lecture 8- respiratory diseases Flashcards
What are the diseases that affect the airways?
Asthma
COPD
Bronchitis
Emphysema*
What are the diseases that impact the alveoli?
Pneumonia
Tuberculosis
Lung Cancer
Acute respiratory distress
syndrome (ARDS)
What is emphysema?
*Emphysema as a singular
disease is a disease of the
alveoli
What happens in spirometry?
Spirometry is the most common of the pulmonary function tests.
It measures lung function, specifically the amount and/or speed of air
that can be inhaled and exhaled.
What does spirometry measure? What is it helpful in assessing?
Spirometry is helpful in assessing breathing patterns that identify
conditions such as asthma, pulmonary fibrosis, cystic fibrosis, and COPD.
What does a spirometry graph look like in a restrictive and obstructive disease?
obstructive takes longer for lung volume to fill up
restrictive the lung volume cannot reach the normal levels
What does Covid do, what are the symptoms and mechanisms?
- Affects Upper and Lower Respiratory Systems
- Causes Pneumonia and Lung Damage (fibrosis)
- Damage in the alveoli results in hypoxia, hypoxaemia
and oedema - Decreased oxygen saturation (SaO2 <93%) or
partial pressure of oxygen (PaO2
) occurs
(hypoxemia). - ~5% of patients will develop ARDS, sepsis, and
multiorgan failure - Many pathophysiological events in COVID-19 affect
either lung perfusion or ventilation - Altered lung mechanics due to progressive lung oedema
related to sustained pulmonary inflammation, alveolar
collapse, atelectasis, and fibrosis further impair global
lung function, resulting in progressive tissue hypoxia
What diseases primarily affect the alveoli and why and which diseases primarily affect the airways and why?
- Primarily Alveoli Affected
- COVID-19 (SARS-CoV-2)
- Pneumonia
- Primarily Airways Affected
- Chronic Obstructive Pulmonary Disease
(COPD) - Asthma
What part of your respiratory system does covide affect?
- Affects Upper and Lower Respiratory Systems
What does covid cause? Where does damage occur and what does this result in?
Causes Pneumonia and Lung Damage (fibrosis)
* Damage in the alveoli results in hypoxia, hypoxaemia
and oedema
Compare early stage and late stages of covid in the alveoli
early- thrombosis occurs
middle- pulmonary oedema occurs
late- fibrosis occurs
What causes pneumonia, what are the symptoms and mechanisms?
- A common acute respiratory infection
- Is a lower respiratory tract infection (LRTI)
- Affects the alveoli and distal airways
What part of the respiratory system does pneumonia affect?
- Is a lower respiratory tract infection (LRTI)
- Affects the alveoli and distal airways
What are the most common causes of pneumonia?
- Bacteria: Streptococcus pneumoniae
- Respiratory Viruses
- Haemophilus influenzae
-sars cov-2
What types of microorganisms can cause pneumonia? What are the atypical types?
Bacteria and viruses
- Legionella pneumophila is an atypical bacteria
Streptococcus pneumoniae is a typical bacteria
- Respiratory Viruses
- Haemophilus influenzae
Sars-CoV-2
Regarding the mechanisms what is the immune resistance and tissue resistance?
go to lecture
Describe the congestion, red hepatization, grey hepatization and resolution stages
Four stages of pneumonia - histopathology
1. Congestion - Pulmonary capillaries dilated and serous fluid
leaks out capillaries into the alveoli
2. Red Hepatization
Red blood cells and immune cells travel to the alveoli. Since
there are more red blood cells, the lungs may appear red. The
lungs also become dry, airless, and firm, often resembling the
liver.
3. Grey hepatization
an avascular stage - lack of blood vessels in the tissue of the
lungs. During this stage, the lungs take on a greyish
colour. Neutrophils in alveolar spaces, rbcs disintegrate
4. Resolution
How many stages of histopathology are there regarding pneumonia?
4
What causes COPD, what are the symptoms and mechanisms?
Causes progressive decline in lung function – poorly reversible airway obstruction
Includes 2 main diseases; Bronchitis (narrowing of small airways) and Emphysema
(damage to alveoli).
Often caused by smoking (in addition to many others)
What does COPD do to the functioning the lungs? What are the 2 main diseases of COPD? What often causes COPD?
Causes progressive decline in lung function – poorly reversible airway obstruction
Includes 2 main diseases; Bronchitis (narrowing of small airways) and Emphysema
(damage to alveoli)
Often caused by smoking (in addition to many others)
Compare the look of normal and emphysematoud lungs
normal- healthy bronchioles and alveoli
COPD- thick and narrow bronchioles with excess mucus
-destruction of alveolar walls
Describe emphysema, bronchitis and smooth muscle hypertrophy and airway fibrosis
- Emphysema
- Abnormal permanent enlargement of airspaces distal to
the terminal bronchioles - Centrilobular emphysema (CLE) and panlobular
emphysema (PLE) - Airways Disease (Bronchitis)
- An infection of the main airways of the lungs(bronchi),
causing them to become irritated and inflamed. - The main symptom is coughing, which may bring up
yellow-grey mucus (phlegm). - Smooth Muscle Hypertrophy and Airway Wall
Fibrosis
* - Smooth muscle mass may or may not be increased in
COPD
Whether or not airway hyperresponsiveness is a primary
cause of fixed airflow obstruction continues to be a topic
of debate - Regardless, chronic airway inflammation from cigarette
smoke causes constriction and hypertrophy of even
normal airway smooth muscle
What are the environmental stimuli that cause bronchitis?
viruses (infant), allergens (child) and tobaco smoke (teen and beyond)
How do the environmental causes of COPD change as someone ages?
viruses (infant), allergens (child) and tobaco smoke (teen and beyond)
Describe the adaptive immune pathway regarding COPD
an altered immune response results in a memory cell (b or t cell) triggering an effector cell (eosinophil or mast cell) that triggers type 2 cytokines which results in end organ dysfunction and cause AECs to produce excess mucus and cause chronic inflammatory disease
Describe the innate immune pathway regarding COPD
as a result of an altered immune response (caused by genetic susceptibility) AECs trigger innate immine cells to go trigger type 2 cytokines which cause ASMCs to trigger airway hyperreactivity- causing chronic inflammatory disease
What are the signs and symptoms of someone with bronchitis COPD?
BRONCHITIS:
SIGNS: Chronic cough & sputum, exertional dyspnoea, overweight, often cyanotic
SYMPTOMS: Fatigue, Low PO2 promotes desaturation of blood and
stimulates erythropoiesis (rbc prod)
* Total lung capacity (TLC) remains unchanged
* Respiratory volume (RV) increased because
residual volume is increased.
If you see an increase in respiratory volume but your lung capacity stays the same what type of condition could that be?
bronchitis
What are the signs and symptoms of someone with emphysema COPD?
SIGNS: distended neck veins, weight loss, prolonged expiration
SYMPTOMS: distress
* Accessory respiratory muscles used
* PO2 ~75 mm Hg – almost full saturation.
* Total lung capacity (TLC) and Respiratory
volume (RV) increased because residual
volume is increased.
What are the signs and symptoms of emphysema?
SIGNS: distended neck veins, weight loss, prolonged expiration
SYMPTOMS: distress
* Accessory respiratory muscles used
* PO2 ~75 mm Hg – almost full saturation.
* Total lung capacity (TLC) and Respiratory
volume (RV) increased because residual
volume is increased.
What is the difference between a sign and a symptom?
sign is a visual distinction and symptom is a condition caused by the disease
How is P02, total lung capacity and respiratory volume affected by emphysema and how are accessory respiratory muscles affected?
- Accessory respiratory muscles used
- PO2 ~75 mm Hg – almost full saturation.
- Total lung capacity (TLC) and Respiratory
volume (RV) increased because residual
volume is increased.
What are the causes, symptoms and mechanisms of asthma?
Intermittent periods of reversible airway obstruction leading to airflow problems
SIGNS:
wheezing, exertional dyspnoea
SYMPTOMS:
distress, tightness in chest
Whata are intrinsic causes? What is allergic asthma?
INTRINSIC CAUSES:
Non-immune mechanism (e.g. cold air temperature, exercise, aspirin)
Allergic asthma is a breathing condition where the airways you breathe through tighten when you inhale an allergen.
Explain the extrinsic mechanism explained throug the diagram
EXTRINSIC CAUSES:
Response to inhaled antigen
* Type I hypersensitivity reaction
where antigen binds to IgE on
surface of Mast cells.
* Mast cells “degranulate”
releasing histamine locally.
* Airway smooth muscle contracts.
* Attraction of other leukocytes
(eosinophils) to the site.
* Mucosal inflammation/oedema
What is asthma airway inflammation a complex process of?
- A complex process of immune cells,
inflammatory cytokines and growth factors.
How is Th2-type inflammation spread across the population?
- Th2-type inflammation occurs in >80% of
children and in the majority of adults
with asthma in association with sensitization
to environmental allergens, such as those
from dust mites, fungi, pets and pollens
What is the lymphocyte 2 response usually composed of?
- The inflammatory infiltrate that
accompanies T helper 2 (Th2) lymphocyte
responses is mainly composed of eosinophils
but also includes mast cells, basophils,
neutrophils, monocytes and macrophages.
What is the pathophysiology of Asthma when regarding the decline of lung function overtime?
- a subset of individuals with asthma exhibit an
accelerated decline in lung function over their
lifetime, - which, in severe chronic disease, manifests as
fixed airflow obstruction. - this decline is especially prominent in lateonset asthma.
there is a decrease in volume and expiratory flow rate
What are the causes, symptoms and mechanisms of cystic fibrosis?
➢A multisystem disease
➢Cause: mutations in the cystic fibrosis
transmembrane conductance regulator
(CFTR)
* chromosome 7
* codes for a c-AMP regulated chloride
channel
* Abnormal mucous product; less volume
and is more sticky than normal.
What is cystic fibrosis? What does it cause and result in?
➢A multisystem disease
➢Cause: mutations in the cystic fibrosis
transmembrane conductance regulator
(CFTR)
resulting in Abnormal mucous product; less volume
and is more sticky than normal.
Describe the mechanism of cystic fibrosis from gene defect all the way to mucus obstruction
- CFTR GENE is defective
- defective ion transport
- defective mucociliary clearance
- mucus obstruction which can cause infection and can cause inflamation and can cause more mucus obstruction (goes in circles)
What are the causes, symptoms and mechanisms for interstitial lung disease?
- Group of ~100 chronic lung
disorders - Characterised by inflammation &
scarring - Known causes
Environmental and
occupational exposure – Si,
Asbestos, Be
Autoimmune disease
Drug-induced
Idiopathic
What is interstitial lung disease, what is it charachterised by? What are the known causes?
- Group of ~100 chronic lung
disorders - Characterised by inflammation &
scarring - Known causes
Environmental and
occupational exposure – Si,
Asbestos, Be
Autoimmune disease
Drug-induced
Idiopathic
What is systemic sclerosis?
Describe the 3 levels of interstitial lung disease
I – lack of alveolar space and lymphocyte
infiltration
II – CD4 cell accumulation
III – lack of CD8 cells (innate response)
Describe the impact of interstitial lung disease regarding bronchitis aleolitis and vasculitis
*Bronchiolitis: inflammation of the
small airways (bronchioles).
*Alveolitis: inflammation of the air
sacs where oxygen and carbon
dioxide exchange in the blood
takes places (alveoli).
*Vasculitis: inflammation that
involves the small blood vessels
(capillaries).
what diseases affect the interstitium?
Interstitial lung disease
what diseases affect the pleura?
Pleural effusion
Mesothelioma
describe empthysema
- Emphysema
- Abnormal permanent enlargement of airspaces distal to
the terminal bronchioles - Centrilobular emphysema (CLE) and panlobular
emphysema (PLE)
describe airways disease (brinchitis)
- An infection of the main airways of the lungs(bronchi),
causing them to become irritated and inflamed. - The main symptom is coughing, which may bring up
yellow-grey mucus (phlegm).
describe Smooth Muscle Hypertrophy and Airway Wall
Fibrosis
- Smooth muscle mass may or may not be increased in
COPD
Whether or not airway hyperresponsiveness is a primary
cause of fixed airflow obstruction continues to be a topic
of debate - Regardless, chronic airway inflammation from cigarette
smoke causes constriction and hypertrophy of even
normal airway smooth muscle
