Steve Stone Cold Austin's Stone Cold Respiratory Facts Flashcards
(90 cards)
Conducting zone
large airways consist of nose, pharynx, larynx, trachea, and bronchi;
small airways consist of bronchioles and terminal bronchioles (large numbers in parallel leading to least airway resistance);
Warms, humidifies, and filters air but does not participate in gas exchange leading to anatomic dead space;
Cartilage and goblet cells extend to end of bronchi;
pseudostratified ciliated columnar cells (beat mucus up and out of lung) extend to beginning of terminal bronchioles, then transition to cuboidal cells;
airway smooth muscles extend to end of terminal bronchioles (sparse beyond this point)
Respiratory zone
Lung parenchyma;
consists of respiratory bronchioles, alveolar ducts, and alveoli;
participates in gas exchange;
mostly cuboidal cells in respiratory bronchioles, then simple squamous cells up to alveoli;
no cilia;
alveolar macrophages clear debris and participate in immune respone
type I pneumocyte
97% of alveolar surface;
line the alveoli;
squamous;
thin for optimal gas diffusion
Type II pneumocyte
secrete pulmonary surfactant causing decreased alveolar surface tension and prevention of alveolar collapse (atelectasis);
cuboidal and clustered;
also serve as precursors to type I cells and other type II cells;
Type II cells proliferate during lung damage
Club or Clara cells
Nonciliated; low-columnar/cuboidal with secretory granules; secrete component of surfactant; degrade toxins; act as reserve cell
Collapsing pressure equation
Collapsing pressure= 2(surface tension)/radius;
alveoli have the tendency to collapse during expiration as radius decreases (law of Laplace);
Surfactant
from type II pneumocytes;
mix of lecithins, the most important one being dipalmitoylphosphatidylcholine;
surfactant synthesis begins around week 26 of gestation, but mature levels not reached until week 35;
Lecithin to sphingomyelin ratio of >2 in amniotic fluid indicates fetal lung maturity
Aspirate a peanut, where will it go when you are standing and laying down
upright- lower portion of right inferior lobe;
supine- superior portion of right inferior lobe
Structures that perforate the diaphragm that are important
at T8= IVC;
at T10= esophagus, CN X;
at T12= aorta, thoracic duct, azygos vein (12 is red, white, and blue);
innervation of diaphragm
C3, 4, 5, innervate (phrenic);
pain from diaphragm can be referred to shoulder (C5), and the trapezius ridge (C3, 4)
determination of physiologic dead space
Vd= Vt x (PaCO2-PeCO2)/PaCO2
minute ventilation (Ve)
total amount of air entering the lung in one minute;
Ve=Vt x respiratory rate
Alveolar ventilation (Va)
Volume of gas per unit time that reaches the alveoli;
Va= (Vt-Vd) x RR
hemoglobin
2 alpha, 2 beta subunits;
T (Taut) form has low O2 affinity (unloads O2);
R (Relaxed) form has high O2 affinity (loads O2);
Fetal Hb has 2 alpha, 2 gamma with lower affinity for 2,3 BPG leading to increased O2 affinity
Methemoglobin
Oxidized form of Hb (ferric, Fe3+) that does not bind O2 as readily, but has increased affinity for cyanide;
iron in hemoglobin should be ferrous, Fe2+, or reduced state;
may present with cyanosis and chocolate-colored blood;
treat this with METHylene blue
how do you treat cyanide poisoning
give nitrites to turn Fe2+ into ferric Fe3+ because methemoglobin bind cyanide more readily;
give thiosulfate to bind this new cyanide forming thiocyanate, which is renally excreted;
Carboxyhemoglobin
form of Hb bound to CO in place of O2;
causes decreased Oxygen binding capacity with a left shift in the oxygen hemoglobin dissociation curve;
decreased O2 unloading in tissue;
Oxygen hemoglobin dissociation curve: what shifts it to the right
Right shift is a decrease in Hb’s affinity for O2 so we get unloading of O2;
Right shift is BAT ACE;
2,3 BPG, Altitude increase, Temperature increase, Acidic, CO2, Exercise;
how to calculate O2 content in blood
O2 content= (O2 binding capacity x % saturation) + dissolved O2
What are profusion limited gases
O2 in a healthy person, CO2, and N2O;
gas equilibrates early along the length of the capillary;
diffusion can be increased only if blood flow increases
What are diffusion limited gases
O2 in a emphysema or fibrosis patient), CO;
gas does not equilibrate by the time blood reaches the end of the capillary;
Equation for pulmonary vascular resistance
PVR= (Ppulm artery- Pleft atrium)/ cardiac output;
Pleft atrium= pulmonary wedge pressure
Alveolar gas equation
PAo2= PIo2 - (Paco2)/R; usually that means PAo2= 150- Paco2/0.8; PAo2= alveolar Po2; PIo2= Po2 in inspired air; Paco2= arterial Pco2; R= respiratory quotient= CO2 produced/O2 consumed; normal A-a gradient= 10-15; increased A-a gradient could mean hypoxia, causes include shunting, V/Q mismatch, fibrosis
hypoxemia
decreased Pao2;
With a normal A-a gradient look for high altitude or hypoventilation;
with an increased A-a gradient look for V/Q mismatch, diffusion limitation, R to L shunt