Term
|
Definition
At beginning of respiratory cycle:
-phrenic nerve is stimulated increasingly
-leads to expansion of airways
-steady increase in flow during early respiratory cycle |
|
|
Term
| Early-Expiratory Neuron Activity |
|
Definition
At expiration, early-expiratory neuron is stimluated:
-phrenic nerve deactivated
-lungs contract |
|
|
Term
|
Definition
stimluated during inspiration
deactivaed immediately during expiration |
|
|
Term
|
Definition
Normal breathing
-Gradual inspiration
-rapid expiration |
|
|
Term
|
Definition
At any given time, not all alveoli are conducting air and some are collapses
-hypothesis-sigh's result in expanding the previously collapsed alveoli |
|
|
Term
|
Definition
| Total collapse of all alveoli |
|
|
Term
|
Definition
Extreme version of a sigh
-you can reach total lung capacity
-same function as sigh |
|
|
Term
|
Definition
(experimental)
Cut the vagus nerve
-Inspiration rate is slower
-Tidal volume is higher
*mechanoreceptors in lungs tranfer sensory signals via vagus nerve-->medulla normally terminates inspiration earlier |
|
|
Term
| Cheyne's Stokes breathing |
|
Definition
| Building frequencies of respiratory cycle, then apnea (no breathing), then another building frequency of the respiratory cycle....continues... |
|
|
Term
|
Definition
Often pre-terminal
Last attempts at breathing |
|
|
Term
| 2 groups of chemoreceptors |
|
Definition
1) Central (located in medulla)
2) Peripheral (carotid body)
-they are oxygen sensors, but they regulate CO2 |
|
|
Term
|
Definition
|
|
Term
|
Definition
-Each weighs about 2 mg
-Most highly perfused tissue in the body (40-50X more than brain)
-Oxygen sensors (Type I Glomus Cells)
-derive from same tissue as nervous system
-Sympathetic and Parasympathetic control |
|
|
Term
| 3 mechanisms of detecting low PCO2 |
|
Definition
1) O2 dissociates from heme-containing protein near K+ Channel
2) Low PO2 somehow elevates Camp
3) Low PO2 inhibits NADPH-oxidase in mitochondria, raising the ratio of reduced-oxidized glutathione |
|
|
Term
| Cell response to low PCO2 |
|
Definition
| Positive charge accumulates in the glomus cell --> repolarization of membrane --> Ca+ channels open --> elevated neurotransmitters (dopamine) --> neurotransmitters bind to postsynaptic receptors --> Generates an action potential --> sent to medulla |
|
|
Term
| Two ways to change pH of instersticial fluid |
|
Definition
1) Respiratory Acidosis
-CO2 increases, decreasing pH
2)Metablic
-Either bicarbonate increases or hydronium ions decrease
Changing CO2 is much more effective than changing bicarbonate |
|
|
