Pulmonary

Question 1

What kind of epithelia line the respiratory tract?

Answer 1

nasal cavity and paranasal sinuses = **cuboidal **

pharynx and larynx = **squamous **

trachea and bronchi = cuboidal

Question 2

What are the main functions of the respiratory system?

Answer 2

primary = respiration

2. voice
3. immune (MALT & alveolar macrophages)
4. metabolic, acid-base balance

Question 3

Describe the respiratory defense system.

Answer 3

**MALT means mucosa-assoc. lymph tissue. **

• forms tonsils in the nasopharynx and pharynx + lymphoid follicles in bronchi

Alveolar macrophages

• phagocytic cells, can be found in sputum. Pulmonary capillaries mobilize leukocytes quickly to sites of infection.

Question 4

What are the main respiratory diseases?

Answer 4

• infectious disease
• immune diseases
• environmentally induced
• circulatory disease
• tumors

Question 5

Compare the infections of the upper respiratory system with those of the so-called middle respiratory system.

Answer 5

**URI: **infection/inflammation of the nose, paranasal sinuses, throat, larynx . . .may spread to the middle ear, and tracheobronchial tree

**MRI: **larynx, trachea, extrapulmonary bronchi.

Question 6

What could cause a “runny nose”?

Answer 6

Most URIs are viruses. In viral infections, lymphocytes, macrophages, and plasma cells infiltrate and cause congestion and edema.

Severe infections can cause ulceration of the mucosal epithelial lining, which allows entry of bacteria.

Question 7

What is croup?

Answer 7

An acute life-threatening infection involving the **larynx. **

Inflammation causes swelling and laryngospasm. The vocal cords spasm and cause “barking cough”. Typically caused by _parainfluenza virus. _

Question 8

Compare epiglotittis and bronchiolitis.

Answer 8

Epiglottitis = **h. influenzae

sudden loss of voice and hoarseness, pain with swallowing. edema and narrowing of the air passage. requires antibiotic therapy.

bronchiolitis = **RSV

wheezing, low-grade fever, SOB. virus invades epithelial cells of the bronchi and bronchioli, causing cell death and desquamation. Edema of airway and dead cells cause obstruction of the bronchi and bronchioli.

Question 9

Compare alveolar and interstitial pneumonia.

Answer 9

aveolar

• focal or diffuse
• most often caused by bacteria
• * often superimposed on pulmonary edema of CHF*

lobar

• usually diffuse
• often bilateral
• most often caused by viruses

Question 10

List the common causes of pneumonia and give specific characteristics about each of these forms of lung infection.

Answer 10

- upper respiratory flora

strep pneumo
H. influenzae
staph aureus

• *- enteric saprophytes**
• E. coli
  p. aeruginosa*

- extaneous pathogens
legionella
TB
herpesvirus, CMV

Question 11

Compare lobar pneumonia and bronchopneumonia with interstitial pneumonia.

Question 12

List 3 complications of bacterial pneumonia.

Answer 12

1. pleuritis
   inflammation commonly >> pleural effusion.
   pus = pyothorax
   fibrous tissue = empyema
2. abscess
   usually associated with highly virulent bacteria (Staph)
3. chronic lung disease
   pus causes destruction and bronchial dilation (bronchiectasis).
   fibrosis >> honeycomb lungs

Question 13

Compare community-acquired pneumonia and hospital-acquired pneumonia.

Answer 13

**primary (community-acquired) = **
affects previously healthy people

secondary (or nosocomial) =
affects those with pre-existing illness

Question 14

What are the clinical signs of pneumonia?

Answer 14

systemic

• fever, chills

local irritation

• coughing, chest pain, expectoration

airway obstruction

• dyspnea, tachypnea

inflammation

• tissue destruction, bleeding

Question 15

Explain the concept of atypical pneumonia and give specific examples of this clinicopathologic entity.

Answer 15

**atypical** = pneumonias that **do not** present with classical symptoms
examples = *viruses, mycoplasma pneumo*

Question 16

Compare primary and secondary tuberculosis.

Answer 16

Primary. . . occurs in a person not previously exposed.
symtoms = mild & lo fever

Secondary. . . is a reactivation of a dormant primary infection or a reinfection.

symptoms = dry cough, fever, loss of appetite, malaise, night sweats, weight loss

Question 17

Which fungi cause pneumonia and under what circumstances?

Answer 17

community acquired = histoplasmosis, coccidiodomycosis

hosptial acquired (esp AIDS) = PCP, candida, aspergillus

Question 18

Which pathogens cause pulmonary abscesses?

Answer 18

most common = s. aureus

less often = klebsiella, pseudomonas

Question 19

Compare chronic obstructive pulmonary disease caused by chronic bronchitis and COPD caused by emphysema.

Answer 19

Chronic bronchitis = “blue bloaters”

• bouts of coughing, purulent mucus, dyspnea
• pulm. HTN, cor pulmonale

emphysema = “pink puffers”

• no bronchial obstruction, no irritation (therefore no coughing)
• tachypnea
• barrel chest

Question 20

What is bronchiectasis, and how does it develop?

Answer 20

a permanent dilation of the bronchi

result of persistent inflammation of the airways. Enzymes from bacteria and leukocytes + mechanical pressure + fibrous scars

Question 21

Compare centrilobular and panacinar emphysema.

Answer 21

• *centrilobular** = widening of the airspae in the center of a lobule and involves predominantly respiratory bronchioles
• most common form of emphysema, smoking*
• *panacinar **= airspaces distal to the terminal bronchioles
• alpha-1AT deficiency*

Question 22

List the most important immune diseases of the respiratory tract.

Answer 22

1. sarcoidosis
2. hypersensitivity pneumonitis
3. bronchial asthma
4. allergic rhinitis

Question 23

Explain the pathogenesis of asthma.

Answer 23

increased responsiveness of the bronchial tree to stimuli

*allergens can trigger the release of mediators from mast cells, which act on the blood vessels and smooth muscle cells. Mediators released from chronic inflammatory cells in the wall of the bronchus also stimulate mucous secretion and contraction of the smooth muscle cells. *

Question 24

Compare extrinsic and intrinsic asthma.

Answer 24

• *extrinsic**
• exogenous allergens
• type 1 hypersensitivity
• *intrinsic**
• nonimmune
• hyperreactivity of the bronchial tissues

Question 25

What is sarcoidosis, and how does it affect the body?

Answer 25

= ***multisystemic ganulomatous disease*** 2x more common in AA women than men 10:1 (CD4:CD8) may have *dyspnea, cough, wheezing, low fever, lymphadeopathy* key = noncaseating granuloma

Question 26

List several important antigens that cause hypersensitivity pneumonitis.

Answer 26

* *farmer's lung**. . . moldy hay * *bagassosis**. . . sugar cane * *maple bark dx**. . . maple bark * *mushroom worker's lung**. . . mushrooms * *humidifier lung**. . . contaminated fluid * *pigeon-breeder's lung**. . . droppings * *furrier's lung**. . . animal pelts

Question 27

Compare acute and chronic hypersensitivity pneumoitis.

Answer 27

**_acute_** *mediated by antibodies that react with inhaled antigens. will evolve over several hours* \* sudden onset dyspnea **_chronic_** *T lymphocyte mediated. granulomas may from in alveolar septa and damages tissue (fibrosis). \* *chronic dyspnea, hyperventilation, ult resp failure

Question 28

What is pneumoconiosis?

Answer 28

= lung diseases caused by inhalation of mineral dusts, fumes, and other particulate matter

Question 29

How does inhalation of mineral particles damage the lungs?

Answer 29

* Coal: less reactive, develops only after long exposure to high levels * silica: more reactive, produce prominent tissue injury * asbestos: insoluble, remain in lungs permanently

Question 30

Explain the effect of air pollutants on the lungs.

Answer 30

small particles = taken up by macrophages (\<5 microm) large particles = stay in nasal mucosa (\>10) ## Footnote *macrophages stimulated by the ingested particles release cytokines (IL-1) and TNF, which promote inflammation and stimulate the proliferation of fibroblasts and the formation of collagen*

Question 31

Explain the pathogenesis of coal-workers' lung disease.

Answer 31

Particles are taken up by macrophages in alveoli. Particles are deposited in centrolobular zones and may be associated with fibrosis or centroacinar emphysema.

Question 32

What is silicosis, and how does it present pathologically?

Answer 32

Inhalation of silica (sand-blasting, mining, stone cutting) ## Footnote * causes fibronodular lesions in the lung parenchyma. Particles taken up by macrophages, which release silica crystals and stimulate fibroblasts to produce collagen* * \*\*TB is a common complycation b/c silica-laden macrophages cannot effectively combat mycobacterial infections*

Question 33

Which lung diseases are related to exposure to asbestos?

Answer 33

1. pulmonary fibrosis 2. pleural fibrosis and pleural plaques 3. lung cancer 4. mesothelioma

Question 34

Explain the pathogenesis of dyspnea caused by various mechanisms.

Answer 34

**large airway obstruction**. . . laryngospasm **small airway obstruction**. . . bronciolitis, asthma **intra-alveolar obstruction**. . . pneumonia, edema alveolar septal lesions **destruction**. . . emphysema **increase in thickness**. . . intersitital fibrosis **collapse**. . . atelectasis **CNS causes**. . . apoplexy of respiratory centers

Question 35

Compare the pathologic findings in wet drowning and dry drowning.

Answer 35

wet drowning: water prevents entry of air, death occurs within minutes dry drowning: reflex laryngospasm closes glottis and prevents air/fluid

Question 36

List four main pathogenetic mechanisms of ventilatory failure and explain how they affect respiration.

Answer 36

1. **Neural control** *depends on CO2 content* e.g. apoplexy 2. **Respiratory muscles** striated muscles dependent on cranial/spinal nerves e.g. polio, tetanus, MG, MD 3. **Chest wall** *can restrict expansion* e.g. kyphoscoliosis 4. **Airways** *alveolar hypoxia* cystic fibrosis, laryngospasm

Question 37

List common causes of acute respiratory distress syndrome.

Answer 37

Shock * trauma * burns * acute cardiac failure Pneumonia * bacterial * viral Toxic lung injury * toxic fumes * cytotoxic drugs * bacterial endotoxins Aspiration of fluids

Question 38

Describe the pathology of acute respiratory distress syndrome and explain its pathogenesis.

Answer 38

alveolar injury = initiating event in viral pneumonia or fumes endothelial injury = initiating event in sepsis *regardless of initial injury, lesions are comprised of hyaline membranes, ruptured alveolar walls, and intra-alveolar edema* see pg. 185 in book

Question 39

What are the possible outcomes of acute respiratory distress syndrome?

Answer 39

1/3 die within days + 1/3 die of pneumonia and heart failure within weeks + 1/3 recover

Question 40

What is atelectasis, and what are its possible causes?

Answer 40

***atelectasis ****is the incomplete expansion or collapse of alveoli.* 1. *deficiency of surfactant* 2. *compression of the lungs from outside* 3. *resorption of air distal to bronchial obstruction*

Question 41

What are the most important neoplasms of the respiratory tract?

Answer 41

lung cancer + carcinoma of the larynx

Question 42

Correlate the pathology of carcinomas of the larynx with clinical findings and prognosis of the disease.

Answer 42

\* all are squamous cell - linked with smoking and chronic alcohol - rare \<40 yrs - can originate in any part of the larynx - present as nodules and ulcerations of the mucosa * patients present relatively early with hoarseness, stridor. 75% 5yr survival. *

Question 43

How common is lung cancer?

Answer 43

Most common malignant disease of internal organs and leading cause of cancer death in the US

Question 44

How is tobacco smoking related to lung carcinoma?

Answer 44

**90% of patients with lung cancer are smokers!** Tobacco smoke has polycyclic hydrocarbons that initiate and promote malignant transformation of cells. Also contains procarcinogens.

Question 45

Explain the histogenesis of various histologic types of lung carcinoma.

Answer 45

*Columnar epithelium undergoes squamous metaplasia, which can progress to carcinoma in situ and invasive squamous cell carcinoma. * adenocarcinomas = mucous/ciliated cells small-cell = neuroendocrine cells large-cell = anaplastic stem cells

Question 46

Compare hilar (central) and peripheral lung carcinoma.

Answer 46

Central = squamous, large-cell, small-cell peripheral = adenocarcinomas

Question 47

Where do lung carcinomas metastasize?

Answer 47

- Liver - Brain - Bone - Adrenals

Question 48

What are the clinical signs of lung cancer?

Answer 48

* *- bronchial irritation/obstruction** * wheezing, dyspnea, hemoptysis* * *- local extension into the mediastinum or pleural cavity** * atelectasis, dysphagia* * *- distant mets** * HSM, neurologic symptoms, Addisons* * *- systemic effects** * weight loss, anorexia, malaise*

Question 49

What are the common paraneoplastic syndromes caused by lung carcinoma?

Answer 49

PTH \>\> hypercalcemia ACTH \>\> Cushing's ADH \>\> hyponatremia

Question 50

Compare pneumothorax and hydrothorax.

Answer 50

pneumothorax = air in the pleural cavity hydrothorax = fluid in pleural cavity

Question 51

Explain the pathogenesis of pleuritis.

Answer 51

**Hallmark = exudate** bacterial pneumo \>\> fibrinous/purulent viral \>\> serous TB \>\> serous or fibrinous, NO PMNs heart failure/edema \>\> transudate

Question 52

What is mesothelioma?

Answer 52

rare malignant tumor of the pleura \*often r/t asbestos

Question 53

What makes interstitial pneumonia unique?

Answer 53

**Interstitial** . . . i*nflammation _affects the alveolar septa_ and **does not** result in exudation of PMNs into the alveolar lumen. Also viruses that cause interstitial pneumonia attach to respiratory epithelial cells \>\> cell necrosis = **"reticular pattern" on x-ray***

Question 54

How is pneumonia diagnosed?

Answer 54

**- x-ray** **- sputum studies** **- peripheral blood studies**

Question 55

What are some unique features of TB?

Answer 55

- acid-fast bacillus (Ziehl-Neelsen) - TB **does NOT** attract PMNs, but forms granulomas - Ghon complex = parenchymal focus and hilar lymph node lesion - Ghon complex = central caseous necrosis surrounded by epithelioid cells, multinucleated giant cells, lymphocytes

Question 56

What is the defnition of chronic bronchitis?

Answer 56

_excessive production_ of *tracheobronchial mucus causing cough and expectoration* for **at least 3 months** during **2 consecutive years. **