KEY NOTES WK 4 Flashcards
1
Q
lungs derived from
A
foregut
2
Q
lungs in which cavity
A
pleural cavity
3
Q
lung buds (respiratory diverticulum) at wk 4 on
A
ventral wall of foregut
4
Q
substances that cause development of lung buds
A
retinoic acid and TBX4 transcription factor
5
Q
endoderm origin
and splanchnic mesodermal origin
A
Endodermal Origin: Epithelium of internal lining in larynx, trachea, bronchi, and lungs
- Splanchnic Mesodermal Origin: Cartilaginous, muscular, and connective tissue components of the trachea and lungs
6
Q
esophageal atresia
A
Proximal esophagus does not connect with the distal part, creating a blind-ending tube
7
Q
tracheoesophageal fistula
A
Connection (fistula) between the trachea and the esophagus
8
Q
visceral and parietal pleura are formed from what in embryo
A
mesoderm –> visceral
somatic mesoderm (more outer) –> parietal
9
Q
4 stages of maturation of lungs in embryo
A
- psuedoglandular stage (branching –> terminal bronchioles)
- canalicular stage –> divide into respiratory bronchioles into alveolar ducts
- terminal sac (saccular) –> primitive alveoli (terminal sac)
- alveolar period –> mature alveoli get capillary contact (36 wks to 8yoa)
10
Q
type I vs type II alveolar epithelial cells
A
type I form blood-air barrier with capillaries around alveolar sacs
type II for surfactant production to reduce surface tension at air-alveolar interface
11
Q
fetal breathing
A
aspiration of amniotic fluid for lung development
12
Q
infant respiratory distress syndrome
A
not enough surfactant –> high surface tension –> alveolar collapse
13
Q
larynx orignation
A
endoderm (internal lining of larynx)
muscles and cartilage from 4th and 6th pharyngeal arches (make thyroid, cricoid and arytenoid cartilage)
14
Q
nerve for larynx
A
vagus nerve
15
Q
visceral and parietal pleura
A
visceral= attached to lung (inner)
parietal= lines internal thoracic cavity (outer)
== pleural sac
16
Q
innervation of parietal vs visceral pleua
A
parietal: general sensory neurons (pain sensitive)
- intercostal nerves for peripheral portion
-phrenic nerves for central portion
visceral: visceral sensory neruons (pain insensitive) via autonomic vagus nerve
17
Q
visceral and parietal pleura are contagious at the
A
hilum (at pulmonary ligament)
18
Q
function of pleura
A
produce and reabsorb pleural fluid
19
Q
pleural space
A
fluid to lubricate gliding breathe movements
surface tension to resist lung collapse
negative pressure (slight less than atmosphere)
20
Q
chest wall vs lungs elastic recoil
A
lungs want to go in
chest wall out
= negative intrapleural pressure
21
Q
pneuomothroax
A
air in pleural space (breaks coupling btwn visceral and parietal pleura)
equalize atomospheirc and pleural pressure = lung collapse
hemothorax= blood fills pleural space
22
Q
pleural recesses
A
areas where lung doesnt fill entire pleural sac in quiet respiration
fluid accumulates here in quiet breathing
lung can expand here in deep inspiration
23
Q
2 pleural recesses
A
costodiaphragmatic and costomediastinal
24
Q
right vs left lung lobe
A
right has 3 lobes and 2 fissures
left has 2 lobes and 1 fissure and cardiac notch (for heart) and lingula (aka like the middle lobe of right lung)
25
hilum of the lung
where blood vessel, air passage, lymphatic and nerves enter and leave the lung
connects it to cardio system
26
2 types of blood supply for lung
1. bronchial circulation (get oxygenated blood to bronchial tree)
2. pulmonary circulation (deoxygenated blood from heart to lungs and vice versa)
27
lymphatic drainage of lung
pulmonary and bronchopulmonary (hilar) nodes --> tracheobronchial (carinal) nodes and paratracheal nodes
then into systemic via right lymphatic duct (right lung) and thoracic duct (left lung)
28
innervation of lungs
PNS and SNS via pulmonary plexus
PNS- vagus nerve = bronchoconstriction and bronchial gland secretion
sympathetic= T1-T4 postganglion sympathetic fibers and cervical sympathetic ganglia
cause bronchodilation and inhibit bronchial gland secretion
SNS controlled by epinephrine
29
bronchial tree
1. Trachea
2. Primary bronchi
3. Secondary bronchi
4. Tertiary bronchi
5. Conducting bronchioles
6. Terminal bronchioles
7. Respiratory bronchioles
8. Alveoli
30
bronchial tree conducting airways (transport and humidify air but not gas exchange)
trachea, primary bronchi, secondary bronchi, and tertiary bronchi.
31
trachea cartilage and muscle
c shaped rings of hyaline cartilage
tracheal muscle
32
where does trachea bifurcate into primary bronchi
carina
33
nasal cavity
humidify with seromucous glands
goblet cells and mucus to trap inhaled particles
IgA to inactivate microorganism
vibrissae (hairs) to filter particulate matter
olfactory neurons for odoriferous substances
34
respiratory epithelium
ciliated cells
goblet cells (with mucin)
brush cells (microbial for chemosensory receptors)
small granule cells
basal cells
35
parts of pharynx
nasopharynx
oropharynx
laryngopharynx
36
larynx catilage
hyaline cartilage (ie..thyroid, cricoid) and smaller elastic cartilage (i.e. epiglottis)
37
epiglottis function
at top of larynx to prevent swallowed food or fluid from entering air passage
38
trachea
c shape hyaline cartilage with trachealis muscle
39
bronchi into bronchioles cartilage and muscle
primary bronchi: full circle of catilage, lots of mucus and glands
bronchioles: lose caritilage, get muscle and MALT, are ciliated to clear debris
--> lack mucosal glands
40
terminal bronchioles cells and function
club cells secrete surfactant, AMPs, cytokines
chemosensory brush cells
stem cells
41
alveoli
cells and fibers
site of gas exchange
type I pneuomcytes (desmosomes and tight junctions)
type II penurmocytes (have lipids, phospholipids, proteins and make surfactant)
dust cells to phagocytose erythrocytes from damaged capillaries
elastic fibers to expand and contract
reticular fibers to prevent collapse
rich capillary network
42
ventilation via Boyles law
pressure and volume inversei
43
inspiration
dripahram contract and flattens down (increase volume)
contract external intercostal muscle (lift ribs and sternum anterior)
pressure decreases (negative pressure) Create vacuum and pull air into lung
44
quiet expiration
passive; inspiratory muscles relax, diaphragm ascends, rib cage descends, elastic lung tissue recoils
45
force expiration
contract expiratory muscles (external and internal oblique, transverse and rectus abdomens)
increase intra-abdominal pressure, ab organs forced against dipgram and raise it
depress rib cage
46
accessory muscles for inspiration and experiation
inspire; SCM, scalene, external intercostal
expire: internal intercostal, rectus abdominis
47
ventilation vs external and internal respiration
ventillaiton= move air in and out of lungs
external respiration= gas exchange in lungs
internal respiration= gas exchange in tissue
48
forces of ventrilation
inspiration: diagram, external intercsotals
expiration: passive and elastic recoil in normal breath but forced expiration is ab muscles and internal intercostals
49
Boyles law drives ventilation
pressure and volume inverse
50
tidal volume
Volume of air inspired or expired with each normal
breath
51
inspiratory reserve volume
Extra volume of air that can be inspired over and
above normal tidal volume
52
expiratory reserve volume
Extra amount of air that can be expired by forceful
expiration after the end of normal tidal expiration
53
residual volume
Volume of air remaining in the lungs after the
most forceful expiration
54
inspiratory capacity
– Tidal volume + inspiratory reserve volume
– Amount of air a person can breath beginning at the normal expiratory level and distending lungs to maximum amount
55
functional residual capacity
– Expiratory reserve volume + residual volume
– Amount of air that remains in the lungs at the end of normal expiration
56
vital capacity
– Inspiratory reserve volume + tidal volume + expiratory reserve volume
– Maximum amount of air a person can expel from the lungs after first filling the lungs to their maximum extent and then expiring to maximum extent
57
total lung capacity
– Vital capacity + residual volume
– Maximum volume to which the lungs can be expanded with the greatest possible inspiratory effect
58
cant measure____ in spirometry so use _____ to measure FRC
residual volume, functional residual capacity and total lung capacity
helium dilution or plethysmography
59
anatomic vs physiologic vs alveolar dead space
anatomic: volume of space of respiratory system (i.e. conducting airways) but doesnt include alveoli where gas exchange occurs
alveolar dead space: if alveolar are ventilated but not perfused (lack blood)
physiologcial dead space: sum of anatomic and alveolar (should be ~ equal to anatomic if healthy)
dead space is inhaled air that doest reach gas exhange areas (ventilation occurs but no gas exhange)
60
minute respiratory volumne
amount of air inhaled or exhaled per minute
= tidal volume x respiratory rate
~6L/min
61
rate of alveolar ventilation per minute
total volume of new air entering gas exhchange area per min
= resp rate x amount of breath that enters alveoli (tidal volume- dead space volume
62
negative pleural pressure via
lung (in) and chest wall (out) elastic recoil in opposite directions
63
airflow resistance effects expiratory time
expiration longer than inspiration
64
lung/ alveoli want to recoil inwards and collapse becasue
compliance
i.e. expand lots with little pressure difference, also means the forces causing collapse aren't that large
65
what affects lung compliance
elasticity and surface tension o lungs
66
surface tension
pull liquid molecules together (liquid wants to hydrogen bond and interact with each other) at the air-liquid interface
liquid wants to minimize contact with air
67
type II alveolar cells make ____ and use proteins A and D as _____ and proteins B and C as _____
surfactant
A and D for opsonins (bind pathogens ~ immune)
B and C for even distribution of surfactant
68
lung compliance curve
at higher pressure lung is stiffer and harder to expand (decrease compliance)
S shaped
69
hysteresis
difference in inflation and deflation curves (for compliance)
surfactant interact more with lung when inflating and less when deflating and elastic recoil too
70
surfactant decreases work of breathing by incrasing
pulmonary compliance
done via decrasing inward recoil of lung caused by surface tension
71
very low lung volumes
airways close because intrapleural pressure exceed atmospheric pressure
72
resistnace changes with lung volume
at low lung volumes airways are smaller and compressed ; so higher restiance (lower conductance) ]
high volumes, airways are open and lower resistance
73
2 sites of major airway resistnace
bronchi and bronchioles
bc small diameter
74
COPD causing increased resistnace in small airways
COPD breathe at higher ____ volumes
higher functional residual capacity/ residual volumes
higher volume to open airways arnd decrase resistance
breathe out and gas velocity increases and so does linear pressure, but less pressure pushing out on wall (Bernoulli)
keep airways open by moving faster and less pressure on walls
75
velocity increases when
expiration and when airway diameter decreases
76
Bernoulli principle
Bernoulli’s Principle states that in a steady, incompressible fluid flow, velocity and pressure are inversely related: high velocity → low pressure and low velocity → high pressure.
In the lungs, airflow velocity increases in narrower airways, causing a decrease in airway pressure, which can contribute to airway resistance in diseases like asthma.
increase velocity, decrease pressure outwards on walls
77
emphysema
destruction of alveolar walls and loss of elastic recoil in lungs
air trapping, reduced gas exhange
78
emphysema is a loss of
elastin, less elastic pull to keep small airways open
increased velocity
collapse walls
hard to exhale
destruction of alveolar walls, loss of elastic recoil, and air trapping
79
daltons law
partial pressure of each gases summed up
(gases in alveoli: CO2, O2, water vapour, N2)
80
pulmonary artery vs aorta blood
pulmonary is low in 02 and high in co2
aorta is high in O2
PO2 highest when leaving lungs
PCO2 highest when entering lungs
81
gas exhange at pulmonary capillary [blood- gas interface]
O2 and CO2 move across alveolar capillary membrane via diffusion
82
respiratory membrane (between alveoli and capillary) contains
layer of surfactant etccc
83
Factors affecting rate of gas diffusion through respiratory membrane
1. thickness of membrane
2. surface area of membrane
3. diffusion coefficient of gas
4. partial pressure difference (and concentration) between 2 sides of membrane
84
what increases thickness of respiratory membraen
edema
lung fibrosis
85
what decreases surface area of respiratory membrane
emphysema
86
diffusion across respiratory membrane follows
Ficks law (thickness, partial pressure difference, area, diffusion constant)
87
exercise impact on oxygenation
During exercise, the time available for oxygenation in the pulmonary capillaries decreases due to increased cardiac output (CO) and faster blood flow through the lungs
88
lung diffusing capacity
total volume of O2 taken up per minute
89
2 components of lung diffusing capacity
1. diffusion process itself
2. time taken for O2 (or CO2) to react with hemoglobin
90
Hb dissociation curve
S shaped
When one O₂ molecule binds to Hb, it increases the affinity for additional O₂ molecules.
Conversely, when one O₂ molecule is released, Hb is more likely to release more O₂.
91
factors that shift Hb curve to the right/ increase p50 making it promote oxygen unloading so that tissues get more oxygen (i.e. in hypoxia, fever, exercise)
increased CO2, acidity, temperateure , 2,3 (DPG) red cells
92
anemia and CO (carbon monoxide) impact on oxygenation
anemia lower O2 content in blood by lowering Hb
CO poisoning reduces CaO2 and shifts curve left
93
3 forms of carbon dioxide transport in blood
1. bicarbonate (mainly)
2. dissolved
3. carbamino-hemoglobin in the red cell
94
carbon dioxide association curve for hemoglobin
quite linear
95
Haldane effect
When oxygen binds hemoglobin. Kicks off carbon dioxide promoting its release (in the lungs)
Oxygenated Hb releases CO₂, while deoxygenated Hb binds CO₂ more easily.
✔ Tissues: Deoxygenated Hb enhances CO₂ uptake.
✔ Lungs: Oxygenation promotes CO₂ unloading and exhalation.
✔ Works opposite to the Bohr Effect, optimizing gas exchange in both lungs and tissues.
96
bohr vs Haldane effect
Bohr effect: COs promotes release of O2 in the tissues —> help Hb release O2 and give to tissues
haldane effect: O2 promotes CO2 rlease in the lungs —> helps Hb unload CO2 for gas exhange
