Term
| How much of the oxygen in blood is bound reversible to hemoglobin? How does the rest circulate? |
|
Definition
97%
remainder is dissolved in the blood |
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Term
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Definition
| amount of gas dissolved is directly proportional to the partial pressure of that gas |
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Term
| Why is it important that we are able to circulate oxygen in blood, bound to hemoglobin? |
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Definition
| oxygen is not very soluble in blood, if we were to rely on dissolved oxygen alone the cardiac output required would be extremely high |
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Term
| Describe the general structure of hemoglobin |
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Definition
| contains 4 heme groups, each with 1 Fe atom available to bind 1 molecule of O2 |
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Term
| What is oxygen saturation |
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Definition
| (amount of oxygen carried) / (total oxygen capacity of the blood) |
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Term
| What is the % of saturation of hemoglobin in the lungs? |
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Definition
|
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Term
| What happens to oxygen saturation in anemia? |
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Definition
| the amount of O2 being transported is reduced proportionally to the amount of hemoglobin present |
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Term
| What is the saturation of hemoglobin coming out of tissue? |
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Definition
|
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Term
| What factors affect hemoglobin saturation? |
|
Definition
pH
temperature
2,3 diphosphoglycerate (DPG) |
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|
Term
| How does pH affect hemoglobin saturation? |
|
Definition
if metabolism increases, [H+] increases
-decreases affinity of Hb for O2
-curve shifts right, need higher pO2 for saturation |
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|
Term
| How does temperature affect hemoglobin saturation? |
|
Definition
increased metabolism = increased heat production
-decreases affinity of Hb for O2
-curve shifts right, need higher pO2 for saturation |
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|
Term
| How does 2,3DPG affect hemoglobin saturation? |
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Definition
| -binds to Hb, decreasing affinity for O2 |
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Term
| How is CO2 transported in the blood? |
|
Definition
-dissolved in solution
-bound to proteins (carbamino compounds)
-as bicarbonate |
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|
Term
| What are carbamino compounds? |
|
Definition
| CO2 bound to NH groups of proteins, especially hemoglobin |
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Term
| What regulates the rhythmic nature of respiration? |
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Definition
| respiratory center of the brain stem (medulla oblongata) |
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Term
| What do inspiratory neurons do? |
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Definition
| stimulate motor neurons in the spinal cord, which in turn stimulate contraction of respiratory muscles |
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Term
| What other network controls inspiratory neurons, besides the respiratory network? |
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Definition
| Central Pattern Generator |
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Term
| What influences the respiratory center? |
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Definition
| pO2, pCO2, H+ concentrations |
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Term
| Describe the steps of the reflex involved with the respiratory center |
|
Definition
1. Stretch detected
2. Signal sent to sensory fiber
3. Information sent to brain stem
4. Decrease in activity sent to inspiratory neurons |
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Term
| What are the two types of chemoreceptors? |
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Definition
central chemoreceptors
periperal chemoreceptors |
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Term
| Where are central chemoreceptors found? How do they work? |
|
Definition
in the brain stem
-indirectly detect changes in pO2 in blood to brain
-CO2 diffuses into cerebrospinal fluid, coverted into bicarbonate and H+
-H+ triggers the central chemoreceptors |
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Term
| Where are peripheral chemoreceptors found? How do they work? |
|
Definition
in carotid and aorta
-detect direct arterial changes in pO2, pCO2 and H+ |
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|
Term
| What are some symptoms of hypoxia? |
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Definition
| confusion, hallucination, loss of consciousness |
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Term
| What are some causes of hypoxia? |
|
Definition
-low pO2 in arteries due to pulm. disease/failure
-reduced transport capability (Hg problem)
-reduced blood flow to tissues
-impaired cell metabolism e.g cyanide poisoning |
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Term
| How is respiration in birds different than other mammals? |
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Definition
-lungs are small & rigid, do not change in volume
-air sacs are distensible, communicate with lungs & bronchi
-inspiration & expiration are active processes
-have unidirectional parabronchi also involved in gas exchange |
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