Term
| where is there more pressure in the lungs? |
|
Definition
| at the bottom - which is why pts with CHF need to sit up right |
|
|
Term
| what does surfactant do overall in the lungs? |
|
Definition
| surfactant (produced by alveolar type II cells) makes the lungs more compliant by breaking surface tension. this ultimately requires the body to do do less work |
|
|
Term
| how is intra-alveolar pressure decreased? what does this do? |
|
Definition
| the diaphragm goes down as the chest wall expands which creates a gradient between the outside and inside of the body - this decreases the intra-alveolar pressure and allows gas exchange to happen |
|
|
Term
| how can bacteria increase physiologic dead space in the lung? |
|
Definition
| WBCs release lysozymes, decrease surfactant, and the bacteria multiply - creating septicemia and pneumoniA |
|
|
Term
| what cells have the mucus elevators that can be harmed by smoking? |
|
Definition
| the pseudostratified columnar cells |
|
|
Term
| can Acute Respiratory Distress Syndrome (ARDS) be treated with surfactant? |
|
Definition
| yes - but pneumothorax may happen |
|
|
Term
| what happens on the CXR as alveoli collapse? |
|
Definition
| lightening of particular zones in the lungs looks like a “honeycomb” |
|
|
Term
|
Definition
| the max amount of air you can inspire and then expire (maximum volume of air that can be voluntarily moved in and out of the respiratory system) |
|
|
Term
|
Definition
| the amount of air normally breathed in and out of the lungs |
|
|
Term
|
Definition
| the amount of air left in the lungs after max exhalation - that which keeps the lungs from collapsing |
|
|
Term
| what is expiratory reserve volume? |
|
Definition
| the amount of air that can be forced out the lungs after normal expiration |
|
|
Term
| what is inspiratory reserve volume? |
|
Definition
| the additional amount of air that can be inhaled after normal inspiration |
|
|
Term
| what is the functional reserve capactity? |
|
Definition
| the amount of air in the lungs after normal tidal expiration |
|
|
Term
| what is inspiratory capacity? |
|
Definition
| the maximal amount of air that can be inspired after a normal tidal expiration |
|
|
Term
| what is the anatomical dead space? |
|
Definition
| the volume of the conducting pathways |
|
|
Term
| what is the physiologic dead space? |
|
Definition
| anatomic dead space plus the alveolar dead space |
|
|
Term
| what is the composition of air? |
|
Definition
| nitrogen: 78%, O2: 21%, and other: 1% |
|
|
Term
| how much O2 is exhaled into a pt in CPR? |
|
Definition
| ~16%, still about 4x what a pt needs |
|
|
Term
| why does blood turn blue when it is deoxygenated? what can be used to monitor this? |
|
Definition
| b/c of O2 isn't getting to Hb, then it isn't absorbing light. pulse ox is used to monitor blood cyanosis |
|
|
Term
| what is the characteristic shape of the Hb saturation curve? |
|
Definition
| sigmoid - you want pts on the ~ 90% saturation, ascending/loading part of the curve |
|
|
Term
| what is normal body pH? what happens to the Hb saturation curve if you drop it? |
|
Definition
| dropping pH will lower the Hb saturation curve (to around 70%), b/c in the presence of acid, Hb will unload O2 (makes sense b/c periphery has more acid - lactic acid and Hb usually unloads O2 there). (shifts curve to the R) |
|
|
Term
| how does pH being higher affect Hb? |
|
Definition
| the higher the pH, the more tightly Hb holds onto O2 (shifts curve to the L) |
|
|
Term
| how does temperature affect Hb? |
|
Definition
| the colder the temp, the tighter Hb will hold onto O2. the warmer the temp, the easier Hb lets go of O2. |
|
|
Term
| how do fetal and adult Hb compare in terms of O2 affinity? |
|
Definition
| fetal Hb has a higher O2 affinity (so they can get it easier from mom) |
|
|
Term
|
Definition
| 2,3 diphosphoglycerate is released during anaerobic glycolysis and helps to unload oxygen at the tissues by decreasing Hb's O2 affinity. this is helpful in anemic or ischemic situations |
|
|
Term
| what do pulmonary function tests assess? |
|
Definition
| how fast the breathing rate is, inspiratory reserve, expiratory reserve, vital capacity |
|
|
Term
| what is the area inside the pressure volume loop called? |
|
Definition
|
|
Term
| how much O2 do you get per gm Hb? |
|
Definition
|
|
Term
| can the food you eat affect your carbon levels, pH, and thus the ability of Hb to bind O2? |
|
Definition
|
|
Term
| what is the alveolar gas equation? |
|
Definition
| PA O2 = (.21)(760-47) - PaCO2/R. where .21=21% O2 in inhaled air, (760-47 torr) is the atmospheric pressure - saturated vapour pressure of water at body temperature. PaCO2: arterial partial pressure of carbon dioxide (normal is 40). R:the carbon dioxide load from the alveolus |
|
|
Term
| what is the partial pressure of O2? |
|
Definition
| the pressure which the oxygen would have if it alone occupied the volume |
|
|
Term
| what is the henderson-hasselbach equation? |
|
Definition
| pH = pK + base/acid OR pH = pK + base/PaCO2 |
|
|
Term
| what will slowing breathing down cause? |
|
Definition
|
|
