Respiratory System Flashcards
(39 cards)
What will be the effect of increased level of CO2 on respiration rate.
It will increase the respiration rate.
What is the effect of panting on dead space ventilation?
The dead space ventilation is increased by panting and provides cooling by evaporation of water from mucus membranes. During panting, although, the respiratory frequency increases, the alveolar volume remain constant by decreasing the tidal volume.
How the diaphragm and intercostal muscles help in inspiration process?
During inhalation, diaphragm contracts and becomes flat. It will increase the volume of thoracic cavity. The intercostal muscles also contract and pull the rib cage up and out. These movements will enlarge the volume of thoracic cavity, therefore, decreasing the pressure. These events make the lungs to inflate and intra-alveolar pressure becomes slightly negative with respect to the atmospheric pressure (about -1 mmHg). It will cause the inflow of air through the respiratory passage.
What is the difference between external respiration and internal respiration?
External Respiration includes the events that help in exchange of gases in lungs. These events are: inflow and outflow of the air between atmosphere and lung alveoli. Exchange of oxygen and carbon dioxide between the lung alveoli and the blood.
Internal Respiration includes the events that help in exchange of gases at cellular level: Diffusion of oxygen and carbon dioxide between blood and the body tissue. Actual metabolism of substances at cellular level.
What is the main function of expiratory center?
The neurons in expiratory center don’t help in expiration because expiration is a passive process.
These neurons only fire impulses when extra expiratory effort is needed during forced expiration like defecation and parturition etc.
How is oxygen carried in the blood?
1.5% oxygen is dissolved in blood, while the rest of the 98.5% of the oxygen is transported bound to hemoglobin and is called oxyhemoglobin.
Why is positive pressure ventilation required, when performing the surgery on the thorax?
During surgery on the thoracic cavity, we need to give artificial respiration under positive pressure to keep the lungs inflated. Any punctured wound in the thoracic cavity may destroy the intra-thoracic negative pressure and may lead to collapsing of the lungs.
Partial Pressure of CO2 is highest in which part of the body and lowest in which organ?
Partial pressure of carbon dioxide is highest in body tissue and lowest in the lung’s alveoli.
Correlate the respiration with Boyle’s law.
The mechanism of inhalation and expiration are based on the Boyle’s law that states, that the pressure of the gas is inversely proportional to its volume. That means if you increase the volume, the pressure will decrease.
What is anatomical dead space?
The respiratory pathway with air except the alveoli. The actual gaseous exchange occurs in alveoli, so the rest of the respiratory pathway having air is called anatomical dead space.
Define Residual volume?
The volume of the air still remaining in the lungs after the most forceful expiration.
A drop in partial pressure to what level, would significantly affect the oxygen saturation of hemoglobin.
The oxygen saturation of hemoglobin falls very fast when partial pressure drops down below 60 mmHg.
List the three ways, the carbon dioxide enter the blood from the tissues.
- About 7% carbon dioxide gets dissolved in blood.
- About 23% of carbon dioxide enters in RBCs and combines with hemoglobin to form carbamino-hemoglobin.
- Rest 70% carbon dioxide also enters the RBCs and combines with water (H2O) to form carbonic acid (H2CO3).
What is the function of pneumotaxic center?
The function of the pneumotaxic center is to inhibit the inspiratory center and allow passive expiration, once inspiration is completed.
What event leads to expiration process?
The expiration is passive process. The diaphragm relaxes and inward movement of the chest wall will compress the lungs and force the air out. These events decrease the volume of thoracic cavity, therefore increasing pressure inside thoracic cavity.
This compression of thoracic cavity increases the intra-alveolar pressure slightly higher than atmospheric pressure and forces the air out.
List all three humeo-chemical factors affecting the respiratory centers, in order of their importance.
- Concentration of CO2 in arterial blood.
- Concentration of H+ ions or pH of blood.
- Concentration of O2 in arterial blood.
Partial pressure of Oxygen is highest in which organ and lowest in what part of the body?
Partial pressure of Oxygen is highest in lung’s alveoli and lowest in other body tissues.
Define the terms eupnea, dyspnea, apnea, hyperpnea, polypnea.
Eupnea: normal breathing
Apnea: absence of breathing
Dyspnea: difficult breathing
Hyperpnea: abnormal increases in rate and depth of breathing.
Polypnea (tachypnea): shallow and rapid breathing (panting)
Does the oxygen saturation of hemoglobin depend on partial pressure of oxygen?
Yes
Define Patrial Pressure.
Partial pressure: is the pressure of gas exerted by individual gas in a mixture of gases. It is directly proportional to the percentage of gas in a total gas mixture.
Name the peripheral chemoreceptors and their main function.
These are aortic bodies and carotid bodies. These peripheral receptors respond to changes in pH of arterial blood to monitor the level of CO2 and oxygen in arterial blood.
Name the artery that is easily approachable for blood collection, require for blood-gas analysis.
Femoral Artery
Name the respiratory centers present in medulla and pons of the brain.
In medulla there are two centers:
1. Inspiratory Center
2. Expiratory Center.
In pons:
Pneumotaxic center.
Where are the central chemoreceptors located in the brain and what is their main function?
Central Chemoreceptors are located in 4th ventricle of the brain to monitor the pH level of CSF (cerebrospinal fluid).
