Diffusion of gases occurs in the alveolar region only and not in the other parts ofrespiratory system. Why?
Question
Diffusion of gases occurs in the alveolar region only and not in the other parts ofrespiratory system. Why?
Solution
The diffusion of gases occurs primarily in the alveolar region of the respiratory system due to several reasons:
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Thin Walls: The walls of the alveoli are extremely thin (about 0.2 micrometers), which allows gases to easily pass through them. This thinness facilitates the diffusion of oxygen and carbon dioxide between the alveoli and the capillaries.
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Large Surface Area: The alveoli provide a large surface area (about 75 m2) for gas exchange. This large surface area increases the efficiency of gas exchange.
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Moist Environment: The alveoli are moist, which aids in the diffusion of gases. Gases diffuse more easily through a moist environment than a dry one.
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Rich Blood Supply: The alveoli are surrounded by a dense network of capillaries, which carry oxygen-rich blood from the lungs to the rest of the body and bring oxygen-poor blood from the body to the lungs. This rich blood supply allows for efficient gas exchange.
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Partial Pressure Gradient: The difference in partial pressures of oxygen and carbon dioxide between the alveoli and the capillaries drives the diffusion of these gases. Oxygen diffuses from the alveoli, where its partial pressure is high, into the capillaries, where its partial pressure is low. Conversely, carbon dioxide diffuses from the capillaries, where its partial pressure is high, into the alveoli, where its partial pressure is low.
The other parts of the respiratory system, such as the trachea and bronchi, have thicker walls and do not have the same surface area or blood supply as the alveoli, making them less suited for gas exchange.
Similar Questions
The exchange of gases in the alveoli of the lungs takes place bySelect an answerASimple diffusionBOsmosisCPassive transportDActive transport
What is diffusion?The passive movement of particles from a high concentration to a low concentrationThe passive movement of particles from a low concentration to a high concentrationThe active movement of particles using energy from respirationThe passive movement of water though a semi-permeable membrane from an area of high concentration to an area of low concentration2Which of the following factors do not speed up diffusion?Small surface area to volume ratioIncrease in temperatureIncrease in concentration gradientLarge surface area to volume ratio3During ventilation, in which order does air enter the following structures to reach the lungs?Bronchi, bronchiole, trachea, alveoliTrachea, alveoli, bronchi, bronchioleTrachea, bronchi, bronchiole, alveoliBronchi, trachea, bronchiole, alveoli4Which one of the following characteristics would you expect to find in alveoli to make them efficient at gas exchange?Small surface areaRich supply of blood capillariesLong diffusion distanceThick walls5Which two mechanisms are important for maintaining the steep concentration gradients of oxygen and carbon dioxide that are necessary for gas exchange?Respiration and ventilationVentilation and circulationVentilation and excretionRespiration and circulation6During gas exchange:Oxygen moves down a concentration gradient from the air in the alveoli to the bloodOxygen moves down a concentration gradient from the blood to the air in the alveoliOxygen moves up a concentration gradient from the blood to the air in the alveoliOxygen moves up a concentration gradient from the air in the alveoli to the blood
Where does gas exchange occur within the respiratory system?Multiple ChoiceIn the pharynxAt the alveoliIn the larynxIn the bronchioles
Alveoli are small sacs found in the lungs. The alveoli are where oxygen (O2) and carbon dioxide (CO2) are exchanged between the organism and the surrounding air.An alveolus is shown in the image below:Which of the following statements is false about the diffusion that occurs in the alveoli?Carbon dioxide will diffuse from an area of high concentration to where there is a low concentration of oxygen.Oxygen diffuses from an area of high concentration in the alveoli into an area of low concentration in the blood. The oxygen is later used in body cells for respiration.Carbon dioxide moves from an area of high concentration in the bloodstream to an area of low concentration in the alveoli. Carbon dioxide is a waste product from the process respiration.
1. Diffusion of respiratory gases takes place at the:respiratory center.alveolocapillary membrane.parietal pleurae.visceral pleurae.22. Carbon dioxide (CO2) is mainly transported in the blood:in the form of bicarbonate.combined with albumin.dissolved in red blood cells.attached to oxygen (O2).23. Which cytokines participate in hematopoiesis?NeutrophilsEosinophilsStimulating factors (CSFs)Basophils24. Which immunoglobulin is found in normal saliva?IgGIgDIgEIgA25. Which finding would support the diagnosis of respiratory acidosis?HyperventilationVomitingAn increase in noncarbonic acidsPneumonia26. Which group of people is most prone to color blindness?ChildrenMalesFemalesElderly persons27. After entering a room of chemical fog, a 20-year-old male cannot stop coughing. Which of the following structures are primarily responsible for his response?Irritant receptors in the trachea and large airwaysIrritant receptors in the nostrilsUpper respiratory tract mucosaUpper respiratory nasal hairs and turbinates28. Under most circumstances, increased work of breathing results in:alterations in alveolar perfusion.increased partial pressure of O2 in the lungs.increased oxygen consumption.decreased PaCO2.29. A patient with one kidney underwent surgery for an adrenal tumor that removed a large portion of the zona glomerulosa. The nurse would expect a postsurgical decrease in the patient’s:sodium.acid.aldosterone.potassium.30. The pressure required to inflate an alveolus is inversely related to:surface tension.minute volume.alveolar radius.wall thickness.31. While planning care for infants, which principles should the nurse remember? (select all that apply) Infants have problems with thermoregulation because they:have decreased metabolic rates.cannot conserve heat.have excess subcutaneous fat.rarely sweat.do not shiver.32. Several years after an amputation the patient continues to sporadically feel pain in the absent hand. What type of pain should the nurse document in the chart?Visceral painChronic painNeuropathic painPhantom limb pain33. For a patient with respiratory acidosis, chronic compensation by the body will include:prolonged exhalations to blow off CO2.kidney excretion of HCO3.protein buffering.kidney excretion of H+.34. How do the releasing hormones that are made in the hypothalamus travel to the anterior pituitary?Hypophyseal portal systemVessels of the zona fasciculataChromophilsMedian eminence35. Erythropoietin is produced in the:kidneys.spleen.liver.bone marrow.36. The nasopharynx is lined with a ciliated mucosal membrane with a highly vascular blood supply. One function of this membrane is to:cool air.humidify air.absorb air.exchange gases.37. A 20-year-old experiences a severe closed head injury as a result of a motor vehicle accident. Which of the following structures is most likely keeping the patient in a vegetative state (VS) 1 month after the accident?Spinal cordCerebellumCerebral cortexBrainstem38. A 65-year-old patient diagnosed with a subarachnoid hemorrhage secondary to uncontrolled hypertension appears drowsy and confused with pronounced focal neurologic deficits. This symptomology would place this hemorrhage at which grade?IVIIIIII39. Which system modulates a patient’s perception of pain?Sensory-discriminative systemAffective-motivational systemReticular-activating systemCognitive-evaluative system40. A nurse should document on the chart that chronic pain is occurring when the patient reports the pain has lasted longer than:3-6 months.1 month.1 year.2-3 years.
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