Test 1 Flashcards
When should you consider thrombolytic therapy for venous thromboemboli?
-Hypotension (clearest indication) -Severe hypoxemia -Severe RV dysfunction by echo -Anatomically very large PE (one lung or greater) Severe proximal DVT Essentially, use in hemodynamically unstable patients
What do you see on lung histology of an individual with hypersensitivity pneumonitis?
poorly formed granulomas
Where do pseudostratified ciliated columnar cells extend to?
extend to beginning of terminal bronchioles
Whats the equation for steady state CO2 excretion?
VCO2= VA x [PACO2/760]
Identify the accessory muscles of inspiration:
external intercostals sternocleidomastoid scalene
If the brainstem is transected between the Apneustic Center and the Pneumotaxic Center, the animal breathes with _____.
inspiratory gasps.
What separates the trachea from the esophagus?
tracheoesophageal septum
List the multiple effects of maternal carbon monoxide on fetal O2 delivery.
-lowers maternal O2 content -left shifts maternal dissociation curve so it doesn’t release O2 as well as it should at the placenta -this lowers umbilical venous PO2 -maternal CO diffuses into fetal circulation —CO competes with O2 for Hb binding sites –CO left shifts fetal dissociation curve making it harder for O2 to be delivered to fetal tissue
shipbuilder/insulation/ pipe fitter=
asbestosis
Post thrombotic syndrome develops in 30% of patients with DVT. What causes it?
damgage to venous valves
mediastinal lymphadenopathy, non-caseating granuloma=
sarcoidosis, fungal infection
Does a D-dimer level have high specificity or high sensitivity?
high sensitivity (if you have low D dimer levels, it’s pretty safe to say you don’t have a venous thromboembolism)
Where do neurogenic tumors (schwannoma, neurofibroma, ganglioneuroma) almost almays occur?
posterior mediastinum
What’s maternal venous blood PO2 and %Sat?
35mmHg, 70%
which medullary respiratory center is necessary for respiratory rhythm?
Pre-Botzinger complex
What are the key differences between usual interstitial pneumonia (idiopathic pulmonary fibrosis) and nonspecific interstitial pneumonia?
-NSIP patients are usually younger and shower a more stable pattern of chronic dyspnea (not progressive) - Radiographically, NSIP typically lacks peripheral honeycombing.
What can mom have that puts baby at risk for respiratory distress syndrome?
Maternal diabetes: high level of insulin can inhibit surfactant production
What diseases increase compliance work?
restrictive diseases
alveolar pressure > 0
expiration
Dynamic airway collapse takes place in intrathoracic airway during ____.
active expiration
What is the normal P50 in adult Hb?
26 mmHg (50% sat.)
In the fetal circulatory system, what site has the highest O2 saturation?
umbilical vein (80% sat)
What’s P50 of fetal blood on the dissociation curve?
Fetal P50 ~ 19 mm Hg vs 26 mm Hg for adult
What patient population does sarcoidosis particularly effect?
African American females (below 40, non-smokers)
What’s a normal FEV1/FVC value (percentage wise)?
80%
What is transudate and what causes it?
thin, clear, serous fluid only; results from a change in hydrostatic and/or oncotic pressures
What’s a typical value for lung compliance?
200ml/cm H20
What stimulates a baby to take its first breath?
asphyxia of birth, drop in temp, tactile stimulation
What is the PAO2 and PACO2 levels when VA/Q = infinity (no perfusion; dead space)?
Alveolar gas has PO2 and PCO2 of humidified inspired air.
What is a normal tidal volume?
500 ml
Equation for functional residual capacity:
FRC= ERV + RV
The larynx is Lined by “pseudostratrified ciliated columnar epithelium” everywhere EXCEPT the superior surface of the epiglottis and the true vocal folds, which are lined by ____.
lined by “stratified squamous non-keratinized epithelium”
In the intact brain, the Pneumotaxic Center _____ the Apneustic Center, and the normal function of the Apneustic Center is not well understood.
INHIBITS
What are the components of the conducting zone of the respiratory tree?
nose, pharynx, larynx, trachea, bronchi, terminal bronchioles
What’s a normal change in O2 content?
Δ O2 Content = 5 ml/100 ml (5 vol%)
Identify the accessory muscles of expiration:
internal intercostals abdominals
What are two random changes that take place at birth (he just slapped it on the last slide of an SDL)?
-a combined metabolic and respiratory acidosis (which is corrected) -a drop in body temp of about 3 degrees Fahrenheit (which is corrected)
birds/hot tubs/ farmers=
hypersensitivity pneumonitis
How do you get the total compliance of the system?
“add in the reciprocal” 1/Ctotal= 1/C lung + 1/C chest wall result is that your total compliance is always less than the individual compliances
What’s the equation to find the PO2 of alveoli?
PAO2= PiO2 - [PACO2/R]
R=0.8 PiO2= [atmospheric pressure- 47] x FiO2
FiO2 is .21 unless states otherwise
What’s used to treat venous thromboemboli acutely?
UFH or LMWH or Fondaparinux
Describe serum RBC changes in the first four months of life:
initially a drop in RBC count b/c increased PO2 shuts down erythropoiesis. Recovers after a few days.
Describe serum bilirubin changes in the first four months of life:
at birth, very little liver function= bilirubin builds up quickly; liver function develops shortly thereafter and bilirubin levels promptly drop
What structures compose the diaphragm?
-septum transversum -pleuroperitoneal membrane -dorsal mesentery of esophagus
What’s fetal umbilical arterial blood PO2 and %Sat?
22mmHg, 58%
In a tension pneumothorax, will the trachea deviate towards or away from the side of the lung collapse?
away from the side of the lung collapse (tracheas are cool with spontaneity, not tension)
What are the outcomes of oligohydramnios?
Potter’s syndrome -Positional deformities in limbs, joint stiffness, flexion contractures -Pulmonary hypoplasia -Flattened facial features (nose/ears)
Describe the epithelium of the nasal vestibule.
stratified squamous keratinized
What are the two main differences between the maternal and fetal dissociation curves?
1) fetal has higher affinity for O2 than adult Hb (left shift) —-b/c fetal has lower affinity for 2,3-BPG 2) there’s a higher concentration of Hb in fetal blood than in maternal blood
What’s a normal A-a gradient?
5-10mmHg
Which cells/mediators are involved in asthma?
mast cells, Th2 t cells, eosinophils
What’s the equation for change in O2 content (also called Fick’s principle)?
change in O2 content= VO2 / CO
VO2 is amount of O2 delivered to the tissue CO=cardiac output
What are the two types of emphysema? Which is the most common type?
centriacinar and panacinar centriacinar is the most common
What is the normal P50 for oxygen (PO2 that gives 50% saturation of Hb)?
=26 mmHg
What disease states increase lung compliance?
emphysema
normal aging (might as well be a disease)
What’s used for long term treatment/prevention of venous thromboemboli?
warfarin
What scan should be used to confirm PE?
spiral CT (unless patient has renal problems, in which case you give them a VQ scan)
Why does absorption (resorption) atelectasis happen more readily if someone is breathing a high O2 gas mixture?
normally, the N2 gas present in the alveoli slows the collapse of the alveoli. If high content O2 is breathed long enough, it washes out the alveolar nitrogen subsequently removing the protection from collapse that N2 provided.
What is used as an index of O2 level in a tissue?
venous PO2
Dynamic airway collapse takes place in extra thoracic airways during ____.
inspiration
If transpulmonary pressure (PA - Ppl) is increased, then lung volume is _____.
increased
What’s the treatment for sarcoidosis?
Tx is steroids, but they often resolve spontaneously without treatment
What’s the normal arterial PO2??
90-95 mmHg
stem cells of the bronchioles
club (clara) cells [are capable of dividing into ciliated or non-ciliated bronchiolar cells]
Rate of diffusion of O2 between air and blood is inversely proportional to ____.
thickness of barrier (distance from alveolar air to RBC)
What type of hypersensitivity reaction is hypersensitivity pneumonitis?
Most patients with hypersensitivity pneumonia have evidence of both Type III (immune complex) and Type IV (delayed-type) hypersensitivity reactions.
What’s the role of surfactant?
decreases surface tension preventing atelectasis (collapse of the alveolus).
What is in a chylous effusion and what causes it?
composed of lymph; often seen in setting of thoracic duct damage from trauma or malignancy
Which cells/mediators are involved in COPD?
alveolar macrophages, CD8 T cells, and neutrophils
What happens when there are problems with tracheoesophageal septum formation?
esophageal atrsesia (abnormally closed) with tracheoesopageal fistula
What’s the FEV1/FVC value (percentage wise) observed in restrictive lung diseases?
>80%
What is oligohydramnios?
a deficiency in the level of amniotic fluid
Rate of diffusion of O2 between air and blood is proportional to ____.
surface area (total area of alveoli)
What Wells score total shows a high risk for DVT?
> or equal to 3
Functions of conducting airways?
warm, humidify, and filter inspired air
Type II pneumocytes take up how much of the epithelial surface of the alveoli?
5%
What causes a spontaneous pneumothorax?
rupture of a sub pleural or intrapleural bleb
Along which nerve do the aortic bodies send their signal to the brain?
vagus
What is compression atelectasis?
is associated with the accumulation of fluid, blood, or air within the pleural cavity, which physically compresses and collapses the adjacent lung.
What are shared features of Diffuse Parenchymal Lung Diseases?
-Dyspnea -Diffuse disease on CXR -Restrictive pattern on PFTs -Impaired oxygenation —-Elevated A-a gradient
What is the PAO2 and PACO2 levels when VA/Q ~1 (normal)?
PAO2= 100 PACO2=40
Atelectasis results in a ____
absolute right to left shunt
Clinically, pleural effusions are characterized by:
- Dullness to percussion 2. Absent breath sounds 3. Absent vocal tactile fremitus
What organs are most often effected by sarcoidosis?
lungs, skin, eyes
What’s the function of Type I pneumocytes?
compose part of the respiratory membrane of the alveoli across which gas exchange occurs
Where is the penumotaxic center located and what does it do?
in the upper pons; Inactive during quiet breathing but become active during exercise. Sends signals to the DRG to cause early termination of inspiration which lowers the tidal volume and shortens the breathing cycle and therefore increases the breathing rate.
What is resistance work?
work done to move air and overcome airway resistance
structures in which the exchange of solutes (incl. gases) b/w maternal and fetal blood take place.
fetal placental villi
What is the volume of the conducting zone (anatomic dead space)?
150 ml
a PO2 of 60 mmHg gives what saturation?
90%
stem cells of the alveoli
type II pneumocytes (make type I pneumocytes)
What are club (Clara) cell functions?
secrete surface antigen agent that reduces surface tension, degrade toxins via CytoP450, regenerate bronchiolar epithelium
What are the components of the respiratory zone of the respiratory tree?
respiratory bronchioles, alveolar ducts, alveoli
How is static compliance different from dynamic compliance?
static compliance is just the change in volume/change in pressure in presence of no airflow. dynamic compliance also includes the contribution of airway resistance (so with airflow)
How do DVT patients classically present?
calf pain, tenderness, swelling, and redness
What is compliance work?
work done to overcome elastic recoil of lungs and thorax
What’s the equation for transpulmonary pressure?
PL= PA - Ppl transpulmonary pressure = alveolar pressure minus pleural pressure
In order, what are the 4 periods of lung development?
1) pseudo glandular period 2) canalicular period 3) terminal sac period 4) alveolar period
What part of the lung is effected by coal workers’ pneumoconiosis?
upper lobe
Type I pneumocytes take up how much of the epithelial surface of the alveoli?
95%
What’s fetal umbilical venous blood PO2 and %Sat?
30mmHg, 80%
Where is compliance higher, apex or base of lung?
compliance is higher at the base
if you see ‘honeycomb’ radiographic changes in the lung, think _____.
usual interstitial pneumonia (First Aid and Pathoma call it idiopathic pulmonary fibrosis)
When do peripheral chemoreceptors become significantly activated to send a signal to the respiratory center of the brain?
when PaO2 is below 60mmHg
What is pleural pressure normally?
-5 cm H20
What medications do you need to be on the lookout for in patients with lung problems?
-chemo -amiodarone -nitrofurantoin
What’s the FEV1/FVC value (percentage wise) observed in obstructive lung diseases?
less than 70%
What’s the equation for O2 content in the blood?
O2 content= (% Sat./100) (1.34)(Hb conc.) + 0.003 PO2
What substances are partially removed by the lungs?
norepinephrine
alveolar pressure = 0 means:
no airflow
What are the different forms (and relative percentages) of CO2 in venous blood?
90% bicarbonate ~5% dissolved CO2 ~5% is carbamate (CO2 attached to Hb)
Describe the cell type transitions from the trachea to the alveoli.
pseudostratified ciliated columnar cells –> ciliated columnar cells –> cuboidal cells –> simple squamous cells
What are some clinical features of sarcoidosis?
-dyspnea or cough -hilar lymphadenopathy -elevated serum ACE -hypercalcemia
What disease states decrease lung compliance?
pulmonary fibrosis pneumonia pulmonary edema
It is important to recognize that thymoma can be seen in approximately 15-20% of patients who have ______.
myasthenia gravis
A distinctive feature of chronic bronchitis is hypersecretion of mucus, beginning in the large airways. What causes it?
This secretion is due to mucous gland hyperplasia in the bronchial mucosa secondary to stimulation from various airborne irritants/pollutants (cigarette smoke, etc).
What diseases increase resistance work?
obstructive diseases
What substances are almost completely removed by the lungs?
-serotonin -prostaglandins E2 and F2a -leukotrienes
At 100% saturation, 1g of Hb can bind how much O2?
1.34ml O2
When are dust cells called “heart failure cells”?
when they phagocytose extravasated RBCs and are filled with hemosiderin
What causes congenital diaphragmatic hernias?
failure of the pleuroperitoneal membrane to form
What is absorption (resorption) atelectasis?
collapse of alveoli due to the near complete resoprtion of alveolar oxygen (not enough gas is left to inflate alveoli)
What’s the equation for alveolar ventilation?
VA= (VT-VD) x (breaths/min)
alveolar pressure < 0=
inspiration
Along which nerve do the carotid bodies chemoreceptors send their signal to the brain?
glossopharyngeal
Central Chemoreceptors Sense CO2 Indirectly by Detecting ___
pH [protons in the CSF and ISF]
What is exudate and what causes it?
fluid with protein and cells; due to increased vessel permeability
What is the PAO2 and PACO2 levels when VA/Q=0(no ventilation; shunt)?
Alveolar gas has PO2 and PCO2 of mixed venous blood due to never seeing alveolar air
What’s the name of the muscle that connects the two free ends of the cartilage rings of the trachea?
trachealis (smooth muscle innervated by ANS)
older patient, velcro crackles=
idiopathic pulmonary fibrosis
Pores between adjacent alveoli that allow equilibration of air pressure within pulmonary segments. Also means by which infections can spread throughout the lung in lobar pneumonia.
Pores of Kohn
What line terminal bronchioles?
simple cuboidal epithelium with many club cells
How do PE patients clinically present?
dyspnea, pleuritic pain, cough, tachypnea, rales, and tachycardia
What are the main differences between olfactory epithelium and respiratory epithelium in the nasal canal?
olfactory epithelium is taller than respiratory epithelium and has less types of cells (lack Goblet cells)
Eggshell calcification =
silicosis
In panacinar emphysema, the acini are uniformly enlarged, from the level of the respiratory bronchiole to the terminal alveoli. What part of the lung is it often seen in, and what is it strongly associated with?
occurs in lower lungs zones and is characteristically seen in patients with alpha-1-antitrypsin deficiency who do not also smoke.
What’s the normal mixed venous blood PO2?
40 mmHg
What are four factors that determine venous P02?
1) metabolic demand 2) blood flow to the tissue 3) arterial PO2 4) shape of O2 dissociation curve of whole blood
How do you prevent and treat respiratory distress syndrome that is caused by lack of sufficient surfactant?
Prevention: glucocorticoid therapy to mom before birth
treatment: synthetic surfactant applied to lungs soon after birth
What’s the normal saturation of mixed venous blood?
75% sat
Where do thymomas occur?
anterior mediastinum
Centriacinar (centrilobular) emphysema occurs when only the central or proximal parts of the acinus (group of alveoli connected to a respiratory bronchiole) are affected, and the distal alveoli are spared. What part of the lung is it often seen in, and what is it strongly associated with?
often seen in the upper lobes of the lungs and is associated strongly with cigarette smoking (‘smoke rises’)
What sort of granulomas are formed in sarcoidosis?
non-necrotizing granulomas
young, African-American female=
sarcoidosis
In a spontaneous pneumothorax, will the trachea deviate towards or away from the side of the lung collapse?
toward the side of the lung collapse (tracheas are cool w/ spontaneity, not tension)
What’s maternal arterial blood PO2 and %Sat?
95mmHg, 98%
DVT predisposition is defined by Virchow’s Triad as:
-venous stasis -activation of blood coagulation -vascular endothelial damage
Equation for vital capacity?
VC= TV + IRV + ERV
Where do cells that have cilia terminate?
respiratory bronchioles
Equation for total lung capacity:
TLC= IRV + TV + ERV + RV
What part of the diaphragm will the septum transversum form?
will form the central tendon of the respiratory diaphragm
Which medullary respiratory center is active during expiration and inspiration?
ventral respiratory group (VRG)
Which medullary respiratory center is active only during inspiration?
dorsal respiratory group (DRG)
What part of the lung is effected by silicosis?
upper lobe
What’s the equation for airflow?
airflow= (Pmouth - PA)/R (pressure in mouth minus alveolar pressure) divided by resistance
What’s the normal oxygen content of blood?
20 ml/dL
At what Left atrial pressure will you start to see pulmonary edema develop?
>25mmHg
What’s the gold standard for diagnosing symptomatic DVT?
duplex scanning (combination of Doppler and real time ultrasound)
What is resorption atelectasis?
occurs when an obstruction, such a mucous plug, foreign body, or tumor, prevents air from reaching distal airways. The entrapped air is slowly resorbed, leading to the collapse of the alveoli.
What cell types end at the beginning of terminal bronchioles?
goblet cells, glands, cartilage
What Wells score total shows a high risk for PE?
>6
What does silicosis increase a patient’s risk for?
increase susceptibility to TB and bronchogenic cancer
What are dust cells?
alveolar macrophages
Type II pneumocytes are characterized by ____.
lamellar bodies that Exocytose Surfactant onto the Alveolar Luminal Surface
