occupy less surface area (~5%)
cuboidal great (type II) alveolar cells
2 functions of great alveolar cells
repair epithelium when squamous cells damaged, secrete pulmonary surfactant
what is pulmonary surfactant
mixture of phosopholipids and protein
where does pulmonary surfactant coat
alveoli and smallest bronchioles
pulmonary surfactant prevents collapse of alveoli upon …
exhalation
what makes up respiratory membrane
1 squamous alveolar cell, squamous endothelial cell (capillary) and shared basement membrane
respiratory membrane is how thick?
0.5μm
3 functions of pleura and fluid (pleural cavity)
reduction of friction, creation of pressure gradient, compartmentalisation
accessory muscles of deep inspiration (7)
erector spinae, scalenes, sternocleidomastoids, pec minor, pec major, serratus anterior, internal intercostals (intercartilaginous part)
Muscles of quiet inspiration (3)
diaphragm, scalenes, external intercostals
Quiet expiration is
passive
Muscles of deep expiration (5)
internal intercostals (interosseous part), external and internal obliques, rectus abdominalis, transversus abdominis
Pneumothorax =
collection of air in pleural space
Latrogenic pneumothorax =
follows procedure e.g. biopsy, mechanical ventilation
Catamenial pneumothorax =
at time of menstruation - endometriosis
Traumatic pneumothorax =
follows chest trauma. can be open or closed
open traumatic pneumothorax =
damage to chest wall
closed traumatic pneumothorax =
chest wall undamaged
primary spontaneous pneumothorax =
no previous lung disease. Tiny blebs = foci of weakness > rupture
blebs of primary spontaneous pneumothorax =
small subpleural thin=walled air containing spaces
primary spontaneous pneumothorax most common in
young adults
secondary spontaneous pneumothorax more common in who
older people
people who develop secondary spontaneous pneumothorax usually have
underlying lung disease
secondary spontaneous pneumothorax usually follows rupture of
bulla/cyst of COPD
tension pneumothorax unique characteristic
engorged veins
tension pneumothorax has valve like mechanism where air can ….. pleural cavity but cannot ….
enter; leave
in tension pneumothorax, pleural pressure …. meaning ventilation and circulation are compromised
rises
safest place for chest drain
5th intercostal space, mid/anterior axillary line
oxygen given to people with pneumothorax to manage
hypoxia
eupnea =
relaxed, quiet breathing
apnoea =
temporary cessation of breathing
dyspnoea =
laboured, gasping, shortness of breath
hyperpnoea =
increased rate and depth of breathing
hyperventilation =
increased pulmonary ventilation - high blood pH
hypoventilation
reduced pulmonary ventilation - low blood pH
Kussmaul respiration =
deep rapid induced by ACIDOSIS
Orthopnoea =
dyspnoea when lying down
tachypnoea =
accelerated respiration
ventral respiratory group has …. and …. neurons - inhibitory fibres (only one fires at once) used for deep respiration
inspiratory and expiratory
neurons of dorsal respiratory group are to the integrating centres in the spinal cord > phrenic nerves to …..; intercostal nerves to ….. for inspiration
diaphragm; external intercostals
dorsal respiratory group controls ….. and …..
inspiration and respiratory rhyhm
dorsal respiratory group has ….. centre only
inspiratory
ventral respiratory group innervates lower motor neurons controlling ……
accessory muscles of respiration
pontine respiratory group receives input from
higher brain centres
pontine respiratory group hastens/delays transition from …. to ….
inspiration; expiration
pontine respiratory group adapts breathing to special circumstances such as (4)
sleep, exercise, vocalisation, emotional reponses
T1-…. power intercostals (inspiration)
T12
T6-… power abdominals - cough, expel, balance and posture
T12
Boyles law =
pressure of gas irreversibly proportional to volume
Charles’s law =
volume of gas proportional to temperature
Dalton’s law =
total pressure of gas mixture = sum of all partial pressures
Henry’s law =
at air water interface ,amount of dissolved gas is determined by solubility and partial pressure in air
INSPIRATION: ribs swing up > parietal pleura follows > visceral pleura follows > alveoli stretched > lung expands > pressure …. > inflow of air
drops
intrapulmonary pressure =
pressure inside respiratory tract at alveoli
On quiet inhalation, intrapulmonary pressure =
-1mmHg
On quiet exhalation, intrapulmonary pressure =
+1mmHg
Intrapleural pressure usually
-4mmHg
Intrapleural pressure drops to …. during inspiration (quiet)
-6mmHg
Intrapleural pressure rises to …. during expiration (quiet)
-3mmHg
Pneumothorax develops because without negative interpleural presure, ……… leads to collapsed lung
elastic recoil
3 factors affecting resistance to airflow
diameter of bronchioles, pulmonary compliance, surface tension of alveoli and distal bronchioles
bronchodilation stimulated by (2)
epinephrine and norepinephrine
bronchoconstriction stimulated by (4)
histamine, acetylcholine, cold air, chemical irritants
pulmonary compliance =
stiffness of lungs
pulmonary surfactant disrupts …. > resists compression due to water and ….. components
hydrogen bonds; hydrophobic
hypoxia =
deficiency of oxygen to tissue/ inability to use oxygen
hypoxaemic hypoxia =
low arterial PO2 > usually due to inadequate pulmonary gas exchange
Ischaemic hypoxia =
inadequate blood circulation
Anaemic hypoxia =
anaemia > oxygen carrying capacity of blood
Histotoxic hypoxia =
metabolic poison prevents tissue using oxygen
hypoxia often marked by
cyanosis
5 factors that effect gas exchange in lungs
pressure gradients of gases, solubility of gases, membrane thickness, membrane area, ventilation-perfusion coupling
tidal volume =
air inhaled/exhaled normal breathing
minute volume =
air exhaled per minute
vital capacity =
exhaled after maximum inspiration
functional residual capacity =
remaining in lungs after normal expiration
total lung capacity =
volume of lungs when maximally inflated
forced vital capacity =
forcibly and quickly exhaled after maximum inspiration
forced expiratory volume =
exhaled during 1st 2nd 3rd second etc of FVC
forced expiratory flow =
average rate of flow during middle half FVC test
Peak expiratory flow rate =
maximum volume during forced expiration
BRUCE protocol -
exercise tolerance testing - 20 minutes can be modified
patients with obstructive lung disease have
narrowed airways
examples of obstructive lung disease (2)
COPD, asthma
in obstructive lung disease FEV1/FVC ratio appears
low
obstructive lung disease if FEV1 less than or ration or less
80%; 0.7
GOLD criteria COPD: mild COPD > FEV1 = …% or more and has … spirometry after bronchodilator
80%; normal
GOLD criteria COPD: moderate COPD > FEV1 = …-….% after ….
50-79%; bronchodilator
GOLD criteria COPD: severe COPD > FEV1 = …-….% after ….
30-49%; bronchodilator
GOLD criteria COPD: moderate COPD > FEV1 = less than ….% after ……
30%; bronchodilator
patients with restrictive lung disease cannot
fully expand lungs
patients with restrictive lung disease have FEV1/FVC ratio that appears
normal
example of restrictive lung disease
pulmonary fibrosis
type I respiratory failure is hy……. and is due to ………..
hypoxaemic; ventilation-perfusion mismatch
type I respiratory failure has PaO2 less than …. with …… PaCO2
60mmHg; normal/low
In type I respiratory failure, hyperventilation increased carbon dioxide removal but does not increase
oxygenation
Type I respiratory failure can be seen in (3)
pulmonary oedema, pneumonia, acute asthma
type II respiratory failure is hy…..
hypercapnic
type II respiratory failure has … CO2 (…… 50mmHg)
high; more than
type II respiratory failure often due to
ventilation-perfusion mismatch
acute type II respiratory failure usually has pH less than
7.3
chronic type II respiratory failure usually has pH ….. due to renal compensation and increase in …..
only slightly decreased; bicarbonate
People with COPD often have …… respiration
pursed lip
Chest x ray COPD often normal but 4 things which could be seen
bullae, overinflation, flattened diaphragm, deficiency of blood vessels in peripheral half of lung fields
COPD can be caused by ….. deficiency
alpha1- antitripsin
alpha1 antitripsin is a glycoprotein usually produced in the ….. that inhibits ……..
liver; neutrophil elastase
gene for alpha 1 antitripsin is on chromosome …
14
hereditary alpha 1 antitripsin deficiency accounts for ~….% of emphysema cases
2
3 main phenotypes for alpha1 antitripsin
MM (normal), MZ (Heterozygous deficiency), ZZ (homozygous deficiency)
1 in how many people are homozygous for alpha1 antitripsin deficiency?
1/5000
homozygotes for alpha1 antitripsin deficiency who develop breathlessness under 40 have radiographic evidence of …… and are usually ….
basal emphysema; cigarette smokers
pneumonia = infection of lung ……, alveoli and airways - usually with virus or ….
interstitium; bacterium
3 classifications of pneumonia by locality
CAP (community acquired), HAP (hospital acquired), VAP (ventilator acquired)
2 classifications of pneumonia by localisation
bronchopneumonia, lobar pneumonia
3 classifications of pneumonia by mechanism/pathogen
bacterial pneumonia, viral pneumonia, aspiration pneumonia
6 symptoms of pneumonia
cough (dry/phlegm), rapid HB, fever, breathlessness, fatigue, headaches
4 risk factors for pneumonia
babies/very young children, elderly, smokers, health conditions/weakened immune system
incidence of pneumonia =
5/1000
pneumonia makes up for …-…% of all lower respiratory tract infections with 1/…. requiring hospitalisation
5-10%; 1/3
COPD is characterised by
airway obstruction which is usually progressive and not fully reversible
COPD = chronic bronchitis +
emphysema
6 risk factors for COPD
tobacco smoke, indoor air pollution, outdoor air pollution, occupational dusts and chemicals, cannabis use, frequent lower respiratory tract infections during childhood
percentage of adult population with COPD
10%
….% of people with COPD die within 5 years of diagnosis
25%
COPD causes how many deaths per year?
30 000
121 symptoms of COPD
smoker/exsmoker 35+; exertional breathlessness; chronic cough; regular sputum production; tachypnoea; palpable liver edge; wheeze; winter exacerbations; tar staining of fingers; central cyanosis; FEV1/FVC ration less than 0.7; barrel chest
3 types of pulmonary fibrosis
replacement fibrosis, focal fibrosis, diffuse parenchymal lung disease
replacement fibrosis =
secondary to lung damage
focal fibrosis =
response to irritants
diffuse parenchymal lung disease =
in fibrosing alveolitis (idiopathic pulmonary fibrosis) + extrinsic allergic alveolitis
3 distributions of pulmonary fibrosis
localised (unresolved pneumonia), bilateral (TB), widespread (drug use)
most common cause of pulmonary fibrosis
idiopathic
3 presentations of pulmonary fibrosis
acute, subacute, chronic
acute pulmonary fibrosis =
fulminant, progressive, remitting, resolving course
subacute pulmonary fibrosis =
resolving, remitting, relapsing, progressive course
chronic pulmonary fibrosis =
insidious and slowly progressive
PROCESS OF PULMONARY FIBROSIS: (1) macrophages and alveolar epithelial cells are activated by several mechanisms > produce growth factors including (4)
fibronectin, platelet-derived growth factor, transforming growth factor beta and IGF-I
PROCESS OF PULMONARY FIBROSIS: (2) fibronectin, platelet-derived growth factor, transforming growth factor beta and IGF-I stimulate the deposition of type I and type II ….
collagens
PROCESS OF PULMONARY FIBROSIS: (3) there are two main features of pulmonary fibrosis: (1) cellular infiltration with ……… and plasma cells > thickening and fibrosis of alveolar walls
T lymphocytes
PROCESS OF PULMONARY FIBROSIS: (3) there are two main features of pulmonary fibrosis: (2) …. > increased cells within alveolar space (mainly macrophages and type II …… shed from alveolar walls)
ALVEOLITIS; pneumocytes
cigarette smoke contains plycyclic aromatic hydrocarbons and nicosamines which are potent carcinogens and mutagens > release enzymes from ……. and ….. > destroy elastin > lung damage
neutrophil granulocytes and macrophages
smoking and asbestos are …. in promoting bronchial carcinoma
synergists
4 effects of smoking on large airways
increase in submucosal gland volume, increase in number of goblet cells, chronic inflammation, metaplasia and dysplasia of surface epithelium
4 effects of smoking on small airways
increase number and distribution of goblet cells, airway inflammation and fibrosis, epithelial metaplasia/dysplasia, carcinoma
3 effects of smoking on parenchyma
proximal acinar scarring, increase in alveolar macrophage numbers, emphysema (centri-acinar/ pan-acinar)
11 cancer causing chemicals in tobacco smoke
tar, arsenic, benzene, cadmium, formaldehyde, chromium, polonium-210, 1,3-butadiene, polycyclic aromatic hydrocarbons, nitrosamines, acrolein
cytokines involved in systemic inflammation in COPD (4)
IL-I(beta), IL-6, IL-18, TNF alpha
acute phase proteins involved in systemic inflammation in COPD
CRP, SAA
smokers have …… within lumen which are capable of releasing …. and proteases > increase emphysema
neutrophil granulocytes; elastases
Imbalance between protease and …. can cause damage in airways
antiprotease
major serum antiprotease example
alpha-1 antitripsin
alpha1 antitripsin can be inactivated by
cigarette smoke
smoke has adverse effect on surfactant which causes …. of lungs
overdistension
CHRONIC BRONCHITIS: hypertrophy of mucus secreting …. in bronchial tree; increased number of … cells; increased …. production
glands; goblet; mucus
CHRONIC BRONCHITIS: infiltration of inflammatory cells - mainly
CD8+
CHRONIC BRONCHITIS: ulcers may form as squamous epithelium replaces
columnar cells
CHRONIC BRONCHITIS: progression of disease = progressive squamous cell …. and ….. of bronchial wall
metaplasia; fibrosis
EMPHYSEMA: classified according to site of damage - 3 types
centri-acinar emphysema, pan-acinar emphysema, irregular emphysema
EMPHYSEMA: centri-acinar emphysema = concentrated around respiratory bronchioles and …. alveolar ducts therefore alveoli are …..
distal; well-preserved
EMPHYSEMA: most common type =
centri-acinar
EMPHYSEMA: pan-acinar emphysema = distension and destruction involve
whole acinus
EMPHYSEMA: pan-acinar emphysema = in extreme form, lungs become mass of
bullae
EMPHYSEMA: pan-acinar emphysema = ventilation-perfusion ….
mismatch
EMPHYSEMA: pan-acinar emphysema = occurs in alpha1 ……. deficiency
antitripsin
EMPHYSEMA: pan-acinar emphysema = shows …….. shadowing
right lung base
EMPHYSEMA: irregular emphysema = scarring and damage affecting lung ….. patchily without regard for acinar structure
parenchyma
Long term, patients with emphysema become …. and respiration becomes …… driven
hypoxaemic; hypoxic
EMPHYSEMA: destruction of elastin > loss of lung elasticity > loss of pressure > …….
hyperinflation
2012, percentage of men who smoke
22%
2012, percentage of women who smoke
19%
2012, overall percentage of population who smoke
20%
nicotine = highly toxic …. and agonist of …… cholinergic receptors
alkaloid; nicotinic
nicotine stimulates neurons of autonomic ganglia and blocks ……..
synaptic transmission
nicotine induces peripheral vasoconstriction, tachycardia and therefore …. blood pressure
raises
nicotine in the brain binds to ….. neurons
dopaminergic
in adrenal medulla, nicotine binds to receptors on …. cells and ultimately causes release of …. into bloodstream
chromaffin; adrenaline
nicotine replacement therapy increases rate of smoking cessation by
70%