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Physio1 Quiz 6
NWHSU Physio 1 Quiz 6
Question | Answer |
---|---|
The conduction zone is made up of? | Trachea, Bronchi, Bronchioles |
Job of conducting zone? | Brings air into lungs |
Where is smooth muscle found? | All parts of the conducting zone |
In what zone does gas exchange occur? | Respiratory zone |
The respiratory zone is made up of? | Respiratory bronchioles, alveolar ducts, alveolar sacs |
What receptors are present on bronchioles? | Beta2 and muscarinic |
Beta2 receptors cause what? | Broncodilation |
Muscarnic receptors cause what? | Broncoconstriction |
Define asthma? | Constriction of terminal broncholes |
How to asthma drugs work? | They are a beta2 agonist. It stimulates the beta2 receptors to cause broncodilation |
What are the 6 causes to asthma? | Exercise, climate, allergies, stress, elevation, chemicals |
Repeated asthma attacks are called? | Status asthmaticus |
What produces surfactant? | Type II pneuomocytes |
What is surfactants job? | Reduce surface tension |
What is the job of alveolar macrophages? | Keep alveoli free of dust and debris |
Define Atelectasis? | Collapsed alveoli due to lack of surfactant |
Define pulmonary artery supply? | Cardiac output from the RIGHT side of the heart |
Is pulmonary blood flow evenly or unevenly distributed? | UNevenly |
How much of tidal volume fills the anatomic dead space? | 1/3 |
Define anatomical dead space? | Volume in the conducting airways. About 150ml |
Define physiological dead space? | Total volume of the lungs that does NOT participate in gas exchange and in a normal persons the physiological dead space is nearly equal to anatomic dead space |
Does physiological dead space participate in gas exchange? | NO |
What happens when the physiological dead space increases? | More and more aveoli in the respiratory zone |
Define minute ventilation? | Volume of air into and out of the lungs per unit time, expressed as minute ventilation which = VT x breaths/min |
Define alveolar ventilation (VA)? | VA= (VT-VD) x breaths/min |
Define hypoxic vasoconstriction? | The lungs are the only tissue that can redirect its own blood flow |
Majority of CO2 in body is carried by? | Bicarbonate |
Majority of O2 in body is carried by? | Oxygen |
How many molecules of oxygen can bind to hemoglobin? | 4 |
Describe restrictive lung disease? | Restricted on OUTSIDE, alveoli can not expand. Ex: Interstitial fibrosis |
Describe COPD? | Problems INSIDE alveoli. Ex: asthma, chronic bronchitis |
During INSPIRATION, the diaphragm moves? | DOWN |
During EXPIRATION, the diaphragm moves? | UP |
What muscles are used in INSPIRATION? | External intercostal muscles |
What muscles are used in EXPIRATION? | Internal intercostal muscles |
Inspiration or expiration more work? | Inspiration |
What is the natural elastic recoil? | Expiration |
Define Emphysema? | Condition where you loose elastic fibers of the lung and as result, compliance increases (cant snap back) |
Is intrapleural pressure positive or negative? | Negative |
Job of intrapleural pressure? | Keeps the alveoli expanded or prevents them from collapsing and helps to keep chest wall intact |
What happens in Pneumothorax? | Alveoli collapse and chest wall collapses |
What keeps alveoli from collapsing? | Surfactant and interpleural pressure |
The larger the alveolus the ____ the collapsing pressure | SMALLER - Law of Laplace |
When is surfactant synthesized? | 24 week gestation |
When is surfactant almost present by? | 35 weeks |
Surfactant is made up of? | DPPC that lines the walls of the alveoli and breaks up the forces bw the liquid molecules lining the alveoli |
During Atelectasis, lung compliance is ? | Decreased |
Define Fick's Law? | Gases move by simple diffusion and volume of gas transferred depends upson diffusion coefficient of the gas, surface area, partial pressure difference, and thickness of the membrane |
What is the diffusion coefficient for CO2? | 20 times more than oxygen |
What affects gas exchange? | Thickness of alveoli, surface area, gas quality, blood flow, # of blood cells |
Define Erythropoietin? | Increase RBC. Comes from the KIDNEYS in response to low O2-then stimulates bone marrow |
Total gas concentration is the sum of? | Dissolved gas, bound gas (O2)s, and chemically modified gas (CO2) |
Mixed venous blood comes from? | Right side of heart from the pulmonary artery (from right ventricle) |
Systemic arterial blood goes to? | Left side of heart by pulmonary vein |
Define Methemglobinemia? | Fe3+ state that does not bind to O2 (causes nitrates, sulfonamides or enzyme deficiency) |
Define Fetal Hb? | Two beta chains are replaced by gamma chains, higher affinity for O2 *Replaced in the first year of life* |
Define Sickle Cell Anemia? | Sickle cell rods taht distort the cell have a decreased affinity for O2 and occludes the blood vessel |
What causes the O2 curve to shift to the RIGHT? | *Bohr effect* Increase:PCO2, Temp, 2,3-DPG (high altitude)Decrease: Ph |
What causes the O2 curve to shift to the LEFT? | Decrease: PCO2, temp, 2,3-DPG Hb-F / Increase: Ph |
Does CO2 reduce/increase the number of sites available for O2? | Reduces |
When CO2 reduces the number of sites available for O2, this causes the O2Hb curve to shift? | To the LEFT |
What two sources make up the physiologic shunt? | Bronchial blood flow and Coronary venous blood |
Bronchial and Coronary blood drains to what ventricle? | Drains to left ventricle rather than going to the lungs to be oxygenated **SO NOT ALL BLOOD HERE IS OXYGENATED |
H+ is buffered by | Hemoglobin (Hb-H)inside the red blood cells |
HCO3 exchanges for what ? | Exchanged for Cl- and is transported in plasma |
What doe Hypoxic vasoconstriction depend upon? | PAO2 (This occurs when there is a drop in PAO2) |
High levels of PAO2 keeps the vascular smooth muscle ___? | Relaxed |
During a drop in PAO2, vasoconstriction occurs and redirects? | Blood flow from poorly ventilated alveoli of the lungs to well ventilated alveoli |
Nitric oxide causes what in smooth muscle? | Relaxation |
What happens in high altitude? | Hypoxemia and global vasoconstriction of the pulmonary arterioles leading to increase in resistance which then leads to right ventricle hypertrophy |
What happens in fetal circulation? | PAO2 is much lower in the fetus than in the mother productin vasoconstriction. Fetus has advantage of carrying HBF |
What happens at birth to the neonate? | First breath increase PAO2 to 100mmhg and pulmonary blood flow increase |
Define hypoxemia? | Decrease in arterial PO2 and is determined by the difference in alveolar (PAO2) and PO2 of systemic arterial blood (PaO2) |
What are the causes of hypoxemia? | High altitude, hypoventilation, diffusion defects, V/Q defects, right to left shunts |
What are a few causes of hypoxia? | Decrease O2 delivery to tissues, decreased cardiac output, decreased O2 content of Hb, Anemia, CO poisoning, cyanide |
Cyanide poisionging interferes with? | Decreased utilization of oxygen in tissues *Problem at celluar level |