Week 6 Flashcards
What thoracic cage disorders cause restrictive conditions?
- Kyphosis
- Scoliosis
- Ankylosing spondylitis (an inflammatory disease that, over time, can cause some of the bones in the spine (vertebrae) to fuse)
- Flail chest
Why does kyphosis, scoliosis, ankylosing spondylitis cause restrictive conditions?
- mechanical restriction of the rib cage causing reduced compliance of chest wall and therefore inability to bring in large volumes during inspiration
What symptoms are seen with restrictive conditions caused by kyphosis, scoliosis, ankylosing spondylitis?
- rapid, shallow breathing
- dyspnea on exertion
- reduction in all lung volumes (for PFTs)
What is flail chest?
- Explain the changes during inspiration and expiration
When there is a flail segment that moves paradoxically to the rest of the chest wall
- On inspiration the chest wall is supposed to expand while the flail segment moves inwards
- On expiration chest wall comes inwards while flail segment moves outwards - bulge
What is poliomyelitis?
- Polio virus that leads to paralysis, muscular atrophy, and often disability and deformity
What is guillan-barre syndrome?
- A rare neurological disorder in which the body’s immune system mistakenly attacks part of its peripheral nervous system
What is amyotrophic lateral sclerosis (ALS)?
- Progressive nervous system disease that affects nerve cells in the brain and spinal cord, causing loss of muscle control
Myasthenia Gravis
- A chronic autoimmune disorder in which antibodies destroy the communication between nerves and muscle, resulting in weakness of the skeletal muscles
Why do neuromuscular disease cause restrictive disorders?
- Difficulty in increasing the volume of the thoracic cavity during inspiration due to weakness of the respiratory muscles
- symptoms don’t present until diaphragm is involved
What are major manifestations of respiratory muscle weakness? (2)
- insufficient ventilation - decreased tidal volume → compensated by increased respiratory frequency
- ineffective cough - caused by weakness of respiratory muscles so individual is unable to expel mucus which predisposes patients to aspiration, pneumonia, respiratory failure
With neuromuscular disease what are the changes in
- FVC
- FEV
- FEV/FVC ratio
- TLC
- DLCO (diffusing capacity)
- decreased
- decreased
- normal
- decreased
- normal because lung parenchyma is unaffected
What is
- FVC
- FEV1
- Forced vital capacity ; This is the amount of air exhaled forcefully and quickly after inhaling as much as you can.
- Forced expiratory volume: measures how much air a person can exhale during a forced breath in the first second
How does nicotine act on nervous system of a user? (3)
- Nicotine enters brain in 10-20 seconds and acts on mesolimbic reward pathways
- With mesolimbic reward pathway activated → there is release of large amounts of dopamine
- This produces mood-elevating and behaviorally reinforcing effects
How does nicotine cause hypercoagulable states?
- There are oxidant gasses in tobacco smoke that induce hypercoagulable state leading to platelet aggregation and thrombosis
- This increases risk of MI
How does nicotine affect sympathetic nervous system?
- It activates the sympathetic NS and leads to increase heart rate, increase BP, myocardial contractility, increase coronary artery vasoconstriction
What are the types of nicotine replacement therapies? (5)
- patch
- gum
- lozenge
- oral inhaler
- nasal spray
How does nicotine replacement therapies (NRTs) affect a smoker?
- work on same addiction pathways to help reduce withdrawal syndromes
- Nicotine delivery is slower to the mesolimbic reward pathways - so smokers doesn’t get the same pleasurable experiences but also don’t get extreme withdrawal symptoms
What are the non-nicotine medicators?
- bupropion
- varenicline
- What is the mechanism of action of bupropion (zyban)?
- What individuals should not get this drug?
- Blocks neural reuptake of dopamine and/or norepinephrine to relieve cravings
- Patients with history of seizures
What is the best effective first line smoking cessation treatment?
two nicotine replacement therapies at the same time
- a long acting formulation + a short acting formulation
* this is to prevent onset of severe withdrawal symptoms
Out of the Nicotine replacement therapies which ones are long acting formulation and short acting formulation?
- Long acting - nicotine patch
- short acting -everything else (gum, lozenge, inhaler, or nasal spray)
What is the difference between obstructive vs restrictive lung disease?
Obstructive lung diseases include conditions that make it hard to exhale all the air in the lungs.
People with restrictive lung disease have difficulty fully expanding their lungs with air.
What diseases are included in obstructive lung disease? (4)
- emphysema → lead to COPD
- chronic bronchitis → lead to COPD
- asthma
- bronchiectasis
Obstructive Lung Disease
What are the changes in spirometry values
- FVC
- FEV1
- FEV1/FVC ratio
- FVC - decreased
- FEV1 - very decreased
- Decreased FEV1/FVC ratio
Restrictive Lung Disease
What are the changes in spirometry values
- FVC
- FEV1
- FEV1/FVC ratio
- Decreased FVC
- Decreased FEV1
- Normal or even increased FEV1/FVC ratio
What disease categories are included in restrictive lung disease? (3)
- Chest wall disorders
- Acute interstitial lung disease such as ARDS (acute respiratory distress syndrome)
- Chronic interstitial lung diseases
- What are bullae in lungs?
- What complications can this lead to?
- Air pockets within lung parenchyma that have thin or poorly defined wall
- Can rupture and cause pneumothorax because air goes into chest cavity and can lead to collapse of the lung
- Bullae can get to a point where it acts as a pump → pumping air into thorax and causing tension pneumothorax
How does emphysema occur after inhaling irritants such as smoking? (4)
- Tobacco smoke makes ROS which starts inflammatory response, inactivates antiproteases
- Neutrophils work against ROS and increase production of proteases which can no longer be regulated by antiproteases and leads to tissue damage - loss of elastic tissue in alveoli
- Since there is less elastic tissue then compliance is larger - alveoli fill up more but have no elastic recoil so air gets trapped in alveoli. This also leads to collapse at alveolar opening/respiratory bronchiole
- It is harder for person to breathe out
Differentiate between the different types of emphysema?
Centriacinar
- What part of respiratory system and pathophysiology
- What part of lungs
- What is risk factor
- Pulmonary emphysema mainly localized to the proximal respiratory bronchioles with focal destruction
- Predominantly found in the upper lung zones
- Seen with smoking
Differentiate between the different types of emphysema?
Panacinar
- What part of respiratory system and pathophysiology
- What part of lungs
- Includes entire alveolar duct and associated with deficiency antiprotease activity (alpha -1- antitrypsin deficiency)
- Lower lung zones
Differentiate between the different types of emphysema?
Paraseptal
- What part of respiratory system
- What part of lungs
- What is risk factor
- Proximal part of acinus (gas exchanging unit of lung) is normal but distal part is primarily involved
- common in upper half of lungs, adjacent to pleura, areas of fibrosis, scarring, or atelectasis
- Young adults with spontaneous pneumothorax
Differentiate between the different types of emphysema?
Irregular
- What part of respiratory system
- What part of lungs
- What is risk factor
- Acinus irregularly involved - almost always associated with scarring
- variable parts of lung
- inflammatory conditions can cause this type
What are some symptoms of emphysema?
- Age range
- Breathing
- Lung noises
- Description of patient
- Shape of thorax/chest
- Cough?
- 50-75 years old
- dyspnea - severe and early in disease (in panacinar dyspnea presents 20-30 yrs earlier than what is seen in centriacinar)
- Wheezing
- Pink puffer- difficulty catching their breath and their faces redden while gasping for air.
- Barrel-chest
- cough - late in disease with scanty sputum
What radiographic findings will you find with emphysema?
- elongated thorax
- flattened diaphragm
- increased radiolucency (darkness) of lungs
What risk factor is very common for emphysema?
smoking
What is the pathophysiology and clinical description of chronic bronchitis?
- Clinical diagnosis of persistent cough for at least 3 consecutive months in at least 2 consecutive years
- Results from continuous inhalation of irritants resulting in mucus hypersecretion due to mucus gland and goblet cell hyperplasia
What are risk factors for chronic bronchitis?
Tobacco smoking and air pollution
What are some symptoms of chronic bronchitis?
- Age range
- Cough?
- Breathing abnormalities?
- Description of patient
- complications from this?
- 40-45 years old
- chronic PRODUCTIVE cough
- dyspnea on exertion - mild and occurs late in disease
- Blue bloater- cyanosis because often take deeper breaths but can’t take in the right amount of oxygen.
- Chronic infections can occur
What changes in pathology can be seen with chronic bronchitis?
- with mucous gland and goblet cell hyperplasia you see airway remodeling
- the amount of remodeling can be determined by the Reid Index
What is the Reid Index?
- ratio of thickness of mucous gland layer to bronchial wall
- < 0.4 is normal
- 0.7 is severe
differentiate between chronic bronchitis and emphysema in…
- age
- dyspnea
- cough
- infections
- airway resistance
- elastic recoil
- chest radiograph
- clinical appearance
image
What are the four types of asthma?
- Atopic (allergic or extrinsic)
- Nonatopic (intrinsic)
- Drug induced
- Occupational
What is asthma?
- Episodic and reversible disease that is defined by increased irritability of the bronchial tree in response to stimuli
Describe early and late phase of atopic asthma?
- Early phase - mast cells release histamine, prostaglandins, and leukotrienes to cause bronchoconstriction, increased mucus production, vasodilation
- Late phase - leukocytes recruited and activated to initiate asthma + damage to epithelium
Describe with more details the process/steps to late phase atopic asthma? (3)
- inhaled allergens elicit a TH2 response
- IL - 4 is sent to B cells so B cells now favor IgE production
- IL-5 does eosinophil recruitment - cause damage to epithelium and induce remodeling
What does remodeling look like in atopic asthma?
- thickened mucus layer
- goblet cell hyperplasia
- thickening of smooth muscle
- increased glands
- angiogenesis
what causes lungs to be uncollapse on autopsy for a person with asthma/
- mucus plug, air cannot escape and leads to inflated lungs at autopsy
- What are Curschmann spirals and charcot-leyden crystals and what do they look like?
- In what condition are they found?
- Curschmann - spiral-shaped mucus plugs from subepithelial mucous gland ducts of bronchi ;;;; Charcot-leyden -microscopic crystals composed of eosinophil protein galectin-10 found in people who have allergic diseases such as asthma;;; image (spirals on left and crystals on right)
- asthma
- What risk factors for nonatopic asthma?
- Onset?
-not well understood
- triggers are respiratory viral infections and inhaled air pollutants
- adult age
- What drugs cause drug induced asthma?
- aspirin/NSAIDs
- What risk factors for occupational asthma?
- Onset?
- fumes, chemical dust, gases, etc
- adult age
What is bronchiectasis?
- Dilation of segments of airway which causes pooling of mucous which is subject to infection
- Sleep allows mucus to pool making the condition worse in the morning
What are some symptoms of bronchiectasis?
- Fever
- Dyspnea
- Hemoptysis (spitting of blood that originated in the lungs or bronchial tubes)
- and more
What are some pathology findings of bronchiectasis in gross anatomy?
dilated airways and mucous
What disease(s) causes bronchiectasis?
- cystic fibrosis
- Ciliary dyskinesia
What is the pathophysiology of cystic fibrosis? (3)
- Disorder of epithelial ion transporters affecting/inhibiting fluid secretion
- Dehydrated mucus is formed which is difficult to move and plugs up airway
- This type of mucus is also a good place for infection to occur - persistent lung infections can occur
- Is cystic fibrosis autosomal recessive or dominant?
- What mutation is associated with CF?
- autosomal recessive
- mutation in CFTR gene on chromosome 7
What is ciliary dyskinesia?
- Primary structural disorder of cilia causing abnormal ciliary motility
- Cilia look normal under the microscope but don’t function properly
- What complications/disorders can be seen along with ciliary dyskinesia?
- is ciliary dyskinesia autosomal recessive or dominant?
- Kartagener syndrome/situs inversus: flipped organs on the wrong side of body
- autosomal recessive
What is type A vs type B COPD?
- Type A is typically emphysema
- Type B is typically chronic bronchitis
What are the three factors that affect airway resistance?
- Pattern of airflow
- Diameter of airway
- Lung volume
How does pattern of airflow affect airway resistance?
If flow becomes turbulent, and the pressure difference is increased to maintain flow, this response itself increases resistance. This means that a large increase in pressure difference is required to maintain flow if it becomes turbulent.
How does diameter of airway affect airway resistance?
- airway resistance is inversely proportional to radius4
- so if radius doubles then airway resistance decreases 16 fold
- extra info:
- airway resistance is proportional to length - so double the length you double the resistance
If larger radius in airway decreases resistance then why do small airways have such low resistance?
- small airways are large in number and together have large surface area. This means that in fact together they have a large radius which decreases resistance in airway
How does lung volume affect airway resistance?
- as lung volume increases, airway resistance decreases
- with more lung volume, there is more expansion of alveoli
- As the alveoli expand they also exert tension on airways, pulling them open (known as radial traction) - thus airway diameter increases as lung inflates and reduces airway resistance
Why do individuals with obstructive disease ventilate at high lung volumes?
Because airway resistance is minimized at high volumes due to radial traction
What are three major causes of increased alveolar CO2?
- increased CO2 production
- hypoventilation
- increased dead space
What happens during forced expiration that limits the amount of air expired at the end of exhalation?
- peripheral ariways collapse and this limits flow
- When you force expiration you cause positive intrapleural pressure which is greater than airway pressure
- this causes collapse of airway
Describe the differences in airway pressures and pleural pressure to determine if airway closes or opens
- If PAW > PPL then airway stays open
- If PPL > PAW then airway closes
What is FRC and RV?
- Functional residual capacity (FRC) is the volume of air present in the lungs at the end of passive expiration
- Residual volume is the amount of air that remains in a person’s lungs after maximal exhalation.
Describe how FRC and RV change in obstructive lung disease and why?
- FRC is increased
- RV is increased
- Both are increased because there is air trapping in obstructive lung disease
Describe how FRC and tidal volume change in restrictive lung disease and why?
- Decreased tidal volume and FRC
- Restrictive diseases stop the lungs from fully expanding. This limits the volume of air and amount of oxygen that a person breathes in
- What does a spirometer measure? (two values that are similar)
- volume of air inspired and expired with time
- FEV1 (volume of air exhaled in first second of expiration)
- FVC (total volume of air exhaled before next inspiration)
- Why is FEV1 reduced in obstructive disease?
- Why is FVC reduced?
- FEV1 is reduced because of increased airway resistance
- FVC is reduced because increased airway resistance causes earlier airway collapse/airway closure/etc
What is typically the ratio of FEV1/FVC for obstructive lung disease?
- less than 80%
normal is 80%
- Why is FEV1 reduced in restrictive disease?
- Why is FVC reduced?
- FEV1 is reduced because of low total lung volume
- FVC is reduced because there is lower lung volume typical for these patients
What is typically the ratio of FEV1/FVC for restrictive lung disease?
- can be higher than 80%
normal is 80%