![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/KSEEB-Solutions.png\")
<\/p>\nQuestion 1.
\nWhat are the protective coverings of lung called?
\nAnswer:
\nParietal pleura and visceral pleura.<\/p>\n
<\/p>\n
Question 2.
\nHow is food prevented from entering the trachea?
\nAnswer:
\nEpiglottis, a flap like structure, prevents the entering of food into trachea by closing the food pipe (Oesophagus).<\/p>\n
Question 3.
\nWhat type of muscle is found in diaphragm?
\nAnswer:
\nSkeletal muscle.<\/p>\n
<\/p>\n
Question 4.
\nWhat is meant by pulmonary ventilation?
\nAnswer:
\nIt is the process of breathing of oxygen – rich air into the lungs and expelling of carbondioxide rich air from the lungs.<\/p>\n
Question 5.
\nWhat is bronchitis?
\nAnswer:
\nIt is the inflammation of bronchi, leading to breathlessness, chest tightness, light sneezing, and cough with the explusion of yellow or green sputum.<\/p>\n
Question 6.
\nWhat is asthma?
\nAnswer:
\nIt is the parietal blocking of bronchi and bronchioles, resulting in breathlessness, chest tightness, wheezing and dry cough.<\/p>\n
Question 7.
\nWhat is emphysema?
\nAnswer:
\nEmphysema is the condition, where the walls of the alveoli lose their elasticity and remain rigid due to a permanent air filled condition.<\/p>\n
<\/p>\n
Question 8.
\nWhat is tidal air volume?
\nAnswer:
\nIt is the amount of air inspired or expired during normal breathing. Normally it is about 500 ml.<\/p>\n
Question 9.
\nState the name of the volume of air remaining in the lungs, after a normal breathing.
\nAnswer:
\nResidual volume.<\/p>\n
Question 10.
\nName the primary site of exchange of gases in our body.
\nAnswer:
\nAlveoli.<\/p>\n
Question 11. Question 1. Question 2. Question 3. Question 4. Question 5. Question 6. Question 7. Question 8. Question 9. Question 10. Question 11. Question 12. Question 13. Question 14. Question 15. Question 16. Question 17. Question 18. Question 19. Question 20. Question 21. Question 22. Question 23. Question 1. Question 2. (a) IRV and ERV Expiratory Reserve volume (ERV) : It is the maximum extra volume of air that can be expired by forceful expiration. It is called as supplementary air. Its volume is 1000 to 1100 ml.<\/p>\n (b) Inspiratory capacity and Expiratory capacity. Expiratory Reserve volume (ERV) : It is the maximum extra volume of air that can be expired by forceful expiration. It is called as supplementary air. Its volume is 1000 to 1100 ml.<\/p>\n (c) Vital capacity and Total lung capacity. Total lung capacity (TLC): It is,maximum volume of air that can enter the lungs during forceful inspiration, Question 3. (b)\u00a0 Residual Volume (RV). It is the volume of air left in the lungs after forceful expiration. (c) It is the spastic contraction of bronchiolar muscles during expiration so that expiration becomes difficult while inspiration remains normal.<\/p>\n Question 4. Question 1. 1. Inspiration (Inhalation): It is the process of drawing air into the lungs the from outside atmosphere (intake of air). During this process, muscles of the diaphragm contract, which increases the length of the thorax. In the mean while intercostal muscles also contract, pulling the ribs outward.<\/p>\n This phenomenon increases width of the thorax, resulting in the expansion of the lungs. As a consequence pulmonary pressure falls. So oxygen rich air rushes into the lungs and fill alveoli.<\/p>\n 2. Exchange of gases : 3. Expiration (exhalation): It is the process of throwing out carbon dioxide from the lungs to outside. During this process, muscles of the diaphragm and intercostal muscles relax causing the collapse of the rib cage. This decreases the volume of the thorax and lungs. As a consequence pulmonary pressure increases. So, carbon dioxide rich air of the alveoli is drawn out through the respiratory passage.<\/p>\n Question 2. Question 3. The vestibule is lined by a hairy skin and mucus secreting glands. The vestibular hairs and mucus filter the dust particles. The nose is also specialized for warming and moistening the incoming air. It also performs olfactory (smelling) functions.<\/p>\n 1. External Nostrils : They lead into a short passage called nasal passage or nasal cavity, which lies above the buccal cavity. The roof of nasal cavity is lined by olfactory mucosa consisting of receptors responsible for smelling. It leads into the pharynx.<\/p>\n 2. Pharynx : It is divided into anterior nasopharynx, middle oropharynx and posterior laryngopharynx. This is a common pipe for both food and air. The bifurcation starts here, and leads separately to digestive tract and the respiratory tract. At the in junction, a cartilaginous lap called epiglottis is present.<\/p>\n 3. Larynx : It is made up of nine pieces of cartilage, there are paired, and three are unpaired. The unpaired cartilages are thyroid cartilage (Adam\u2019s apple), epiglottic cartilage (epiglottis), and cricoid cartilage. Paired ones are the arytenoids, comiculate and cuneiform cartilages. On the inner surface, it is formed into foldings called vocal cords, which help in the production of sound and hence called as the sound box.<\/p>\n 4. Trachea: It is commonly called as windpipe. It is 12 cm in length, and 2.5 cm in diameter. It is surrounded by a C shaped hyaline, which prevents the tracheal wall from collapsing. The trachea divides into two branches called bronchi. Each bronchus opens into lungs.<\/p>\n 5. Lungs : Lungs are present in the lower half of the thoracic cavity. They are covered by connective tissue called pleural membrane. There is a space between the two lungs called as Mediastinum where the heart is situated. The right lung is divided into three unequal lobes, and left lung is divided into two lobes. The pleural membrane is a double membranous structure.<\/p>\n The outer membrane is known as \u2018Parietal Pleura\u2019 and the inner membrane is known as \u201cVisceral Pleura\u201d. The space in between the two membranes is known as \u2018Pleural Space\u2019 filled with pleural fluid\/serous fluid, which acts like a shock absorber.<\/p>\n Each bronchus that enters into the lung is known as Primary bronchus which further divides into secondary, tertiary, quaternary and terminal bronchus. Terminal bronchus gives rise to many bronchioles. The last branch is referred as respiratory bronchiole, which further divides to form alveolar duct. The alveolar duct ends with sap like structure called Alveolus, where exchange of respiratory gases takes place.<\/p>\n Question 4. Definition : Respiration occurs in four phases. 2. External respiration : The exchange of Oxygen, and Carbon dioxide between the alveoli of lungs and blood.<\/p>\n 3. Internal respiration : The exchange of Oxygen, and Carbon dioxide between blood and body cells.<\/p>\n 4. Cellular oxidation : The process in which, carbohydrates like Glucose are oxidized in the body cells to release energy, which occurs in the presence of oxygen.<\/p>\n Human Respiratory System :<\/p>\n Nose: The nose communicates with the outside, through a pair of openings called as nostrils. The nostrils lead to a cavity called nasal cavity. The right and left nasal cavities are separated by a nasal septum. The anterior part of the nasal cavity which is just behind the nostrils is called vestibule. The vestibule is lined by a hairy skin and mucus secreting glands. The vestibular hairs and mucus filter the dust particles. The nose is also specialized for warming and moistening the incoming air. It also performs olfactory (smelling) functions.<\/p>\n 1. External Nostrils : They lead into a short passage called nasal passage or nasal cavity, which lies above the buccal cavity. The roof of nasal cavity is lined by olfactory mucosa consisting of receptors responsible for smelling. It leads into the pharynx.<\/p>\n 2. Pharynx : It is divided into anterior nasopharynx, middle oropharynx and posterior laryngopharynx. This is a common pipe for both food and air. The bifurcation starts here, and leads separately to digestive tract and the respiratory tract. At the injunction, a cartilaginous lap called epiglottis is present.<\/p>\n 3. Larynx : It is made up of nine pieces of cartilage, there are paired, and three are unpaired. The unpaired cartilages are thyroid cartilage (Adam\u2019s apple), epiglottic cartilage (epiglottis), and cricoid cartilage. Paired ones are the arytenoids, corniculate and cuneiform cartilages. On the inner surface, it is formed into foldings called vocal cords, which help in the production of sound and hence called as the sound box.<\/p>\n 4. Trachea: It is commonly called as It is 12 cm in length, and 2.5 cm in diameter. It is surrounded by a C shaped hyaline, which prevents the tracheal wall from collapsing. The trachea divides into two branches called bronchi. Each bronchus opens into lungs.<\/p>\n 5. Lungs : Lungs are present in the lower half of the thoracic cavity. They are covered by connective tissue called pleural membrane. There is a space between the two lungs called as Mediastinum where the heart is situated. The right lung is divided into three unequal lobes, and left lung is divided into two lobes.<\/p>\n The pleural membrane is a double membranous structure. The outer membrane is known as \u2018Parietal Pleura\u2019 and the inner membrane is known as \u201cVisceral Pleura\u201d. The space in between the two membranes is known as \u2018Pleural Space\u2019 filled with pleural fluid\/serous fluid, which acts like a shock absorber.<\/p>\n Each bronchus that enters into the lung is known as Primary bronchus which further divides into secondary, tertiary, quaternary and terminal bronchus. Terminal bronchus gives rise to many bronchioles. The last branch is referred as the respiratory bronchiole, which further divides to form the alveolar duct. The alveolar duct ends with sap like structure called Alveolus, where exchange of respiratory gases takes place.<\/p>\n Structure of Alveoli : 6. Alveoli : Mechanism of breathing : Inspiration : Expiration : External respiration.<\/p>\n The exchange of gases takes place between alveoli of the lungs and the blood is known as \u2018External respiration\u2019. It takes place mainly by the process of diffusion. The air pressures are expressed as partial pressure. The partial pressure of 02<\/sub> is represented as PO2<\/sub>, and the partial pressure of CO2<\/sub> as PCO2<\/sub>. The diffusion takes place from the region of their higher partial pressure to the region of their lower partial pressure.<\/p>\n The exchange of O2<\/sub>, and CO2<\/sub> between the alveoli and blood can be expressed as follows. Alveoli of the lungs contain 107 mm of Hg of oxygen and the blood contains 45 mm of Hg of oxygen. Hence due to more partial pressure of O2<\/sub> in the alveoli, O2<\/sub> diffuses into the blood. Mean while CO2<\/sub> diffuses in the opposite direction. The PCO2<\/sub> of the blood capillaries is around 46mm of Hg. While the oxygenated blood capillaries is around 46mm of Hg. While the oxygenated blood has PCO2<\/sub> of about 36 mm of Hg. Therefore CO2<\/sub> diffuses from blood capillaries to alveoli.<\/p>\n This can be schematically represented as follows. Internal respiration : Respiratory volumes :<\/p>\n The volume of air getting in and getting out of the lungs can be measured and expressed as the respiratory volume.\u00a0 The instrument used to measure respiratory volume is respirometer or spirometer.<\/p>\n 1. Tidal volume (TV): It is the volume of air inhaled or exhaled with each inhalation and exhalation without any extra effort. Its volume is 500 ml.<\/p>\n 2. Inspiratory Reserve volume (IRV): It is the maximum extra volume of air than can be inspired. It is also called as complementary air. Its volume is 2500 – 3000 ml.<\/p>\n 3. Expiratory Reserve volume (ERV) : It is the maximum extra volume of air that can be expired by forceful expiration. It is called as supplementary air. Its volume is 1000 to 1100 ml.<\/p>\n 4. Residual volume (RV): It is die volume of air that remains inside the lungs at the end of forceful expiration. Its volume is 1100 -1200 ml.<\/p>\n 5. Vital Capacity (VC): It is the total volume of air that can be expelled from the lungs during maximum exhalation. 6. Total lung capacity (TLC): It is maximum volume of air that can enter the lungs during forceful inspiration, Transport of gases by blood :<\/p>\n 1. Oxygen: 3% of oxygen is transported in a dissolved state in plasma whereas 27% is in a bound state. The RBC\u2019s present in the blood are responsible for the transport of oxygen. The RBC contains the respiratory pigment-Haemoglobin which has great affinity towards oxygen.<\/p>\n Haemoglobin contains non-protein part haem or iron, and protein part globin. Each hemoglobin molecule is able to carry four molecules of oxygen. During the transport of O2<\/sub>, the O2<\/sub> readily combines with haemoglobin to form oxy-haemoglobin. Hence O2<\/sub> is transported in this form to the tissue cells. When the oxygenated blood enters the region of body cells, oxy-haemoglobin dissociates giving off O2<\/sub> to the cells. The haemoglobin (RBC) returns to the blood to repeat the process. CO2<\/sub> is produced within the body cell as a metabolic waste product of oxidative metabolism. As of carbonic acid : About 23% of CO2<\/sub> is found associated with the globin part of haemoglobin to form carbamino haemoglobin in the RBC. The formation of carbamino haemoglobin is highly influenced by a relative high Pco2<\/sub> in the tissues. As bicarbonates of Na+<\/sup> and K+<\/sup>. The IT ions combine with haemoglobin to form haemoglobinic acid. The HCO3<\/sub> ions being quite diffusible, diffuse from the RBC into the plasma. To maintain the electrostatic neutrality of the plasma, many chloride ions (Cl–<\/sup>) diffuse from the plasma into RBC. This diffusion of bicarbonate ions from RBC into plasma and of chloride ions from plasma into RBC to maintain ionic balance between RBC and plasma, in known is chloride shift or Hamburger\u2019s phenomenon.<\/p>\n ‘The HCO–<\/sup>3<\/sub> ions that enter the plasma combine with sodium ions, and potassium ions to form Sodium bicarbonate (NaHCO3<\/sub>), and Potassium bicarbonate (KHCOa<\/sub>) respectively.<\/p>\n The above reactions can be schematically represented as follows. When the deoxygenated blood reaches the lungs, it finds itself in a situation where the PO<\/sub>\u00a0is high, <\/p>\n Regulation of respiration: Respiratory Disorders : Symptoms [Effect]:<\/p>\n Treatment : Emphysema: Occupation a Lung diseases: The lungs are indirectly affected due to these particles, which can induce allergy or diseases such as occupational asthma.<\/p>\n Bronchitis: Karnataka 1st PUC Biology Question Bank Chapter 17\u00a0Breathing and Exchange of Gases 1st PUC Biology Breathing and Exchange of Gases One Marks Questions and Answers Question 1. What are the protective coverings of lung called? Answer: Parietal pleura and visceral pleura. Question 2. How is food prevented from entering the trachea? Answer: Epiglottis, a flap …<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/88423"}],"collection":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/comments?post=88423"}],"version-history":[{"count":0,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/88423\/revisions"}],"wp:attachment":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/media?parent=88423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/categories?post=88423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/tags?post=88423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nA major percentage (97%) of oxygen is transported by RBCs in blood. How does the remaining percentage (3%) of O2<\/sub> gets transported?
\nAnswer:
\nIt gets dissolved in the plasma of blood.<\/p>\n1st PUC Biology Breathing and Exchange of Gases Two Marks Questions and Answers<\/h3>\n
\nExplain transport of carbon dioxide by haemoglobin.
\nAnswer:
\nAs carbon dioxide from the tissues enter into blood, a small quantity of about 45% enters into RBCs. In the RBCs, carbondioxide combines with haemoglobin and forms carbamino- haemoglobin. The carbamino-haemoglobin on reaching the lungs dissociates into haemoglobin, and carbon dioxide.
\nCO2<\/sub> + HbNH2<\/sub> \u2192 HbNHCOOH.<\/p>\n
\nExplain Hamburger\u2019s phenomenon.
\nAnswer:
\nHCO3<\/sub> ions produced by the dissociation of H2<\/sub>CO3<\/sub> inside the RBC, diffuse into plasma. To maintain electrostatic neutrality of plasma, chloride ions move into RBCs. This diffusion of HCO ions from RBCs into plasma, and chloride ions from plasma into RBCs to maintain ionic balance is called Hamburger\u2019s phenomenon or Chloride shift.<\/p>\n<\/p>\n
\nWhat are the changes that takes place during inspiration?
\nAnswer:
\nInspiration (Inhalation) :
\nIt is the process of drawing air into the lungs from the atmosphere (intake of air). During this process, muscles of the diaphragm contract, which increases the length of the thorax. In meanwhile intercostal muscles also contract, pulling the ribs outward. This phenomenon increases width of the thorax, resulting in the expansion of the lungs. As a consequence pulmonary pressure falls. So oxygen rich air rushes into the lungs and fill the alveoli.<\/p>\n
\nWrite any four differences between inspiration and expiration.
\nAnswer:<\/p>\n\n\n
\n Inspiration<\/strong><\/td>\n Expiration<\/strong><\/td>\n<\/tr>\n \n 1. It is a process of drawing air oxygen into the lungs from outside.
\n2. Diaphragm and intercostal muscles contract.
\n3. Due to this the volume of thorax, increases and lungs expand.
\n4. Pulmonary pressure falls.<\/td>\n1. It is a process of leaving out carbon -dioxide from the lungs to outside.
\n2. Diaphragm and intercostal moscles relax.
\n3. Due to this the volume of thorax, decreases and lungs get compressed.
\n4. Pulmonary pressure increases.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\nBriefly explain external respiration.
\nAnswer:
\nIt is the exchange of carbon dioxide for oxygen in the alveoli of the lungs. It takes place due to a partial pressure gradient of the carbon dioxide and oxygen between the blood and alveoli respectively.<\/p>\n<\/p>\n
\nDifferentiate external respiration from internal respiration.
\nAnswer:<\/p>\n\n\n
\n External respiration:<\/td>\n Internal respiration:<\/td>\n<\/tr>\n \n It is the exchange of gases by\u00a0 diffusion between alveolar value and the wall of blood capillaries.<\/td>\n It is the exchange of gases between blood and the tissues of the body.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\nHaemoglobin is an Oxygen carrier. Explain.
\nAnswer:
\nHaemoglobin is called oxygen carrier because about 97% of the oxygen is transported by. RBCs. RBCs contain haemoglobin. Haemoglobin has affinity towards oxygen. Hence haemoglobin binds with oxygen molecules to form oxyhaemoglobin,
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-17-Breathing-and-Exchange-of-Gases-1.png\")
\nOxyhaemoglobin is a very unstable compound. Hence it dissociates into haemoglobin, and molecular oxygen, when it reaches tissues.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ‘<\/p>\n
\nMention the function of nasal cavity during breathing.
\nAnswer:
\nThe nasal cavity performs the following functions.<\/p>\n\n
\nMention the various parts of human respiratory system in their connnect sequence.
\nAnswer:
\nThe human respiratory system comprises of:
\na. Nostrils, and nasal passage.
\nb. Pharynx.
\nc. Larynx.
\nd. Trachea.
\nf. Bronchiole
\ng. Alveoli.<\/p>\n<\/p>\n
\nDefine vital capacity. What is its significance?
\nAnswer:
\nVital Capacity (VC): It is the total of fume of air that can be expelled from the lungs during maximum exhalation.
\nVC = IVR + ERV
\n500 + 2500+ 1100 = 4100 ml approx<\/p>\n
\nExplain the process of inspiration under normal conditions.
\nAnswer:
\nInspiration :
\nThe process of intake of air (O2<\/sub>) from the atmosphere into the lungs is known is inspiration. It is an active process. During inspiration the following changes take place in the thoracic cavity.<\/p>\n\n
<\/p>\n
\nHow is respiration regulated?
\nAnswer:
\nThe medulla and pons contain respiratory centres which regulate the rate of respiration. The rhythmicity centre of medulla maintains the basic rhythm of respiration. It has a group of neurons namely. dorsal group (mspiratory neurons), and ventral group (expiratory neurons) which control the movements of diaphragm and the intercostal muscles respectively. The centres in pons influence the rhythmicity centre for its activity.<\/p>\n
\nWhat is the effect of PCO2<\/sub>\u00a0on oxygen transport?
\nAnswer:
\nAt low PCO2<\/sub>\u00a0blood carries more O2<\/sub> and at high PCO2<\/sub>, oxygen globin dissociates to release O2<\/sub><\/p>\n
\nWhat happens to the respiratory process in a person going up a hill?
\nAnswer:
\nRespiratory rate increases due to the reduced oxygen content in air at higher altitudes.<\/p>\n
\nWhat is the site of gaseous exchange in an insect?
\nAnswer:
\nTrachea.<\/p>\n
\nWhat is Tidal volume? Find out the Tidal volume (approximate value) for a healthy human in an hour.
\nAnswer:
\nTidal volume (1V): It is the volume of air inhaled or exhaled with each inhalation and exhalation without any extra effort. Its volume is 500 ml.<\/p>\n
\nDiffusion of gases occurs in the alveolar region only, and not in the other parts of the respiratory system. Why?
\nAnswer:
\nBecause, the delicate and thin walls of the alveolar region permit diffusion easily.<\/p>\n
\nA fluid – filled double membranous layer surrounds the lungs. Name it, and mention its important functions.
\nAnswer:
\nThe double membrane layer contianing the pleural fluid is called Pleural Sac. Functions frictionless movement of lungs and development of negative pressure.<\/p>\n<\/p>\n
\nArrange the following terms based on their volumes in an ascending order
\n(a) Tidal volume (TV)
\n(b) Residual Volume (RV)
\n(c) Inspiratory Reserve Volume (IRV)
\n(d) Expiratory Capacity (EC).
\nAnswer:
\nTidal Volume (500 ml) \u2192 Residual Volume (1100 – 1200ml) \u2192 Expiratory Capacity (1500 – 1600ml) \u2192 Inspiratory Reserve Volume (2500 – 3000ml).<\/p>\n
\nComplete the missing terms:
\n(a) Inspiratory Capacity (IC) = … + IRV.
\n(b) …. = TR + ERV.
\nAnswer:
\n(a) TV (b) EC (Expiratory Capacity).<\/p>\n
\nState the different modes of CO2<\/sub> transport in blood.
\nAnswer:
\nThree modes :<\/p>\n\n
<\/p>\n
\nFor completion of the respiration process, write the given steps in their proper sequential manner.
\n(a) Diffusion of gases (O2<\/sub>, and CO2<\/sub>) across alveolar membrane.
\n(b) Transport of gases by blood.
\n(c) Utilisation of O2<\/sub> by the cells for catabolic reactions and resultant release of CO2<\/sub>.
\n<\/span>(d) Pulmonary ventilation by which, atmospheric air is drawn in and CO2<\/sub> rich alveolar air is released out.
\n(e) Diffusion of O2<\/sub>, and CO2<\/sub>\u00a0between blood and tissues.
\nAnswer:
\nc \u2192 e \u2192 b \u2192 a \u2192 d.<\/p>\n
\nExplain the role of neural system in the regulation of respiration.
\nAnswer:
\nThe medulla and pons contain respiratory centres which regulate the rate of respiration. The rhythmicity centre of medulla maintains the basic rhythm of respiration. It has a group of neurons namely. dorsal group (respiratory neurons), and ventral group (expiratory neurons) which control the movements of the diaphragm and the intercostal muscles respectively. The centres in pons influence the rhythmicity centre for its activity.<\/p>\n1st PUC Biology Breathing and Exchange of Gases Three Marks Questions and Answers<\/h3>\n
\nWhat are the major transport mechanisms for CO2<\/sub>? Explain.
\nAnswer:
\nCO2<\/sub> is produced within the body cell as a metabolic waste product of oxidative metabolism.
\nCO2<\/sub> is transported from cells to the alveoli through the following forms.<\/p>\n\n
\nDistinguish between<\/p>\n
\nAnswer:
\nInspiration Reserve volume (IRV): It s the maximum extra volume of air that can be inspired. It is also called as complementary air. Its volume is 2500 – 3000 ml<\/p>\n<\/p>\n
\nAnswer:
\nInspirstory Reserve volume (LRV): It s the maximum extra volume of air than can be inspired. It is also called as complementaiy air. Its volume is 2500 – 3000 ml.<\/p>\n
\nAnswer:
\nVital Capacity (VC): It is the total olume of air that can be expelleif from the lungs during maximum exhalation.
\nVC = TV + IRV + ERV
\n= 500 + 2500 + 1100
\n= 4100 ml approx.<\/p>\n
\nTLC = VC + RV = 4100 + 1600 = 5200 approx.<\/p>\n
\nDefine the following terms :
\n(a) Tidal volume
\n(b) Residual volume
\n(c) Asthma.
\nAnswer:
\n(a) Tidal Volume (TV). It is the volume of air inhaled or exhaled during normal breathing.
\nIts volume is 500 ml.<\/p>\n
\nIts volume is 1100 – 1200 ml.<\/p>\n<\/p>\n
\nName the organs of respiration in the following organisms:
\n(a) Flatworm
\n(b) Birds
\n(c) Frog
\n(d) Cockroach.
\nAnswer:
\n(a) Flatworm : Absent. Cell surface does gaseous exchange.
\n(b) Birds : Lungs and distensible air sacs.
\n(c) Frog: Skin, buccopharyngeal lining and lungs.<\/p>\n1st PUC Biology Breathing and Exchange of Gases Five Marks Questions and Answers<\/h3>\n
\nWhat is breathing? Explain the mechanism.
\nAnswer:
\nIt is a process of intake of oxygen, and leaving out carbon dioxide from the lungs. The mechanism of breathing involves.<\/p>\n
\nThe alveoli are closely surrounded by a thin wallet epithelium , having capillary network. The oxygen is under high pressure in alveoli, because of its higher concentration. Similarly carbon dioxide concentration, and pressure will be more in the capillaries containing impure blood. So, the exchange occurs by diffusion through the capillary walls. The oxygen is drawn into the blood, and carbon dioxide is pushed into the alveoli.<\/p>\n<\/p>\n
\nExplain the transport of carbon dioxide by the blood.
\nAnswer:
\nCO2<\/sub> is produced within the body cell as a metabolic waste product of oxidative metabolism.
\nCO2<\/sub> is transported from cells to the alveoli through the following forms.<\/p>\n\n
\nDescribe the structure of human respiratory system.
\nAnswer:
\nNose: The nose communicates with the outside, through a pair of openings called as nostrils. The nostrils lead to a cavity called nasal cavity. The right and left nasal cavities are separated by a nasal septum. The anterior part of the nasal cavity which is just behind the nostrils is called vestibule.<\/p>\n<\/p>\n<\/p>\n
\nExplain the mechanism of breathing with neat labelled sketches.
\nAnswer:
\nMechanism of breathing:
\nBreathing involves three distinct processes.
\n1. Inspiration or inhalation.
\n2. Expiration or exhalation.
\n3. Pause: It is a short period after expiration.<\/p>\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-17-Breathing-and-Exchange-of-Gases.4.png\")
<\/p>\n1st PUC Biology Breathing and Exchange of Gases Text Book Questions and Answers<\/h3>\n
\nRespiration is a process, which involves cellular oxidation of Glucose to release energy.
\nor
\nThe process of intake of O2<\/sub> and removal of CO2<\/sub> between the atmosphere and the organisms, for the oxidation of food substances is known as Respiration.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 ,<\/p>\n
\n1. Breathing or pulmonary ventilation : The exchange of Oxygen, and Carbon dioxide . between atmosphere and lungs. It includes two phases:<\/p>\n\n
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\nAlveoli are the structural, and functional units of lungs. Alveoli are the sites of gaseous exchange. It is estimated that there are about 300 millions of alveoli in.each lung. Each alveolus is approximately 0.1 mm in diameter with extremely thin walls. The walls are highly vascularized by the blood capillaries. The walls of the alveoli are lined by Simple squamous epithelium.<\/p>\n<\/p>\n
\nBreathing involves three distinct processes.<\/p>\n\n
\nThe process of intake of air (O2<\/sub>) from the atmosphere into the lungs is known is inspiration. It is an active process. During inspiration the following changes take place in the thoracic cavity.<\/p>\n\n
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\nThe process of elimination of O2<\/sub> or CO2<\/sub> from the lungs is known as expiration. It is a passive process during this process the following changes occur in the thoracic cavity.<\/p>\n\n
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\nExchange of gases between blood, and body cells is known as internal respiration. The of the oxygenated blood in die capillaries is about 107 mm of Hg whereas the tissue cells have 107 of about 45 mm of Hg. Hence 02<\/sub> diffuses from blood capillaries into the tissue cells. Mean while CO2<\/sub> diffuses in the opposite direction. The PCQ2<\/sub> of the tissue cells is around 46mm of Hg. While the oxygenated blood has PC02<\/sub> of about 36 mm of Hg. Therefore CO2<\/sub> diffuses from tissue cells into the blood capillaries.
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\nVC = TV + IRV + ERV
\n= 5O0 + 2500 + 1100
\n= 4100 ml approx.<\/p>\n
\nTLC = VC+ RV = 4100+ 1600 = 5200 approx.<\/p>\n<\/p>\n
\nHb + 402<\/sub> \u2192 Hb (O2<\/sub>).<\/p>\n
\nHb + (O2<\/sub>)4<\/sub> \u2192 Hb 4O2<\/sub>).
\nTransport of CO2<\/sub> by blood:<\/p>\n
\nCO2<\/sub> is transported from cells to the alveoli through the following forms.
\n1. In the form of carbonic acid (7%).
\n2. In the form of carbamino haemoglobin (23%).
\n3. In the form of bicarbonates of Sodium and Potassium (70%).<\/p>\n<\/p>\n
\nAbout 7% of CO2<\/sub> is removed in the form of carbonic acid. It combines with the water present in the plasma of the blood to form carbonic acid (H2<\/sub>CO3<\/sub>)
\nCO2<\/sub> + H2<\/sub>O H2<\/sub>CO3
\n<\/sub>As in the form of carbamino haemoglobin:<\/p>\n
\nCO2<\/sub> + Hb \u2192 HbCO2<\/sub> (HbNHCOOH)
\nWhen deoxygenated blood reaches the lungs, the reactions described above go in a reversible and finally CO2<\/sub> enters the lungs.<\/p>\n<\/p>\n
\nAbout 70% of CO, a eliminated in the form of bicarbonates of sodium, and potassium. When oxygenated blood flows through the body tissues, CO2<\/sub> diffuses from the tissues into the RBC. A greater part of CO2<\/sub> diffused into the RBC, reacts with water to form carbonic acid [H2<\/sub>CO3<\/sub>]. In the RBC, this reaction is accelerated by an enzyme called Carbonic anbydrase. The formed carbonic acid splits into H+<\/sup>, and HCO3- ions.<\/p>\n<\/p>\n
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\nand PCO2<\/sub> is low. With this sudden change in the conditions, the reactions described above go in a reverse fashion. This can be schematically represented as follows.
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\nThe medulla and pons contain respiratory centres which regulate the rate of respiration. The rhythmicity centre of medulla maintains the basic rhythm of respiration. It has a group of neurons namely, dorsal group (inspiratory neurons), and ventral group (expiratory neurons) which control the movements of diaphragm and the intercostal muscles respectively. The centres in pons influence the rhythmicity centre for its activity.<\/p>\n
\nAsthma (Bronchial asthma) :
\nIt is a common disorder of the lower parts of the respiratory system involving smaller bronchi and bronchioles. It is caused due to the allergic reaction to foreign substances in the respiratory system. The substances which are responsible for asthma are called allergic substances or allergic agents.
\nIn allergic asthma, the individuals become allergic to certain allergens like platinum salts, sulphur dioxide and aeroallergic agents like pollengrains, dust and animal dandruff. Asthma is also caused due to bacterial infection to bronchi, and bronchioles.<\/p>\n<\/p>\n\n
\nIf the asthma is caused due to bacteria, it can be treated by antibiotics. The allergic asthma can also be treated by giving broncho-dialator drugs like Threaphilline.<\/p>\n
\nThe loss of elasticity of walls of alveoli resulting in their expansion is called emphysema. It is induced by cigarette smoke, and other irritants.<\/p>\n
\nA number of lung diseases arise due to occupational or environmental hazards.<\/p>\n\n
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\nIt is the inflammation of bronchi, induced by allergens like cigarette smoke or polluted air. The symptoms include productive cough, expelling a thick greenish yellow sputum. The bronchial lining is induced for the overproduction of mucous which supports bacterial growth leading to chronic bronchitis.<\/p>\n1st PUC Biology Question Bank with Answers<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"