Respiratory1

Question 1

Which cells secrete surfactant? What is the most important lecithin in surfactant?

Answer 1

Type II cells.

Diplamitoylphosphatidylcholine is the most important lecithin.

Question 2

What are the vertebral levels of the IVC, esophagus and aorta?

Answer 2

IVC: T8
Esophagus: T10
Aorta: T 12

“I ate 10 eggs at twelve.”

Question 3

What is the inspiratory reserve volume?

Answer 3

Air that can still be inspired after normal inhalation.

Question 4

What is tidal volume?

Answer 4

Quiet/normal inspiration (~500mL).

Question 5

What is expiratory reserve volume?

Answer 5

Air that can still be expired after normal expiration.

Question 6

What is the residual volume?

Answer 6

The air that you can’t get rid of.

Question 7

What is vital capacity?

Answer 7

IRV + TV + ERV

Question 8

What is total lung capacity?

Answer 8

The sum of all the parts, ~6L

Question 9

What is Hg made up of?

Answer 9

4 parts: alpha 1/2, beta 1/2

There is a fetal Hg, too, which has a greater affinity for O2 than adult Hg.

Question 10

What is methemoglobin?

Answer 10

Hg with oxidized Fe3+ instead of the normal Fe2+. It does not bind to O2 as well. “Chocolate brown blood.”

Question 11

What does “ACE BATs Right” stand for?

Answer 11

Things that RIGHT shift the dissociation curve.

Altitude
CO2
Exercise
BPG (2,3-BPG)
Acid (low pH)
Temperature

Question 12

What is the most important aspect regarding pulmonary resistance?

Answer 12

Radius.

Resistance = 8nl/(pi x r^4)

Question 13

What are the two types of hypoxemia?

Answer 13

Normal A-a gradient: high altitude, hypoventilation

Increased A-a gradient: V/Q mismatch, diffusion limitation, R to L shunt.

Question 14

What are four causes of hypoxia?

Answer 14

Decreased cardiac output
Hypoxemia
Anemia
CO poisoning

Question 15

What’s the difference in FEV1/FVC in obstructive vs. restrictive lung disease?

Answer 15

Restrictive: FEV1/FVC >= 80%

Obstructive: FEV1/FVC

Question 16

What are some causes of pulmonary HTN?

Answer 16

Primary: inactivation mutation of BMPR2, leads to proliferation of smooth muscles, poor prognosis.

Secondary: COPD, mitral stenosis, recurrent thromboemboli, autoimmune (SLE), sleep apnea, high altitude

Question 17

What is a hallmark of Obesity Hypoventilation Syndrome?

Answer 17

The pt gets used to being hypoxic, the thermostat gets reset.

decreased PaO2 and increased PaCO2 during waking hours.

Question 18

What are common complications to lung cancer?

Answer 18

SPHERE

Superior vena cava syndrome
Pancoast tumor
Horner syndrome
Endocrine (paraneoplastic)
Recurrent laryngeal
Effusions (pleural and pericardial)

Question 19

Tell me some stuff about adenocarcinoma.

Answer 19

Most common primary lung cancer in non-smokers.

Mutations: k-RAS, EGFR and ALK

Question 20

Tell me some stuff about squamous cell carcinoma.

Answer 20

Cavitation
Cigarettes
Calcium (produces PTHrP)

Histology: keratin pearls and intercellular bridges (looks like tram tracks)

Question 21

Tell me some stuff about small cell carcinoma.

Answer 21

Very aggressive, undifferentiating, inoperable
ACTH production (Cushing’s symptoms)
ADH production
Amplification of myc oncogenes
Abs against presynaptic Ca++ channels (Lambert-Eaton syndrome with proximal muscle weakness)

Question 22

Tell me some stuff about large cell carcinoma.

Answer 22

Highly anaplastic tumor, poor prognosis, surgery works about 50% of time.

Question 23

Tell me some stuff about bronchial carcinoid tumor.

Answer 23

Histology: rosette pattern
Best prognosis
Symptoms due to mass effect, occasionally carcinoid syndrome (5-HT like syndrome)

Question 24

What is a pancoast tumor?

Answer 24

Carcinoma in apex of lung. Can cause Horner syndrome (ptosis, miosis, anhydrosis).

Question 25

What is the most common setting for a spontaneous pneumothorax?

Answer 25

Tall, thin, young me bc of a ruptured bleb. More common in Marfans, Ehler-Danlos and homocystinuria.

Question 26

What is the most common setting for a tension pneumothorax?

Answer 26

Usually in setting of trauma or infxn. Trachea deviates away from side of lesion. “Reach for needle first” Medical emergency… don’t have time to image.

Question 27

What does it mean if pleural effusion has low or high protein content?

Answer 27

low = transudate = due to CHF, nephrotic syndrome, or hepatic cirrhosis

high = exudate = malignancy, pneumonia, collagen vascular disease, trauma

Question 28

What is superior vena cava syndrome?

Answer 28

An obstruction of SVC that causes facial swelling, JVD and upper extremity swelling.

Medical emergency; can raise intracranial pressure.