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All questions of Breathing and Exchange of Gases for NEET Exam
Intercostal muscles occur in [1988]- a)abdomen
- b)thigh
- c)ribs
- d)diaphragm
Correct answer is option 'C'. Can you explain this answer?
Intercostal muscles occur in [1988]
a)
abdomen
b)
thigh
c)
ribs
d)
diaphragm
|
Abhishek Choudhary answered |
Intercostal muscles (External intercostal & Internal intercostal) are attached with the ribs which help in the movement of rib cage during breathing.
Blood analysis of a patient reveals an unusually high quantity of carboxyhaemoglobin content. Which of the following conclusions is most likely to be correct?The patient has been inhaling polluted air containing unusually high content of [2004]- a)carbon disulphide
- b)chloroform
- c)carbon dioxide
- d)carbon monoxide
Correct answer is option 'D'. Can you explain this answer?
Blood analysis of a patient reveals an unusually high quantity of carboxyhaemoglobin content. Which of the following conclusions is most likely to be correct?The patient has been inhaling polluted air containing unusually high content of [2004]
a)
carbon disulphide
b)
chloroform
c)
carbon dioxide
d)
carbon monoxide
|
Ayush Chavan answered |
Carboxyhaemoglobin is the stable product formed by the association of CO and Hb in the blood. The association of carbon dioxide and haemoglobin forms carbamino haemoglobin.
The carbon dioxide is transported via blood to lungs as [1995]- a)dissolved in blood plasma
- b)in the form of carbonic acid only
- c)in combination with haemoglobin only
- d)carbaminohaemoglobin and as carbonic acid
Correct answer is option 'D'. Can you explain this answer?
The carbon dioxide is transported via blood to lungs as [1995]
a)
dissolved in blood plasma
b)
in the form of carbonic acid only
c)
in combination with haemoglobin only
d)
carbaminohaemoglobin and as carbonic acid
|
Deepak Joshi answered |
Carbon dioxide is transported via blood to lungs mostly as carbaminohaemoglobin and carbonic acid. It is released in lungs in exchange with oxygen.
Which one of the following mammalian cells is not capable of metabolising glucose to carbon-dioxide aerobically? [2007]- a)unstraited muscle cells
- b)liver cells
- c)red blood cells
- d)white blood
Correct answer is option 'C'. Can you explain this answer?
Which one of the following mammalian cells is not capable of metabolising glucose to carbon-dioxide aerobically? [2007]
a)
unstraited muscle cells
b)
liver cells
c)
red blood cells
d)
white blood
|
Raghav Khanna answered |
Since RBCS do not have mitochondria so they can respire only anaerobically.
Which one of the following is a possibility for most of us in regard to breathing, by making a conscious effort? [2011M]
- a)One can breathe out air totally without oxygen.
- b)One can consiously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all
- c)One can breathe out air through eustachian tubes by closing both the nose and the mouth.
- d)The lungs can be made fully empty by forcefully breathing out all air from them
Correct answer is option 'B'. Can you explain this answer?
Which one of the following is a possibility for most of us in regard to breathing, by making a conscious effort? [2011M]
a)
One can breathe out air totally without oxygen.
b)
One can consiously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all
c)
One can breathe out air through eustachian tubes by closing both the nose and the mouth.
d)
The lungs can be made fully empty by forcefully breathing out all air from them
|
Naveen Menon answered |
The process of breathing involves the pathway of the human respiratory system and includes the nasal cavities, oral cavities, pharynx, trachea, primary bronchi, secondary bronchi and lungs with bronchioles and alveoli present. Breathing is a 2-fold process which includes breathing in and breathing out. During this process, the diaphragm which is the dome-shaped sheet of muscle located below the lungs contracts and expands along with the intercostal muscles to force air in and out of the lungs. Since intercostal muscles are also involved in the process of respiration, deeper respiration results in the movement of ribs too. Hence most of us can consciously breathe in and breathe out by moving the diaphragm alone.
Which one of the following organs in the human body is most affected due to shortage of oxygen? [1999]- a)intestine
- b)skin
- c)kidney
- d)brain
Correct answer is option 'D'. Can you explain this answer?
Which one of the following organs in the human body is most affected due to shortage of oxygen? [1999]
a)
intestine
b)
skin
c)
kidney
d)
brain
|
Rajeev Sharma answered |
Brain is the most vital organ. It stops functioning in the absence of O2.
The quantity 1200 ml in the respiratory volumes of a normal human adult refers to [1996]
- a)residual volume
- b)maximum air that can be breathed in and breathed out
- c)expiratory reserve volume
- d)total lung capacity
Correct answer is option 'A'. Can you explain this answer?
The quantity 1200 ml in the respiratory volumes of a normal human adult refers to [1996]
a)
residual volume
b)
maximum air that can be breathed in and breathed out
c)
expiratory reserve volume
d)
total lung capacity
|
Maitri Mukherjee answered |
The total volume of air that can be expelled from the lungs after maximum inspiration and then expiring to the maximum is known as the vital capacity. The volume of air that remains inside lungs at the end of maximum forceful expiration is the residual volume. Expiratory reserve volume is the maximum extra volume of air that can be expired by forceful expiration after a normal tidal expiration. Total lung capacity is the maximum volume of air that can be contained in the lungs after maximum inspiration.
Skin is an accessory organ of respiration in- a)humans
- b)frog [1990]
- c)rabbit
- d)lizard
Correct answer is option 'B'. Can you explain this answer?
Skin is an accessory organ of respiration in
a)
humans
b)
frog [1990]
c)
rabbit
d)
lizard
|
Arya Khanna answered |
In addition to lungs, skin is also an organ of respiration in frog. It is practically the only mode of respiration when the frog is under water or hibernating. Skin is richly supplied with blood and is permeable to gases. That is way frogs always stay near water to keep their skin moist. It is further kept moist by secretion of mucus from its glands, and does not become dry out of water.
The alveolar epithelium in the lungs is[1990]- a)nonciliated columnar
- b)nonciliated squamous
- c)ciliated columnar
- d)ciliated squamous
Correct answer is option 'B'. Can you explain this answer?
The alveolar epithelium in the lungs is[1990]
a)
nonciliated columnar
b)
nonciliated squamous
c)
ciliated columnar
d)
ciliated squamous
|
Dipanjan Chawla answered |
The very thin alveolar wall (about 0.0001 mm) is composed of moist, nonciliated, squamous epithelial cells.
In alveoli of the lungs, the air at the site of gas exchange, is separated from the blood by- a)alveolar epithelium only [1997]
- b)alveolar epithelium and capillary endothelium
- c)alveolar epithelium, capillary endothelium and tunica adventitia
- d)alveolar epithelium, capillary endothelium, a thin layer of tunica media and tunica adventitia
Correct answer is option 'B'. Can you explain this answer?
In alveoli of the lungs, the air at the site of gas exchange, is separated from the blood by
a)
alveolar epithelium only [1997]
b)
alveolar epithelium and capillary endothelium
c)
alveolar epithelium, capillary endothelium and tunica adventitia
d)
alveolar epithelium, capillary endothelium, a thin layer of tunica media and tunica adventitia
|
|
Raghav Khanna answered |
Alveoli are the site of the respiratory exchange of gases. Oxygen from the alveolar air diffuses through the alveolar epithelium and the capillary endothelium into the capillary blood and carbon dioxide diffuses in the opposite direction.
Select the correct events that occur during inspiration. [2020]
(i) Contraction of diaphragm
(ii) Contraction of external inter costal muscles
(iii) Pulmonary volume decreases
(iv) Intra pulmonary pressure increases- a)(i), (ii) and (iv)
- b)Only (iv)
- c)(i) and (ii)
- d)(iii) and (iv)
Correct answer is option 'C'. Can you explain this answer?
Select the correct events that occur during inspiration. [2020]
(i) Contraction of diaphragm
(ii) Contraction of external inter costal muscles
(iii) Pulmonary volume decreases
(iv) Intra pulmonary pressure increases
(i) Contraction of diaphragm
(ii) Contraction of external inter costal muscles
(iii) Pulmonary volume decreases
(iv) Intra pulmonary pressure increases
a)
(i), (ii) and (iv)
b)
Only (iv)
c)
(i) and (ii)
d)
(iii) and (iv)
|
Jyoti Sengupta answered |
Inspiration is initiated by contraction of diaphragm which increases volume of thoracic chamber in antero-posterior axis and contraction of external inter –costal muscles which lifts up the ribs and sternum causing increases in volume of thoracic chamber in dorsoventral axis.
Which two of the following changes (a–d) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)? [2010](i) Increase in red blood cell size
(ii) Increase in red blood cell production
(iii) Increased breathing rate
(iv) Increase in thrombocyte count
Changes occurring are:- a)(ii) and (iii)
- b)(iii) and (iv)
- c)(i) and (iv)
- d)(i) and (ii)
Correct answer is option 'A'. Can you explain this answer?
Which two of the following changes (a–d) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)? [2010]
(i) Increase in red blood cell size
(ii) Increase in red blood cell production
(iii) Increased breathing rate
(iv) Increase in thrombocyte count
Changes occurring are:
(ii) Increase in red blood cell production
(iii) Increased breathing rate
(iv) Increase in thrombocyte count
Changes occurring are:
a)
(ii) and (iii)
b)
(iii) and (iv)
c)
(i) and (iv)
d)
(i) and (ii)
|
Rohan Unni answered |
At high altitude, the body undergoes numerous changes in order to increase oxygen delivery to cells and improve the efficiency of oxygen usage. The early changes include increased breathing rate and increased red blood cell production
Carbon dioxide is transported from tissues to respiratory surface by only [1993]- a)plasma and erythrocytes
- b)plasma
- c)erythrocytes
- d)erythrocytes and leucocytes
Correct answer is option 'A'. Can you explain this answer?
Carbon dioxide is transported from tissues to respiratory surface by only [1993]
a)
plasma and erythrocytes
b)
plasma
c)
erythrocytes
d)
erythrocytes and leucocytes
|
|
Rajeev Sharma answered |
CO2 from the respiratory tissues to the lungs is transported by the blood in 3 ways :
(i) In dissolved state or as a physical solution : Very small amount physically dissolved in plasma (7% i.e. @ 0.3 ml of CO2 by each 100 ml of blood)
(ii) Bicarbonate ions : @ 70% (i.e. @ 2.5 ml per 100 ml of blood) CO2 diffuses in plasma & then into RBCs where it (in the presence of carbonic anhydrase) combines with H2O to form carbonic acid which is almost spontaneously dissociated into hydrogen ion & bicarbonate ions.
(iii) Carbaminohaemoglobin : @ 23% (i.e. @ 1 ml of CO2 per 100 ml of blood) combines with haemoglobin forming an unstable compound
What is vital capacity of our lungs?- a)Inspiratory reserve volume plus tidal volume
- b)Total lung capacity minus expiratory reserve volume
- c)Inspiratory reserve volume plus expiratory reserve volume
- d)Total lung capacity minus residual volume
Correct answer is option 'D'. Can you explain this answer?
What is vital capacity of our lungs?
a)
Inspiratory reserve volume plus tidal volume
b)
Total lung capacity minus expiratory reserve volume
c)
Inspiratory reserve volume plus expiratory reserve volume
d)
Total lung capacity minus residual volume
|
|
Rajeev Sharma answered |
Vital capacity of lungs is largest possible expiration after largest possible inspiration that is greatest. Volume of air can be exchanged in single respiration or amount of air breath in and out with greatest possible efforts.
VC = TRV +TV + ERV
= 3000 + 500 + 1100
= 4600 ml.
VC = TRV +TV + ERV
= 3000 + 500 + 1100
= 4600 ml.
Which of the following are the correct statement for respiration in human [2012]- a)Cigarette smoking may lead of inflammation of bronchi
- b)Neural signals from pneumotaxic centre in pons region of brain can increase the duration of inspiration
- c)Workers in grinding and stone - breaking industries may suffer from lung fibrosis
- d)About 90% of carbon dioxide (CO2) is carried by haemoglobin as carbamino haemoglobin.
Correct answer is option 'C'. Can you explain this answer?
Which of the following are the correct statement for respiration in human [2012]
a)
Cigarette smoking may lead of inflammation of bronchi
b)
Neural signals from pneumotaxic centre in pons region of brain can increase the duration of inspiration
c)
Workers in grinding and stone - breaking industries may suffer from lung fibrosis
d)
About 90% of carbon dioxide (CO2) is carried by haemoglobin as carbamino haemoglobin.
|
Shounak Nair answered |
(a) and (c) . Neural signals from pneumotaxic center in pons region of brain can limit the duration of inspiration. About 25% of carbodioxide (CO2) is carried by haemoglobin as carboxyhaemglobin.
Air is breathed through [1994]- a)Trachea — lungs — larynx — pharynx — alveoli
- b)Nose — larynx — pharynx — bronchus — alveoli — bronchioles
- c)Nostrils — pharynx — larynx — trachea — bronchi — bronchioles — alveoli
- d)Nose — mouth — lungs
Correct answer is option 'C'. Can you explain this answer?
Air is breathed through [1994]
a)
Trachea — lungs — larynx — pharynx — alveoli
b)
Nose — larynx — pharynx — bronchus — alveoli — bronchioles
c)
Nostrils — pharynx — larynx — trachea — bronchi — bronchioles — alveoli
d)
Nose — mouth — lungs
|
|
Ayush Chavan answered |
The pathway of inhaled air is - Nostrils - pharynx (common passage for food & air) - larynx (voice box) - trachea (the wind pipe) - bronchi (2 for each side lungs) - bronchioles (give arise to alveolar ducts) - alveoli (the exchange site for gases in the form of small sacs or pouches).
When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe? [NEET 2015 / AIPMT 2015 ]- a)Rising CO2 concentration
- b)Falling CO2 concentration
- c)Rising CO2 and falling O2 concentration
- d)Falling O2 concentration
Correct answer is option 'A'. Can you explain this answer?
When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe? [NEET 2015 / AIPMT 2015 ]
a)
Rising CO2 concentration
b)
Falling CO2 concentration
c)
Rising CO2 and falling O2 concentration
d)
Falling O2 concentration
|
Mohit Rajpoot answered |
Excess CO2 mainly stimulates the respiratory centre of the brain and increases the inspiratory and expiratory signals to the respiratory muscles. O2 does not have a significant direct effect on the respiratory centre of the brain in controlling respiration.
Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL respectively. What will be his expiratory capacity if the residual volume is 1200 mL? [2019]- a)2700 mL
- b)1500 mL
- c)1700 mL
- d)2200 mL
Correct answer is option 'B'. Can you explain this answer?
Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL respectively. What will be his expiratory capacity if the residual volume is 1200 mL? [2019]
a)
2700 mL
b)
1500 mL
c)
1700 mL
d)
2200 mL
|
Mira Joshi answered |
Expiratory capacity is the total volume of air a person can expire after normal inspiration. It includes tidal volume and expiratory reserve volume.
EC = TV + ERV = 500 + 1000 = 1500 mL
EC = TV + ERV = 500 + 1000 = 1500 mL
Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively? [2018]
- a)Inflammation of bronchioles; Decreased respiratory surface
- b)Increased number of bronchioles; Increased respiratory surface
- c)Increased respiratory surface; Inflammation of bronchioles
- d)None of these
Correct answer is option 'A'. Can you explain this answer?
Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively? [2018]
a)
Inflammation of bronchioles; Decreased respiratory surface
b)
Increased number of bronchioles; Increased respiratory surface
c)
Increased respiratory surface; Inflammation of bronchioles
d)
None of these
|
Preeti Iyer answered |
Asthma is a difficulty in breathing, causing wheezing due to inflammation of bronchi and bronchioles.
Emphysema is a chronic disorder in which abnormal distension of the bronchioles or alveolar sacs of the lungs occurs due to which respiratory surface is decreased for the exchange of oxygen and carbon dioxide.
Select the favorable conditions required for the formation of oxyhemoglobin at the alveoli. [2021]- a)High pO2, high pCO2, less H+, higher temperature
- b)Low pO2, low pCO2, more H+, higher temperature
- c)High pO2, low pCO2, less H+, lower temperature
- d)Low pO2 high pCO2 more H+, higher temperature
Correct answer is option 'C'. Can you explain this answer?
Select the favorable conditions required for the formation of oxyhemoglobin at the alveoli. [2021]
a)
High pO2, high pCO2, less H+, higher temperature
b)
Low pO2, low pCO2, more H+, higher temperature
c)
High pO2, low pCO2, less H+, lower temperature
d)
Low pO2 high pCO2 more H+, higher temperature
|
Avantika Gupta answered |
Formation of Oxyhemoglobin at Alveoli
Oxyhemoglobin is formed when oxygen molecules bind with hemoglobin in the red blood cells. The favorable conditions required for the formation of oxyhemoglobin at the alveoli are:
High pO2: The partial pressure of oxygen in the alveoli should be high to facilitate the binding of oxygen with hemoglobin.
Low pCO2: The partial pressure of carbon dioxide in the alveoli should be low to prevent the formation of carbaminohemoglobin, which is formed when carbon dioxide binds with hemoglobin.
Less H+: A low concentration of hydrogen ions (H+) is required to maintain the pH of the blood at a slightly alkaline level, which is optimal for the binding of oxygen with hemoglobin.
Lower temperature: A lower temperature in the alveoli is favorable for the binding of oxygen with hemoglobin.
Therefore, the correct option is C, which includes all the favorable conditions required for the formation of oxyhemoglobin at the alveoli.
Oxyhemoglobin is formed when oxygen molecules bind with hemoglobin in the red blood cells. The favorable conditions required for the formation of oxyhemoglobin at the alveoli are:
High pO2: The partial pressure of oxygen in the alveoli should be high to facilitate the binding of oxygen with hemoglobin.
Low pCO2: The partial pressure of carbon dioxide in the alveoli should be low to prevent the formation of carbaminohemoglobin, which is formed when carbon dioxide binds with hemoglobin.
Less H+: A low concentration of hydrogen ions (H+) is required to maintain the pH of the blood at a slightly alkaline level, which is optimal for the binding of oxygen with hemoglobin.
Lower temperature: A lower temperature in the alveoli is favorable for the binding of oxygen with hemoglobin.
Therefore, the correct option is C, which includes all the favorable conditions required for the formation of oxyhemoglobin at the alveoli.
Which of the following factors are favourable for the formation of oxyhaemoglobin in alveoli? [2024]- a)High pO2 and High pCO2
- b)High pO2 and Lesser H+ concentration
- c)Low pCO2 and Lesser H+ concentration
- d)Low pCO2 and High temperature
Correct answer is option 'B'. Can you explain this answer?
Which of the following factors are favourable for the formation of oxyhaemoglobin in alveoli? [2024]
a)
High pO2 and High pCO2
b)
High pO2 and Lesser H+ concentration
c)
Low pCO2 and Lesser H+ concentration
d)
Low pCO2 and High temperature
|
EduRev NEET answered |
The formation of oxyhemoglobin in the alveoli is primarily influenced by the partial pressure of oxygen ( pO2 ), partial pressure of carbon dioxide ( pCO2), hydrogen ion concentration ( H+ ), and temperature. Understanding these factors will help in selecting the right option that describes the conditions favorable for maximizing the binding of oxygen to hemoglobin in the lungs.
1. Oxygen Partial Pressure ( pO2 ): High pO 2 enhances the formation of oxyhemoglobin. In the alveoli, where gas exchange occurs, the pO2 is relatively high, making it a favorable condition for oxyhemoglobin formation as oxygen molecules bind readily to hemoglobin.
2. Carbon Dioxide Partial Pressure ( pCO2 ): Lower pCO2 is favorable in the alveoli for oxyhemoglobin formation. High pCO2 leads to a lower pH (due to formation of carbonic acid), which can cause the release of O2 from hemoglobin (Bohr effect), reducing hemoglobin's affinity for oxygen.
3. Hydrogen Ion Concentration ( H+): Lesser H+ concentration, or higher pH, increases the affinity of hemoglobin for oxygen. In alkaline conditions (higher pH), hemoglobin is more likely to bind oxygen, thus forming oxyhemoglobin.
4. Temperature: Temperature also affects oxygen binding. Lower temperatures generally enhance the uptake of oxygen by hemoglobin. However, since the lung environment maintains a stable temperature, significant fluctuations in temperature are less of a consideration in this context compared to pO2 , pCO2 , and H+ concentration. Given these points, Option B - High pO2 and Lesser H+ concentration - best describes the conditions that are favorable for the formation of oxyhemoglobin in the alveoli. High pO2 ensures that more oxygen molecules are available to bind with hemoglobin, and a lower H+ concentration (higher pH) reduces the release of oxygen from hemoglobin, thereby increasing oxygen uptake.
1. Oxygen Partial Pressure ( pO2 ): High pO 2 enhances the formation of oxyhemoglobin. In the alveoli, where gas exchange occurs, the pO2 is relatively high, making it a favorable condition for oxyhemoglobin formation as oxygen molecules bind readily to hemoglobin.
2. Carbon Dioxide Partial Pressure ( pCO2 ): Lower pCO2 is favorable in the alveoli for oxyhemoglobin formation. High pCO2 leads to a lower pH (due to formation of carbonic acid), which can cause the release of O2 from hemoglobin (Bohr effect), reducing hemoglobin's affinity for oxygen.
3. Hydrogen Ion Concentration ( H+): Lesser H+ concentration, or higher pH, increases the affinity of hemoglobin for oxygen. In alkaline conditions (higher pH), hemoglobin is more likely to bind oxygen, thus forming oxyhemoglobin.
4. Temperature: Temperature also affects oxygen binding. Lower temperatures generally enhance the uptake of oxygen by hemoglobin. However, since the lung environment maintains a stable temperature, significant fluctuations in temperature are less of a consideration in this context compared to pO2 , pCO2 , and H+ concentration. Given these points, Option B - High pO2 and Lesser H+ concentration - best describes the conditions that are favorable for the formation of oxyhemoglobin in the alveoli. High pO2 ensures that more oxygen molecules are available to bind with hemoglobin, and a lower H+ concentration (higher pH) reduces the release of oxygen from hemoglobin, thereby increasing oxygen uptake.
The figure shows a diagrammatic view of human respiratory system with labels A, B, C and D. Select the option which gives correct identification and main function and/or characteristics. [NEET 2013]
- a)B-pleural membrane-surrounds ribs on both sides to provides cushion against rubbing.
- b)C-Alveoli-thin walled vascular bag like structures for exchange of gases.
- c)D-Lower end of lungs-diaphragm pulls it down during inspiration
- d)A - trachea - long tubes up ported by complete cartilaginous rings for conducting inspired air.
Correct answer is option 'B'. Can you explain this answer?
The figure shows a diagrammatic view of human respiratory system with labels A, B, C and D. Select the option which gives correct identification and main function and/or characteristics. [NEET 2013]
a)
B-pleural membrane-surrounds ribs on both sides to provides cushion against rubbing.
b)
C-Alveoli-thin walled vascular bag like structures for exchange of gases.
c)
D-Lower end of lungs-diaphragm pulls it down during inspiration
d)
A - trachea - long tubes up ported by complete cartilaginous rings for conducting inspired air.
|
|
Abhishek Choudhary answered |
Alveoli are very thin, irregular walled bag like structures for gaseous exchange. Tracheae bronchi and bronchioles are supported by incomplete cartilaginous rings. Double layered pleural membrane surrounds the lungs with pleural fluid between them. It reduces friction on the lung surface.
Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because [NEET 2016 Phase 2]- a)There is a negative pressure in the lungs
- b)There is a negative intrapleural pressure pulling at the lung walls
- c)There is a positive intrapleural pressure
- d)Pressure in the lungs is higher than the atmospheric pressure.
Correct answer is option 'B'. Can you explain this answer?
Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because [NEET 2016 Phase 2]
a)
There is a negative pressure in the lungs
b)
There is a negative intrapleural pressure pulling at the lung walls
c)
There is a positive intrapleural pressure
d)
Pressure in the lungs is higher than the atmospheric pressure.
|
Ambition Institute answered |
Intrapleural pressure is the pressure of air within the pleural cavity. Intrapleural pressure is always negative, which acts like a suction to keep the lungs inflated and prevent them from collapsing. The negative intrapleural pressure is due to three main factors: surface tension of the alveolar fluid; elasticity of lungs; elasticity of thoracic wall. Normally, there is a difference between intrapleural and intrapulmonary pressure, which is called transpulmonary pressure. This transpulmonary pressure creates the suction to keep the lungs inflated. If there is no pressure difference, there is no suction and lungs will collapse.
Approximately seventy per cent of carbon dioxide absorbed by the blood will be transported to the lungs: [NEET 2014 / AIPMT 2014 ]- a)As bicarbonate ions
- b)In the form of dissolved gas molecules
- c)By binding to R.B.C.
- d)As carbamino - haemoglobin
Correct answer is option 'A'. Can you explain this answer?
Approximately seventy per cent of carbon dioxide absorbed by the blood will be transported to the lungs: [NEET 2014 / AIPMT 2014 ]
a)
As bicarbonate ions
b)
In the form of dissolved gas molecules
c)
By binding to R.B.C.
d)
As carbamino - haemoglobin
|
|
Mohit Rajpoot answered |
- About 70% of CO2 (about 2.5ml per 100 ml. of blood), received by blood from the tissues, enters the RBCs where it reacts with water to form carbonic acid (H2CO3).
- Carbonic anhydrase, exclusively found in RBCs, speeds up the formation of H2CO3 and rapidly converts it back to carbon dioxide and water when blood reaches the lungs. Almost as rapidly as formed, all carbonic acid of RBCs dissociates into hydrogen (H+) and bicarbonate ions (HCO-3).
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of [2017]- a)Inspiratory reserve volume
- b)Tidal volume
- c)Expiratory reserve volume
- d)Residual volume
Correct answer is option 'D'. Can you explain this answer?
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of [2017]
a)
Inspiratory reserve volume
b)
Tidal volume
c)
Expiratory reserve volume
d)
Residual volume
|
|
Jyoti Sengupta answered |
Residual volume is the volume of air which remains in the lungs after the most forceful expiration. This residual air enables the lungs to continue exchange of gases even after maximum exhalation. Due to this, lungs do not collapse even after forceful expiration.
The exchange of gases in the alveoli of the lungs takes place by [1998]- a)simple diffusion
- b)osmosis
- c)active transport
- d)passive transport
Correct answer is option 'A'. Can you explain this answer?
The exchange of gases in the alveoli of the lungs takes place by [1998]
a)
simple diffusion
b)
osmosis
c)
active transport
d)
passive transport
|
|
Ayush Chavan answered |
Gaseous exchange between blood (dissolved phase) and alveolar air (gaseous phase) across respiratory membrane occurs by simple diffusion. Obviously, it depends upon the concentration gradient (=partial pressure) of the concerned gases in blood and alveolar air.
Although much CO2 is carried in blood, yet blood does not become acidic, because [1995]- a)it is absorbed by the leucocytes
- b)blood buffers play an important role in CO2 transport.
- c)it combines with water to form which is neutralized by NaCO3
- d)it is continuously diffused through tissues and is not allowed to accumulate
Correct answer is option 'B'. Can you explain this answer?
Although much CO2 is carried in blood, yet blood does not become acidic, because [1995]
a)
it is absorbed by the leucocytes
b)
blood buffers play an important role in CO2 transport.
c)
it combines with water to form which is neutralized by NaCO3
d)
it is continuously diffused through tissues and is not allowed to accumulate
|
|
Raghav Khanna answered |
CO2 enters RBC and reacts with water to form carbonic acid. Carbonic acid dissociates to form bicarbonate and hydrogen ions. Some bicarbonate ions are transported in erythrocytes while some diffuse into the blood plasma. Exit of bicarbonate ions change the ionic balance between the plasma and erythrocytes. To restore this balance chloride ions diffuse from plasma into erythrocytes. Due to this the pH of blood is maintained.
Asthma may be attributed to [NEET 2016 Phase 2]- a)Inflammation of the trachea
- b)Accumulation of fluid in the lungs
- c)Bacterial infection of the lungs
- d)Allergic reaction of the mast cells in the lungs.
Correct answer is option 'D'. Can you explain this answer?
Asthma may be attributed to [NEET 2016 Phase 2]
a)
Inflammation of the trachea
b)
Accumulation of fluid in the lungs
c)
Bacterial infection of the lungs
d)
Allergic reaction of the mast cells in the lungs.
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Avik Patel answered |
Understanding Asthma
Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, which leads to difficulty in breathing. The primary underlying cause of asthma is often linked to an allergic reaction, particularly involving mast cells.
Key Factors Contributing to Asthma
- Allergic Reactions
- Asthma is frequently triggered by allergens such as pollen, dust mites, pet dander, and mold.
- When a person with asthma is exposed to these allergens, mast cells in the lungs release histamines and other inflammatory substances.
- This immune response causes airway inflammation, leading to symptoms like wheezing, coughing, chest tightness, and shortness of breath.
- Inflammation of the Airways
- The airways in asthmatic individuals become inflamed, which narrows the passage for air to flow.
- This inflammation is a direct result of the body’s immune response to allergens or irritants.
- Role of Mast Cells
- Mast cells are a type of white blood cell that play a crucial role in allergic reactions.
- When they encounter an allergen, they trigger the release of various chemicals that exacerbate airway inflammation.
Conclusion
In summary, asthma is primarily attributed to an allergic reaction involving mast cells in the lungs. While factors like inflammation of the trachea or lung infections can contribute to respiratory issues, the hallmark of asthma lies in its allergic nature. Understanding this can help in better management and treatment of the condition.
Asthma is a chronic respiratory condition characterized by inflammation and narrowing of the airways, which leads to difficulty in breathing. The primary underlying cause of asthma is often linked to an allergic reaction, particularly involving mast cells.
Key Factors Contributing to Asthma
- Allergic Reactions
- Asthma is frequently triggered by allergens such as pollen, dust mites, pet dander, and mold.
- When a person with asthma is exposed to these allergens, mast cells in the lungs release histamines and other inflammatory substances.
- This immune response causes airway inflammation, leading to symptoms like wheezing, coughing, chest tightness, and shortness of breath.
- Inflammation of the Airways
- The airways in asthmatic individuals become inflamed, which narrows the passage for air to flow.
- This inflammation is a direct result of the body’s immune response to allergens or irritants.
- Role of Mast Cells
- Mast cells are a type of white blood cell that play a crucial role in allergic reactions.
- When they encounter an allergen, they trigger the release of various chemicals that exacerbate airway inflammation.
Conclusion
In summary, asthma is primarily attributed to an allergic reaction involving mast cells in the lungs. While factors like inflammation of the trachea or lung infections can contribute to respiratory issues, the hallmark of asthma lies in its allergic nature. Understanding this can help in better management and treatment of the condition.
The process of migration of chloride ions from plasma to RBC and of carbonate ions from RBC to plasma is [1999]- a)chloride shift
- b)ionic shift
- c)atomic shift
- d)Na+ pump
Correct answer is option 'A'. Can you explain this answer?
The process of migration of chloride ions from plasma to RBC and of carbonate ions from RBC to plasma is [1999]
a)
chloride shift
b)
ionic shift
c)
atomic shift
d)
Na+ pump
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Rajat Roy answered |
During the transport of CO2 through the blood, bicarbonate ions diffuse out of RBCs while chloride ions from plasma enter the RBCs to maintain ionic equilibrium. This is called chloride shift.
Which one of the following is one of the paths followed by air/O2 during respiration in an adult male Periplaneta americana as it enters the animal body? [NEET Kar. 2013]- a)Hypopharynx, mouth, pharynx, trachea, tissues
- b)Spiracle in metathorax , trachea , tracheoles, oxygen diffuses into cells
- c)Mouth, bronchial tube, trachea, oxygen enters cells
- d)Spiracle sinprothorax, tracheoles, trachea, oxygen diffuses into cells
Correct answer is option 'B'. Can you explain this answer?
Which one of the following is one of the paths followed by air/O2 during respiration in an adult male Periplaneta americana as it enters the animal body? [NEET Kar. 2013]
a)
Hypopharynx, mouth, pharynx, trachea, tissues
b)
Spiracle in metathorax , trachea , tracheoles, oxygen diffuses into cells
c)
Mouth, bronchial tube, trachea, oxygen enters cells
d)
Spiracle sinprothorax, tracheoles, trachea, oxygen diffuses into cells
|
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Deepak Joshi answered |
The number of spiracles in cockroach is 10-pairs (2-pairs in thoracic and 8-pairs in abdominal region). The thoracic pairs of spiracles are present on pleuron between prothorax - mesothorax and metathorax. Each spiracle opens into a chamber called atrium. After atrium the tracheal tube ramifies into fine branches of tracheae, and then tracheoles.
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude [1995, 2006]- a)atmospheric O2 level is less and hence more RBCs are needed to absorb the required amount of O2 to survive
- b)there is more UV radiation which enhances RBC production
- c)people eat more nutritive food, therefore more RBCs are formed
- d)people get pollution - free air to breathe and more oxygen is available
Correct answer is option 'A'. Can you explain this answer?
People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude of 5400 metres have around 8 million. This is because at high altitude [1995, 2006]
a)
atmospheric O2 level is less and hence more RBCs are needed to absorb the required amount of O2 to survive
b)
there is more UV radiation which enhances RBC production
c)
people eat more nutritive food, therefore more RBCs are formed
d)
people get pollution - free air to breathe and more oxygen is available
|
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Abhishek Choudhary answered |
At the altitude of 5400 meters the low atmospheric pressure of O2 will be too low so the solubility of oxygen in the blood will be very less hence the oxygen carried by each RBC will be too less. But to fulfill the oxygen requirement of the body blood has to carry more oxygen to the body tissue and this is done by the increased no. of RBCs.
Figure shown schematic plan of blood circulation in humans with labels A to D. Identify the label and give its function’s. [NEET 2013]
- a)B-Pulmonar y arter y-takes blood from heart to lungs, PO2 = 90 mm Hg
- b)C-Vena Cava - takes blood from body parts to right auricle, PCO2 = 45 mm Hg
- c)D - Dorsal aorta - takes blood from Heart to body Part PO2 = 95 mm Hg
- d)A-Pulmonary vein - takes impure blood from body parts, PO2 = 60 mm Hg
Correct answer is option 'B'. Can you explain this answer?
Figure shown schematic plan of blood circulation in humans with labels A to D. Identify the label and give its function’s. [NEET 2013]
a)
B-Pulmonar y arter y-takes blood from heart to lungs, PO2 = 90 mm Hg
b)
C-Vena Cava - takes blood from body parts to right auricle, PCO2 = 45 mm Hg
c)
D - Dorsal aorta - takes blood from Heart to body Part PO2 = 95 mm Hg
d)
A-Pulmonary vein - takes impure blood from body parts, PO2 = 60 mm Hg
|
|
Raghav Khanna answered |
A is Pulmonary vein which takes pure blood from lungs to heart. B is dorsal aorta which takes pure blood from heart to various body parts. C is Vena cava which takes impure blood from various body pars to right auricle of heart. D is pulmonary artery which takes impure blood from heart to lungs.
When CO2 concentration in blood increases, breathing becomes [2004]- a)shallower and slow
- b)there is no effect on breathing
- c)slow and deep
- d)faster and deeper
Correct answer is option 'D'. Can you explain this answer?
When CO2 concentration in blood increases, breathing becomes [2004]
a)
shallower and slow
b)
there is no effect on breathing
c)
slow and deep
d)
faster and deeper
|
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Deepak Joshi answered |
The breathing becomes faster and deeper in order to oxygenate the blood at a fast rate. Shallow and slow breathing occurs during rest.
Oxygen dissociation curve of haemoglobin is[1994]- a)Sigmoid
- b)Hyperbolic
- c)Linear
- d)Hypobolic
Correct answer is option 'A'. Can you explain this answer?
Oxygen dissociation curve of haemoglobin is[1994]
a)
Sigmoid
b)
Hyperbolic
c)
Linear
d)
Hypobolic
|
|
Deepak Joshi answered |
It is the relationship between the percentage saturation of haemoglobin (by volume) in the blood and the oxygen tension (in partial tension) PO2 of the blood.
It is usually a sigmoid plot. Haemoglobin molecules can bind up to four oxygen molecules in a reversible way. The shape of the curve results from the interaction of bound oxygen molecules with incoming molecules. The binding of the first molecule is difficult. However, this facilitates the binding of the second and third molecules, and it is only when the fourth molecule is to be bound that the difficulty increases, partly as a result of crowding of the haemoglobin molecule, partly as a natural tendency of oxygen to dissociate.
It is usually a sigmoid plot. Haemoglobin molecules can bind up to four oxygen molecules in a reversible way. The shape of the curve results from the interaction of bound oxygen molecules with incoming molecules. The binding of the first molecule is difficult. However, this facilitates the binding of the second and third molecules, and it is only when the fourth molecule is to be bound that the difficulty increases, partly as a result of crowding of the haemoglobin molecule, partly as a natural tendency of oxygen to dissociate.
The O2-Hb dissociation curve is a sigmoidal curve that represents the relationship between O2 concentration and the percentage saturation of Hb. As the concentration increases from about 90% there is a significant plateau in the curve, which has several important biological repercussions.
Listed below are four respiratory capacities (i–iv) and four jumbled respiratory volumes of a normal human adult: [2010]
Which one of the following is the correct matching of two capacities and volumes?
- a)(ii) 2500mL, (iii) 4500mL
- b)(iii) 1200mL, (iv) 2500mL
- c)(iv) 3500 mL, (i) 1200mL
- d)(i) 4500 mL, (ii) 3500mL
Correct answer is option 'C'. Can you explain this answer?
Listed below are four respiratory capacities (i–iv) and four jumbled respiratory volumes of a normal human adult: [2010]
Which one of the following is the correct matching of two capacities and volumes?
a)
(ii) 2500mL, (iii) 4500mL
b)
(iii) 1200mL, (iv) 2500mL
c)
(iv) 3500 mL, (i) 1200mL
d)
(i) 4500 mL, (ii) 3500mL
|
|
Ayush Chavan answered |
Respiratory Capacities:
- i) Inspiratory Capacity (IC): The maximum volume of air that can be inhaled after a normal expiration.
- ii) Functional Residual Capacity (FRC): The volume of air remaining in the lungs after a normal expiration.
- iii) Vital Capacity (VC): The maximum volume of air that can be exhaled after a maximum inhalation.
- iv) Total Lung Capacity (TLC): The total volume of air that the lungs can hold.
Respiratory Volumes:
- 1200mL: This volume doesn't match any of the capacities given.
- 2500mL: This volume matches with FRC (Functional Residual Capacity).
- 3500mL: This volume doesn't match any of the capacities given.
- 4500mL: This volume matches with IC (Inspiratory Capacity).
Therefore, the correct matching of two capacities and volumes is:
- Functional Residual Capacity (FRC): 2500mL
- Inspiratory Capacity (IC): 4500mL
So, the correct answer is option C: (iv) 3500 mL, (i) 1200mL0mL Inspiratory volume 3500mL
- i) Inspiratory Capacity (IC): The maximum volume of air that can be inhaled after a normal expiration.
- ii) Functional Residual Capacity (FRC): The volume of air remaining in the lungs after a normal expiration.
- iii) Vital Capacity (VC): The maximum volume of air that can be exhaled after a maximum inhalation.
- iv) Total Lung Capacity (TLC): The total volume of air that the lungs can hold.
Respiratory Volumes:
- 1200mL: This volume doesn't match any of the capacities given.
- 2500mL: This volume matches with FRC (Functional Residual Capacity).
- 3500mL: This volume doesn't match any of the capacities given.
- 4500mL: This volume matches with IC (Inspiratory Capacity).
Therefore, the correct matching of two capacities and volumes is:
- Functional Residual Capacity (FRC): 2500mL
- Inspiratory Capacity (IC): 4500mL
So, the correct answer is option C: (iv) 3500 mL, (i) 1200mL0mL Inspiratory volume 3500mL
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Biology 31 Years NEET Chapterwise Solved Papers
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