Pulmonology A&P

Question 1

What divides the upper and lower respiratory tract?

Answer 1

the larynx (below the vocal cords is lower respiratory tract)

Question 2

Conducting Zone vs Respiratory Zone

Answer 2

• conducting zone: transfers air to and from the lungs
  
  • nose, pharynx, larynx, trachea, bronchi, to terminal bronchioles
• Respiratory Zone: site of gas exchange at alveoli
  
  • respiratory bronchioles, alveolar ducts, alveoli

Question 3

Where is the trachea located

Answer 3

anterior to esophagus, extends from larynx to ~T5

Question 4

What is located in the mediastinum?

Answer 4

heart, esophagus, trachea, great vessels

Question 5

Location of Oblique fissures and Horizontal fissure (R lung)

Answer 5

• oblique fissures: T3 spinous process to 6th rib mid-clavicular
• Horizontal fissure (R lung): 4th rib anteriorly, to 5th rib at mid axillary line

Question 6

Parietal pleura has what type of sensation?

Answer 6

pain sensation in response to injury or inflammation: Phrenic nerve (refers pain C3,C4, C5)

• phrenic nerve also innervates mediastinal and diaphragmatic part

Question 7

Visceral Pleura and lung tissue have what type of sensation?

Answer 7

• have visceral sensory reflexes but no pain sensation
• have parasympathetic innervation from Vagus nerve CNX
• also innervated by sympathetic fibers from the sympathetic trunks
• will have visceral reflexes such as cough and stretch reflexes

Question 8

Type I Alveolar Cells

Answer 8

simple squamous epithelium supported by elastic basement membrane

Question 9

Type II Alveolar Cells

Answer 9

secrete surfactant

• surfactant: lipoproteins
  
  • coats the alveoli to reduce surface tension to prevent collapse of alveoli

Question 10

Alveolar Macrophages

Answer 10

aka dust cells, mononuclear phagocytes

• engulf debris and prepare it for removal via lymph nodes

Question 11

Inspiration

Answer 11

• passive (resting): diaphragm contracts
  
  • external intercostals contracts
• active (forced or strained):
  
  • sternocleidomastoid and scalenes contract

Question 12

Expiration

Answer 12

• passive (resting:
  
  • diaphragm relaxes
• active (forced, strained):
  
  • internal intercostals
  • abdominal muscles

Question 13

Transmural Pressure Gradient

Answer 13

the difference in pressure between the pleural cavity and the atmosphere or alveoli

• approx -4mmHg
• normal atmospheric pressure: 760mmHg

Question 14

High Compliance vs Low Compliance

Answer 14

• high compliance: loose, easy inflation
  
  • typically destruction of airspace or decreased elasticity
    
    • ex: emphysema
• Low compliance: stiff, hard to inflate
  
  • typically connective tissue changes or fluid build up
    
    • ex: fibrosis, edema, ARDS

Question 15

P_O2 deoxygenated vs oxygenated

Answer 15

P_o2 deoxygenated = 40mmHg

P_O2 oxygenated = 100mmHg

Question 16

P_CO2 at the tissues versus the alveoli

Answer 16

P_CO2 at tissue = 46mmHg

P_CO2 at alveoli = 40mmHg

Question 17

V/Q ratio

Answer 17

• V= airflow (ventilation)
• Q = blood flow (perfusion)
• normal V/Q (ventilation/perfusion) ratio on average ~0.8
• ***highest ventilation and perfusion are both highest at the base of the lungs***

Question 18

What causes high V/Q?

Answer 18

ventilation > perfusion

blockage of blood flow → no gas exchange

Question 19

What causes low V/Q?

Answer 19

ventilation

• blockage of airway → diverted away from non-ventilated alveoli to areas of better ventilation → SHUNT

Question 20

What causes decreased hemoglobin saturation and increased oxygen unloading?

Answer 20

• increased temp
• increased CO₂
• increased H⁺ levels
• shifts the hemoglobin saturation curve to the Right

Question 21

What causes increased saturation of the hgb and decreased oxygen unloading?

Answer 21

decreased temperature

decreased CO2 levels (ph> 7.6)

Question 22

Chloride Shift

Answer 22

HCO₃^- is returned to the plasma through HCO₃^- channels that swap Cl^- for HCO₃^-

Question 23

When CO₂ enters the blood via diffusion gradients at tissue what happens to it?

Answer 23

• slow reaction, converts to HCO3- when it interacts with water in the plasma
• fast reaction, converts to HCO3- quickly in RBCs due to enzyme carbonic anhydrase
• the HCO3- rxn reverses at the lungs to release CO2 and CO2 is transported out of the plasma into the alveoli

Question 24

Central Chemoreceptors and Breathing

Answer 24

• sense pH changes in the CSF
• CO2 enters the CSF through the BBB
• pH decreases when CO2 = high
• low CSF pH = increased breathing rate
• Note: become insensitive to chronically high levels of CO2

Question 25

Peripheral Chemoreceptors

Answer 25

* directly detect pH, CO2, and O2 in the arterial circulation * low pH and high arterial CO2 = increased breathing rate * low O2 (only very low \<60mmHg) = increased breathing rate

Question 26

Bronchiolitis obliterans

Answer 26

fibrotic changes permanently scar the lungs, occlude airways

Question 27

Atelectasis

Answer 27

collapse of lung tissue that occurs due to a variety of conditions * _compression atelectasis_: external pressure on lungs due to tumors, pneumothorax, abdominal torsion * _absorption atelectasis_: obstructed or hypoventilated alveoli from inhalation of concentrated O₂ or anasthesia * _Surfactant Impairment_: decreased production in premature infants, ARDS, anesthesia, mechanical ventilation * \*\*\*post surgical care = deep breathing, ambulation, position changes\*\*\*

Question 28

Parenchyma

Answer 28

the functional tissue of an organ, excluding the connective tissue and the supportive tissue

Question 29

First line medication for smoking cessation

Answer 29

varenicline (chantix) * varenicline use with nicotine replacement products should generally be avoided → can cause n/v, headaches, dizziness, GI upset

Question 30

Smoking Cessation Options

Answer 30

1. varenicline (Chantix) 2. nicotine replacement products 3. antidepressants 1. bupropion 2. nortriptyline

Question 31

Nicotine Withdrawal

Answer 31

a theory says that a drop in dopamine release in the brain after long periods of exposure to nicotine leads to mood disorders, cravings for tobacco, and other sxs

Question 32

Cystic Fibrosis and Genetics

Answer 32

mutation in the CFTR gene autosomal recessive

Question 33

Asthma and Genetics

Answer 33

* asthma runs in families * polygenic, multifactorial disorder * ADAM33, filigrin and other genes associated with atopy are associated with asthma

Question 34

Alpha-1-antitrypsin deficiency

Answer 34

inherited disorder that may lead to lung and liver disease * this deficiency causes neutrophil elastase to destroy alveoli and cause lung disease (like emphysema/COPD) * the abnormal alpha-1 antitrypsin can also accumulate in the liver and cause damage * Environmental Factors: tobacco smoke, chemicals and dust can also impact the severity of this deficiency * **autosomal dominant with codominance features**

Question 35

Sarcoidosis and genetics

Answer 35

both environmental and genetic factors * siblings of patients with sarcoidosis are 5x as likely of developing sarcoidosis * HLA (human leukocyte antigen) alleles have been consistently associated with sarcoidosis susceptibility