Resp Flashcards
What does mucus in respiratory epithelium do
Prevent dehydration of the epithelium
Trapped particles from inspired air
What are the swell bodies, where are they located and what are their significance
They are a thin plexus of blood vessels under the epithelium in the nose
They warm and humidify inspired air
They easily burst an cause nose bleeds
Where do each of the nasal sinuses drain into
Ethmoid drains into the upper turbinate
Maxillary drains into the middle turbinate
Frontal drains into the anterior aspect of the roof of the nasal cavity
Sphenoid drains into the posterior aspect of the roof of the nasal cavity
What is the olfactory epithelium and where is located
It is adapted for detection of odours and located in below the cribiform plate in the roof of the nasal cavity
The unmyelinated
What do the serous glands of Bowman and where are they found
They are found deep to the olfactory epithelium
They produce watery secretions that act as solvent for odorous substance
They irrigate the surface of the epithelium and refresh the olfactory epithelium
What is the difference between cilia and stereocilia
Stereocilia are immobile
What is the epithelium of the vocal cords
Stratified squamous epithelium
What is the epithelium of the larynx
Pseudostratified ciliated columnar epithelium with goblet cells (respiratory epithelium)
How many rings of cartilage hold open the trachea
12 - 15 C shaped rings
Which muscles lies at the back of the C shaped rings of the trachea
Trachealis muscle - it is smooth muscle
What kind of lymph nodes are found in the bronchi and how do they differ from normal lymph nodes
Part of the MALT (mucosa associated lymph tissue)
Normal lymph nodes are in a discrete encapsulated collection of lymphoid tissue
MALT are less discrete, do not have a capsule and are in mucosa
Difference between histology of the bronchi and the bronchioles
Bronchi contain hyaline cartilage
Bronchioles have no cartilage but a thick band of smooth muscle
Give some characteristics of the terminal bronchioles
They end the conducting part of the airways
Have simple cuboidal epithelium
Have clara cells
Lack cilia
Give some characteristics of the respiratory epithelium
They have simple cuboidal epithelium (form an acinus)
Non- ciliated
Are the terminal bronchiole bigger than respiratory epithelium
The respiratory epithelium is bigger than the terminal bronchioles
What do the type 2 pnuemocytes do
They synthesise store and secrete surfactant over the lining of the air sacs and facilitate inflation of the air sacs during inspiration
surfactant reduces surface tension and prevents desication
They are also stem cells from which Type 1 pnuemocyte come from
Length of air-blood barrier
Usually between 0.2 to 0.6um (same as 200 to 600nm)
If it is more than 1.2um then diffusion is seriously impaired
Which type of collagen lies in the walls of the alveoli
Reticulin (collagen 3)
What happens to particle- carrying alveolar macrophages, particle- carrying fixed septal macrophages and macrophages with large indigestible matter
Particle-carrying alveolar macrophages - enter respiratory and terminal bronchioles and into the musco-cilliary escalator
Particle-carrying fixed septal macrophages - remain in interstitium of lungs and enter lymphatics
Macrophages with large indigestible - macrophages fuse together to form giant cells, might induce granuloma formation
Give the layers of the blood- air barrier
Type 1 pnuemocytes
Basement membrane
Capillary endothelium
Give the nerve supply to the frontal sinus
The ophthalmic branch of the trigeminal nerve
Give the structures lining the outline of the maxillary sinus
Roof - floor of the orbit
Apex - zygomatic process of the maxill
Base - lateral wall of the nose
Floor - alveolar process near the teeth
Give the nerve innervating the maxillary sinus
The maxillary branch of the trigeminal nerve
Where does the maxillary sinus drain into
Through the hiatus semilunaris into the middle meatus
What nerve innervates the ethmoid sinus
The ophthalmic and maxillary branch of the trigeminal nerve
What structures lie close to the sphenoid sinus
Medial to the cavernous sinus which contains the carotid artery, cranial nerve 3, 4, 5 and 6
Inferior to the optic canal, dura and pituitary gland
What nerve innervates the sphenoid sinus
The ophthalamic branch of the trigeminal nerve
Where does the sphenoid sinus empty into
The sphenoethmoidal recess which is lateral to the nasal septum
Where does the ethmoid sinus drain into
Through the semilunar hiatus into the middle meatus
What does the internal superior laryngeal nerve do
Supplies sensation to all muscles of the larynx
How would you distinguish pulmonary arteries from pulmonary veins histologically
Pulmonary arteries have longitudinal elastic fibres running along their walls
Pulmonary veins have clearly defined media
What is the vestibule of the larynx
The area between the true and false vocal cords
Premature babies often experience a deficiency of surfactant in their lungs and this is because cells that produce surfactant develop late in gestation (28 weeks). What is the name of the condition and what does it cause
Infantile respiratory distress syndrome
There is lack of surfactant to reduce surface tension which makes it easier to inflate alveoli so there is widespread collapse of the alveoli
What does the ring of smooth muscle of the bronchioles do? What is its innervation and what is the consequence of continuous stimulation
Contraction of the smooth muscle causes bronchoconstriction (reduces lumen of the diameter of the bronchiole)
It is innervated by autonomic nervous system
parasympathetic nerves cause bronchoconstriction
Sympathetic nerves causes bronchodilation (beta-2-adrenoreceptors)
Continued contraction would cause
- reduced airflow
- seen in anaphylaxis and asthma
- causes breathlessness and a wheeze
What do the nasal sinuses do
Lower the weight of the skull
Add resonance to the voice
Humidify and warm inspired air
Lined by respiratory epithelium
Where can Reinkes space be found
In the vocal cords
It is stratified squamous epithelium encircling loose irregular fibrous tissue
Has almost no lymphatics
Lies superficial to the vocalis muscle
Order of airways
Trachea Main bronchi Lobar bronchi Segmental bronchi Bronchioles Terminal bronchioles (last of conducting airways) Respiratory brnchioles Alveolar duct Alveolus Alveolar sac
What is the purpose of clara cells
Oxidise inhaled toxins
Antiprotease function
Produce surfactant
Stem cell purpose
What does the interstitium of the alveoli contain
Collagen and elastin fibres
Fibroblasts
Macrophages
Pores of Kohn (holes in alveoli walls)
What is the purpose of the pores of Kohn and what is its significance
Holes in alveoli wall
Helps to equalise pressure between adjacent alveoli
Helps lungs to inflate evenly
Can allow infection to spread quickly
What is special about visceral pleura layers
Layer of mesothelial cells Fibrocollagenous connective tissue - irregular external elastic layer - interstitial fibrocollagenous layer - irregular internal elastic layer
Where do the intercostal veins drain into
The azygous vein on the right side and the hemi-azygous veins on the left side
Which nerves and blood vessels supply the foregut, midgut and hingut
Foregut - great splanchnic nerves arising from T5 - T9 (Coeliac axis)
Midgut - lesser splanchnic nerves arising from T10 - T11 (Superior mesenteric artery)
Hindgut - least splanchnic nerves arising from T12 ( Inferior mesenteric artery)
Where can pain be felt in the foregut, midgut and hindgut
Foregut - epigastrium
Midgut - umbillicus
Hindgut - suprapubic area
Where do the left and right vagus nerve enter the diaphragm and with which structure
They enter the diaphragm at T10 with the oesophagus
The left vagus nerve is anterior to the oesophagus
The right vagus nerve is posterior to the oesophagus
Where does the thoracic duct drain into
Into the confluence of the left subclavian vein and the internal jugular vein on the left side of the neck
What is trans-oesophagheal echo (TOE) used for
A trans-oesophagheal probe can be put into the oesophagus which is posterior to the mitral valve and can be used to get good images of it (sits on the posterior aspect of the heart)
What can damage to the stellate ganglion (T1) cause
Loss of sympathetic innervation to the face and eye No face sweating (anihydrosis) Drooping eyelid (ptosis) Constricted eye pupil (miosis) Eyes drawn in (enopthalmus) This is known as horners syndrome
What structures drain into the azygous vein
The posterior and lateral chest wall
The posterior and lateral abdominal wall
What do the sympathetic nerves attach to the central nervous system
T1 - L2
Where does the nasolacrimal duct drain into
The inferior meatus
What gives motor innervation to the cricothyroid muscle
The external superior laryngeal nerve (branch of the vagus nerve)
What gives motor innveration to the muscle of the larynx except the cricothyroid muscle
The left and right recurrent laryngeal nerve
What gives sensory innervation to the muscles of the larynx
The internal superior laryngeal nerve
Where does the right recurrent laryngeal nerve loop
Under the right subclavian artery in the neck
What can blood gas measure
PaCO2
PaO2
pH
HCO3-
What is health psychology
Health psychology emphasises the role of psychological factors in the cause, progression and consequences of health and illness
Aims to put theory into practice by promoting health behaviours and preventing illness
Give the 3 categories of health behaviours
Health behaviour
Illness behaviour
Sick role behaviour
What does health behaviour consist of
It is aimed at preventing disease (e.g eating healthily)
What does illness behaviour consist of
Aimed at seeking remedy (e.g like going to the doctor)
What does the sick role behaviour consist of
Any activity aimed at getting well (e.g taking prescribed medications and resting)
Give some examples of health damaging and health impairing behaviour
Smoking Alcohol and substance abuse Risky sexual behaviour Medication compliance Vaccinations
Give some examples of health promoting behaviour
Healthy eating Exercising Attending health checks Medication compliance Vaccinations
Give some examples of modifiable risk factors
Diet/ Excess weight (obesity) Smoking Alcohol intake Lack of exercise Sleep and stress
Give some examples of non-modifiable risks
Gender
Sex
Genetics/Family History
Give an example of a population level intervention
Health promotion - which is the process of enabling people to exert control over the determinants of health thereby improving health e.g
Health promotion campaigns like Change 4 Life, Stoptober, Movember, Everyone likes a drink but no one likes a drunk
Promoting screening and immunisations
- cervical smear screening
- MMR vaccine
Give an example of an individual level intervention
Patient centred approach - which give care responsive to individual needs
Give example of primary intervention at an individual’s behaviour, local community and population level using alcohol consumption
Individual’s behaviour - level of alcohol consumption and individual health outcomes
Local community - local alcohol sales, alcohol related crime and accident
Population level - national alcohol sales and consumption, national statistics on alcohol related crime and A&E events
What is unrealistic optimism
This is when individuals continue to engage in health damaging behaviour due to inaccurate perceptions of risk and susceptibility
Give factors that affect people’s perception of risk
- Lack of personal experience with the problem
- belief that the problem is preventable by personal action
- belief that if it has not happened by now, it is unlikely to ever happen
- belief that the problem is infrequent
Also Health beliefs Situational rationality Culture variability Socioeconomic factors Stress
Give some models and theories of behaviour change
- Health belief model (HBM)
- Theory of planned behaviour
- Stages of change (transtheoretical) model
- Motivational interviewing (MI)
- Social marketing
- Nudging (choice architecture)
- Financial incentives
- Social norms theory
Give the 4 aspects of the Health belief model
The individual will change if they believe;
- they are susceptible to the condition (e.g heart disease)
- it has serious consequences (e.g death)
- taking action will reduce susceptibility (e.g stopping smoking)
- the benefits of taking action outweigh the costs (e.g good health instead of heart failure)
Give the aspects of the theory of planned behaviour and give the 3 factors that determines intention
- Proposes the best predictor of behaviour is ‘‘intention’’
3 factors that determine intention
- a persons attitude to the behaviour = attitude
- the perceived social pressure to undertake the behaviour = subjective norm
- a persons appraisal of their ability to perform the behaviour = perceived behavioural control
Give examples of the 3 factors that affect the intention in the theory of planned behaviour model
Attitude = I do not think smoking is a good thing
Subjective Norm = most people who are important to me want me to give up smoking
Perceived behaviour control = I believe I have the ability to give up smoking
Behavioural intention - I intend to give up smoking
Explain the aspects the stages of change model (transtheoretical moel)
This models sees the individuals in discrete ordered stages rather than on a continuum
It proposes 5 stages of change;
Precontemplation (not ready yet) Contemplation (thinking about it) Preparation (30 days to get ready) Action (3 to 6 months of doing it) Maintenance (more than 6 months of the behaviour)
Give the 5 aspects of the transtheoretical model, the time required for it and examples with smoking
Precontemplation (not yet ready) - no intention of giving up smoking
Contemplation (thinking about it) - beginning to consider quitting smoking
Preparation (30 days to prepare) - getting ready to quit smoking
Action (3 to 6 months doing it) - engaging in giving up smoking now
Maintenance (more than 6 months dong it) - steady non-smoker
In the UK, how many people per year are affected by community acquired pneumonia and how many of these are admitted to hospital and die?
250000
33% are admitted to hospital
10% of those admitted to hospital die
Give some symptoms of acute respiratory distress syndrome?
Respiratory failure
Water and neutrophils fill the alveoli
Endothelial leak - mass of protein and fluid
Lungs - reduced compliance, increased shunting
Heart - hypoxia, pulmonary hypertension and reduced cardiac output
How are pathogens recognised in the body
Through pathogen recognition receptors (PRRs)
Like for signalling e.g Toll-like receptors (TLRs) and Nod-like receptors (NLRs)
Like for endocytic e.g Mannose receptors, Glucan receptors and Scavenger receptors
How is acute inflammation initiated
Epithelial cells produce hydrogen peroxide
Macrophages converge
They respond to pathogen associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs)
Give some example of Toll-like receptors and their uses
TLR2 recognises lipotechoic acid (LTA) in gram positive bacteria
TLR4 recognises lipopolysaccharide (LPS) in gram negative bacteria
Give the primary and secondary granules present in neutrophils
Primary - myeloperoxidase, elastase, cathpsins, defensins
Secondary - receptors, lysozyme, collagenase
Give the 6 functions of the neutrophil
- identify the threat (opsonin on pathogen/host, host mediators, host adhesion molecules)
- activation (signal transduction pathways including calcium, protein kinases, phospohlipases, G proteins)
- adhesion (margination is caused by selectins, adhesion is caused by integrins)
- migration/ chemotaxis (detecting a concentration gradient and moving along it)
- phagocytosis (membrane invagination forming phagosome and fuses with lysosomes to form phagolysosome)
- bacterial killing (lysosomal enzymes e.g cathepsins, elastase and reactive oxygen species) (reactive oxygen species created by NADPH oxidase)
What is physiological dead space
The area in the airways that do not contribute to ventilation
Anatomical (125) + alveoli (50) = 175m/s
Difference between ganglion location and neurone length of the parasympathetic and sympathetic nerves
Parasympathetic nerves have ganglion close to the target organ
- pre-ganglionic (pre-synaptic) nerves are long
- post-ganglionic (post-synaptic) nerves are short
Sympathetic nerves have ganglion close to the vertebrae (sympathetic chain)
- pre-ganglionic (pre-synaptic) nerves are short
- post-ganglionic (post-synaptic) nerves are long
What are the cranial parasympathetic nerves
1973
Nerve 10, 9, 7 and 3
How is smooth muscle tone in the airways regulated
Regulated by inflammation
Regulation by the autonomic nervous system
What is the dominant control of bronchoconstriction
The parasympathetic nervous system
How does bronchoconstriction occur
Vagus nerve (long pre-ganglionic) stimulation synapses on the parasympathetic ganglia in the airway wall
Short post-synaptic nerve fibres reach the smooth muscle and release acetylcholine (ACH)
Acetylcholine acts on the M3 muscarinic receptors in the smooth muscle of the airways
This causes airway smooth muscle constriction
What is the action of the drugs that inhibit the parasympathetic nervous system in excessive bronchoconstriction conditions like asthma
Anti-muscarinic and anti-cholinergic
They block the M3 receptors of the smooth muscle in the airways which then causes bronchodilation
Short acting muscarinic antagonists (SAMA) e.g ipratropium bromide (atrovent)
Long acting muscarinic antagonists (LAMA) e.g tiotropium, glycopyrrhonium
Which receptors does noradrenaline act on, in which nervous system and what do they cause
Alpha receptors - cause vasodilation
Beta receptors - cause vasoconstriction
Beta-2-receptors - causes bronchodilation (think beta-2-agonists encourage its action)
Instead of SAMAs and LAMAs, what drugs can be use instead to cause bronchodilation
Short acting beta agonists (SABAs) e.g Salbutamol
Long acting beta agonists (LAMAs) e.g formoterol and salmeterol
SABAs and LABAs prevent bronchoconstriction and relieve acute bronchoconstriction, they also reduce the rates of exacerbatios
What does the non-adrenergic non-cholinergic nervous system (NANC system) do in the airways
Nothing really
Give some chemical epithelial barriers (molecules) produced by respiratory epithelium
Anti-proteinases e.g SLPI, lysozyme and phospholipase A
Anti- fungal peptides e.g alpha-defensins
Anti- microbial pepties e.g beta-defensins
Surfactant A and D - they opsonise pathogens for enhanced phagocytosis
What is a cough
An expulsive reflex that protects the lungs and respiratory passages from foreign bodies
Causes of a cough
Irritants e.g smoke, fumes, dust
Diseased conditions e.g COPD and tumours
Infections e.g influenza
What is a sneeze
The involuntary expulsion of air containing irritants from the nose
Causes of a sneeze
Irritation of the nasal mucosa
Excess fluid in the airways
What is a pack year history and how is it calculated
It measures the smoking history of patients
20 cigarettes in a pack
To calculate
Number of years x number of packs per day smoked = pack years
2 years x 2 packs (40 cigarettes a day) = 4 pack years
1 year x 0.5 pack (10 cigarettes a day) = 0.5 pack years
What is global health
Health problems, issues and concerns that transcend national boundaries, may be influenced by circumstances or experiences in other countries and are best addressed by cooperative actions and solutions
Where was the greatest number of cases in ebola in 2014
Liberia
Where did the ebola outbreak start in 1976
In Democratic republic of congo
Where did the ebola outbreak start in 2014
In Guinea
What is the leading cause of death globally
Cardiovascular disease (heart disease)
Followed by cancer
Important risk factors for mortality and disability in poor countries
Underweight
Unsafe sex
Unsafe sanitation and drinking water
Important risk factors for mortality and disability in developed countries
Tobacco
High blood pressure
Alcohol
High cholesterol
Give some countries that demonstrate patterns of population change
Rapid growth e.g democratic republic of Congo
Slow growth e.g United States
Negative growth e.g Germany
What is the biggest global health challenge
Access to information
What are the Millennium Development Goals (MDGs)
The millennium development goals are the eight goal that were meant to be achieved by 2015 to address the world’s main development challenges
These include
1) Eradicate extreme poverty and hunger
2) Achieve Universal Primary education
3) Promote Gender Equality and empower women
4) Reduce Child Mortality
5) Improve Maternal health
6) Combat HIV/AIDs, Malaria and other diseases
7) Ensure environmental sustainability
8) Develop a global partnership for development
Smoking is a public health concern, roughly how many deaths are associated with in the UK as of 2016
77,900 deaths in the UK in 2016
About 13 deaths per minute in the UK
Explain basic smoking cessation programmes
Before consultation - posters and flyer giving risks of smoking and ways to quit
During consultation - ask about their smoking history (pack years), 2% quit with GP advise and 5% quit with repetition, use different theories of behavioural change to help them set a quitting date e.g stages of change (transtheoretical) model
Stop smoking centers - one to one or group sessions, include education on the risks of smoking and different techniques to stop, counselling and also access to medication (nicotine replacement therapy, Buproprion and Varenicline
Medication
Nicotine replacement therapy (NRT) - 12 to 18 years old can only use this, it is contraindicated in those who have had a recent myocadial infarction, arrythmias and stroke
Buproprion (also called Zyban) - used 1 or 2 weeks before stop date of smoking - contraindication in pregnant and breastfeeding women, epileptic, seizures, eating disorders and bipolar disorders
Varenicline (Champix) - use 1 week before stop date of smoking - contraindicated in pregnant women and breast feeding women and those with history of psychiatric illness
Types of smoking cessation services
- self help materials
- quitlines (NHS stop smoking service)
- group behavioural counselling
- brief interventions by healthcare professionals at GP practice
What is dsynopnea
Difficulty breathing or laboured breathing
What is cyanosis
Blue colouration to the skin due to poor circulation or inadequate oxygen of the blood
What is haemoptysis
Coughing up blood
What is cor pulmonale
This is abnormal enlargement of the right side of the hear (right ventricle) due to severe pulmonary hypertension
Would a response to bronchodilators be an indication of asthma or COPD
An indication of asthma
Give the aetiology, symptoms and management of COPD
COPD is the presence of structural change and narrowing of the small airways due to chronic inflammation, causes a loss of alveolar attachment to small airways and elastic recoil
Aetiology (caused by)
- cigarette smoking (also including secondhand smoking, cigar and pipe)
- indoor air pollution (cooking and heating with open fires)
- outdoor air pollution
- occupational exposure (fumes, irritants and vapour)
- alpha 1 antripysin deficiency
Symptoms
- persistent cough
- dsynopea (laboured breathing)
- sputum production
- wheeze
- winter exacerbations
Diagnosis
- with a spirometer that measures FEV1, FVC and SVC to produce a scalloped flow-volume loop
Management
- seen as successful with reduction of exacerbations of disease
- smoking cessation
- pulmonary rehabilitation
- medical managment
Medication used include
- inhaled broncodilators (SAMA,SABA, LAMA, LABA)
- oral corticosteroids
- theophylline
- mucolytics
- long term antibiotics
- long term oxygen therapy and short burst oxygen therapy (in cylinders)
Multidisciplinary team management and interventions
Doctors Practice nurses Physiotherapists - lead pulmonary rehabilitation Respiratory nurse specialists - lead pulmonary rehabilitation Clinical psychologists Liaison psychiatrists Pharmacists Dieticians Occupational therapists Social servics Assertive outreach nurses Palliative care experts
What is alpha 1 antitrypsin deficiency
This is an autosomal recessive condition
- alpha1 antitrypsin is a serine protease inhibitor produced by hepatocytes
- it opposes the alveolar elastase enzyme activity that breaks down alveolar wall and leads to emphysema
- excess deformed alpha 1 antitrypsin can also build up in the liver and cause liver issues
What is airways restriction and give exmaples
Disease that limits inspirations
Pulmonary fibrosis
Asbestosis
What is airways obstruction and give examples
Disease that limits expiration
COPD
Asthma
Emphysema
Chronic bonchitis
Give some lung functions tests and their uses
Spirometry - measures FEV1, FVC and VC (only direct lung measurement it takes is vital capacity), - simply take a deep breath and exhale as hard and fast as you can - used to create flow-volume loop
Body plethysmography - measures IC, FRC, ERV and vital capacity so total lung capacity can be calculated - sit in a box
Gas dilution (nitrogen washout technique) - measures FRC, all air in lungs - patient breathes in 100% oxygen which displaces nitrogen in lungs, the exhaled nitrogen volume and concentration are measured
Diffusion capacity (DLCO) - measures how well oxygen diffuses from the lungs into blood - patient inhales deep breath from a tube and holds their breath for 10 seconds then exhaled back into the tube which takes a sample of gases, nose clip is worn, inert gas inhaled e.g carbon monoxide
Give the phases of respiratory embryological development
Embryonic 0-5 weeks - lung buds enlarge to form right and left main bronchi
Pseudoglandular 5-17 weeks - major airways defined, nests of angiogenesis, cilia formed
Cannalicular 16-25 weeks - terminal bronchioles, capillary beds and alveolar ducts
Alveolar 25 weeks - alveolar budding, thinning and complexification
What is the purpose of the systemic blood vessels
To deliver oxygen to hypoxic tissues
What does O2 and CO2 act as in systemic blood vessels
CO2 is a vasodilator (hypoxia and acidosis are also vasodilators)
O2 is a vasoconstrictor
What does O2 and CO2 act as in the pulmonary blood circulation
O2 is a vasodilator
CO2 is a vasoconstrictor (hypoxia and acidosis are also vasoconstrictors)
What are the surface active phospholipids in surfactant
Phosphatidyl choline
Phosphatidyl glycerol
Phosphatidyl inositol
Surfactant proteins A, B, C, D
When is surfactant produced
34 weeks from gestation
Large increase 2 weeks prior to birth
What accelerates surfactant production
Distension by alveoli
Steriods
Adrenaline
How is surfactant defieciency managed
Warmth Surfactant replacement (if intubated) Oxygen and fluids Continuos positive airways pressure - to maintain lung volumes and reduce the work of breathing Positive pressure ventilation if needed
What is meant by the term prophylaxis
Prophylaxis is a treatment or action taken to prevent a disease developing
Which drug is given for prophylaxis of COPD
Tiotropium is given to prevent exacerbation of COPD, it is a long acting anticholinergic bronchodilator
Which drugs are being used to treat deterioration of COPD and what would their role be
Steroids - reduced inflammation
Antibiotics e.g amoxicillin - kill bacteria
Oxygen - to increases oxygen intake
Can amoxicillin be taken with food
Amoxillin is an antibiotic and can be taken with or without food
What does GTN stand for and what does it do
GTN stands for glyceryl trinitrate and it is used to vasodilate the coronary arteries. It increases blood supply to the heart to reduce the risk of myocardial damage and treat myocardial pain (angina)
Give two routes by which GTN is administered to the patient
Sublingually (sl)
Transdermally (top)
Why is GTN not used orally
-first pass metabolism through the hepatic portal system substantially reduces the bioavailability of the GTN
- after a drug is swallowed, it is absorbed by the GI tract
- it enters the hepatic portal system and goes to the liver
- the liver metabolises many drugs including GTN
- this first pass reduces the bioavailability of drugs
-however drugs absorbed through the mucosa of the mouth or skin enter the systemic circulation so the sublingual and transdermal routes are preffered
What does PRN on a prescription mean
PRN stands for “pro Re Nata” which means use as needed to the maximum advised limit
Give 10 different routes of administration for drugs and their abbreviations
- oral (po)
- intravenous (iv)
- rectal (pr)
- subcutaneous (sc)
- intramuscular (im)
- intra-nasal (in)
- topical or transdermal (top)
- sublingual (sl)
- inhaled (inh)
- nebulised (neb)
Why are salbutamol and clenil modulate administered by inhalation instead of orally
- to avoid first pass metabolism
- so that the drugs get directly into the small airways and exert an effect
Give some routes of administration for ramipril, bendroflumethiazide, amlodipine and lansoprazole
Oral (po) for all of them
Give the route of administration for paracetamol
Oral (po), rectal (pr) and intravenous (iv)
Give the route of administration for diclofenac
Oral (po) , rectal (pr) and topical (top)
Give the route of administration for salbutamol
Inhaled (inh), nebulised (neb), oral (po) and intravenous (iv)
Give the route of administration for clenil modulate
Inhaled (inh)
What does a patient do with an FP10 and how much is the payment
They take it to a chemist or pharmacy in England and it costs 9 pounds
Who can complete a yellow FP10D
-dentist
Who can complete a blue FP10MDA
A GP - these are used for drugs like methadone
Who can complete a purple or green FP10P, PN, SP or CN
Nurses or pharmacists
Im guessing P is pharmacy, SP is supplementary prescriber, CN and PN and nurses
What is an FP10
It is a prescription that can be completed by a GP, nurse, pharmacy prescriber, supplementary prescriber or hospital doctor in England
Who prescribes with a green FP10
- GP
What is the minimum information required for a legal prescription for a non-controlled drug
- prescriber’s signature
- prescriber’s address (usually the practice’s address and usually contains a number to identify individual prescriber)
- a date
- patient’s details (name and address)
- information about the product supplied
Give the diameter of the pores of kohns
1-2um
Which muscle lines the free end of the c shaped cartilage in the trachea
The trachealis muscle -it is smooth muscle
What are nares
The anterior nares are the part of the nose you can put your fingers in
What are turbinates and meatus
Turbinates are the shelf like structures in the nose
Meatus are the spaces in between the turbinates
What is choana
The posterior nares
Where does the nasolacrimal duct drain into
The inferior meatus
Name the paranasal sinus, where they drain and their innervation
Frontal sinus
- through the frontonasal duct at the hiatus semilunaris
- the opthalmic branch of the trigeminal nerve
Sphenoid sinus
- into the sphenoethmoidal recess in the roof of the nasal cavity
- the opthalmic branch of the trigeminal nerve
Ethmoidal sinus
- anterior part into hiatus semilunaris, middle part into the ethmoidal bulla, the posterior part into the superior meatus
- the opthalmic and maxillary branch of the trigeminal
Maxillary sinus
- middle meatus
- maxillary branch of the trigeminal nerve
Where does the pharynx begin and end
- begins at the base of the skull
- ends at the cricoid cartilage at C6
What does the eustachian tube do
Supply air to the middle ear
Which two fold contain the palatine tonsils of the pharynx
- the palatoglossal folds
- the palatopharyngeal folds
What is the vulvular function of the larynx
Prevents liquids entering the lung
Give the 9 cartilages of the larynx
- cricoid
- thyroid
- epiglottis
- arytenoid x2
- cuneiform x2
- cornicular x2
How much air does minute ventilation transport
5 litres
How much gas exchange area is there in each lung
20m2 area per lung
Where does the trachea start and end
From C6 to T5 at the carina
What is the difference between the larynx and the trachea
- larynx is in the upper part of the trachea
- larynx is called the voice box
Where does the larynx start and finish
Starts at C3 and finishes at C6
How long is the right main bronchus
1-2.5cm
How long is the left main bronchus
5cm
How many orders of branching does the pulmonary arteries have
17
For inspiration to occur, will the intra-alveolar pressure be positive or negative
Negative
How many alveoli are in one lung
300,000,000 per lung
How many capillaries per alveolus
1000
At rest, when haemoglobin fully saturated with oxygen
25% way through
What is dead space
Volume of inspired air not contributing to ventilation
CO has how much greater affinity for Hb than O2
200 times
How does CO influence the curve shift
CO causes the curve to shift to the left and loss of the sigmoid shape occurs
Factors that affect Peak Flow
Age
Gender
Height
What does spirometry measure
Tbc
What does the peak flow measure
Tbc
Give the two types of NHS press releases and examples
Reactive: defending the NHS reputation e.g.
- following news reports of infection control issues
- increased mortality at specific hospitals
- justifying why an expensive monoclonal antibody was not funded
Proactive: Improve and protect population health e.g.
- social marketing messages (five-a-day, change for life campaign)
- emergency preparedness
- early recognition and symptom awareness (act FAST)
Give 3 examples of vaccine preventable communicable diseases
Measles
Mumps
Rubella
Why do people smoke
-influence of background (smoking in parents, siblings, peers; relatively deprived neighbourhoods; schools where smoking is common)
-tightly regulated addiction
•Individual differences
•Social, economic, personal, and political influences all play an important part in determining patterns of smoking prevalence and cessation
•Behaviour, habit, cues
Give the physical and psychological effects of nicotine making it addictive
Physical
- nicotine activates the nicotinic acetylcholine receptors in the brain and cause a release of dopamine in the nucleus accumbens
- it is a stimulant and tolerance can be built to it
Psychological
-withdrawal can be experienced
What has been identified as the biggest cause of inequality of death rates in the rich and poor in the UK
Smoking
Estimated cost of smoking to the NHS (2019)
2.4 billion pounds
Total cost of smoking to society
12.5 billion pounds
Cost of loss of productivity due to smoking breaks at work
3.3 billion pounds
Cost of absences from work (absenteism)
1.3 billion pounds
Give a study that shows evidence that smoking causes early death and disease
The 1951 doctor study
After a 40 year follow up (by 1991) they found that the non smokers had 80% who lived till 70 and 33% who lived till 85. They found that the smokers had 50% who lived till 70 and 8% who lived till 85
Detail the 2007 smoking ban in public places law
- the legal minimum age for buying tobacco products was raised to 18 in the great britain
- it was made illegal to smoke in enclosed public places except bus shelters, hotel rooms, nursing homes and psychiatric ward (till july 2009)
When was it made illegal to display tobacco products in large stores and small stores
In large stores - 2012
In small stores - 2015
When was it made illegal to smoke in cars containing children
2015
In May 2017, what law was imposed on smoking companies
-standardised packaging was introduced where tobacco companies had to cover 65% of the packet with health warnings
Who and when was the first report on smoking and carcinoma of the lung published in the British Medical Journals
1950, Richard Doll and Austin Bradford-Hill
When did parliament ban cigarette advertising on TV
In August 1965
What did the 1986 act do
The 1986 protection of children (Tobacco) Act amended the children and young persons Act 1933 to make it an offense to sell tobacco products to under 16
Give some types of nicotine replacement therapy
- patches
- gum
- lozenges
- nasal sprays
- microtab
- inhalers
Give some non-nicotine pharmacological interventions for smoking
- buproprion (zyban)
- varenicline (champix)
Are more people more or less likely to smoke
Less likely to smoke
Where can IgA be found
In mucus secretions and mucus membranes
What are epitopes and paratopes
Epitopes are the part on an antigen that the antibodies attach to
Paratopes are the specific (varible) region on an antibody
Which conditions are type 1 hypersensitivity associated with
- asthma
- anaphalaxis
- hayfever
- peanut allergy
Which conditions are type 2 hypersensitivity associated with
- triggered by immunoglobulins bound to surface antigens
- good pastures syndrome
- non-respiratory e.g Grave’s disease and myaesthenia gravis
Which conditions are type 3 hypersensitivity associated with
- formation of precipitating antibodies to organic dusts, the granulomata then heal by fibrosis
- antibodies and targets circulate (e.g. chronic bacterial endocarditis). Little lumps of antibody and target get deposited in the skin, lung, kidneys etc and activate immunity, resulting in tissue damage
- lupus (SLE)
- farmer’s lung
- pigeon fancier’s lung
- malt worker’s lung
- mummy handler’s lung
- snuff-taker’s lung
- rat handler’s lung
- woodworker’s lung
- basement lung
- humidifier lung (amoebae)
- cheese-washer’s lung
- paprika slicer’s lung
- compost lung
What causes type 3 hypersensitivity
-formation of precipitating antibodies to organic dusts, the granulomata then heal by fibrosis
What causes type 4 hypersensitivity
- formation of granulomas, slow process, granulomas are little walled-off areas nailing nasty things in place
- dependent upon activation of T cells
Which conditions are type 4 hypersensitivity associated with
- sarcoIdosis
- TB
Give the causes of hypoxaemia
- alveolar hypoventilation
- reduced PiO2
- ventilation/perfusion mismatching (v/q)
- diffusion abnormality
Give the alveolar gas equation
PAO2= PiO2 - PaCO2/R
Give 3 ways CO2 is carried in the blood
- bound to haemoglobin (23%)
- dissolved in plasma
- as HCO3-
What are the physiological causes of high CO2
- alveolar ventilation (v’A) is reduced due to reduced minute ventilation
- alveolar ventilation due to increase in dead space ventilation by rapid shallow breathing
- alveolar ventilation due to increased dead space ventilation by V/Q mismatching
- increased CO2 produced
Give the pH range of blood
Ph 7.35-7.45
What is the pH of blood
Ph 7.4
Give a weak acid and weak base in the body
- HCO3- weak base
- H2CO3 weak acid
Give the 3 main buffering systems used to regulate pH of the body fluids (blood)
- intracellular and extracellular buffers
- the lungs eliminating CO2
- renal HCO3- reabsorption and H+ elimination
Give an example of a volatile acid produced by metabolic processes in the body and how it is excreted
- carbonic acid
- equilibrium with CO2 and excreted by lungs as CO2
Give examples of non volatile (fixed) acids produced by metabolic processes in the body and how they are controlled in the body
- sulphuric acid, hydrochloric acid
- these are not eliminated by the lungs
- buffered by body proteins or extracellular buffers then excreted by renal systems
What does the Henderson-Hasselbalch equation calculate
-pH
What does the HCO3- and the PCO2 in the Henderson-Hassel balch equation reflect
- HCO3- reflects the generation of non-volatile acids buffered an eliminated by renal system
- PCO2 reflects dissolved CO2 in the blood and its elimination by the lungs
Compensation for respiratory acidosis
-as PCO2 rises, HCO3 must rise so renal compensation (produces HCO3-)
What would be observed in respiratory acidosis
- increased PaCO2
- decreased pH
- mild increased HCO3-
What would be observed in respiratory alkalosis
- decreased PaCO2
- increased pH
- mild decreased HCO3-
What would be observed in metabolic acidosis
- reduced bicarbonate HCO3-
- decreased pH
What would be observed in metabolic alkalosis
- increased bicarbonate
- increased pH
Give examples of endocytic pattern recognition receptors
- mannose receptors
- glucan receptors
- scavenger receptors
How many neutrophils are made each minute
80 million
Give the primary and secondary granules of a neutrophil
Primary
- myeloperoxidase
- elastase
- cathepesins
- defensins
Secondary
- receptors
- lysozymes
- collagenase
Which membrane enzyme generates ROS
-NADPH oxidase generates reactive oxygen species (ROS)
Give an example of an X linked and an autosomal recessive condition that cause the generation of the reactive oxygen species (ROS)
- cytochrome B91KD (X linked)
- P47 cytosolic factor (autosomal recessive) - interferon restores P47 activity
At the end of the 5th week, a septum divides the foregut and airways, what is it called
-the transoesophageal septum (also called the oesphago-tracheal septum)
Give fetal blood circulation
Think 1, 2, 3
- 1 umbilical vein (becomes ligamentum tere)
- 2 umbilical arteries (become medial umbilical ligaments)
- 3 fetal shunts which are ductus venosus, foreamen ovale and ductus arteriosus (become respectively
What is surface tension
A measure of the force acting to pull a liquid’s surface molecules together at an air-liquid interface
What is COPD
- Persistent airflow limitation that is usually progressive and associated with enhanced chronic inflammatory response
- Mixture of small airway disease and parenchymal destruction
- Small airways collapse due to destruction of pulmonary elastic tissue causing further obstruction
Main symptoms are shortness of breath, persistent cough and sputum production
What is asthma
- Excess mucous secretions lead to narrowing of the airways increasing airway resistance
- Voluntary respiratory effort increases which in turn increases resistance and causes small airways to collapse
- FRC increases leaving over expanded lungs
What is emphysema
- Enlargement of the alveolar sacs by the destruction of alveolar walls
- Reduced surface for gas exchange
- Reduced oxygenation of blood
What is a pulmonary arterial wedge pressure and what does it measure (include the formular)
- balloon on a catheter pushed from peripheral vein into the right atrium, right ventricle and then into the pulmonary artery then inflated
- used as an indirect estimate of left atrial pressure
mPAP - PAWP = CO x PVR
mPAP is mean pulmonary arterial pressure
PAWP is pulmonary arterial wedge pressure
How does hereditary pulmonary arterial hypertension affect the individual
- endothelial dysfunction
- smooth muscle proliferation
Give 3 respiratory condition that single gene changes are responsible for, include the gene responsible, its function and the pattern of inheritance
- cystic fibrosis, CFTR, Cl-ion transport channel, autosomal recessive
- alpha-1-antitrypsin deficiency , SERPINEA1, anti-protease, autosomal recessive
- hereditary pulmonary arterial hypertension (HPAH), BMPR2, endothelial dysfunction and smooth muscle proliferation, autosomal dominant
What percentage of pulmonary arterial hypertension carriers develop it (penetrance)
-20% of carriers develop it
In first aid, what does a coherent answer to “are you okay” indicate
- that the airways are clear
- breathing ok
- circulation is perfusing the brain
In first aid, give 3 ways you would conduct an initiate assessment and collect information
DRABC, DOTS and SAMPLE
Danger Response Airways Breathing Circulation
Deformities
Open wounds
Tenderness
Swellings
Signs and symptoms Allergies Medication Past medical history Last oral intake (food and drink) Event leading to injury or illness
What is a seizure
-uncontrolled electrical activity in the brain which may produce physical convulsions
What is epilepsy and how many people are diagnose with it each year
- epilepsy is the tendency of recurrent seizures
- 87 people are diagnosed with epilepsy every day?
Causes of epilepsy
- post head injury
- flashing lights
- alcohol poisoning
- drugs
- hypoglycemia (low blood sugar)
- brain tumour
- infection/hyperpyrexia
- lack of oxygen
When do you call 999 in a seizure
- if its their first one
- lasts longer than 5 minutes
- repeated seizures occur
- unresponsive for more than 10 mins after seizure
- injury occurs
What is a syncope (fainting)
-loss of consciouness due to temporary reduction in blood flow to the brain
When should 999 be called with syncope
-if consciousness is not regained within two minutes
What are the types of burns that can be sustained
- dry burn caused by naked flames, friction, hot water bottles in diabetic neuropathy
- a scald caused by wet heat e.g steam or a cup of tea
- radiation burns e.g sunburn or radiotherapy
- cold burns e.g frostbite
How much do burn accidents cost the NHS a year
20 million pounds per year
Give the classification of burns
- superficial -outer layer of the skin
- partial thickness - all layers of the skin
- full thickness - tissues and structures under the skin e.g muscles and nerves
When do you call 999 with a burn
- when it is bigger than the size of the casualty’s hand
- it is on the face, hands, feet or genitals
- it involved the airways (mouth and or nose)
- it is a full thickness burn
- it extends around a limb
What is a fracture and the difference between closed and open fracture
- a fracture is a crack or break in a bone
- a closed fracture is where the damage to the bone is under the skin
- an open fracture occurs when pieces of bone puncture the skin
What does a splint do in a fracture
- support an injured limb
- immobilise the injury
- reduce pain
- prevent further damage to nerves and blood vessels
What is shock
-a critical condition that is brought on by a sudden drop in blood flow through the body
What can cause shock
- heart attack or heart failure
- fluid loss from bleeding, dehydration, diarrhoea, vomiting or burns
- anaphylaxis
- blood vessel failure
What are the two main types of strokes
Ischaemic stroke and haemorrhagic stroke
- ischaemic stroke - 80% of strokes are ischaemic, occurs when an artery supplying part of the brain is blocked, starving the distal brain tissue of the oxygen
- haemorrhagic stroke - occurs when a blood vessel in the brain bursts and the bleeding puts pressure on the brain tissue
What does FAST stand for
Face
Arms
Speech
Time
Where can a sample of arterial blood be taken from and what can be measured
- radial, brachial and femoral artery
- PaO2, PaCO2, pH [H+] acidity, HCO3- bicarbonate
Give the determinants of PaCO2 and PaCO2 equation
-alveolar ventilation
PaCO2 = 1/alveolar ventilation
PaCO2 = kV’CO2/ V’A
Give an alveolar gas equation that does not take into account pH2O
PAO2 = PiO2 - PaCO2/R
R is the respiratory quotient and is the CO2 produced/O2 consumed
What is the respiratory quotient (R) normally and how does it change with a carbohydrate or fatty diet
- normally 0.8 with normal diet
- 1 with a high carbohydrate diet
- 0.7 with a fat rich diet
What is minute ventilation
- volume of air breathed in and out in one minute
- usually about 5 litres
What is pulmonary barotrauma
-air leaks from burst alveoli causing -pneumothorax -pneumomediastinum - air leaked into the mediastinum -subcutaneous emphysema -problem with pressure
What is arterial gas embolism (AGE)
- gas enters circulation via torn pulmonary veins
- small transpulmonary pressure can lead to arterial gas embolism
- normally occurs within 15 mins of surfacing
- need urgent recompression
- problem with pressure
What is decompression illness
- ascent causing fall in pressure and solubility
- causes gas bubbles in different parts of the body
Type 1 is cutaneous only
Type 2 is neurological
What is inert gas narcosis
- most common is nitrogen narcosis
- worsens with increasing pressure
- increased PiN2
What is the normal range for PaO2
11-13kPa
How much of the drug warfarin is bound to plasma proteins and how much is freely dissolved in plasma and is it the free warfarin or the plasma bound warfarin that is responsible for the cation of the drug
99% of warfarin is bound to plasma proteins and 1% is free in plasma.
The free warfarin (1%) is responsible for the action of the drug
What happens if tamoxifen is given to a patient taking warfarin
Tamoxifen increases the effects of warfarin and so increases the risk of bleeding by an unknown mechanism
The active metabolite of tamoxifen, 4-hydroxytamoxifen, competitively binds to the intracellular oestrogen receptor. What is meant by competitive binding?
Competitive binding means that both the tamoxifen and oestrogen bind (‘compete for’) to the same oestrogen receptor
-if 4-hydroxytamoxifen bind to the oestrogen repceptor, it prevents oestrogen binding so reduces the effects of oestrogen.
How does warfarin affect vitamin K in the liver
-warfarin blocks the effects of vitamin K in the liver
What substances are produced in the liver using vitamin K and what is the effect of blocking the action of vitamin K
Vitamin K is used within the liver to make clotting factors 2, 7, 9 and 10 (think 1972)
Blocking the action of vitamin K leads to an inability to form blood clots efficiently
What is the effect of drinking alcohol whilst on warfarin and how does this affect clotting
- drinking can increase the anticoagulant effects of warfarin causing bleeding
- drinking can affect the ability of the liver to manufacture the clotting factors 2, 7, 9 and 10 (think 1972)
What route of administration is used to deliver the betamethasone to the diseased skin and what implications does this delivery have on possible systemic side effects
- betamethasone is delivered topically on skin
- an advantage to this is that a high dose is delivered to diseased skin and small dose enters the systemic circulation
- systemic effects of topical steroids can include hypothalamic pituitary adrenal axis suppression, Cushing’s syndrome, diabetus mellitus, osteoporosis and growth retardation in children
- less than 2% of the topical steroid is absorbed systemically
- penetration is related to the thickness of the stratum corneum at the site of application
How can we increase the efficacy of betamethasone without increasing the dose and what other skin products can exacerbate eczema
- to increase efficacy,
- drugs in aqueous cream will absorbed different to drugs in paraffin based ointment
- using an occlusive dressing can increase absorption by up to 10 times
- vigorous rubbing increases local blood supply an increase systemic absorption
- zerobase emollient cream can cause local skin or allergic reactions
- perfumed creams, shower gels or bubble baths can exacerbate eczema
Give the environmental influences of asthma
- pollens
- infectious agents
- fungi
- pets
- animals
- air pollution
Give the occupational influences of asthma
- car spray paints
- resins
- cleaning agents (low molecular weight agents)
- laboratory animal workers (high molecular weight agents)
- wood dust
What is hypersensitivity pneumonitis
- an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled dusts
- hot tub lung is a disease example of this condition
What are the 10 principles of screening according to Wilson and Jungner
Wilson and Jungner classic screening criteria
- The condition sought should be an important health problem.
- There should be an accepted treatment for patients with recognized disease.
- Facilities for diagnosis and treatment should be available.
- There should be a recognizable latent or early symptomatic stage.
- There should be a suitable test or examination.
- The test should be acceptable to the population.
- The natural history of the condition, including development from latent to declared disease, should be adequately understood.
- There should be an agreed policy on whom to treat as patients.
- The cost of case-finding (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole.
- Case-finding should be a continuing process and not a “once and for all” project.
Have an awareness of the NHS bowel cancer screening program and other cancer screening programs
Screening in pregnancy
- sickle cell and thalassaemia (10 weeks)
- infectious diseases (HIV, hepatitis B and syphillis)
- Down’s syndrome, Edwards’ syndrome and Patau’s syndrome
- 11 physical conditions in the baby (20 week scan)
Newborn screening - newborn blood spot test and physical examination
Diabetic eye screening - offered annually to diabetics who are 12 and over
Cervical screening - offered to women aged 25 to 49 every 3 years, aged 50 to 64 every 5 years
Breast screening - offered routinely to women from 50 to 71st birthday
Bowel cancer screening -offered to men and women aged 60 to 74 every 2 years
Abdominal aortic aneurysm (AAA) screening - offered to men when they turn 65
Give 8 red flag symptoms for bowel cancer
- weight loss
- palpable mass on rectal/abdominal examination
- night sweats
- fever
- change in bowel habits
- lethargy/malaise
- faecal incontinence
- nocturnal diarrhoea
Is the first part of expiration active or passive
Active
-active slowing of inspiration
During ascent which remains constant and which changes in FiO2 and PiO2
FiO2 remains constant
PiO2 decreases
How does ascent in altitude affect control of respiration (at 10,000 feet)
- hypoxia leads to
- hyperventilation
- increases minute ventilation
- lowers PaCO2
- alkalosis initially but compensated for by renal bicarbonate excretion
- tachycardia
What is extremely high altitude
-over 18,000 feet
What are the normal blood gas ranges at sea level
PaO2 10.5 - 13.5 kPa
PaCO2. 4.6 - 6 kPa
pH 7.36 - 7.44
What are the blood gas ranges at Everest
PaO2 4 kPa
PaCO2. 1.5 kPa
pH 7.56
Give examples of 3 high altitude illnesses
- acute mountain sickness
- high altitude pulmonary oedema (HAPE)
- high altitude cerebral oedema (HACE)
Definition of acute mountain sickness
- lake louise score of 3
- must have a headache and one other symptom
How do you treat acute mountain sickness
-descent from high height
How to treat high altitude pulmonary oedema
- O2
- descent
- gamow bag
- steroids
- Ca2+ blockers
If the total lung capacity in a 23 year old female diver is 8 litres at the surface. What will this volume be at 160m of seawater during breath hold diving?
Use Boyle's law which is P1V1 = P2V2 1 atm x 8 litre =17 atm x V1 1 x 8 = 17 x V 8 = 17 x V 8/17 = V V = 0.470 litres which is 470 mls
Think 160/10 is 16, then add 1 (sea level atm) to the 16 = 17
What is pulmonary barotrauma
- air leaks from burst alveoli Causes -pneumothorax -pneumomediastinum (air leaks into the mediastinum) -subcutaneous emphysema -problem with pressure
What is an arterial gas embolism (AGE)
- gas enters circulation via torn pulmonary vein
- small transpulmonary pressure can lead to arterial gas embolism
- normally occurs within 15 mins of surfacing
- urgent recompression
- problem with pressure
What is decompression illness
Ascent causing fall in pressure and solubility of gases
-causes gas bubbles in different parts of the body
Type 1 is cutaneously only
Type 2 is neurological
What is inert gas narcosis
- most common is nitrogen narcosis
- worsens with increasing pressure
- increased PiN2
Give 5 known occupational causes of COPD
- silica
- coal
- grain
- cotton
- cadmium
Give some symptoms of CNS oxygen toxicity
Think ConVENTID
Convulsions Visions Ears ringing Nausea Twitching Irritability Dizziness
What is pulmonary oxygen toxicity
- Lorrain smith effect is noticed
- PiO2 > 0.5ATA
- a common problem with intensive care uni patients on 100% oxygen
- relieved by PiO2 <0.5 ATA
- FVC can be useful to monitor
What is the partial pressure of nitrogen and oxygen at sea level and at 10 meters of sea water due to Dalton’s law
At sea level - partial pressure N2 = 0.78, O2 = 0.209
At 10 meters of sea water - partial pressure N2 = 1.56, O2 = 0.418
Breathing air at 10 msw (meters of sea water) is the same PaO2 as breathing 42% (instead of 21%) O2 at sea level
What is Dalton’s Law
Total pressure exerted by a mixture of gasses is equal to the sum of the pressure that would be exerted by each of the gases if it alone were present and occupied the total volume
What are the physiological changes caused by the diving reflex
- apnoea
- bradycardia
- peripheral vasoconstriction
What is Henry’s Law
The amount of a gas dissolved in a liquid at a given temperature is directly proportional to the partial pressure of the gas
What are the effects of henry’s law
- proportionally more gas dissolves in the tissue at depth
- if ascent is at a rate that exceeds the body’s capacity to clear the excess gas, then inert gas bubbles may form in the tissues leading to decompression illness
What is Boyle’s law
-at constant temperature the absolute pressure of a fixed mass of gas is inversely proportional to its volume
1 atmosphere absolute (ATA) is equal to
- 10 metres of sea water (msw)
- 33 feet of sea water (fsw)
- 101.3 kilopascals (kPa)
- 760 mmHg/torr
- 1000 millibars
How is PiO2 caculated
PiO2 (PiGas) = Patm x FiO2 (FiGas)
PiO2 = 100kPa x 0.21
PiO2 = 21kPa at sea level
How can PaO2 be calculated
PaO2 = PAO2 - (A-aDO2)
- calculate the alveolar gas equation to get PAO2
- then put PAO2 in the equation
- PaCO2 can be measured in the alveolar gas equation from arterial blood gas
Give the barometric pressure kPa for the following altitude (metres) 0, 4800, 6300, 8100 and 8848
- 0m = 101kPa
- 4800m = 57kPa
- 6300m = 46kPa
- 8100m = 37.5kPa
- 8848m = 33.5kPa
What is somatic hyper-mutation
-exposure to relevant antigen triggers replication with errors in variable region DNA replication generating further diversity
What is immune tolerance
-a state of unresponsiveness of the immune system to antigens that normally have the capacity to elicit an adaptive immune response
What leads to autoimmune disease
-failure to establish self-tolerance leads to autoimmune disease where our immune system attacks our own antigens e.g rheumatoid arthriti, systemic lupus erythematosis
What is affinity maturation in adaptive immunity
-selection for higher affinity clones
What is the basis of diversity and specificity in immunity
-generation of pathogen-specific variable regions in lymphocyte receptors
What is central and peripheral tolerance in adaptive immunity
- central tolerance is in the thymus or bone marrow, lymphocytes that react with self antigens are deleted or develop into suppressor ‘Tregs’ (T helper cells)
- peripheral tolerance is in the lymph nodes, autoreactive clones escaping central tolerance are deleted or suppressed by ‘Tregs’ (usually in lymph gland, lymph tissue and circulation)
How are memory cells distinguished from naive cells
- high affinity receptors
- increased lifespan
- faster and stronger response to stimulation
How does antigen presenting cells activate T cytotoxic cells
- antigen presenting cell (APC) ingests bug
- bug antigen is displayed on APC cell surface with MHC1 (major histocompatibility complex 1) molecule. Both must be recognised
- CD8 cells activated to become cytotoxic
How do activated cytotoxic T cells kill their target
- they kill pathogen-infected or tumour cells by pore formation
- cytotoxic T cell binds to infected cell
- perforin makes holes in infected cell’s membrane
- infected cell lyses
What can defective cytotoxic T cell responses lead to
- increase viral infections
- may promote progression of cancer
How do antigen presenting cells activate T helper cells
- antigen presenting cells (APC) ingests bug
- bug antigen displayed on APC cells surface with MHC2 (major histocompatibility complex 2) molecule. Both must be recognised
- interactions with T cell receptors and co-inhibitory/co-stimulatory receptors releases cytokines
- CD4 cells differentiate into a range of T helper subtypes - Th1 cell, Tfh cell and Th2 cell
What is the principle of necessity
Tbc
What are IgE associated with
- mast cells
- allergic reactions
What IgG associated with
- make up more than 80% of circulating antibodies
- interact with phagocytes
What are IgA associated with
- mucosal immunity (gut and lung)
- good at opsonising (promotes phagocytosis) and fixing complement
What are IgM associated with
- immature plasma cells secrete IgM
- IgM is always present in early immune response
- good at neutralising and agglutinating
Give 4 effector functions of antibodies
- neutralisation. - antibodies cover biologically active portion of microbe or toxin
- agglutination - antibody cross-links cells forming clumps
- opsonisation - FC region of antibody binds to receptor of phagocytic cels triggering phagocytoses
- complement fixation - FC region of antibody binds complement proteins so complement is activated
What are vaccines derived from
- dead or attenuated bacteria
- capsular polysaccharide
- viral proteins
In immunity, failure to eliminate pathogens lead to
-chronic inflammation
In immunity, failure of antibody production leads to
-recurrent or severe bacterial infection
In immunity, failure of tolerance leads to
-autoimmune disease
In immunity, failure of T cell function leads to
-opportunistic infections such as bacteria, parasites, fungi, viruses and tumours
Which cells are infected by HIV virus
-CD4+ (T helper cells)
What is an antigen
-a molecule capable of inducing a specific immune response on the part of the host organism.
Can be
-proteins
-polysaccharides
-lipids
-DNA
Can be soluble or part of cell or pathogen
Give 3 conditions from failure of tolerance
- rheumatoid arthritis (anti-citrullinated proteins)
- graves disease (anti-TRH receptors)
- vasculitis (anti-neutrophil)
How is diversity generated in early development via DNA rearrangements
- through VDJ recombination
- all but one of each of V (50 variable), D (27 diversity) and J (6 joining) segments in both the heavy and light chains)
What is a malignant tumour of the pleura membrane called
A mesothelioma
the main peripheral chemoreceptors are located in
the carotid arteries and aortic arch
Changes in oxygen, carbon dioxide and H+ ions stimulates which chemoreceptor
Carotid chemoreceptors
Give some conditions that cause type 1 respiratory failure
- pulmonary embolism
- pneumothorax
- pneumonia
Give some conditions that cause type 2 respiratory failure
- COPD
- severe motor neurone disease
Does adrenaline cause bronchodlation
Yes
Would someone with chronic type 2 respiratory failure have a high or low HCO3-
- a high HCO3-
- because their body would have become accustomed to the high PaCO2 levels which would initially cause a low HCO3- but after time the body would make it high again
How does rheumatoid arthritis affect the lungs
- in rheumatoid arthritis, autoantibodies are formed against modified (e.g citrullinated) proteins in joints
- smoking induces citrullinated proteins in the lungs
- autoantibodies may cause lung epithelial injury
What is positive vasculitis (ANCA)
- anti-neutrophil cytoplasmic antibodies (ANCA)
- overactive neutrophil which attack blood vessels in various organs particularly the kidney and lung
- can cause glomerulonephritis and pulmonary haemorrhage
What causes inflammation to be chronic
A persistent initiating cause
- persistant infection e.g mycobacteria, abscess
- persistent irritant e.g smoking, gall stones
- foreign bodies e.g inhalation of food
Inappropriate cellular response
- autoimmunity e.g rheumatoid arthritis
- granulomatosis disease e.g sarcoidosis
Structural abnormalities
- bronchiectasis e.g local defences malfunction
- diverticular disease
What are the consequences of chronic inflammation
- systemic e.g malaise, weight loss, fever, sweats, anaemia
- tissue destruction e.g cavity formation
- fibrosis e.g strictures, organ dysfunction
- growth disorders like metaplasia, neoplasia e.g carcinoma of the bronchus in pulmonary fibrosis
What is bronchiectasis
-dilated, scarred airways
What are the 3 patterns of chronic inflammation
- chronic suppurative inflammation (mainly innate cells e.g neutrophils)
- chronic autoimmune inflammation (mainly adaptive cells, can lead to fibrosis)
- chronic granulomatous inflammation (mainly adaptive cells, can lead to fibrosis)
Lung abscess are an examples of which pattern of chronic inflammation
-chronic suppurative inflammation
What are granulomas
-small nodules composed of organised collections of macrophages, ‘epitheliod’ and giant cells
Give 3 causes of chronic granulomatous inflammation
- infections (tuberculosis)
- foreign bodies (inhaled antigens in hypersensitive pneumonitis)
- aberrant inflammation (vasculitis, Crohn’s disease)
- unknown (sarcoidosis)
Give 4 causes of chronic lung abscesses
- organism (staplylococcus)
- obstruction (tumour or inhaled foreign bodies)
- tissue damage (aspiration of gastric contents)
- impaired immune system (e.g diabetes)
Define respiratory failure. Define type 1 respiratory failure and its causes. Define type 2 respiratory failure and its causes. Which type does Mary have? Which type does her sister have?
Respiratory failure is when not enough blood is passing from your lungs into the blood or when not enough carbon dioxide is not being removed from the blood
Type 1 respiratory failure is cause by low oxygen in the blood (hypoxemia) and normal or low CO2 (hypocapnia)
PaO2 < 8Kpa
PaCO2 < 6Kpa
Causes of type 1 respiratory failure are;
- Pulmonary oedema
- Pnuemonia
- Acute respiratory distress syndrome (ARDS)
- Chronic pulmonary fibrosis alveolitis
- V/Q mismatch due to alveoli hypoventilation
- High altitude
- Shunt
- Diffusion problem
Type 2 respiratory failure is low blood oxygen (hypoxemia) and high blood CO2 (hypercapnia)
Causes of type 2 respiratory failure are;
- COPD
- Respiratory muscle weakness (Guillian-Barre syndrome)
- inadequate alveoli ventilation due to reduced breathing effort
- Depression of central respiratory centre (heroin overdose)
- Neuromuscular problems
Describe the control of respiration
Medulla Oblongata
Dorsal respiratory group (DRG)
- Dorsal respiratory group neurons fire through the spinal motor neurones to activate the inspiratory muscles to contract (diaphragm and intercostal muscles)
Ventral respiratory group (VRG)
- the respiratory rythmn generator is located in the pre-Botzinger complex of the upper part of the ventral respiratory group, it maintains the basal respiratory rate
- During quiet breathing, VRG neurons activate inspiratory muscle contraction
- Neurons fire when large increase in ventilation needed e.g exercise
- In active expiration, VRG neurones cause expiratory muscles to contract e.g pectoralis major, pectoralis minor
Both are bilateral and project into the bulbo-spinal motor neurone pools
Dorsal respiratory group is active during inspiration
Ventral respiratory group is active during inspiration and expiration
Pons
- apneustic centres - in the lower part of the pons and causes inspiration
- pneumotaxic centre (pontine respiratory group) - in the upper part of the pons and it swiches off inspiratory muscles to prevent hyperinflation which then causes exhalation
