Term
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Definition
1.Maintain oxygen levels
2.Control Carbon dioxide and pH of body fluids |
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Term
| muscles involved in quiet inspiration |
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Definition
| diaphragm main muscle operating and is innervated by 1 of the 2 phrenic nerves that originate in cervical plexuses |
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Term
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Definition
| diaphragm contracts and moves up to 10cm. External intercostal muscles pulls ribs upwards, forwards, and outwards. Accessory muscles involved which consist of scalene muscles of the neck and sternocleidomastoideus |
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Term
| what happens if you cut the phrenic nerve |
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Definition
| the diaphragm will not be innervated and no longer contract |
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Term
| muscles involved in quiet expiration |
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Definition
| elastic recoil of lungs and elastic recoil of rib cage |
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Term
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Definition
1.abdominal wall muscles: during contraction, they raise the pressure in the abdominal cavity, pushing diaphragm up into thoracic cavity.
2. internal intercostals: during contraction ribs are pulled downward, backwards, and inwards.(external oblique, internal oblique, transversus abdominus, rectus abdominus) |
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Term
| Diseases which increase airway resistance |
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Definition
| COPD (asthma, bronchitis, emphysema) |
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Term
| acetylcholine does what to airway diameter |
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Definition
increases airway resistance by constricting bronchi/bronchioles.
Muscarinic receptors involved
-parasympathetic nerve endings release ACh from vagus nerve |
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Term
| epinephrine does what to airway diameter |
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Definition
decreases airway resistance by dilating bronchi/bronchioles
-use beta adrenergic receptors
-symphathetic activation from adrenal medulla |
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Term
| locations/functions of the nerve centers that make up the central controller of respiration |
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Definition
-upper pons pneumotaxic center: Fine tunes basic rhythm
-lower pons apneustic center: controls basic rhythm of breathing |
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Term
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Definition
| In medulla and respond to Hydrogen ions in the CSF (which increase when blood CO2 increases) |
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Term
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Definition
| In carotid and aortic bodies which respond mainly to low oxygen. |
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Term
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Definition
| stretch receptors in smooth muscles of the airways that respond to distension of the lungs. slow breathing rate by increasing the time taken up in breathing out |
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Term
| pH of CSF closely follows what? |
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Definition
| pCO2 in blood. drop in pH of CSF caused by high pCO2 in blood stimulates medullary chemoreceptors |
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Term
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Definition
| near ventral surface of medulla near exit of 9/10th cranial nerves. Respond to changes of hydrogen ion concentration in the extracellular fluid bathing them, which is dependent on the pH of the CSF. |
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Term
| Peripheral chemoreceptors |
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Definition
located in carotid and aortic bodies.
-Carotid bodies lie near carotid artery
-fibers from cartoid bodies ascend in Hering's nerve which is a branch of glossopharyngeal nerve
-fibers from aortic bodies ascend in vagus nerve
Major response to low pO2 in the arterial blood flowing through them. response increases rapidly once partial pressure of oxygen in arterial blood falls below 100mmHg. (pO2 in blood leaving pulmonary capillaries is about 104mmHg) |
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Term
| What is the effect of metabolic acidosis on respiration and what sensors are involved? |
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Definition
Low pH in blood and low pCO2.
-increased ventilation which causes the fall in partial pressure of CO2.
-chief site of pH effect is peripheral chemoreceptors |
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Term
| what is oxygen toxicity and how can it be avoided? |
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Definition
Breathing pure oxygen in high quantities can cause damage to endothelial cells of the pulmonary capillaries causing pulmonary edema.
Avoided: Reduce oxygen concentration you are breathing in. |
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Term
| why is carbon monoxide a dangerous gas |
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Definition
| binds to hemoglobin with higher affinity than oxygen. Result is carboxyhemoglobin which can't bind to oxygen. |
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Term
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Definition
stores oxygen in skeletal muscles.
-protein that contains iron and is similar to hemoglobin.
-even for low partial pressures of oxygen; myoglobin is saturated with oxygen
-does not transport oxygen in blood, only stores oxygen in skeletal muscles, where partial pressure of oxygen is low |
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Term
sickle cell anemia
African americans mostly affected |
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Definition
mutation in beta chain of hemoglobin molecule
-carry sickle cell gene: homozygous Hb S disease
-When HbS loses its oxygen, it forms long rods that make red cells ridgid and sickled in shape which interferes with oxygen delivery.
Leads to Anemia since sickle cells have short lifetime |
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Term
| 3 ways Carbon dioxide can be transported in blood |
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Definition
1.Dissolved: 20x more soluble in water than oxygen. about 5-6% of carbon dioxide in the blood is in dissolved form
2.Carbamino compounds: CO2 can bind to hemoglobin=carbaminohemoglobin. Has lower affinity for oxygen than hemoglobin. Only 5-7% or less of carbon dioxide is transported in the blood by this method.
3.Bicarbonate (know reaction)CO2 dissolves in plasma while tiny fraction converted to H2CO3 |
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