Usmle Step 1 Dit: Respiratory

Front 1

Conducting zone of the respiratory tree consists of what structures?

Back 1

Large airways: Nose, pharynx, larynx, trachea and bronchi

Small airways: Bronchioles and terminal bronchioles

Front 2

Respiratory zone of respiratory tree

Back 2

Bronchioles, alveolar ducts, and alveoli

Front 3

What muscles are used to facilitate inspiration during exercise?

Back 3

Scalene, external intercostals

Front 4

What muscles are used to facilitate expiration during excercise?

Back 4

Transversus abdominalis, rectus abdominalis, internal and external oblique, internal intercostals

Front 5

What cell types line the traquea?

Back 5

Ciliated columnar epithelium.

Front 6

How will traquea cells change in response to chronic smoking?

Back 6

Squamous metaplasia

Front 7

What area of the respiratory tree warms, humidifies and filters air but does not participate in gas exchange?

Back 7

Anatomic dead space

Front 8

What cell types line the respiratory bronchioles?

Back 8

Mostly cuboidal cells in respiratory bonchioles

Front 9

Cell that takes up 97% of alveolar surface

Back 9

Type I pneumocytes

Front 10

Cell that takes up 3% of alveolar surface

Back 10

Type II pneumocytes

Front 11

Cell that secretes pulmonary surfactant

Back 11

Type II pneumocytes

Front 12

Large cuboidal and clustered pulmonary cells

Back 12

Type II pneumoncytes

Front 13

Simple squamous cells unable to replicate that are thin in order to optimize gas diffusion

Back 13

Type I pneumocytes

Front 14

What are the functions of type II pneumocytes?

Back 14

- Secrete pulmonary surfactant (which decreases alveolar surface tension and prevents alveolar collapse)

- Precursors to type I and II cells. They proliferate during lung damage.

Front 15

What test confirms lung maturity during fetal life?

Back 15

Lecithin-to-sphingomyelin ratio >2.0 in amniotic fluid indicates fetal lung maturity

Front 16

What is the embryological origin of the diaphragm?

Back 16

- Septum transversum

- pleuroperitoneal membrane

- Dorsal mesentary of the esophagus

- Abdominal wall

Front 17

Who innervates the diaphragm?

Back 17

- C3, 4 and 5

C3,4 and 5 keeps the diaphragm alive

Front 18

What structure perforates the diaphragm at T8?

Back 18

Inferior vena cava

Front 19

What structure perforates the diaphragm at T10?

Back 19

Esophagus, vagus (CN 10)

Front 20

What structure perforates the diaphragm at T12?

Back 20

Aorta, thoracic duct, azygos vein

Front 21

When abdominal structures enter the thorax:

Back 21

Diaphragmatic hernia

Front 22

Most common form of diaphragmatic hernia?

Back 22

Sliding hiatal hernia

Front 23

Flattened abdomen, cyanosis, inability to breath

Back 23

Diaphragmatic hernia

Front 24

Associated with polyhydramios, can cause lung hypoplasia, most often one-sided

Back 24

Diaphragmatic hernia

Front 25

Which lung has 3 lobes?

Back 25

Right lung

Front 26

Most common site for inhaled foreign bodies, why?

Back 26

Right lung; because its wider and more vertical

Front 27

What lung has 2 lobes?

Back 27

Left lobe has Less Lobes and lingula

Front 28

What arteries irrigate bronchopulmonary segments?

Back 28

pulmonary artery and bronchial artery

Front 29

What is a bronchopulmonary segment?

Back 29

Bronchus and 2 arteries

Front 30

Air that can still be breathed in after normal inspiration

Back 30

Inspiratory reserve volume (IRV)

Front 31

Air that moves into lung with each quiet inspiration, typically 500 ml

Back 31

Tidal volume (TV)

Front 32

Air that can still be breathed out after normal expiration

Back 32

Expiratory reserve volume (ERV)

Front 33

Air in lung after maximal expiration that cannot be measured of spirometry

Back 33

Residual volume (RV)

Front 34

IRV + TV

Back 34

Inspiratory capacity

Front 35

RV + ERV

Volume in lungs after normal expiration

Back 35

Functional residual capacity (FRC)

Front 36

TV + IRV + ERV

Maximum volume of gas that can be expired after a maximal inspiration

Back 36

Vital capacity (VC)

Front 37

IRV + TV + ERV + RV

Volume of gas present in lungs after a maximal inspiration

Back 37

Total lung capacity (TLC)

Front 38

How is physiologic dead space calculated?

Back 38

Vd=Vt x PaC02 - PeC02 / PaC02

Vd= physiological dead space

Vt= tidal volume

PaC02= PC02 arterial blood

PeC02= Expired air

Front 39

The point where airway and alveolar pressures are 0

Back 39

FRC

Front 40

Change in lung volume for a given change in pressure

Back 40

Compliance

Front 41

In what conditions is compliance decreased? And how is the FRC?

Back 41

Pulmonary fibrosis, pneumonia and pulmonary edema

If compliance is decreased, FRC is increased

Front 42

In what conditions is compliance increased? And how is the FRC?

Back 42

Emphysema and normal aging

If compliance is increased, FRC is decreased

Front 43

True or false: P02 and PC02 exert opposite effects on pulmonary and systemic circulation

Back 43

True

Front 44

What occurs when PA02 decreases in the lung?

Back 44

Hypoxic vasoconstriction that shifts blood away from poorly ventilated regions of the lung to well ventilated regions of the lung.

Front 45

Low alveolar oxygen, chronic vasoconstriction, pulmonary HT, Cor pulmonale

Back 45

COPD

Front 46

What changes in radius affect airway resistance?

Back 46

Bronchoconstriction (Decreased radius and increased resistance)

- Anaphylaxis, bronchospasm, asthma, parasympathetic stimulation.

Bronchodilation (increases radius and decreases resistance)

- sympathetic stimulation, B blockers

Front 47

What changes in viscosity affect airway resistance?

Back 47

Helium (used medically to reduce resistance in some patients with tumors that decrease radius)

Front 48

What is the cause of primary pulmonary hypertension?

Back 48

BMPR2 gene (which normally functions to inhibit vascular smooth muscle proliferation)

Front 49

How is the prognosis for primary pulmonary HTN?

Back 49

Very poor

Front 50

What is the cause of secondary pulmonary HTN?

Back 50

- COPD and fibrosis (due to destruction of lung parenchyma

- Mitral stenosis (Increased resistance and pressure)

- Recurrent thromboemboli

- Autoimmune disease (increased inflammation-hypertrophy)

- Left to right shunt (stress and endothelial injury)

- Sleep apnea or living at high altitudes (hypoic vasoconstriction)

Front 51

What is the normal pulmonary artery pressure?

Back 51

10-14 mmHg

Front 52

How is pulmonary HTN defined?

Back 52

>25 mmHg or 35 mmHg during exersize

Front 53

What is the treatment for pulmonary HTN?

Back 53

Bosentan and ambriosentan: competitevely antagonize endothelin-1 receptor, decreasing pulmonary vascular resistance

Other tx: Iloprost, epopostenol, sildenafil ("Revatio": inhibits phosphodiasterase), nifedipine

Front 54

What cell types line alveolar sacs?

Back 54

simple squamous cells up to alveoli