Resp

Front 1

Central chemoreceptors

Back 1

Medulla

Directly sense decreasing pH (increasing H+)

Stimulated by PCO2 via BBB diffusion and formation of H+


* COPD pts w/ chronic hypercapnia: high [CO2] stops stimulating respiratory center - hypoxia remains only remaining drive, so if supplemental O2 is admin this is dangerous because then the stimulus disappears and respiration is inhibited --> respiratory failure

Front 2

Peripheral chemoreceptors

Back 2

Carotid/aortic bodies

Respond to hypoxia (senses PaO2)

Front 3

Right lobe aspiration

Back 3

Right side because right main stem bronchus more vertical and wider than left

If aspirate while upright = inferior portion of inferior lobe

If aspirate while supine = superior portion of inferior lobe

Front 4

Pulmonary artery and bronchus

Back 4

RALS

Right, Anterior

Left, Superior

Front 5

Diaphragm structures

Back 5

Perforating diaphragm

T8 = IVC
T10 = esophagus, vagus (2 trunks)
T12 = aorta, thoracic duct, azygous vein

Diaphragm innervation: C3-5 = phrenic N.
Referred pain = shoulder and neck

Front 6

Pulmonary vessel anatomical relationships

Back 6

Pulmonary trunk = unox blood
- conus arteriosus from RV
- at sternal angle --> R+L pulmonary arteries (most superior vessels in hilum of each lung)

Right pulmonary artery
- passes laterally
- posterior to asc. aorta & SVC
- to R hilum of R lung

Left pulmonary artery
- anterior to descending thor. aorta
- to L hilum of L lung

Pulmonary veins = ox. blood
- 2 pulm v. / lung exit hilum anteriorly & inferiorly pulm arteries
- 4 pulm veins drain into the LA

Front 7

Thoracocentesis

Back 7

Miclavicular line = 5-7 ribs

Midaxillary line = 7-9 ribs

Paravertebral line = 9-11 ribs

Front 8

Exercise: Muscles of respiration

Back 8

Inspiration = external intercostals, scalenes, sternomastoids

Expiration = rectus abdominis, internal/external obliques, transversus abdominis, internal intercostals

Front 9

Angiotensin converting enzyme (ACE)

Back 9

AngioI --> Angio II cnversion

Inactivates bradykinin
(ACE-I's increase bradykinin and cause cough, angioedema)

Kallikrein - activates bradykinin

Front 10

Capacity

Back 10

sum of >2 volumes

Vital capacity = TV + IRV + ERV

FRC = RV + ERV
* lowest PVR

IC = IRV + TV

TLC = IRV + TV + ERV + RV

Front 11

Ventilation

Back 11

Minute ventilation = includes all air
Tidal vol x (breaths/min)

Alveolar ventilation = refers ONLY to air participating in gas exchg/min
Tidal vol - dead space x (breaths/min)

Dead space = vol of air that does NOT participate in gas exchg; apex of lung contributes most to this

Vd = Vt x (PaCO2- PeCO2)/PaCO2

Front 12

Hb modifications

Back 12

TISSUE HYPOXIA (from dec O2 sat)

Methemoglobin:
- Nitrite drugs cause Fe2+ (normal iron in Hb)-->Fe3+
- Fe3+ Hb does not bind O2 as readily but has inc affinity for CN-
- CN- also inhibit cyto c oxidase (but preferentially bonds to MetHb instead)
* Note: partial P of O2 in blood remains NORMAL b/c amt of dissolved O2 in plasma = same (O2's partial P is not related to Hb fxn)
- Tx: Thiosulfate binds CN- --> thiocyanate (renally excreted) or tx w/ methylene blue

CarboxyHb:
- CO bound instead of O2 to Hb
- Dec O2 binding --> Lshift on curve
- Dec O2 tissue unloading

Front 13

O2-Hb dissociation curve

Back 13

Right-shift = decreased Hb affinity for O2 = O2 tissue unloading caused by an increase in ALL factors:
- dec O2 affinity, inc P50
- inc metabolic needs
- inc PCO2
- inc temp
- inc H+/dec pH
- high altitude, inc 2,3,-DPG

Left-shift: a decrease in ALL factors:
- inc Hb-O2 affinity, dec P50
- dec met needs
- dec PCO2, dec temp
- dec H+/inc pH
- dec 2,3,-DPG
- Fetal Hb!!!

P50 = partial P of O2 in blood at which Hb is 50% sat (26mmHg is nl)

Front 14

Perfusion limited

Back 14

Rapidity with which alveolar air equilibrates with partial P of O2 + CO2 in blood depends on how quickly a given vol. of blood can course through alveolar capillaries

CO2, N2O

Gas equilibrates early along length of capillary
Diffusion can be increased only if blood flow increases

Front 15

Diffusion limited

Back 15

O2 (emphysema, fibrosis), CO

Gas does not equilibrate by time blood reaches end of capillary

Front 16

Pulm HTN

Back 16

Nl pulm artery pressure = 10-14mmHg
Pulm HTN = >25 mmHg or >35 mmHg during exercise
S2 split present

If 1* - due to inactiv mut in BMPR2 that normally functions to inhibit vascular smooth muscle proliferation; requires lung transplant

Front 17

PVR

Back 17

PVR = [P(pulm artery) - P(Latrium)]/CO

R = 8nl/pie(r^4)
* major site of airway R = med-sized bronchi (>2mm)
* small airways do not contribute to R as much b/c of PARALLEL arrangement

Parasymp stim = inc R
Symp stim = dec R

Front 18

Total O2 content

Back 18

Affected by 3 main variables:

1. [Hb]
2. O2 saturation of Hb
3. Partial P of O2 dissolved in blood

Front 19

A-a gradient

Back 19

PAO2 - PaO2 = 10-15 (nl)

PAO2 = 150 - PACO2/0.8

Helps determine cause of hypoxemia

Front 20

Hypoxemia

Back 20

Dec PaO2

If normal A-a grad:
1. High altitude
2. Hypoventilation

If inc A-a grad:
1. V/Q mismatch
2. Diffusion limitation
3. R-L shunt

Front 21

Hypoxia

Back 21

Dec O2 deliv to tissues

1. Dec CO
2. Hypoxemia
3. Anemia
4. CN poisoning
5. CO poisoning

Front 22

Ischemia

Back 22

Loss of blood flow

1. Impeded arterial flow
2. Reduced venous drainage

Front 23

CO2 transport

Back 23

CO2 transported from tissues --> lungs in 3 forms:

1. Bicarbonate (transported in blood) = 90%
2. CarbaminoHb (bound to Hb) = 5%
3. Dissolved CO2 (5%)

Front 24

Sleep apnea

Back 24

Central (no resp effort) v. Obstructive (resp effort)

Peritubular cells in renal cortex sense hypoxia and respond by releasing EPO --> 2* polycythemia

Front 25

Physical lung findings: bronchial obstruction

Back 25

- absent/dec breath sounds over area
- dec resonance
- dec fremitus
- trach deviation TOWARDS sign of lesion

Front 26

Pleural effusion

Back 26

- dec breath sounds over effusion
- dull resonance
- dec fremitus

Front 27

Pneumonia

Back 27

- bronchial breath sounds over lesion
- dull resonance
- inc fremitus

Front 28

Tension pneumothorax

Back 28

dec breath sounds
hyperresonance
absent fremitus
trach dev AWAY from side of lesion

Front 29

Lung CA complications

Back 29

Pancoast tumor
- may affect cervical symp plexus --> Horner's syndrome (ptosis, miosis, anhidrosis)
- can invade brachial plexus --> weakness/paresthesias of arm

SVC syndrome
- SVC has thin walls so easily compressible by mediastinal masses
- usu assoc w/ bronchogenic CA or NHL
- sx's include dyspnea, cough, facial swelling, UE/ncek swelling, tracheal compromise

Front 30

Squamous Cell Carcinoma

Back 30

Hilar mass central, from bronchys
Cavitation
Smoking associated
PTHrP --> hypercalcemia
Keratin pearls and intracellular bridges

Front 31

Small cell Carcinoma

Back 31

Central location
ACTH/ADH production
LE syndrome
NE cells w/ granules

Front 32

Lobar Pneumonia

Back 32

4 stages
1. Congestion
- 1st 24h
- red heavy boggy w/ vascular dilation, alveolar exudate w/ bacteria

2. Red hepatization
-2-3d; red firm lobe
- alveolar exudate 2/ erythrocytes, neutrophils, fibrin

3. Gray hepatization
- 4-6d
- gray brown firm lobe w/ RBCs disintegrated, alevolar exudate contains neutrophils + fibrin

4. Resolution
- restoration of normal architecture
- enzymatic dig of exudate

Front 33

Pulmonary alveolar proteinosis

Back 33

autoAbs against GM-CSF

impaired surfactant CL by alveolar macrophages

Front 34

Chylothorax

Back 34

Disruption of thoracic duct in posterior chest via malignant neoplasms (NH lymphoma)

Front 35

Farmer's Lung

Back 35

= hypersensitivity pneumonitis
Type III/IV reaction (Type IV only when chronic exposure to Ag)
Granulomas can form but dz abates when Ag exposure stops