22228173
Beschreibung
Karteikarten von Evian Chai, aktualisiert more than 1 year ago
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Erstellt von Evian Chai
vor mehr als 4 Jahre
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| Frage | Antworten |
| During inspiration, respiratory muscles.... During normal expiration, respiratory muscles..., lungs... empty through .... | Contract Relax Passively Elastic Recoil |
| How do changes in pO2 change ventilation? | Little effect until the value is below 8kPa, then steep rise in ventilation |
| How does hyperventilation impact arterial pCO2? | It lowers them below the normal values of 5.3kPa aka hypocapnia |
| How does pH changes affect the pCO2 ventilation curve? Metabolic acidosis Metabolic alkadosis | Increase in pH/pCO2 shifts curve to the LEFT, increasing ventilation rate (Y axis) for the same alveolar pCO2 (x axis) |
| How does the Hering-Breuer Inflation Reflex negative feedback loop work? | 1. Inspiration stretches airways 2. Stretch receptors in bronchial smooth muscle activated 3. Vagus nerve sends impulses to DRG 4. DRG inhibits inspiratory neurons 5. This inhibits further inspiration, allowing time for passive expiration |
| How is rhythmicity induced by the central respiratory rhythm generator (DRG+VRG) in forced breathing? | Expiratory and inspiratory neurons are stimulated |
| How is rhythmicity induced by the central respiratory rhythm generator (DRG+VRG) in normal breathing? | Inspiratory neurons are stimulated while expiration is passive |
| How do inspiratory/expiratory neurons interact with each other? | They mutually inhibit each other, leading to alternating stimulation of inspiratory/expiratory muscles |
| When irritants enter lungs, 1. Irritants activate ...between epithelial cells 2. ...nerve sends signals to the .... 3. Leads to ..., ..., ... release, ...breathes | 1. Irritant receptors 2. Vagus, medulla 3. Coughing, bronchoconstriction, surfactant release, deeper breathes |
| The diaphragm is stimulated by the phrenic nerve, which originates from... Intercoastal muscles are innervated by the ... | 1. Brain stem between C3-C5 2. Spinal intercoastal nerves |
| The Dorsal Respiratory Group contains ...neurons that stimulate... muscles in rhythmic bursts ONLY It is innervated by the...nerve and recieves input from ...receptors in the lungs | 1. Inspiratory 2. Inspiratory 3. Vagus 4. Stretch receptors in the lungs |
| Which respiratory group is responsible for spontaneous rhythmic electrical pacemaker activity? It stimulates ... AND .... It recieves input from ... and ... | 1. Ventral respiratory group 2. Inspiratory neurons and expiratory neurons 3. Dorsal respiratory group, central chemoreceptors |
| The ... is the generator of basic rhythmicity. It consists of the ..., the ... and the ... | 1. Brain stem 2. Hypothalamus 3. Pons 4. Medulla oblongata |
| What are the two parts of the pons and what is their general role? | 1. Pneumotaxic center 2. Apneustic centre Both offer fine-tuning of rhythmicity from the medulla |
| Which part of the pons smooths transitions between expiraton/inspiration by regulating DRG? | Pneumotaxic centre, it also inhibits apneustic centre/phrenic nerve to decrease inhalation |
| Which part of the pons stimulates DRG to promote inspiration and increase breath duration? What does it recieve input from? | Apneustic center Pneumotaxic centre/pulmonary stretch receptors |
| What are the main O2 sensing cells in the respiration? What do they sense? Where are they located? | 1. Glomus Cells 2. They sense pO2 not O2 content mainly. They also sense changes in pCO2/[H+], but only 20% 3. They are located in the carotid body as PERIPHERAL chemoreceptors |
| What do glomus cells do in response to changes in pO2/pCO2/[H+]? | They release dopamine |
| What contributes to the involuntary control of breathing? | 1. The hypothalamus 2. The limbic system Both in response to temp/emotional changes |
| What contributes to the voluntary control of respiration? | Motor neurons in the cerebral cortex that can bypass the medulla+override respiratory centre |
| What are the main (80%) detectors of CO2 in respiration? What do they detect? Where are they located? | 1. Central chemoreceptors 2. They detect changes in pCO2/[H+] 3. They are located in the medulla (hence central) |
| What does raised pCO2 cause (4)? | 1. Peripheral vasodilation 2. Depressed CNS 3. Respiratory acidosis 4. Can lower pO2, cause hypoxia |
| What does reduced pCO2 cause? (3) | 1. Cerebral vasoconstriction 2. Cerebral hypoxia/dizziness 3. Respiratory alkalosis |
| What does the pons receive input from? Where does it feed this? | Pons recieves input from the cerebrum/hypothalamus It feeds this into the medullary respiratory center |
| What is breathing normally controlled by? | The autonomic nervous system |
| What is hypoventilation? What does it do to pCO2? What is hypercapnia? | Underventilation in proportion to metabolic demand Increase in pCO2 above normal values (>6kPa aka hypercapnia) |
| What is synergy between pO2 and pCO2, and how does this affect ventilation? | Synergy is when the combination of changes in pO2 (hypoxia) and pCO2 (hypercapnia) multiplies impact on ventilation Shifts pO2 and ventilation curve UP so 6 fold increase |
| What is the definition of hyperventilation? | Hyperventilation is overventilation in proportion to metabolic demand |
| What is the relationship between alveolar pCO2 and ventilation? | Linear relationship so small changes in pCO2 lead to large changes in ventilation |
| What is the respiratory rhythm generator in the brain stem? What does it contain? | The medulla The dorsal respiratory group (2 per side) and the ventral respiratory group (1 per side) |
| Why do central chemoreceptors not directly sense plasma pH? | H+/HCO3- cannot diffuse across the blood brain barrier Instead, indirect detection in CSF as CO2 after H+/HCO3- forms CO2+H20 |
| Summary of neural control of breathing |
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