Pulmonary

Front 1

Major cause of morbidity + mortality in premies

Back 1

insufficient alveoli or surfactant

Front 2

Is lung repair possible in adults?

Back 2

Yes, b/c of stem cells

Front 3

5 stages of lung devel

Back 3

1) Embryonic
2) Pseudoglandular
3) Canalicular
4) Terminal sac
5) Alveolar

Front 4

Embryonic pd

Back 4

Lung originates from endoderm
Buds off ventrally near foregut
L/R patterning

Front 5

Embryo diff btwn L + R lungs?

Back 5

3 R lobes, 2 L lobes
10 R bronchopulm segments, 8 L

Front 6

Pseudoglandular pd

Back 6

Reproducible branching (1st 16 generations)

Front 7

Canalicular pd

Back 7

Random branching (16-23 divisions)
Fetus can survive at end of this pd b/c of vasculature

Front 8

Terminal sac pd

Back 8

Type I + II alv cell

Front 9

Alveolar pd

Back 9

> 80% alveoli formed after birth (lung is unique here)

Front 10

When are most alveoli formed?

Back 10

After birth (>80%)

Front 11

What determines bronchiolar branching?

Back 11

Mesenchyme instructs branching of lung buds (epi-mesench interxns impt)

Front 12

FGF-10

Back 12

in distal mesenchyme
impt for branching (growth of tip)
mitogenic + chemoattractant
netrin (expr in trach ts) = anti-FGF, inhibs budding
"sprouty" = anti-FGF, inhibs growth

Front 13

Shh (sonic hedgehog)

Back 13

in epi
impt for branching (bifurcation of tip)
inhibs FGF in mesench

Front 14

Type I v II alveolar cells

Back 14

Type I = thin/squamous, gas exchange, 95% of alv SA (40% of cell pop)
Type II = cuboidal, secre surfactant, 5% of alv SA (60% of cell pop)

Front 15

BMP-4

Back 15

stims distal cell types in bronch
inhib'd by Gremlin (which stims prox)

Front 16

Wnt

Back 16

impt for prox-distal patterning
stims distal + inhibs prox cell types

Front 17

Distal v prox epi

Back 17

Distal epi = type I + II alveoli
Prox epi = ciliated + non-ciliated

Front 18

Distal v. prox mesenchyme

Back 18

Distal = mostly vasc
Prox = strxal support

Front 19

RDS

Back 19

(respiratory distress synd)
= insufficient surfactant --> underflated lungs

Front 20

Most common tracheoesophageal fistula?

Back 20

Type A (85%)
= blind esoph pouch, trach conns to esoph underneath

Front 21

2 main parts of respiratory sys

Back 21

1) conducting (trachea --> bronchi --> bronchioles)
2) respiratory (distal bronchioles)

Front 22

Fxn of conducting part

Back 22

warm, moisten, filter inspired air

Front 23

Fxn of respiratory part

Back 23

gas exchange

Front 24

Histo (epi) of conducting part

Back 24

pseudostratified squamous epi

Front 25

Histo (epi) of respiratory part

Back 25

simple columnar --> cuboidal --> squamous epi

Front 26

Cell types in conducting part

Back 26

Goblet
Ciliated
Basal
Pulm Neuroendocrine cells (Kulchitsky)

Front 27

Cilia strx

Back 27

9+2 microtubules arrangement

Front 28

Kartagener's synd

Back 28

mutation in dynein (the ATPase that mks cilia motile) --> chronic bronchitis + sterility

Front 29

Vocal folds epithelium

Back 29

Stratified squamous (instead of PCC) b/c they are under stress

Front 30

Respiratory metaplasia

Back 30

columnar --> squamous epi replacement, usu in smokers
("metaplasia" = reversible replacemt)

Front 31

Pore of Kohn

Back 31

connects adjacent alveoli of same + adjacent respiratory bronchioles

Front 32

Cells in respiratory part

Back 32

Type I alveolar cells
Type II
Clara cells
Brush cells
Macrophages

Front 33

6 causes of hypoxemia

Back 33

Low inspired O2 (hi altitude, CO poisoning)
Diffusion impairment (pulm edema, ARDS)
R-->L shunt (lung atelectasis)
hypoventilation (sedatives, trauma)
V/Q mismatch (asthma, pulm emboli)
Low CO

Front 34

Partial Pressures of Dry air v. Tracheal air v. Alveolar gas

Back 34

Dry air = PO2 + PN2
Tracheal air = Add PH2O
Alveolar gas = Add PCO2

Front 35

How much O2 is nlly bound to Hb?

Back 35

1.34 ml O2 per Hb
Very little O2 dissolved in blood (~1%)
Nl O2 sat = 20.1 ml O2/100 ml blood

Front 36

How big is our O2 reserve?

Back 36

100 aa blood --> 40 vv blood, but avg person only uses abt 25% of O2
PO2 inside cells = 5 mmHg
ATP synth only req 1 mmHg

Front 37

What does cooperativity of Hb (i.e. its ability to dump O2 to ts) primarily depend on?

Back 37

Stability of deoxy Hb!

Front 38

What factors stabilze deoxy Hb?

Back 38

Bohr effect (low pH, i.e hi H+)
CO2 metabolism (mk H+)
2,3-DPG (md in glycolysis, stabilizes Hb)

Front 39

3 Factors that affect blood O2 affinity

Back 39

pH
2,3-DPG
temperature (less impt)

Front 40

Causes of L shift

Back 40

Hi pH
Low DPG
Low temp

Front 41

Causes of R shift

Back 41

Low pH
Hi DPG
Hi temp

Front 42

What's worse, L or R shift?

Back 42

L shift worse b/c need really low PO2 b4 O2 is released into ts

Front 43

Carboxyhemoglobin

Back 43

CO always out-competes O2 to bind to Hb --> less O2 carrying capacity AND causes L shift (b/c messes up deoxy Hb) + leads to body wide inflam by interfering w/ intracell NO binding
Prob in CO poisoning or air pollution

Front 44

How to measure O2 status

Back 44

ABG
Pulse oximetry

Front 45

Pulse oximetry (Pulse ox)

Back 45

= frxnal O2 sat = oxyHb/(total Hb = oxy + deoxy + CO + met Hb's)
At hi COHb + MetHb, pulse ox becomes worse estimate of O2 sat b/c really hard to tell diff btwn CO/MetHb + oxyHb

Front 46

Congen impairmts of O2 delivery

Back 46

Singe alpha chain mut --> L shift
Single B chain mut --> R shift