{"id":27046,"date":"2022-09-20T14:44:01","date_gmt":"2022-09-20T09:14:01","guid":{"rendered":"https:\/\/apboardsolutions.com\/?p=27046"},"modified":"2022-09-20T14:44:01","modified_gmt":"2022-09-20T09:14:01","slug":"ap-inter-2nd-year-zoology-study-material-chapter-1b","status":"publish","type":"post","link":"https:\/\/apboardsolutions.com\/ap-inter-2nd-year-zoology-study-material-chapter-1b\/","title":{"rendered":"AP Inter 2nd Year Zoology Study Material Chapter 1(b) Breathing and Exchange of Gases"},"content":{"rendered":"

Andhra Pradesh BIEAP AP Inter 2nd Year Zoology Study Material<\/a> Lesson 1(b) Breathing and Exchange of Gases Textbook Questions and Answers.<\/p>\n

AP Inter 2nd Year Zoology Study Material Lesson 1(b) Breathing and Exchange of Gases<\/h2>\n

Very Short Answer Questions<\/span><\/p>\n

Question 1.
\nDefine vital capacity. What is its significance?
\nAnswer:
\nVital capacity :
\nThe maximum volume of air a person can breathe in after forced expiration. This includes ERV (Expiratory Reserve Volume), TV (Tidal Volume), and IRV (Inspiratory Reserve Volume) (or) the maximum volume of air a person can breathe out after forced inspiration (VC = TV + IRV + ERV).<\/p>\n

Question 2.
\nWhat is the volume of air remaining in lungs after a normal expiration?
\nAnswer:
\nThe volume of air that remains in the lungs after normal expiration is called ‘Functional Residual Capacity (FRC)’.
\nFRC = ERV + RV
\nERV = 1000 to 1100 ml
\nRV = 1100 to 1200 ml. So
\nFRC = 2100 to 2300 ml.<\/p>\n

Question 3.
\nDiffusion of oxygen occurs in the alveolar region only and not in other parts of respiratory system. How do you justify the statement?
\nAnswer:
\nAlveoli are primary sites of exchange of gas by simple diffusion. Aleveolar region is having enough pressure gradient to facilitate diffusion of gases. Other regions of the respiratory system doesn\u2019t have the required pressure gradient.<\/p>\n

High pO2<\/sub>, low pCO2<\/sub>. lesser H+<\/sup> concentration, low temperature conditions in alveoli favourable for diffusion of O2<\/sub> ahd formation of oxyhaemoglobin. Solubility of gases as well as thickness of the membrane are also some of the important factors that can effect the ratio of diffusion.<\/p>\n

Question 4.
\nWhat is the effect of pCO2<\/sub> on oxygen transport?
\nAnswer:
\npCO2<\/sub> plays an important role in the transport of oxygen. At the alveolus, the low pCO2<\/sub> and high pO2<\/sub> favours the formation of oxyhaemoglobin. At the tissues, the high pCO2<\/sub> and low pO2<\/sub> favours the dissociation of oxygen from oxyhaemoglobin. Hence, the affinity of haemoglobin for oxygen is enhanced by the decrease of pCO2<\/sub> in blood. Therefore, oxygen is transported in blood as oxyhaemoglobin and oxygen dissociates from it at the tissues.<\/p>\n

\"AP<\/p>\n

Question 5.
\nWhat happens to the respiratory process in man going up a hill?
\nAnswer:
\nWhen a man is going up a hill or doing some strenous exercise then there is more consumption of oxygen and resulting in more demand of oxygen. As a result there is an increased breathing rate to fill the gap.<\/p>\n

Question 6.
\nWhat is tidal volume? Find out the tidal volume in a healthy human, in an hour?
\nAnswer:
\nTidal Volume (TV) :
\nVolume of air inspired (or) expired during normal inspiration (or) expiration. It is approximately 500 ml i.e., a healthy man can inhale (or) exhale approximately 6000 to 8000 ml of air per minute (or) 3,60,000 to 4,80,000 ml per hour.<\/p>\n

Question 7.
\nDefine oxyhaemoglobin dissociation curve. Can you suggest any reason for its sigmoidal pattern?
\nAnswer:
\nThe oxyhaemoglobin dissociation curve is a graph showing the percentage of oxyhaemoglobin at various partial pressures of oxygen.<\/p>\n

Reasons for Sigmoidal pattern :
\nIn alveoli, where there is a high pO2<\/sub>, low pCO2<\/sub> lesser H+<\/sup> and low temperature, the factors are all favourable for formation of oxyhaemoglobin. In the tissues where low pO2<\/sub>, high pCO2<\/sub>, high H+<\/sup> concentration and higher temperature exist, the conditions are favourable for dissociation of oxygen from oxyhaemoglobin under these conditions. Oxygen dissociation curve shift away from the Y-axis and form sigmoid curve.<\/p>\n

Question 8.
\nWhat are conchae?
\nAnswer:
\nThese are curved bones that make up the upper portion of the nasal cavity. There are different conchae in the nose, such as interior concha, medial concha and superior concha. The nasal concha bones are also referred’to as turbinate pones.<\/p>\n

Question 9.
\nWhat is meant by chloride shift?
\nAnswer:
\nChloride shift:
\nIt refers to the exchange of chloride and bicarbonate ions between erythrocytes and plasma. It is also called Hamburger\u2019s phenomenon.<\/p>\n

Question 10.
\nMention any two occupational respiratory disorders and their causes in human beings?
\nAnswer:
\nOccupational respiratory disorders ate caused by exposure of the body to the harmful substances.
\nE.g.:
\n1) Asbestosis:
\nIt occurs due to chronic exposure to asbestos dust in the people Working in asbestos factory.<\/p>\n

2) Silicosis :
\nIt occurs because of long term exposure to ‘silica dust’ in the people working in mining industries, quarries etc.,<\/p>\n

Question 11.
\nName the muscles that help in normal breathing movements?
\nAnswer:
\nMuscles of diaphragm and external inter-costal muscles help in the process of normal breathing movements.<\/p>\n

Question 12.
\nDraw a diagram of oxyhaemoglobin dissociation curve?
\nAnswer:
\n\"AP<\/p>\n

Short Answer Questions<\/span><\/p>\n

Question 1.
\nExplain the process of inspiration and expiration under normal conditions.
\nAnswer:
\nInspiration : Intake of atmospheric air into the lungs is called inspiration. It is an active process, as it takes place by the contraction of the muscles of the diaphragm and the external inter-costal muscles which extend in between the ribs. The contraction of diaphragm increases the volume of thoracic chamber in the anterio posterior axis. The contraction of external inter costal muscles lifts up the ribs and sternum causing an increase in the dorso- ventral axis.<\/p>\n

The overall increase in the thoracic volume causes a similar increase in the pulmonary volume. An increase in the pulmonary volume decreases the intra-pulmonary pressure to less than that of the atmosphere, which forces the air from the outside to move into the lungs, that is inspiration.<\/p>\n

Expiration :
\nRelease of alveolar air to the exterior is called expiration. It is a passive process. Relaxation of the diaphragm and external inter-costal muscles returns the diaphragm and sternum to their normal positions, and reduces the thoracic volume and thereby the pulmonary volume. This leads to an increase in the intra-pulmonary pressure to slightly above that of the atmospheric pressure, causing the expulsion of air from the lungs, that is called expiration.<\/p>\n

Question 2.
\nWhat are the major transport mechanisms for CO2<\/sub>? Explain.
\nAnswer:
\nCarbondioxide is transported in three ways.
\n1. In dissolved state :
\n7% of CO2<\/sub> is transported in dissolved state through plasma.
\nCO2<\/sub> + H2<\/sub>O \u2192 H2<\/sub>CO3<\/sub>.<\/p>\n

2. As Carbamino compounds:
\nAbout 20-25% of CO2<\/sub> combine directly with free amino group of haemoglobin and forms Carbamino haemoglobin in a reversible manner.
\nHb – NH2<\/sub> + CO2<\/sub> \u2192 Hb – NHCOO–<\/sup> + H+<\/sup>.
\npCO2<\/sub> and pO2<\/sub> could affect the binding of CO2<\/sub> to haemoglobin.
\n\u2014 when pCO2<\/sub> is high and pO2<\/sub> is low as in the tissues, binding of more CO2<\/sub> occurs.
\n\u2014 when pCO2<\/sub> is low and p02 is high as in the alveoli, dissociation of CO2<\/sub> carbamino
\n– haemoglobin takes place, (i.e., CO2<\/sub> which is bound to haemoglobin from the tissues is delivered at the alveoli)<\/p>\n

3. As Bicarbonates :
\nAbout 70% of CO2<\/sub> is transported as bicarbonate. RBCs contain a very high concentration of the enzyme, carbonic anhydrase and a minute quantity of the same is present in plasma too. This enzyme facilitates the following reaction in both the directions.
\n\"AP<\/p>\n

At the tissues where partial pressure of CO2<\/sub> is high due to catabolism, CO2<\/sub> diffuses into the blood and forms carbonic acid which dissociates into HCO–<\/sup>3<\/sub> + H+<\/sup><\/p>\n

At the alveolar site where pCO2<\/sup> is low, the reaction proceeds in the opposite direction leading to the formation of CO2<\/sup> and water. Thus CO2<\/sup> is mostly trapped as bicarbonate at the tissues and transported to the alveoli where it is dissociated out as CO2<\/sup>.<\/p>\n

Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2<\/sub> to the alveolar air.<\/p>\n

\"AP<\/p>\n

Question 3.
\nHow is respiratory movements regulated in man?
\nAnswer:
\nIn human beings the respiratory movements are regulated by neural system.
\n1. A special centre present in the medulla region of brain, called ‘respiratory rhythm centre’ is primarily responsible for this regulation.<\/p>\n

2. Another centre present in the pons of the brain stem called ‘pneumotaxic centre’ can moderate the functions of the respiratory rhythm centre. Neural signal from and this centre can reduce the duration of inspiration and thereby alter the respiration rate.<\/p>\n

3. A chemo-sensitive area is situated adjacent to the respiratory rhythm centre which is highly sensitive to CO2<\/sub> and H+<\/sup>. Increase in these substances can activate this centre, which inturn can send signals to the respiratory rhythm centre to make necessary adjustments in the respiratory process by which these substances can be eliminated.<\/p>\n

4. Receptors associated with aortic arch and carotid artery also recognize changes in CO2<\/sub> and H+<\/sup> concentration and send necessary signals to the respiratory rhythm centre for necessary actions.<\/p>\n

The role of oxygen in the regulation of the respiratory rhythm is quite insignificant.<\/p>\n

Question 4.
\nDistinguish between a) IRV and ERV b) Inspiratory capacity and Expiratory capacity c) Vital capacity and Total lung capacity.
\nAnswer:
\na) IRV and ERV:
\nIRV (Inspiratory Reserve Volume) :
\nThe maximum volume of air that can be inhaled during forced breathing, in addition to the tidal volume. This is about 2500 ml to 3000 ml.<\/p>\n

ERV (Expiratory Reserve Volume) :
\nThe maximum volume of air that can be exhaled during forced breathing in addition to the ‘tidal volume’. This is about 1000 ml to 1100 ml.<\/p>\n

b) Inspiratory capacity and Expiratory capacity :
\nInspiratory capacity (IC) :
\nThe total volume of air, a person can inhale after normal expiration’. This includes tidal volume and inspiratory reserve volume.
\nIV = TV + IRV
\nIt is about 3000 ml to 3500 ml.<\/p>\n

Expiratory capacity (EC) :
\nThe total volume of air, a person can expire after a ‘normal inspiration’. This includes tidal volume and expiratory reserve volume.
\nEC = TV + ERV<\/p>\n

c) Vital capacity and Total lung capacity:
\nVital capacity (VC) :
\nThe maximum volume of air a person can breathe in after ‘forced expiration’. This includes ERV TV and IRV (or) the maximum volume of air, a person can > breathe out after forced inspiration.
\nVC = TV + IRV + ERV<\/p>\n

Total lung capacity (TLC) :
\nThe total volume of air accommodated in the lungs at the end of forced inspiration.
\nThis includes RV ERV, TV and IRV
\nTLC = ERV + IRV + TV + RV (or)<\/p>\n

Question 5.
\nDescribe disorders of respiratory system.
\nAnswer:
\nDisorders of respiratory system.<\/p>\n

1) Asthma:
\nAsthma is a difficulty in breathing caused due to inflammation of bronchi and bronchioles. Symptoms include coughing, difficulty in breathing and wheezing.<\/p>\n

2) Emphysema:
\nIt is a chronic disorder in which alveolar walls are damaged and their walls coalesce due to which respiratory surface area of exchange of gases is decreased. One of the major causes of this<\/p>\n

3) Bronchitis :
\nBronchitis is the inflammation of the bronchi, resulting in the swelling of mucus lining of bronchi, increased mucus production and decrease in the diameter of bronchi. Symptoms include chronic cough with thick sputum.<\/p>\n

4) Pneumonia :
\nThe infection of lungs caused by Streptococcus pneumoniae and also by certain Virus, Fungi, Protozoans and Mycoplasmas. Symptoms include inflammation of lungs, accumulation of mucus in alveoli and impaired exchange of gases, leading to death if untreated.<\/p>\n

Occupational dissorders :
\nThese are caused by exposure of the body to the harmful substances.
\nE.g.:
\ni) Asbestosis:
\nIt occurs due to chronic exposure to asbestos dust in the people working in asbestos industry.<\/p>\n

ii) Silicosis :
\nIt occurs because of long term exposure to silica dust.<\/p>\n

iii) Siderosis :
\nIt occurs due to deposition of iron particles in tissues.<\/p>\n

iv) Black lung disease :
\nIt develops from inhalation of coal dust.<\/p>\n

Long Answer Questions<\/span><\/p>\n

Question 1.
\nDescribe the respiratory system in man.
\nAnswer:
\nThe human respiratory system composed of external nostrils, nasal chambers, nasopharynx, larynx, trachea, bronchi, bronchioles and lungs. It is responsible for the process of respiration that is vital to the survival of living beings.<\/p>\n

1) External nostrils :
\nA pair of external nostrils opens out above the upper lip. They lead into nasal chambers through the nasal passages.<\/p>\n

2) Nasal chambers:
\nThey lie above the palate and are separated from each other by a nasal septum. Each nasal chamber can be differentiated into three parts gamely; i) Vestibular part – which has hair and sabaceous gland’s to prevent the entry of dust particles, ii) Respiratory part – involved in the conditioning the temperature, iii) Olfactory part – is fined by an Olfactory epithelium.<\/p>\n

3) Naso-pharynx :
\nNasal chambers lead into nasopharynx through a pair of internal nostrils. Nasopharynx is a portion of pharynx, the common chamber for the passage of food and air. Nasopharynx leads into oropharynx, and opens through glottis of larynx into the trachea.<\/p>\n

4) Larynx :
\nThis is also called voice box or Adam’s apple, connects the pharynx with the trachea. Larynx is the organ of voice as well as an air passage extending from the root of the tongue to the trachea. It is well developed in man. It consist of a) Vocal cord b) Glottis c) Epiglottis.
\na) Vocal cord : These are muscular folds that projects from lateral walls.
\nb) Glottis : Narrow passage between the true and false vocal cords of the larynx.
\nc) Epiglottis : It is a thin leaf like elastic cartilaginous flap attached to the thyroid cartilage to prevent the entry of food into the larynx through the glottis.<\/p>\n

5) Trachea :
\nTrachea is also called windpipe. It is a straight tube extending upto the mid-thoracic cavity. The wall of the trachea is supported by 16-20 ‘C’ shaped rings of hyaline cartilage. These rings are incomplete dorsally and keep the trachea always open preventing collapse. Internally the trachea is lined by pseudostratified ciliated epithelium.<\/p>\n

6) Bronchi and Bronchioles :
\nOn entering the mid thoracic cavity, trachea divides into right and left primary bronchi. Each primary bronchus enters the corresponding lung and divides into secondary bronchi that further divides into tertiary bronchi. Each tertiary bronchus divides and redivides to form primary, secondary, tertiary, terminal and respiratory bronchioles. Each respiratory bronchiole terminates in a cluster of alveolar ducts which ends in alveolar sacs.
\n\"AP<\/p>\n

7) Lungs :
\nThese are paired, situated in the thoracic chamber which is anatomically an air tight chamber. Lungs are covered by a doubled layered pleura with pleural fluid between them. It reduces friction on the lung surface. The outer pleural membrane is in close contact with the thoracic lining where as the inner pleural membrane is in contact with lung’s surface. The part starting with external nostrils upto the terminal bronchioles constitute the conducting part, whereas the alveoli and their ducts form the respiratory or exchange part of respiratory system. The conducting part transports the atmospheric air to the alveoli, clears it from foreign particles, humidifies and also bring the inhaled air to the body temperature. Exchange part is the site of actual diffusion of and between blood and atmospheric air.<\/p>\n

\"AP<\/p>\n

Question 2.
\nWrite an essay on the transport of oxygen and carbondioxide by blood.
\nAnswer:
\nBlood is the medium for the transport of oxygen and carbondioxide.<\/p>\n

Transport of oxygen :
\nOxygen is transported from the lungs to the tissues through the plasma and RBC of the blood. 100 ml of oxygenated blood can deliver 5 ml of O2<\/sub> to the tissues under norpial condtions.<\/p>\n

i) Transport of oxygen through plasma:
\nAbout 3% of O2<\/sub> is carried through the blood plasma in dissolved state.<\/p>\n

ii) Transport of oxygen by RBC :
\nabout 97% of oxygen is transported by the . haemoglobin of RBC in the blood. Haemoglobin is a red coloured iron containing pigment present in the RBCs. Each haemoglogin molecule can carry a maximum of four molecules of oxygen. Binding of oxygen with haemoglobin is primarily related to the partial pressure of O2<\/sub>. At lungs, where the partial pressure of O2<\/sub> is high, oxygen binds to haemoglobin in a reversible manner to form oxyhaemoglobin. This is called oxygenation of haemoglobin.
\nHb + 4O2<\/sub> -\u00bb Hb (O2<\/sub>)4<\/sub>.<\/p>\n

At the tissues, where the partial pressure of O2<\/sub> is low oxyhaemoglobin dissociates into haemoglobin and oxygen. The other factors such as partial-pressure of CO2<\/sub>, H+<\/sup> concentration (pH), and the temperature influence the binding of oxygen with haemoglobin. For example in alveoli high pO2<\/sub>, low pCO2<\/sub> high H+<\/sup> concentration lower temperature are favourable for formation of oxyhaemoglobin. In tissues low pO2<\/sub>, high pCO2<\/sub> high H+<\/sup> concentration and high temperature conditions are favourable for. dissociation, of oxygen from oxyhaemoglobin.<\/p>\n

Transport of Carbondioxide:
\nCarbondioxide is transported in three ways,
\n1. In dissolved state :
\n7% of CO2<\/sub> is transported in dissolved state through plasma.
\nCO2<\/sub> + H2<\/sub>O \u2192 H2<\/sub>CO2<\/sub>.<\/p>\n

2. As Carbamino compounds:
\nAbout 20-25% of CO2<\/sub> combine directly with free amino group of haemoglobin and forms Carbmino haemoglobin in a reversible, manner.
\nHb – NH2<\/sub> + CO2<\/sub> \u2192 Hb – NHCOO–<\/sup> +H+<\/sup>.<\/p>\n

pCO2<\/sub> and pO2<\/sub> could affect the binding of CO2<\/sub> to haemoglobin.<\/p>\n

\u2014 when pC02 is high and pO2<\/sub> is low as in the tissues, binding of more CO2<\/sub> occurs.
\n\u2014 when pCO2<\/sub> is low and pO2<\/sub> is high as in the alveoli, dissociation of CO2<\/sub> carbamino – haemoglobin takes place, (i.e., CO2<\/sub> which is bound to haemoglobin from the tissues is delivered at the alveoli)<\/p>\n

3. As Bicarbonates :
\nAbout 70% of CO2<\/sub> is transported as bicarbonate. RBCs contain a very high concentration of the enzyme carbonic anhydrase and a minute quantity of the same is present in plasma too. This enzyme facilitates the following reaction in both the directions.
\n\"AP<\/p>\n

At the tissues where partial pressure of CO2<\/sub> is high due to catabolism, CO2<\/sub> diffuses into the blood and forais carbonic acid which dissociates into HCO–<\/sup>3<\/sub> + H+<\/sup><\/p>\n

At the alveolar site where pCO2<\/sub> is low, the reaction proceeds in the opposite direction leading to the formation of CO2<\/sub> and water. Thus CO2<\/sub> is mostly trapped as bicarbonate at the tissues’and transported to the alveoli where it is dissociated out as CO2<\/sub>.<\/p>\n

Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2<\/sub> to the alveolar air.<\/p>\n","protected":false},"excerpt":{"rendered":"

Andhra Pradesh BIEAP AP Inter 2nd Year Zoology Study Material Lesson 1(b) Breathing and Exchange of Gases Textbook Questions and Answers. AP Inter 2nd Year Zoology Study Material Lesson 1(b) Breathing and Exchange of Gases Very Short Answer Questions Question 1. Define vital capacity. What is its significance? Answer: Vital capacity : The maximum volume … Read more<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[14],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/27046"}],"collection":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/comments?post=27046"}],"version-history":[{"count":1,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/27046\/revisions"}],"predecessor-version":[{"id":27051,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/27046\/revisions\/27051"}],"wp:attachment":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/media?parent=27046"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/categories?post=27046"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/tags?post=27046"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}