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Last region of respiratory tree where goblet cells are found
Cells that mediate gas exchange
Type I pneumocytes
Cells that secrete surfactant
Type II pneumocytes
Way to measure fetal lung maturity
Lecithin:sphingomyelin ratio in amniotic fluid should be over 2
Which lung is the lingula found on?
Most common site for inhaled foreign body to lodge
Where is the pulmonary artery, relative to the bronchus, in each lung?
At what level does the IVC perforate the diaphragm?
At what level do the esophagus and vagus perforate the diaphragm?
At what level do the aorta, thoracic duct, and azygos perforate the diaphragm?
Functions of ACE
- Converts angiotensin I to angiotensin II
- Inactivates bradykinin
Role of kallikrein
Definition of vital capacity
Maximal air volume that can be pushed in and out of the lungs: tidal volume + inspiratory reserve volume + expiratory reserve volume
Definition of functional residual capacity
Air left in lungs after normal expiration: expiratory reserve volume + residual volume
Region of lung that is the largest contributor to functional dead space
When does airway pressure equal atmospheric pressure?
Factors that favor the tense conformation of Hb
- Decreased oxygen pressure, increased carbon dioxide pressure
- 2,3 BPG
Treatment for methemoglobinemia
Effect of carboxyhemoglobin
Carbon monoxide binds to Hb much more strongly than oxygen. This displaces oxygen from hemoglobin, causes a left shift of the Hb/O2 dissociation curve, and decreases oxygen delivery to the tissues.
In whom does 2,3 BPG concentration increase, and why?
- COPD patients
- People who live at high altitudes
Increased 2,3 BPG promotes unloading of oxygen in the tissues, which compensates for a low oxygen pressure
Effect of decreased oxygen pressure in the lungs
Vasoconstriction shunts blood in the lungs away from poorly ventilated areas (diffuse hypoxia in the lungs can lead to pulmonary hypertension
Cause of primary pulmonary hypertension
Inactivating mutation in the BMPR2 gene (which normally functions to inhibit vascular smooth muscle proliferation)
How much oxygen can one gram of hemoglobin bind to?
Alveolar arterial gradient
- Alveolar oxygen - arterial oxygen
- Normal is 10-15 mmHg
Five causes of hypoxemia
- High altitude
- V/Q mismatch
- Diffusion limitation
- Right to left shunt
Five causes of hypoxia (decreased oxygen delivery to the tissues)
- Decreased cardiac output
- Cyanide poisoning
- CO poisoning
Where are ventilation and perfusion highest?
Base of the lungs--but perfusion is a lot higher than ventilation
What is the V/Q ratio if the airways are obstructed?
What is the V/Q ratio if blood flow is obstructed?
Why does bicarb turn back to carbon dioxide in the lungs?
Oxygenation of Hb causes H+ to be released from Hb; H+ protenates bicarb, converting it back into CO2 and water
What happens to the body's acid base balance at high altitudes?
- Decreased oxygen concentrations cause hypoxemia
- Hypoxemia activates central respiratory centers, leading to hyperventilation
- Hyperventilation decreases CO2, which causes respiratory alkalosis
- ("acute mountain sickness" can be treated with acetazolamide)
- The kidneys excrete bicarb to compensate for the respiratory alkalosis
When is FEV1/FVC ratio decreased?
Obstructive lung disease
What is the Reid index, and in what disease does it increase?
- The ratio of gland depth:bronchiolar wall
- Increases over 50% in chronic bronchitis, due to hypertrophy of mucus-producing glands
What happens to bronchiolar smooth muscle in asthma patients?
Why do asthmatics have a pulsus paradoxus?
- High negative pressure in the thorax during inspiration increases venous return to the right ventricle
- The right ventricle distends and compresses the left ventricle, causing systolic pressure to weaken during inspiration
What happens to the FEV1:FVC ratio in restrictive lung disease?
- It stays normal, or increases
- Both FEV1 and FVC go down in restrictive lung disease, but FEV1 tends to go down less, since stiff lungs are good at expelling air
Name three drugs that cause pulmonary fibrosis
What lobes are affected by coal worker's lung?
Eggshell calcification on hilar lymph nodes
Which alveoli are most vulnerable to surfactant deficiency?
The smaller ones, since collapsing pressure decreases with radius
1. Squamous cell carcinoma
2. Bronchial adenocarcinoma
3. Small cell carcinoma
- Small cell--central
Lung cancer that has psammoma bodies on biopsy
Lung cancer with small, dark blue cells that stain positive for chromogranin
Small cell carcinoma