Respiratory II Flashcards
Be able to trace the pathway of oxygen and carbon dioxide traveling from the atmosphere to the tissues of your body and back to the atmosphere
- O2 inhaled and enters alveoli
- pulmonary gas exchange occurs
- into pulmonary capillaries and attaches to a red blood cell
- blood goes into left atrium and get dispursed to tissue cells
- in systemic capillaries where O2 is dissolved the systemic gas exchange occurs
- CO2 is picked up and goes to the right atrium then to lungs where CO2 is dissolved
- pulmonary gas exchange takes place and then exhaled
Explain pulmonary (external) and tissue (internal) respiration
Pulmonary (external): O2 will diffuse from alveoli into pulmonary capillaries, CO2 moves opposite direction into alveoli
Tissue (internal): O2 will diffuse from systemic capillaries into tissue, CO2 moves opposite direction into blood
Know the two different ways O2 is transported in the blood
1.5% dissolved in plasma
98.5% carried by hemoglobin on RBC
Know how hemoglobin transports O2. Know how the PO2 affects the dissociation of oxygen from hemoglobin
Balance equations (refer to ppt)
The greater the PO2-more O2 will combine w/ hemoglobin
Describe the three ways CO2 is transported in the blood. Know the chemical equation which describes the combining of carbon dioxide and water to form carbonic acid which then breaks down into a hydrogen ion and bicarbonate ion.
Bicarbonate ions (70%)- CO2 + H2O -> H2CO3 -> H+ + HCO3-
RBC’s-globin part, carbaminohemoglobin (23%)
Dissolved in plasma (7%)
Explain factors affecting Hb affinity or release of oxygen to the tissues. Know how this involves O2, temperature, pH, CO2 and BPG.
O2 is lower in tissues
temp in tissue is higher
CO2 in tissue is higher
pH in tissue is acidic
BPG (biphosphoglycerate) is higher
Be able to explain respiratory acidosis and alkalosis.
Acidosis: abnormally high PCO2 in systemic arterial blood, inadequate exhalation
Alkalosis: abnormally low PCO2 in systemic arterial blood, O2 deficiency
Define chloride shift. Why is it important?
Maintains ionic balance between plasma & RBC’s when conversion of CO2 to bicarbonate ions, to prevent acidosis/alkalosis
Be able to explain ventilation perfusion coupling in tissues. Understand what is happening in metabolically active and inactive tissues in terms of respiratory and cardiovascular function
Active Tissue: lower O2 in tissue, high CO2 so low pH (Bohr effect, acid pH), warmer BPG=dilate blood vessels to move the O2 from blood to tissue
Inactive Tissue: higher O2, lower CO2 so normal pH (no Bohr effect, don’t unload O2 into tissue), normal temp, lower BPG=constrict blood vessels around tissues for less O2 exchange
Be able to explain ventilation perfusion coupling in the lungs
O2 is high and CO2 is low=dilate blood vessels around alveoli & move more O2 into capillaries
Know the role of the respiratory center. Know where it is located and that it controls the basic rhythm of respiration.
Controls basic rhythm of respiration
pons & medulla
Know that the cortex allows you to voluntarily alter breathing patterns. Why can’t you hold your breathe until you die? Which blood gas stimulates breathing? What is hyperventilation and how do you treat it?
Cortex allows you to volunatarily alter breathing patterns
Build up of CO2 which goes to ANS
CO2
Hyperventalation: slight decrease in CO2, breathe into paper bag
ANS affect? What is the parasympathetic vs. the sympathetic actions on the smooth muscle of the bronchioles
Sympathetic: relax smooth muscle, dilates airways, E/NOR
Parasympathetic: normal ACh (asthma attack or allergic reactions constrict distal bronchiole smooth muscle)
What sets the “respiratory rhythm”? How does PCO2, PO2, arterial pH influence the rate and depth of breathing?
-The Medullary Rhythmicity Area sets respiratory rhythm
-Central and peripheral chemoreceptors monitor levels of O2 and CO2 and provide input to respiratory area.
-arterial pH stimulates receptors in the inspiratory center and muscles of respiration to contract more frequently and forcefully to maintain proper levels.
Where in the body do we find chemoreceptors? What gases do the respond too?
Chemoreceptors are found in the medulla. They respond to H+ or CO2
