Respiratory Flashcards
What is the most superior portion of the respiratory tract?
The nose/nasal cavity
What is the function of the nose/nasal cavity?
Increase the temperature of the air, increase the humidity, filter the air and take particles to be swallowed.
What is the inside of the nose like?
Initially skin with hairs in the vestibule then the SA is doubled by the turbinates which are inside
Describe the Turbinates and area around them.
Superior meatus - olfactory epithelium, cribriform plate and sphenoid sinus.
Middle has semi-lunaris sinus openins and inferior as nasolactimal duuct
What are the names of the sinuses?
Frontal, Maxillary, ethmoid and sphenoid
Describe the frontal sinus
in frontal bone in midline septum over the orbit and across superciliary arch. innervated by opthalmic division of trigemina V
Describe the mailiary sinus
opens into the middle meatus through the hiatus semilunaris
Ethmoid sinus describe it.
they are labyrinthine between the eys through the semilunar hiatus as well opthalmic and maxillary trigeminal nerve
Sphenoid sinus
is medial to the cavernous sinus inferior to optic canal duran and pituitary gland it empties into the sphenoethmoidal recess lateral to the nasal septum innervated by opthalmic divison of the trigeminal nerve
what are the boundaries and sections of the pharynx
skull base to C6, split into nasopharynx oropharynx and laringopharynx
What happens in the nasopharynx
Eustachian tube enders with the ears
What are the names of the laryngeal cartilages?
Single- epiglottis, theyroid and cricoid
Double Cuneiform Corniculate and Arytenoid
What is the innervation of the larynx?
The vagus suplies all of the innervation to the larynx.
there are two branches the Superior laryngeal nerve and the recurrent larengeal nerve.
The superior larengeal provides sensory to above the glottis and the external branch does the motor inntervation to cricothyroid.
the recuurant larengeal nerve provides sensort innervation to the infra glottis, and motor innervation to all the internal muscles other than cricothyroid
Where is the Carina?
T4/5
What shape is the trachea?
Oval
What shape are tracheal cartilages?
Semicircular cartilages
What is the difference between the right and left main broncus?
the right is shorter 1-3cm long and more vertically disposed the left is less vertical and longer at 5cm
What is the lingular lobe?
probably reminant of left middle lobe
What are the names of the lobes of the lungs?
Right- upper lower(with linguilla)
Left upper, middle and lower lobe
What are the divisions of the lungs?
lungs lobes segments
name the airways names
Trachea, R/L main bronchus, lobar bronchi, segmental bronchi, terminal bronchiole(end of conduction), respiratory bronchioles alveolar duct alveoli.
What is the lung acinus?
Functional unit of the lung made of many small alveoli
What are the types of cells in the Alveoli?
Type 1 surface area, Type 2 surfactant, Alveolar macrophages basement membrane and capillary endothelial cells
What is difference of the visceral and parietal pleura?
Visceral adherent to the lungs, single cell layer has only autonomic(stretch) receptorsparietal is on walls has pain sensation
What is the bronchial circulation?
Bronchial circulation, is the blood suply to yhe lung and the pulmonary arteries follow the bronchi.
What is the rough svolume of air through the lungs in a minute?
5litres
which nerve innervates the diaphragm?
the phrenic C3,4,5
What is the significance of the interpleural space?
has a few mililitres of fluidto lubricate its is a potential space
What is ventilation and perfusion?
ventilation is the movement of air in and out of the lung. perfusion is a blood supply to the area of the lung.
What is dead space?
volume of air not contributing to ventilation?
What are the divisions of dead space?
Anatomic 150mls and alveolar 25mls isn’t much blood there so physiological dead space is both 175ml
What can affect the perfusion of a lung?
pulmonary artery pressure, pulmonary venous pressure and alveolar pressure.
What is hypoxic pulmonary vasoconstriction?
when there are low levels of oxygen in the lung the vessels constrict
PaCO2, PACO2 Pi O2 mean what?
arterial CO2 alveolar CO2 pressure of inspired O2
Vdot A V dot CO2 mean what?
alveolar ventilation and CO2 production
How is CO2 carried in the blood?
Dissolved in plasma, Attached to haemoglobin and as carbonic acid
What are physiological causes of high CO2?
reduced minute ventilation, shallow rapid breathing as lots is dead space, Vdot A reduced by increased dead space ventilation, Increased CO2 production
What is the equation for arteriolar CO2
k times Vdot CO2 (prod)/ Alveolar ventilation
What is the alveolar gas equation?
PAO2=PiO2- PaCO2/Resp quotient.
What cause hypoxaemia low O2
Alveolar hypoventilation, reduced O2 pressure V/Q mismatch and diffusion abnormality.
What factors affect binding of Oxygen with Haemoglobin?
CO, 2,3 DPG, pH, temperature
What does carbonic anhydrase catalyse?
The joining of carbon dioxide and water.
What are the non immune defences of the lung?
Cough nasal hairs mucus cilia
What are the features of inflamation?
Calor (heat) Rubor (redness) Dolor (pain) Tumour (swelling) Functio laesa (loss of function)
What are the physcial inflamatory features?
Vasodilatation leadint to more plasma exudation, activation of biochemical cascades, migration of leukocytes into the tissues such as neutropils and monocytes
What is the double edged sword in body’s response to disease?
Inflamation fights infection but lots of people will die from inflamation.
What is the cause of COPD?
smoking fossil fuels etc but due to inflamation in the lungs
What is ARDS?
Respiratory failure, water and neurtrophils fill the alveoli is part of multi-system failure. untreatble but supportive care. there is endothelial leak leadind to stiff lungs, there is shunting v/Q mismatch, the pulmonary constricution reduced cardiac output
Adaptive immune cells are made where?
in the bone marrow
What is the origin of the blood cells?
haematopoeitic stem cells.
How does inflamation become initiated?
The epithelium produces hydrogen peroxide when dammaged. this response is amplified by specialist macrophages like Kupffer alveolar macrophages histocytes. the response is done by recognising pathogen associated molecular patterns or damage associated molecular patterns.
What are alveolar macrophages?
They are macrophages that absorb bacteria and probe environment there are many difference with macrophages within one tissue.
What percentage of wbc are neutrophils?
70%80 millin are made each minute. they contain granules wich release myeloperoxidates elastase or secondary receptors lysoszyme and collagenase
How can neutrophils be turned off?
macrophages can absorb neutrophils and change type.
what are the roles of neutrophils?
activation after identification, adhesion, migration/chemotaxis, phagocytosis, bacterial killing
Describe the neutrophil receptors?
recognise cell walls lipids and peptides of bacteria
host mediator cytokines
host opsonins like immunoglobulins. and adhesion molecules
Describe nutrophil activation
stimulus response coupling, signal transduction pathways and release granules
Describe neutrophil adhesion
margination- selectins where they go to endothelium, adhesion integrins to migrate through the wall require a change in neutrophil and endothelium
Describe neutrophil migration
ability to dectect concentration gradient and move along the gradient
Describe phagocytosis
invagination called phagoome, and granules joing called a phagolysosome
Describe neutrophil bacteral killing
lysosomal enzymes elastase and reactive oxygen species. ROS generated there are many and genetic prolems can affect.
What is airway tone?
the contraction or relaxation of muscle in the airways.
What are some differences between asthma and COPD?
Asthma- usually younger than 50 not linked to smoking, infrequent sputum, lots of allergies, stable with exacerbations, normalise spiromitry with treatment, intrmittent symptoms, responds to treatment.
COPD- Usually older than 35, 10 pack year, comon in chronic bronchitis, no link with allergies, progressive with exacerbations, unlikely to improve persistent symptoms, doesn’t respond well to treatment there is a lot of asthma
What regulates the airways smooth muscle tone?
the autonomic nervous system and is regulated by inflamation.
Describe the effect of the parasympathetic nervous system on the airways
it causes bromchoconstriction the vagus nerve does this, they release acetyl choline which acts on muscarinic receptors(M3) in muscle cells.
How can excessive bronchoconstriction be treated?
You use drugs that inhibit/ block the M3 receptor called anti-cholinergics or anti-muscarinics
What are SAMAs?
Short acting muscarinic antagonists. They include ipratropium bromide (Atrovent) which can be used as inhaled treatment to relax airways they arent used too often as long acting are bettter, are uses in acute management
What is a LAMA?
long acting muscarinic antagonist. They have a long duration of many hours such as tiotropium they increase bronchodilation. they seem to reduce acute attacks they also affect the mucus production
What is the effect of the sympathetic nervous system on the airways?
Release noradrenaline with activates adrenergic receptors there are alpha and beta. in humans they mainly do blood vessels but also do the smooth muscle beta 2 receptor acivation causes relaxation of smooth muscle
What is a SABA?
Short acting beta2 agonists such as salbutamol.
What is a LABA?
Long acting beta 2 agonist like salmeterol or formoterol.
How are SABA/LABAs given for asthma?
With steroids, uses in acute rescue of bronchoconstriction and to prevent bronchoconstriction which reduces rates of exacerbations
What are the adverse effects of Beta2 agonists?
drives potassium into the cells so causes low levels in the blood, it can increase the heart rate. can cause hyperglycaemia.
What is the main factor the governs drug deposition and other factors?
particle size makes a difference. The device(dry powder inhalter or mdi) the flow rate of inhalation, underlying disease or regional differences in lung ventilation
What is important about asthma treatment?
concordance is low, inhaler education is key and correct device selection is vital
What are the goals of asthma treatment?
Get control of symptoms, relief of symptoms
What are the immeiate management of asthma?
Oxygen up to 60%, Salbutamol nebuliser prednisolone(steroid tablet), give magnesium or aminiphylline IV
What are the functions of the lungs?
Oxygenation of blood, release of carbon dioxide, synthesis activation and inactivation of vasoactive substances, hormones, neuropeptides, lung defence speech vomiting defecation childbirth
What are the three levels of defence in the lung?
intrinsic, innate, and adaptive
What are some of the nonspecfic defence mechanisms in the respiratory system.
Anti-proteases lysoszomes phospholipase A, Anti fugal peptides ant microbial peptides, surfactant that can opsonize pathogens for phagocytosis. there are also non-pathogenic bacteria.
What is the biggest defence in the lungs?
mucus production and release with cilliary escalator
What is the host defence in the alveolar gas exchange?
surfactant and a physical barrier
What is periculliary fluid?
the fluid around the cilia wafts the fluid and the mucous moves over the top.
What is coughing?
reflext to expell foreign bodies, or an irritating particulate. can be volunatry and involuntary
What is sneezing?
it is an involuntary expulsion of nasal irritation. from pollen smoke or too much fluid.
How do cells come back after dammage?
spreading and dedifferentiation and then cell migration and proliferation and re differentiation but doesn’t get fully better. this is functional plasticity
what happens if a bronchiole is blocked?
the gas exchange is blocked, then bacteria and bad can’t get out causes infection.
What can cause a mucus plug?
goblet cell metaplasia where there are too many goblet cells due to tissue damage.
What are the named volumes on a analysis graph that you might have?
Total lung capacity, vital capacity, residual volume, inspiratory reserve volume, expiratory reserve volume, forced tidal volume, functional residual capacity, inspiratory capacity.
What are other measured values?
FEV1 forced expiratory volume in one second, FVC forced vital capacity, peak expiratory flow, lung volumes transfer factor estimates
What is the difference between volume time and flow volume plots?
volume time is steep curve to plateau. flow volume is a steep upward curve then slower plateau to 0 flow after. in normal person it should be a straight line after PEF has been reached.
What are important things to note on flow/volume plot?
Peak flow is top point, FEF is the flow at when 25% has been exhaled.
What are the units for peak flow?
L/min. can use a peak flow or spirometer. they need to blow very hard! (effort dependent)
What are the problems with measuring the total lung capacity?
can’t expel all the air in the lungs only the forced vital capacity.
How can total lung volume be measured?
Gas dilution- doesnt measure air in communicating bullae closed circuit helium or open circuit nitrogen washout. with helium known amount added and when you breath out measures concentration
Body box or plethysmography- can measure gas in bullae, patient pants with open glottis against a shutter to produce changes in the pressure of the box in proportion to the volume of air in the chest.
How can we estimate transfer rates?
Using carbon monoxide to estimate DL CO wich is a measure of interaction of alveolar surface area alveolar capillary perusion capillary volume and haemoglobin concentration. need 10 second breath hold.
What is a low FEV1?
Anything about 80% or greater of you predicted value.
What is it called when FVC is lower than 80% of predicted value?
Airways restriction.
What is FEV1/FVC when its lower called?
less than 0.7 is airways obstruction this reduces with age.
What does an astmatic flow volume loop?
the lower one is scalloped and the FEV1 is lower
What are the blood gases in acute asthma?
PaO2 normal, Pa CO2 low,pH normal or elevated,HCO3 normal
What are the flow loop for a COPD patient?
scalloped and lower PEF.
What are the symptoms of asthma?
Airways obstruction and PEF variation but variable problems. normal or reduced FEV1 normal FVC, PEF usually lower at times, MEF scalloped TLC high or normal, normal DLco
What are the symptoms of COPD?
FEV1 reduced significantly, FVC may be normal or reduced, PEF not variable, MEF low scalloped shape, Low transfer rates.
What is dynamic hyperinflation?
refers to the increase in end-expiratory lung volume (EELV) that may occur in patients with airflow limitation when minute ventilation increases. pasically tidal levels increased
What is COPD blood gas like?
low PaO2 High Pa CO2 in type 2 low in type 1 pH normal may have elevated HCO3 if chronic acidosis is present.