Week 1 Flashcards
1
Q
Lung anatomy:
- Progression of lung structures? (6) Branches?
- Zones? (2)
- 2 jobs of the lungs?
A
- Trachea –> Bronchi (1-3) –> Bronchioles (4) –> Terminal bronchioles (5-16) –> Resp. bronchioles (17-19) –> Alveolar ducts (21-22) –> Alveolar sacs (23)
- Conducting zone (1-16) (no gas exchange); respiratory zones (17-23)
2
Q
- Stages of lung development:
1. ) Embryonic: Event? Branching? Age?
2. ) Pseudoglandular: Branching? Age?
3. ) Canalicular: Events? (2) Age?
4. ) Saccular: Events? Age?
5. ) Alveolar: Events? (2) Age?
A
- ) Foregut endoderm extends into mesenchyme; 3 rounds of branching to establish lobes; 4-6 weeks
- ) 14 rounds of branching to form terminal bronchioles; 6 to 16 weeks
- ) Terminal branches divide into 2+ bronchioles; surfactant produced; 16 to 28 weeks
- ) Respiratory bronchioles subdivide into terminal sacs; 28 to 36 weeks
- ) Lung grows and alveoli mature; capillary network develops; 36 weeks to 4 to 6 years
3
Q
- Mechanism of breathing:
- Muscles involved with inspiration? Movement?
- Muscles involved with expiration? Movement?
- Diaphragm of obstructive disease pt? Volume? Force generated?
- Increased diaphragm length =?
- Intrapleural pressure? It helps stick what to what?
- Flow equation?
- How does elastic recoil work? Purpose?
A
- Diaphragm moves downward; external intercostals/accessory muscles moves ribcage up and out
- none with quiet breathing; some on abdominal wall and internal IC’s that push down and in with exercise
- Lung has higher volume at end of expiration thus diapgragm can’t shorten as much and less force is generated
- greater force generated
- Pressure in the intrapleural space; lung to chest cavity
- Flow = Patm - P lung
- When inspiratory muscles relax; elastic recoil decreases volume of lung and pushed air out
4
Q
- Chest wall compliance? Ex of uncompliant lung? Increased compliance? Implications? Lung volume and transpulmonary pressure of each?
- 3 examples of decreased compliance conditions? All have what in common?
- What is surface tension? Effect on compliance? Effect on alveolar size? LaPlace equation?
- Role of surfactant?
- Conditions that decrease surfactant?
A
- how easily a change in pressure causes a change in volume; pulm fibrosis low volume, increased trans pulm pressure; emphysema (decreased elastin with less recoil) greater volume but less transpulm pressure
- old age, obesity, scar tissue; less volume in
- force due to favorable water-water interactions and unfavorable air-water interactions; lower; smaller; P = 2xT/r
- replace polar water molecules at H20/air border making it more energetically favorable
- Pulm edema; RDS
5
Q
- Micro-anatomy:
- What courses with bronchi? Do they provide O2 to conducting system? Route of pulm veins?
- Provides O2 to conducting system? Mixes with pulmonary supply how?
- Bronchial veins drain into?
- Under columnar epi? Secrete mucus? What are basal cells? Location? Next loose CT layer? Within this layer?
- Closer to alveolar sac: More what? Closer to bronchi?
- Alveoli have many what?
- 2 cells on alveoli septum?
A
- pulmonary arteries; no; sweep up toward hilus
- Bronchial arteries; anastamoses
- azygous vein
- Basal lamina; goblet cells; progenitar cells for goblet and columnar epithelia cells; within epithelium; lamina propia; capillaries, leukocytes, nerves
- clara cells; goblet cells
- macrophages
- type 1 and 2 pneumocytes (secrete surfactant)
6
Q
- PiO2 in airways? PH20? Percent O2 of air?
- Alveolar gas equation?
- R equation? R carbs? Protein? Fat? Normal diet?
- R if patient is breathing 100% O2?
- Alveolar ventilation equation CO2? O2?
- Rate limiting step for CO2 removal? Not?
- Hypernia? Def? When?
- Hypoventilation? Def? When?
- Hyperventilation? Def? When?
- PaO2 with SaO2 of 100%?
A
- 122 torr; 47 torr; 21%
- PAO2 = PIO2 - PACO2 / R
- R = VCO2 (min) / VO2 (min); 1, 0.8, 0.7, 0.8
- 1
- PAO2 = PIO2 - (PACO2/R) + k
- PACO2 = VCO2/ VA * k
- Ventilation (slow); diffusion (fast)
- Shallow or slow breathing; Low VA, high PaCO2; Obstructive disease
- Fast or deep breathing at rest; High VA, normal PaCO2; exercise
- Increased depth of breathing due to metabolic demand; High VA, low PaCO2; High altitude
- 100 torr
7
Q
- Arterial O2 content equation? Normal value bound to Hb? Free?
- O2 solubility equation? Normal value O2? CO2? CO2 dissolves?
- Axes for dissoc. curves?
- Equation related to gas diffusion from alveoli to pulm caps? Ficks law? O2 diffusion diseases? (2) CO2 diffusion?
- PO2 in alveoli? In arterial? PCO2?
- Typical minute perfusion in lung?
- Effect of O2 tension?
- Increased Q with exercise via?
A
- CaO2 = Hb bound O2 + Freely diss. O2; 20.4 ml O2/ml100 ml blood; 0.3
- aO2 = [O2]/PaO2; 0.0013 mM/torr; 0.03mM/Torr; much better in blood
- % O2 sat (y); PO2 (torr) (x)
- Flux = delta P x A / d (thickness) x k; Interstitial disease increases thickness; emphysema decreases area; occurs readily even with disease
- 100; 40; 45; 40
- Different lung O2 levels, pulm vaso con occurs in hypoxic areas
- Capillary recruitment and vasodil.
8
Q
- What is a shunt? Causes? (4)
- Effect of gravity on V and Q?
- How does body deal with V/Q mismatch? Arterial O2 content in low V/Q area and high V/Q area?
- Effect on CO2 content? Causes of V/Q mismatch? (2)
A
- Blocked aveoli with normal perfusion but decreased ventilation; obstructive disease, pneumonia, heart defects, bronchial circulation
- Increased perfusion at base of lung therefore ventilation at base of lung increases as well
- Keep total values about the same; drops to a greater degree then a high V/Q due to Hb carrying capacity being maxed out
- CO2 content remains relatively the same; Gravity and obstructive disease
9
Q
- 4 things that shift dissoc. curve to the right?
- Oxygen tissue delivery equation?
- CaO2 equation?
- Fick: Equation for amount used?
- Hypoxemia? Sea level? Altitude? What is low? Causes? (5)
- Hypoxia? Level? Causes? (3)
A
- High H+, temp, PCO2, 2,3 DPG
- Volume delivered/ min; D = Q x CaO2
- CaO2 = SaO2 x [Hb] x 1.39
- VO2 = Q x (SaO2 - SvO2) x [Hb] x 1.39
- Low O2 conc. in blood (PaO2); 80 torr; 65 torr; low O2 inspired; low alveoli PAO2; diffusion problem; shunt; V/Q mismatch
- Low O2 to muscles; Low CO, delivery problems (anemia, CO poisoning), hypoxemia
10
Q
- ) Low PIO2 (altitude): PaO2? SaO2? PaCO2? A-a gradient? Test used?
- ) Low PAO2 (COPD):
- ) Diffusion issue with interstitial disease?
- ) Shunt (pneumonia)?
- ) V/Q mismatch?
- ) Anemia?
- ) CO poisoning?
A
- ) Down, down, down, normal
- ) Down, down, up, normal; measure PaCO2
- ) down, down, normal; high; CO single breath
- ) Low, low, normal; high; 100% O2
- ) Low, low, normal; high; 100% O2
- ) normal for all; measure Hb
- ) Normal but SaO2 is low; measure CO-Hb
11
Q
V/Q:
- Best value? Normal?
- What is dead space? Anatomic? Alveolar? Phys? Causes what? PaCO2?
- What is a shunt? Bronchial circ? Extreme of?
- Dead space causes? (5) What happens with rapid shallow breathing? Deep slow breathing?
- Causes of low V/Q? (6)
- Causes of shunt? (3)
- How to differentiate shunt from low V/Q?
A
- 1; 0.8
- Ventilation of unprefused alveoli; trachea; unprefused alveoli; V anat + V alv; work without benefit; increases
- Blood passing through without getting oxygenated; 1-2% of CO; low V/Q
- rapid shollow breathing; PE; low CO; ventilator; emphysema; upper airway ventilated only; opposite
- Asthma, bronchitis, hypo vent., emphysema, interstitial lung disease; congent. heart disease; fistula, tumor
- Heart failure transudate; pneumona, ARD
- Increased Fraction of O2 will fix low V/Q
12
Q
- Hypoxemia vs. desaturation?
- How does pulse ox work?
- Problem with pulse ox?
- Sensitive to? (3)
- Hypoxemia:
a. ) Normal A-a gradient causes? (6)
b. ) Increased A-a gradient causes? (5)
A
- Hypoxemia = low PaO2
Desaturation = low SaO2 - Deoxy HB : Oxy HB
- CO could be attached
- Light temp, nail polish
- Altitude, hypoventilation, obesity, central apnea, NM disease, drugs
- Extreme exercise, interstitial lung disease; diffusion problem; Low V/Q; shunt
13
Q
- Function of medulla with respiration?
- Peripheral chemoreceptors are located where? Respond to? (3) How fast?
- Central chemoreceptor location? Responds to? How fast? 80% of the response to?
- Permeability of BBB? Permeable to? Implications? CSF buffering capacity? Why? Implications?
A
- Takes signals from peripheral and central chemo receptors and sends out signals to control ventilation
- Carotid bodies (carotid artery) and aortic bodies; low arterial O2, high arterial PCO2, high arterial H+; fast
- Medulla ventral surface (signals to medulla from medulla); H+ receptor surrounded by CSF senses arterial CO2; slow; PaCO2 long term
- Impermeable to ions; lipid soluble CO2; CO2 crosses and reacts with H2O to make H+ ions; low; no proteins/hemoglobin; very sensitive receptors
14
Q
- Peripheral response? (5 steps?)
- Central response? (5 steps?)
- Input response of cortex? Limbic system? Pons? Irritant receptors? Pulm stretch receptors?
- Change in altitude response?
- Exercise response?
A
- Low PIO2 –> Low aO2 –> Increased activation of O2 receptors –> Increased vent. –> Inc PaO2
- Increased vent. –> Low PaCO2 –> Low PCO2 CSF –> Low H+ CSF –> Less activation of central H+ receptors –> Negative feedback on ventilation
- voluntary breathing; emotions; pons-medulla interaction; irritants in lung; changes in posture
- Renal compensation via decreasing bicarb. reabsorption; loss of bicarb in CSF then protons are freed and is normal
- At low/moderate levels of exercise, CO2 receptors modulate increased ventil. (linear); at high exercise, peripheral H+ receptors are activated to increase ventilation at a non linear rate
15
Q
- Airway radius resistance eq?
- Flow eq?
- PNS bronchoconstrictors? (2)
- SNS bronchodilators? (4)
- Airway is open when?
- Lung volume on resistance?
- Dynamic airway collapse?
- Minute ventilation? Eq?
- Alveolar ventilation?
A
- R = 1 / r^4
- Flow = P / R
- ACh, histamine
- NE, isoproteronol, albuterol, PCO2 in bronchioles
- Intrapleural pressure is less than airway pressure
- Increase vol = Decr. resis
- Forced expiration leads to big intrapleural pressure which collapses airway
- Airflow into lung/ min; MV = TV x breathing rate
- Volume into alveoli per minute
