All questions of Respiratory System for Grade 9 Exam
The alveoli of lungs are lined by- a)Squamous epithelium
- b)Columnar epithelium
- c)Cuboidal epithelium
- d)Simple epithelium
Correct answer is option 'A'. Can you explain this answer?
The alveoli of lungs are lined by
a)
Squamous epithelium
b)
Columnar epithelium
c)
Cuboidal epithelium
d)
Simple epithelium
|
Hansa Sharma answered |
- The respiratory or gas-exchange surface consists of millions of small sacs, or alveoli, lined by a simple squamous epithelium.
- This epithelium is exceedingly thin to facilitate the diffusion of oxygen and CO2.
- The alveolar walls also contain cuboidal surfactant-secreting cells.
In frog cutaneous respiration takes place- a)In water
- b)On land
- c)In hibernation
- d)All (Always)
Correct answer is option 'D'. Can you explain this answer?
In frog cutaneous respiration takes place
a)
In water
b)
On land
c)
In hibernation
d)
All (Always)
|
Rajat Kapoor answered |
Frog Respiration. The frog has three respiratory surfaces on its body that it uses to exchange gas with the surroundings: the skin, in the lungs and on the lining of the mouth. While completely submerged all of the frog's repiration takes place through the skin.
The term ‘Glycolysis’ has originated from the Greek words:
- a)Glyco and lysis
- b)Glycose and lysis
- c)Glykos and lysis
- d)Glyko and lysis
Correct answer is option 'C'. Can you explain this answer?
The term ‘Glycolysis’ has originated from the Greek words:
a)
Glyco and lysis
b)
Glycose and lysis
c)
Glykos and lysis
d)
Glyko and lysis
|
Mira Sharma answered |
He word glycolysis is of Greek origin, where 'glykos' means sweet, and 'lysis' means splitting. Hence, Glycolysis literally means "sugar splitting" or "sugar breaking"; this accurately describes the process of glycolysis, in which a 6-carbon sugar molecule is broken down into two 3-carbon molecules. There are three stages in glycolysis which are Investment stage, Splitting stage and Energy Yielding stage. Glycolysis consists of ten separate reactions, each catalyzed by a different enzyme.
Oxygen in expired air- a)10%
- b)16%
- c)19%
- d)4%
Correct answer is option 'B'. Can you explain this answer?
Oxygen in expired air
a)
10%
b)
16%
c)
19%
d)
4%
|
Syed Hussain answered |
After a human breathes in Earth's air (roughly 78 percent nitrogen and 21 percent oxygen), he or she exhales a mixture of compounds similar to the air inhaled: 78 percent nitrogen, 16 percent oxygen, 0.09 percent argon, and four percent carbon dioxide.
The pharynx opens into the larynx by a slit-like aperture called
a) Bronchusb)Epiglottisc)Glottisd) TracheaCorrect answer is option 'C'. Can you explain this answer?
|
Vijay Bansal answered |
Nasopharynx lined by ciliated pseudostratified epithelia, oropharynx and laryngopharynx lined by non keratinized epithelium. Mouth serves as an alternate route for air when nasal chambers are blocked. Foramen by which pharynx opens into larynx called glottis. In general it remains open. During swallowing it is closed. It provides passage for air. Pharyns leads into the oesophagus through an aperture called gullet. In general condition it remains closed and opens at the time of swallowing. During swallowing epiglottis closes the glottis.
Respiration is- a)Physical process
- b)Chemical process
- c)Physico chemical process
- d)None
Correct answer is option 'C'. Can you explain this answer?
Respiration is
a)
Physical process
b)
Chemical process
c)
Physico chemical process
d)
None
|
|
Rajeev Saxena answered |
Respiration is the biochemical process in which the cells of an organism obtain energy by combining oxygen and glucose, resulting in the release of carbon dioxide, water, and ATP (the currency of energy in cells).
When we examine the equation for cellular respiration, we see that the reactants are glucose and oxygen (for aerobic respiration), and the products are carbon dioxide, water, and ATP. Note the number of oxygen, carbon dioxide, and water molecules involved in each 'turn' of the process.
Very high number of alveoli present in a lung is meant for- a)More space for increasing volume of inspired air
- b)More area for diffusion
- c)Making the organ spongy
- d)Increasing nerve supply
Correct answer is option 'B'. Can you explain this answer?
Very high number of alveoli present in a lung is meant for
a)
More space for increasing volume of inspired air
b)
More area for diffusion
c)
Making the organ spongy
d)
Increasing nerve supply
|
|
Tejas Kumar answered |
Explanation:
Alveoli are tiny air sacs present in the lungs where gas exchange occurs. The number of alveoli present in the lungs is very high, which serves the purpose of providing a large surface area for diffusion of gases. This is important because the process of respiration involves the exchange of gases between the lungs and blood. The alveoli provide a large surface area for this exchange to occur efficiently.
More area for diffusion:
The high number of alveoli in the lungs provides a large surface area for diffusion of gases. Oxygen from the air diffuses through the alveolar walls and into the bloodstream. At the same time, carbon dioxide diffuses out of the bloodstream and into the alveoli to be exhaled out of the body.
More space for increasing volume of inspired air:
The high number of alveoli also allows for the lungs to expand and increase in volume when we inhale, allowing for more air to enter the lungs. This is important for efficient gas exchange as it ensures that more oxygen can be taken in and more carbon dioxide can be expelled.
Making the organ spongy:
The high number of alveoli in the lungs also gives the organ a spongy texture. This allows the lungs to be flexible and accommodate changes in volume during breathing.
Increasing nerve supply:
While the high number of alveoli does not directly increase the nerve supply to the lungs, it does allow for more efficient gas exchange. This ensures that the body's cells receive the oxygen they need and allows for the removal of carbon dioxide, which can have harmful effects on the body if allowed to build up.
In summary, the high number of alveoli in the lungs provides a large surface area for diffusion of gases, allows for more space for increasing volume of inspired air, gives the organ a spongy texture, and allows for more efficient gas exchange, which is important for the body's overall health and function.
Alveoli are tiny air sacs present in the lungs where gas exchange occurs. The number of alveoli present in the lungs is very high, which serves the purpose of providing a large surface area for diffusion of gases. This is important because the process of respiration involves the exchange of gases between the lungs and blood. The alveoli provide a large surface area for this exchange to occur efficiently.
More area for diffusion:
The high number of alveoli in the lungs provides a large surface area for diffusion of gases. Oxygen from the air diffuses through the alveolar walls and into the bloodstream. At the same time, carbon dioxide diffuses out of the bloodstream and into the alveoli to be exhaled out of the body.
More space for increasing volume of inspired air:
The high number of alveoli also allows for the lungs to expand and increase in volume when we inhale, allowing for more air to enter the lungs. This is important for efficient gas exchange as it ensures that more oxygen can be taken in and more carbon dioxide can be expelled.
Making the organ spongy:
The high number of alveoli in the lungs also gives the organ a spongy texture. This allows the lungs to be flexible and accommodate changes in volume during breathing.
Increasing nerve supply:
While the high number of alveoli does not directly increase the nerve supply to the lungs, it does allow for more efficient gas exchange. This ensures that the body's cells receive the oxygen they need and allows for the removal of carbon dioxide, which can have harmful effects on the body if allowed to build up.
In summary, the high number of alveoli in the lungs provides a large surface area for diffusion of gases, allows for more space for increasing volume of inspired air, gives the organ a spongy texture, and allows for more efficient gas exchange, which is important for the body's overall health and function.
In the process of transport of CO2 which phenomenon occurs between RBCs and plasma- a)Osmosis
- b)Adsorption
- c)Chloride shift
- d)Absorption
Correct answer is option 'C'. Can you explain this answer?
In the process of transport of CO2 which phenomenon occurs between RBCs and plasma
a)
Osmosis
b)
Adsorption
c)
Chloride shift
d)
Absorption
|
Gayatri Pillai answered |
**Chloride Shift in the Transport of CO2 between RBCs and Plasma**
The correct phenomenon that occurs between red blood cells (RBCs) and plasma during the transport of carbon dioxide (CO2) is the **chloride shift**.
During gas exchange in the lungs, oxygen (O2) is taken up by hemoglobin in the RBCs, while CO2 is released from the tissues and diffuses into the blood. CO2 is mainly transported in the blood in three forms: dissolved CO2, bicarbonate ions (HCO3-), and carbamino compounds.
**Chloride Shift Process:**
1. **CO2 Loading in the Tissues:** In the tissues, CO2 diffuses into the RBCs and reacts with water (H2O) to form carbonic acid (H2CO3) through the action of the enzyme carbonic anhydrase.
2. **Formation of Bicarbonate Ions:** Carbonic acid (H2CO3) dissociates into bicarbonate ions (HCO3-) and hydrogen ions (H+). The bicarbonate ions are then transported out of the RBCs into the plasma in exchange for chloride ions (Cl-) through a process called the chloride shift.
3. **Reverse Chloride Shift in the Lungs:** In the lungs, where the partial pressure of CO2 is lower, the reverse process occurs. Bicarbonate ions (HCO3-) are transported back into the RBCs in exchange for chloride ions (Cl-) from the plasma.
4. **CO2 Unloading in the Lungs:** Inside the RBCs, carbonic acid (H2CO3) is formed again, which then dissociates into CO2 and water (H2O) due to the action of carbonic anhydrase. The CO2 is then released from the RBCs into the alveoli of the lungs, where it can be exhaled.
**Purpose of the Chloride Shift:**
The chloride shift plays a crucial role in CO2 transport as it helps maintain the electrochemical balance and pH of the RBCs. By exchanging bicarbonate ions (HCO3-) for chloride ions (Cl-), it prevents the accumulation of excess bicarbonate ions in the RBCs and maintains the electrical neutrality of the cells. This is important for the proper functioning of various cellular processes.
In summary, during the transport of CO2 between RBCs and plasma, the chloride shift is the phenomenon where bicarbonate ions (HCO3-) are exchanged for chloride ions (Cl-) to facilitate the movement of CO2 out of the tissues and into the lungs. This process helps maintain the electrochemical balance and pH within the RBCs.
The correct phenomenon that occurs between red blood cells (RBCs) and plasma during the transport of carbon dioxide (CO2) is the **chloride shift**.
During gas exchange in the lungs, oxygen (O2) is taken up by hemoglobin in the RBCs, while CO2 is released from the tissues and diffuses into the blood. CO2 is mainly transported in the blood in three forms: dissolved CO2, bicarbonate ions (HCO3-), and carbamino compounds.
**Chloride Shift Process:**
1. **CO2 Loading in the Tissues:** In the tissues, CO2 diffuses into the RBCs and reacts with water (H2O) to form carbonic acid (H2CO3) through the action of the enzyme carbonic anhydrase.
2. **Formation of Bicarbonate Ions:** Carbonic acid (H2CO3) dissociates into bicarbonate ions (HCO3-) and hydrogen ions (H+). The bicarbonate ions are then transported out of the RBCs into the plasma in exchange for chloride ions (Cl-) through a process called the chloride shift.
3. **Reverse Chloride Shift in the Lungs:** In the lungs, where the partial pressure of CO2 is lower, the reverse process occurs. Bicarbonate ions (HCO3-) are transported back into the RBCs in exchange for chloride ions (Cl-) from the plasma.
4. **CO2 Unloading in the Lungs:** Inside the RBCs, carbonic acid (H2CO3) is formed again, which then dissociates into CO2 and water (H2O) due to the action of carbonic anhydrase. The CO2 is then released from the RBCs into the alveoli of the lungs, where it can be exhaled.
**Purpose of the Chloride Shift:**
The chloride shift plays a crucial role in CO2 transport as it helps maintain the electrochemical balance and pH of the RBCs. By exchanging bicarbonate ions (HCO3-) for chloride ions (Cl-), it prevents the accumulation of excess bicarbonate ions in the RBCs and maintains the electrical neutrality of the cells. This is important for the proper functioning of various cellular processes.
In summary, during the transport of CO2 between RBCs and plasma, the chloride shift is the phenomenon where bicarbonate ions (HCO3-) are exchanged for chloride ions (Cl-) to facilitate the movement of CO2 out of the tissues and into the lungs. This process helps maintain the electrochemical balance and pH within the RBCs.
In Man, the structure with a function similar to spiracles of cockroach are- a)Lungs
- b)Alveoli
- c)Bronchioles
- d)Nostrils
Correct answer is option 'D'. Can you explain this answer?
In Man, the structure with a function similar to spiracles of cockroach are
a)
Lungs
b)
Alveoli
c)
Bronchioles
d)
Nostrils
|
Santosh Kumar answered |
Respiratory tubules open outside the body by the spiracles in CockroachEach spiracle open into a large chamber called atrium or tracheal chamber as like nostril.
Which one is the cofactor of carbonic anhydrase?- a)Cu
- b)Zn
- c)Fe
- d)Mg
Correct answer is option 'B'. Can you explain this answer?
Which one is the cofactor of carbonic anhydrase?
a)
Cu
b)
Zn
c)
Fe
d)
Mg
|
Janani Singh answered |
Cofactor of carbonic anhydrase
Carbonic anhydrase is an enzyme that catalyzes the reversible hydration of carbon dioxide to bicarbonate ions. It is present in red blood cells and plays a crucial role in the transportation of carbon dioxide from the tissues to the lungs. The cofactor of carbonic anhydrase is Zn (zinc).
Explanation
Carbonic anhydrase requires a metal ion cofactor for its activity. The metal ion binds to the active site of the enzyme and participates in the catalytic reaction. Several metal ions have been found to be cofactors of carbonic anhydrase, including Cu (copper), Fe (iron), Mg (magnesium), and Zn (zinc). However, Zn is the most common and important cofactor of carbonic anhydrase.
Zinc ion (Zn2+) acts as a Lewis acid and binds to a water molecule, which then acts as a base to facilitate the transfer of a proton from carbonic acid to water, forming bicarbonate and a hydronium ion. The hydronium ion is then removed by another water molecule, regenerating the active site of the enzyme.
Zinc is essential for the activity of carbonic anhydrase, and its deficiency can lead to severe metabolic disorders such as osteoporosis, growth retardation, and immune dysfunction.
Conclusion
In conclusion, the cofactor of carbonic anhydrase is Zn (zinc). Zinc is essential for the activity of the enzyme, and its deficiency can lead to severe health problems.
Carbonic anhydrase is an enzyme that catalyzes the reversible hydration of carbon dioxide to bicarbonate ions. It is present in red blood cells and plays a crucial role in the transportation of carbon dioxide from the tissues to the lungs. The cofactor of carbonic anhydrase is Zn (zinc).
Explanation
Carbonic anhydrase requires a metal ion cofactor for its activity. The metal ion binds to the active site of the enzyme and participates in the catalytic reaction. Several metal ions have been found to be cofactors of carbonic anhydrase, including Cu (copper), Fe (iron), Mg (magnesium), and Zn (zinc). However, Zn is the most common and important cofactor of carbonic anhydrase.
Zinc ion (Zn2+) acts as a Lewis acid and binds to a water molecule, which then acts as a base to facilitate the transfer of a proton from carbonic acid to water, forming bicarbonate and a hydronium ion. The hydronium ion is then removed by another water molecule, regenerating the active site of the enzyme.
Zinc is essential for the activity of carbonic anhydrase, and its deficiency can lead to severe metabolic disorders such as osteoporosis, growth retardation, and immune dysfunction.
Conclusion
In conclusion, the cofactor of carbonic anhydrase is Zn (zinc). Zinc is essential for the activity of the enzyme, and its deficiency can lead to severe health problems.
The most important function of diaphragm of mammals is- a)To devide the body cavity into compartments
- b)To protect lungs
- c)To aid in respiration
- d)To aid in ventilation
Correct answer is option 'D'. Can you explain this answer?
The most important function of diaphragm of mammals is
a)
To devide the body cavity into compartments
b)
To protect lungs
c)
To aid in respiration
d)
To aid in ventilation
|
Supriya Senapati answered |
The diaphragm is a dome-shaped muscular structure. It separates the thoracic and the abdominal region of the body.
The main function of the diaphragm is to aid in ventilation. During the process of inspiration and expiration, it contracts and relaxes simultaneously to change the volume of thoracic cavity which creates a pressure difference between the lungs and outer atmosphere which helps to inhale and exhale.
During inspiration the diaphragm contracts and increases the volume of the thoracic cavity, and decreases the pressure inside the lungs, thus the air enters inside the lungs.
During expiration the diaphragm relaxes and decreases the volume of the thoracic cavity, and increase the pressure inside the lungs, thus the air is forced out of the lungs.
So, the correct answer is option D.
The main function of the diaphragm is to aid in ventilation. During the process of inspiration and expiration, it contracts and relaxes simultaneously to change the volume of thoracic cavity which creates a pressure difference between the lungs and outer atmosphere which helps to inhale and exhale.
During inspiration the diaphragm contracts and increases the volume of the thoracic cavity, and decreases the pressure inside the lungs, thus the air enters inside the lungs.
During expiration the diaphragm relaxes and decreases the volume of the thoracic cavity, and increase the pressure inside the lungs, thus the air is forced out of the lungs.
So, the correct answer is option D.
Lungs have a large number of narrow tubes called- a)Bronchi
- b)Alveoli
- c)Bronchioles
- d)Tracheae
Correct answer is option 'C'. Can you explain this answer?
Lungs have a large number of narrow tubes called
a)
Bronchi
b)
Alveoli
c)
Bronchioles
d)
Tracheae
|
Nandini Patel answered |
The narrow tubes found inside lungs are called bronchioles.
When we breathe, air travels from the nose or mouth, and goes down the trachea and reaches the part called carina. From here the tube branches into two, creating two bronchi that lead to left and right lung each. From there onwards, the bronchi split into smaller and smaller bronchioles until it terminates in the alveoli where gas exchange occurs.
How much oxygen, blood supplies to tissues in one circulation- a)75%
- b)1.34%
- c)25%
- d)7%
Correct answer is option 'C'. Can you explain this answer?
How much oxygen, blood supplies to tissues in one circulation
a)
75%
b)
1.34%
c)
25%
d)
7%
|
Pooja Shah answered |
Blood supplies approximately 25% of oxygen to the tissues in one circulation as the partial pressure of oxygen in arterial blood is 75-95mmHg.
Which one of the following mammalian cells is not capable of metabolising glucose to carbon dioxide aerobically?- a)Unstriated muscle cells
- b)White blood cells
- c)Liver cells
- d)Red blood cells
Correct answer is option 'D'. Can you explain this answer?
Which one of the following mammalian cells is not capable of metabolising glucose to carbon dioxide aerobically?
a)
Unstriated muscle cells
b)
White blood cells
c)
Liver cells
d)
Red blood cells
|
|
Naina Bansal answered |
Cell organelles and nucleus are absent in mature red blood cells, therefore, aerobic respiration do not take place.
Oxygen dissociation curve of haemoglobin is- a)Sigmoid
- b)Hyperbolic
- c)Linear
- d)Hypobolic
Correct answer is option 'A'. Can you explain this answer?
Oxygen dissociation curve of haemoglobin is
a)
Sigmoid
b)
Hyperbolic
c)
Linear
d)
Hypobolic
|
Shyamal Modak. answered |
Acc. to NCERT it is sigmoid.
NCERT page 274 section 17.4.1. Transport of O2
fig. 17.5
NCERT page 274 section 17.4.1. Transport of O2
fig. 17.5
Inhibitory centre and pneumotaxis centre concerned with
- a)Respiration
- b)Digestion
- c)Reflexaction
- d)Breathing
Correct answer is option 'D'. Can you explain this answer?
Inhibitory centre and pneumotaxis centre concerned with
a)
Respiration
b)
Digestion
c)
Reflexaction
d)
Breathing
|
|
Akshay Chavan answered |
Inhibitory centre and pneumotaxis centre are both located in the brainstem and are involved in the regulation of breathing.
Inhibitory Centre:
- Located in the medulla oblongata
- Responsible for controlling the rate and depth of breathing
- Activated when levels of carbon dioxide in the blood increase, leading to an increase in respiratory rate to remove excess carbon dioxide
- Also activated when levels of oxygen in the blood decrease, leading to an increase in respiratory rate to increase oxygen intake
Pneumotaxis Centre:
- Located in the pons region of the brainstem
- Responsible for controlling the duration of each breath
- Activated by signals from the inhibitory centre
- Helps fine-tune the breathing rate and depth by adjusting the inspiratory and expiratory volumes
In summary, the inhibitory centre and pneumotaxis centre work together to regulate breathing, ensuring that the body receives enough oxygen and removes excess carbon dioxide.
Inhibitory Centre:
- Located in the medulla oblongata
- Responsible for controlling the rate and depth of breathing
- Activated when levels of carbon dioxide in the blood increase, leading to an increase in respiratory rate to remove excess carbon dioxide
- Also activated when levels of oxygen in the blood decrease, leading to an increase in respiratory rate to increase oxygen intake
Pneumotaxis Centre:
- Located in the pons region of the brainstem
- Responsible for controlling the duration of each breath
- Activated by signals from the inhibitory centre
- Helps fine-tune the breathing rate and depth by adjusting the inspiratory and expiratory volumes
In summary, the inhibitory centre and pneumotaxis centre work together to regulate breathing, ensuring that the body receives enough oxygen and removes excess carbon dioxide.
The structure which prevents the entry of food into respiratory tract is- a)pharynx
- b)Larynx
- c)Glottis
- d)Epiglottis
Correct answer is option 'D'. Can you explain this answer?
The structure which prevents the entry of food into respiratory tract is
a)
pharynx
b)
Larynx
c)
Glottis
d)
Epiglottis
|
Srishti Dam answered |
The epiglottis is a leaf-shaped flap of cartilage located behind the tongue, at the top of the larynx, or voice box. The main function of the epiglottis is to seal off the windpipe during eating, so that food is not accidentally inhaled.
Epiglottis is made of stratified columnar epithelium tissue (non-ciliated) .
Epiglottis is made of stratified columnar epithelium tissue (non-ciliated) .
What percentage of CO2 flows in blood in form of bicarbonates- a)7%
- b)23%
- c)50%
- d)70%
Correct answer is option 'D'. Can you explain this answer?
What percentage of CO2 flows in blood in form of bicarbonates
a)
7%
b)
23%
c)
50%
d)
70%
|
|
Shyamal Modak. answered |
It is written in NCERT. Ans. is D
For proper transport of O2 and CO2 blood should be- a)Slightly acidic
- b)Strongly acidic
- c)Strongly alkaline
- d)Slightly alkaline
Correct answer is option 'D'. Can you explain this answer?
For proper transport of O2 and CO2 blood should be
a)
Slightly acidic
b)
Strongly acidic
c)
Strongly alkaline
d)
Slightly alkaline
|
|
Rishabh Shah answered |
Explanation:
Transport of oxygen (O2) and carbon dioxide (CO2) in the blood is a crucial process for the proper functioning of the body. The pH of the blood plays a significant role in this process.
Acidic and alkaline conditions:
pH is a measure of the acidity or alkalinity of a substance. The pH scale ranges from 0 to 14, with 7 being neutral, less than 7 being acidic, and greater than 7 being alkaline. Blood pH is tightly regulated, with a normal range of 7.35 to 7.45.
Blood pH and transport of O2 and CO2:
The transport of O2 and CO2 in the blood is facilitated by the binding of these gases to hemoglobin (Hb) and other proteins. The binding of O2 to Hb is influenced by the pH of the blood. In an acidic environment, Hb has a higher affinity for O2, which means it binds more readily. On the other hand, in an alkaline environment, Hb has a lower affinity for O2, which means it releases O2 more readily.
Similarly, the transport of CO2 in the blood is also influenced by the pH of the blood. CO2 can combine with water (H2O) in the blood to form carbonic acid (H2CO3), which can then dissociate into hydrogen ions (H+) and bicarbonate ions (HCO3-). In an acidic environment, there are more H+ ions, which combine with HCO3- to form H2CO3 and release CO2. In an alkaline environment, there are fewer H+ ions, which means more HCO3- is available to combine with H+ ions and form H2CO3, which can then be converted back to CO2.
Slightly alkaline pH:
From the above explanation, it is clear that blood pH should be slightly alkaline (between 7.35 to 7.45) for the proper transport of O2 and CO2. This pH range ensures that Hb binds O2 readily in the lungs (where the pH is slightly more alkaline) and releases O2 readily in the tissues (where the pH is slightly more acidic). It also ensures that CO2 is released readily in the lungs (where the pH is slightly more acidic) and transported to the lungs as HCO3- (where the pH is slightly more alkaline).
Therefore, the correct answer is option 'D' (Slightly alkaline).
Transport of oxygen (O2) and carbon dioxide (CO2) in the blood is a crucial process for the proper functioning of the body. The pH of the blood plays a significant role in this process.
Acidic and alkaline conditions:
pH is a measure of the acidity or alkalinity of a substance. The pH scale ranges from 0 to 14, with 7 being neutral, less than 7 being acidic, and greater than 7 being alkaline. Blood pH is tightly regulated, with a normal range of 7.35 to 7.45.
Blood pH and transport of O2 and CO2:
The transport of O2 and CO2 in the blood is facilitated by the binding of these gases to hemoglobin (Hb) and other proteins. The binding of O2 to Hb is influenced by the pH of the blood. In an acidic environment, Hb has a higher affinity for O2, which means it binds more readily. On the other hand, in an alkaline environment, Hb has a lower affinity for O2, which means it releases O2 more readily.
Similarly, the transport of CO2 in the blood is also influenced by the pH of the blood. CO2 can combine with water (H2O) in the blood to form carbonic acid (H2CO3), which can then dissociate into hydrogen ions (H+) and bicarbonate ions (HCO3-). In an acidic environment, there are more H+ ions, which combine with HCO3- to form H2CO3 and release CO2. In an alkaline environment, there are fewer H+ ions, which means more HCO3- is available to combine with H+ ions and form H2CO3, which can then be converted back to CO2.
Slightly alkaline pH:
From the above explanation, it is clear that blood pH should be slightly alkaline (between 7.35 to 7.45) for the proper transport of O2 and CO2. This pH range ensures that Hb binds O2 readily in the lungs (where the pH is slightly more alkaline) and releases O2 readily in the tissues (where the pH is slightly more acidic). It also ensures that CO2 is released readily in the lungs (where the pH is slightly more acidic) and transported to the lungs as HCO3- (where the pH is slightly more alkaline).
Therefore, the correct answer is option 'D' (Slightly alkaline).
Oxygen haemoglobin dissociation curve will shift to right on decrease of- a)Acidity
- b)Carbon dioxide concentration
- c)Both 1 & 2
- d)pH
Correct answer is option 'D'. Can you explain this answer?
Oxygen haemoglobin dissociation curve will shift to right on decrease of
a)
Acidity
b)
Carbon dioxide concentration
c)
Both 1 & 2
d)
pH
|
|
Vijay Bansal answered |
The strength with which oxygen binds to hemoglobin is affected by several factors. These factors shift or reshape the oxyhemoglobin dissociation curve. A rightward shift indicates that the hemoglobin under study has a decreased affinity for oxygen.
Which of the following statement is true about Trachea, in a respiratory system?- a)It functions as passages of air to each alveolus.
- b)It functions for sound production.
- c)It acts as a passage for air to bronchi.
- d)It lowers the surface tension.
Correct answer is option 'C'. Can you explain this answer?
Which of the following statement is true about Trachea, in a respiratory system?
a)
It functions as passages of air to each alveolus.
b)
It functions for sound production.
c)
It acts as a passage for air to bronchi.
d)
It lowers the surface tension.
|
Anjali Sharma answered |
The trachea serves as a passage for air, moistens and warms it while it passes into the lungs, and protects the respiratory surface from an accumulation of foreign particles.
Which one of the following statement is correct?- a)Chest expands because air enters into the lungs
- b)Air enters into the lungs because chest expands
- c)The muscles of the diaphragm contracts because air enters into the lungs
- d)All of the above statements are correct
Correct answer is option 'B'. Can you explain this answer?
Which one of the following statement is correct?
a)
Chest expands because air enters into the lungs
b)
Air enters into the lungs because chest expands
c)
The muscles of the diaphragm contracts because air enters into the lungs
d)
All of the above statements are correct
|
Pragati Mishra answered |
Inhalation or inspiration is an active process.
we ,with the help of the intercoastal muscles, increase the volume of thoracic cavity ,thus increasing the volume of lungs. This creates a negative pressure inside the lungs as compared to external surrounding and therefore due to negative pressure, air comes inside the lungs.
we ,with the help of the intercoastal muscles, increase the volume of thoracic cavity ,thus increasing the volume of lungs. This creates a negative pressure inside the lungs as compared to external surrounding and therefore due to negative pressure, air comes inside the lungs.
Expiratory muscles contract at the time of
- a)Deep inspiration
- b)Normal inspiration and expiration
- c)Forceful expiration
- d)Normal expiration
Correct answer is option 'C'. Can you explain this answer?
Expiratory muscles contract at the time of
a)
Deep inspiration
b)
Normal inspiration and expiration
c)
Forceful expiration
d)
Normal expiration
|
|
Vijay Bansal answered |
Expiration muscles come into action when you force expiration. The expiratory muscles are the abdominal muscles and intercostals. It is rare if a patient is contracting abdominal muscles for quiet breathing and he is trying to force expiration.
Expiration involves
- a)Relaxation of diaphragm and intercostal muscles
- b)Contraction of diaphragm and intercostal muscles
- c)Contraction of diaphragm muscles
- d)Contraction of intercostal muscles
Correct answer is option 'A'. Can you explain this answer?
Expiration involves
a)
Relaxation of diaphragm and intercostal muscles
b)
Contraction of diaphragm and intercostal muscles
c)
Contraction of diaphragm muscles
d)
Contraction of intercostal muscles
|
|
Priyanka Nath answered |
Expiration is a process by which the foul air (carbon dioxide) is expelled out from the lungs. It is a passive process which occurs in the diaphragm and internal intercostal muscles in the following manner-
i) Diaphragm: The muscle fibres of the diaphragm relax making it convex, decreasing the volume of tge thoracic activity.
ii) Internal intercostal muscles: These muscles contract so that they pull the ribs downward and inward decreasing the size of the thoracic activity. So, the correct answer is option (A) .
i) Diaphragm: The muscle fibres of the diaphragm relax making it convex, decreasing the volume of tge thoracic activity.
ii) Internal intercostal muscles: These muscles contract so that they pull the ribs downward and inward decreasing the size of the thoracic activity. So, the correct answer is option (A) .
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of:- a)Expiratory reserve volume
- b)Residual volume
- c)Inspiratory reserve volume
- d)Tidal volume
Correct answer is option 'B'. 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:
a)
Expiratory reserve volume
b)
Residual volume
c)
Inspiratory reserve volume
d)
Tidal volume
|
Gaurav Kumar answered |
- The volume of air remaining in the lungs even after a forcible expiration is called residual volume.
- This residual volume prevents the lungs from collapsing.
"Emphysema" is a condition in which -- a)Repiratoy centre inhibited
- b)Lot of fluid in the lungs
- c)The walls seperating the alveoli break
- d)Lungs have more O2
Correct answer is option 'C'. Can you explain this answer?
"Emphysema" is a condition in which -
a)
Repiratoy centre inhibited
b)
Lot of fluid in the lungs
c)
The walls seperating the alveoli break
d)
Lungs have more O2
|
|
Tanvi Dear answered |
When any person consume cigarette then it harms the inner wall of alveoli so in response of it alveoli secrete some chemicals which destroy the smoked particles present near by alveolar wall but with them wall also ruptures .it leads to decresing surface area of alveoli which makes difficult to respire ..And this infectious condition is emphysema .
Hope It Helps Uh
Hope It Helps Uh
If expiratory reserve volume is 1100 ml residual volume is 1200 ml and tidal volume is 500 ml, what shall be the functional residual capacity- a)1600 ml
- b)2800 ml
- c)2300 ml
- d)1200 ml
Correct answer is option 'C'. Can you explain this answer?
If expiratory reserve volume is 1100 ml residual volume is 1200 ml and tidal volume is 500 ml, what shall be the functional residual capacity
a)
1600 ml
b)
2800 ml
c)
2300 ml
d)
1200 ml
|
|
Raghav Bansal answered |
Functional Residual Capacity (FRC) is the volume of air that will remain in the lungs after a normal expiration. This includes expiratory reserve volume i.e. 1100ml plus 1200ml or 2300ml.
Which of the following is not the function of the respiratory system?- a)Regulate blood pH.
- b)Helps in gaseous exchange.
- c)Contains receptors for the sense of smell.
- d)Protection against blood loss.
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not the function of the respiratory system?
a)
Regulate blood pH.
b)
Helps in gaseous exchange.
c)
Contains receptors for the sense of smell.
d)
Protection against blood loss.
|
|
Priya Menon answered |
- The respiratory system helps in the regulation of blood pH, gaseous exchange and also contain receptors of smell, produces vocal sound and filter inspired air.
- While the cardiovascular system protects against blood loss by the formation of blood clots.
Inhibition of respiratory centre is termed- a)Bradypnoea
- b)Apnoea
- c)Anoxia
- d)Tachypnoea
Correct answer is option 'B'. Can you explain this answer?
Inhibition of respiratory centre is termed
a)
Bradypnoea
b)
Apnoea
c)
Anoxia
d)
Tachypnoea
|
|
Rajeev Saxena answered |
Temporary absence or cessation of breathing is called as apnoea. The respiratory center is located in the medulla oblongata. It controls the rate and depth of respiratory movements of the diaphragm and other respiratory muscles. Injury to this center may lead to apnoea.
Sneiderian membrane occurs on- a)Larynx
- b)Nasoturbinals
- c)Maxillo turbinals
- d)Ethmoturbinals
Correct answer is option 'B'. Can you explain this answer?
Sneiderian membrane occurs on
a)
Larynx
b)
Nasoturbinals
c)
Maxillo turbinals
d)
Ethmoturbinals
|
Naina Menon answered |
The soft tissue is flapped back to expose the underlying lateral wall of the left maxillary sinus.The bone has been removed with a piezoelectric instrument, exposing the underlying Schneiderian membrane, which is the lining of the maxillary sinus cavity.
Right lung of Rabbit has- a)2 lobes
- b)4 lobes
- c)5 lobes
- d)6 lobes
Correct answer is option 'B'. Can you explain this answer?
Right lung of Rabbit has
a)
2 lobes
b)
4 lobes
c)
5 lobes
d)
6 lobes
|
|
Rajeev Saxena answered |
So option B
Right lung of rabbit is divided into four lobes namely the anterior azygous, right anterior right posterior and posterior azygous.
The function of tracheal cilia is to- a)Pass mucus out
- b)Pass mucus in
- c)Pass air out
- d)Pass air in
Correct answer is option 'A'. Can you explain this answer?
The function of tracheal cilia is to
a)
Pass mucus out
b)
Pass mucus in
c)
Pass air out
d)
Pass air in
|
Jyoti Kapoor answered |
The function of cilia in the trachea and bronchi is to protect the airways from being damaged or infected by particles of dust or foreign matter.
Explanation:
Air that is inhaled may not necessarily be free of dust particles. For this reason, there must be something to remove the potentially harmful matter from the body. The cilia in the trachea and bronchi act as a defence system for the body by keeping the airways clear of mucus, dust, dirt, and other foreign matter. This allows us to breathe easily without disruption. For example, in Beijing, the air is so full of dust that many people must wear masks to protect themselves from breathing in the harmful particles.
Larynx is a modified portion of- a)Pharynx
- b)Trachea
- c)Bronchus
- d)Lungs
Correct answer is option 'B'. Can you explain this answer?
Larynx is a modified portion of
a)
Pharynx
b)
Trachea
c)
Bronchus
d)
Lungs
|
|
Jyoti Kapoor answered |
It connects the inferior part of the pharynx (hypopharynx) with the trachea. The laryngeal skeleton consists of six cartilages: three single (epiglottic, thyroid and cricoid) and three paired (arytenoid, corniculate, and cuneiform).
The maximum volume of air contained in the lung by a full forced inhalation is called- a)Vital capacity
- b)Tidal volume
- c)Total lung capacity
- d)Inspiratory capacity
Correct answer is option 'C'. Can you explain this answer?
The maximum volume of air contained in the lung by a full forced inhalation is called
a)
Vital capacity
b)
Tidal volume
c)
Total lung capacity
d)
Inspiratory capacity
|
|
🌟 answered |
Total volume of air that can be accommodated in the lungs at the end of forced inspiration is called Total Lung Capacity ...
TLC = IRV + TV + ERV + RV
= 3000+500+ 1000+1200
= 6000ml ( approx )
5700 to 6000ml
TLC = IRV + TV + ERV + RV
= 3000+500+ 1000+1200
= 6000ml ( approx )
5700 to 6000ml
Bulk of carbon dioxide is transported by __________- a)dissolved state
- b)plasma as bicarbonate
- c)carbamino haemoglobin
- d)methamoglobin
Correct answer is option 'B'. Can you explain this answer?
Bulk of carbon dioxide is transported by __________
a)
dissolved state
b)
plasma as bicarbonate
c)
carbamino haemoglobin
d)
methamoglobin
|
EduRev NEET answered |
- Nearly 70% carbon dioxide is transported by plasma as sodium bicarbonate. Approximately, 5-7% of carbon dioxide is transported in dissolves form in plasma.
- About 20-25% carbon dioxide react with the amine group of haemoglobin and form carbamino-haemoglobin.
Effect of CO2 concentration on dissociation of oxyhaemoglobin is called- a)Bohr's effect
- b)Haldane effect
- c)Hamburger effect
- d)Gaudi Kov's effect
Correct answer is option 'A'. Can you explain this answer?
Effect of CO2 concentration on dissociation of oxyhaemoglobin is called
a)
Bohr's effect
b)
Haldane effect
c)
Hamburger effect
d)
Gaudi Kov's effect
|
|
Megha Basu answered |
Bohr's Effect:
Bohr's effect refers to the effect of carbon dioxide (CO2) concentration on the dissociation of oxyhemoglobin (HbO2) into oxygen (O2) and hemoglobin (Hb). This phenomenon was discovered by Danish physiologist Christian Bohr in the early 20th century.
Explanation:
When CO2 is produced in tissues, it diffuses into the bloodstream and reacts with water (H2O) to form carbonic acid (H2CO3) through an enzyme called carbonic anhydrase. Carbonic acid then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
1. Formation of Carbonic Acid:
CO2 + H2O ⇌ H2CO3
2. Dissociation of Carbonic Acid:
H2CO3 ⇌ H+ + HCO3-
The increase in H+ ions leads to a decrease in blood pH, causing the blood to become more acidic. This decrease in pH triggers Bohr's effect, which facilitates the release of oxygen from hemoglobin.
3. Effect on Hemoglobin Affinity for Oxygen:
The binding of oxygen to hemoglobin is influenced by the pH and CO2 concentration. When the CO2 concentration is high, such as in actively metabolizing tissues, the following changes occur:
- Increased CO2 concentration leads to an increase in H+ ions, causing a decrease in pH.
- The decrease in pH leads to a decrease in the affinity of hemoglobin for oxygen.
- Hemoglobin releases its bound oxygen more readily due to the decreased affinity.
- This oxygen can then be utilized by the metabolizing tissues for cellular respiration.
4. Shift of Oxygen-Hemoglobin Dissociation Curve:
Bohr's effect causes a rightward shift in the oxygen-hemoglobin dissociation curve. This shift indicates a decreased affinity of hemoglobin for oxygen at a given partial pressure of oxygen (PO2).
- At the same PO2, the amount of oxygen released from hemoglobin increases in the presence of higher CO2 concentration.
- This shift allows for enhanced oxygen unloading in tissues where CO2 is being produced as a byproduct of cellular respiration.
Summary:
Bohr's effect describes the relationship between CO2 concentration, pH, and oxygen release from hemoglobin. As CO2 concentration increases, it leads to the formation of carbonic acid, which dissociates into H+ ions and HCO3-. The increase in H+ ions decreases blood pH, triggering a decrease in hemoglobin's affinity for oxygen. This facilitates the release of oxygen from hemoglobin, allowing it to be utilized by metabolizing tissues. The effect is represented by a rightward shift in the oxygen-hemoglobin dissociation curve.
Bohr's effect refers to the effect of carbon dioxide (CO2) concentration on the dissociation of oxyhemoglobin (HbO2) into oxygen (O2) and hemoglobin (Hb). This phenomenon was discovered by Danish physiologist Christian Bohr in the early 20th century.
Explanation:
When CO2 is produced in tissues, it diffuses into the bloodstream and reacts with water (H2O) to form carbonic acid (H2CO3) through an enzyme called carbonic anhydrase. Carbonic acid then dissociates into hydrogen ions (H+) and bicarbonate ions (HCO3-).
1. Formation of Carbonic Acid:
CO2 + H2O ⇌ H2CO3
2. Dissociation of Carbonic Acid:
H2CO3 ⇌ H+ + HCO3-
The increase in H+ ions leads to a decrease in blood pH, causing the blood to become more acidic. This decrease in pH triggers Bohr's effect, which facilitates the release of oxygen from hemoglobin.
3. Effect on Hemoglobin Affinity for Oxygen:
The binding of oxygen to hemoglobin is influenced by the pH and CO2 concentration. When the CO2 concentration is high, such as in actively metabolizing tissues, the following changes occur:
- Increased CO2 concentration leads to an increase in H+ ions, causing a decrease in pH.
- The decrease in pH leads to a decrease in the affinity of hemoglobin for oxygen.
- Hemoglobin releases its bound oxygen more readily due to the decreased affinity.
- This oxygen can then be utilized by the metabolizing tissues for cellular respiration.
4. Shift of Oxygen-Hemoglobin Dissociation Curve:
Bohr's effect causes a rightward shift in the oxygen-hemoglobin dissociation curve. This shift indicates a decreased affinity of hemoglobin for oxygen at a given partial pressure of oxygen (PO2).
- At the same PO2, the amount of oxygen released from hemoglobin increases in the presence of higher CO2 concentration.
- This shift allows for enhanced oxygen unloading in tissues where CO2 is being produced as a byproduct of cellular respiration.
Summary:
Bohr's effect describes the relationship between CO2 concentration, pH, and oxygen release from hemoglobin. As CO2 concentration increases, it leads to the formation of carbonic acid, which dissociates into H+ ions and HCO3-. The increase in H+ ions decreases blood pH, triggering a decrease in hemoglobin's affinity for oxygen. This facilitates the release of oxygen from hemoglobin, allowing it to be utilized by metabolizing tissues. The effect is represented by a rightward shift in the oxygen-hemoglobin dissociation curve.
During inspiration muscles of diaphragm- a)Contracts
- b)Expands
- c)No effect
- d)Coiled like string
Correct answer is option 'A'. Can you explain this answer?
During inspiration muscles of diaphragm
a)
Contracts
b)
Expands
c)
No effect
d)
Coiled like string
|
Srikant Shekhar answered |
Normally it is dome shaped.now for inspiration we have to increase the volume of thoracic cavity.in order to do so the diaphragm contracts and gets flattened.
Which of the following is not supported by cartilaginous rings- a)Primary bronchioles
- b)tertiary bronchioles
- c)tracheae
- d)Alveoli
Correct answer is option 'D'. Can you explain this answer?
Which of the following is not supported by cartilaginous rings
a)
Primary bronchioles
b)
tertiary bronchioles
c)
tracheae
d)
Alveoli
|
|
Neha Chakraborty answered |
Understanding Cartilaginous Structures in the Respiratory System
The respiratory system comprises various structures, each playing a crucial role in facilitating breathing. One important feature is the presence of cartilaginous rings, which provide structural support to specific airways.
Role of Cartilaginous Rings
- Cartilaginous rings are C-shaped structures made of hyaline cartilage.
- They prevent the collapse of airways during respiration.
- These rings are essential in maintaining open passages for airflow in the trachea and bronchi.
Supported Structures
- Trachea: The trachea is supported by cartilaginous rings that keep it open, allowing air to travel to the bronchi.
- Primary Bronchi: The primary bronchi, which branch from the trachea, also have cartilaginous rings that ensure they remain patent for air passage.
- Tertiary Bronchi: The tertiary bronchi (or segmental bronchi) continue to have cartilaginous support, providing stability as they branch further into the lungs.
Unsupported Structures
- Alveoli: Unlike the structures mentioned above, alveoli do not have cartilaginous rings. They are tiny air sacs where gas exchange occurs, composed primarily of elastic fibers and epithelial cells. The absence of cartilage allows for the flexibility needed during the breathing cycle.
Conclusion
In summary, the correct answer to the question is option 'D' (Alveoli), as they do not have cartilaginous rings supporting their structure, unlike the trachea, primary bronchi, and tertiary bronchi, which all rely on these rings for structural integrity.
The respiratory system comprises various structures, each playing a crucial role in facilitating breathing. One important feature is the presence of cartilaginous rings, which provide structural support to specific airways.
Role of Cartilaginous Rings
- Cartilaginous rings are C-shaped structures made of hyaline cartilage.
- They prevent the collapse of airways during respiration.
- These rings are essential in maintaining open passages for airflow in the trachea and bronchi.
Supported Structures
- Trachea: The trachea is supported by cartilaginous rings that keep it open, allowing air to travel to the bronchi.
- Primary Bronchi: The primary bronchi, which branch from the trachea, also have cartilaginous rings that ensure they remain patent for air passage.
- Tertiary Bronchi: The tertiary bronchi (or segmental bronchi) continue to have cartilaginous support, providing stability as they branch further into the lungs.
Unsupported Structures
- Alveoli: Unlike the structures mentioned above, alveoli do not have cartilaginous rings. They are tiny air sacs where gas exchange occurs, composed primarily of elastic fibers and epithelial cells. The absence of cartilage allows for the flexibility needed during the breathing cycle.
Conclusion
In summary, the correct answer to the question is option 'D' (Alveoli), as they do not have cartilaginous rings supporting their structure, unlike the trachea, primary bronchi, and tertiary bronchi, which all rely on these rings for structural integrity.
Wall of alveoli is composed of- a)Simple squamous epithelium
- b)Simple cuboidal epithelium
- c)Pseudostratified epithelium
- d)Simple columnar epithelium
Correct answer is option 'A'. Can you explain this answer?
Wall of alveoli is composed of
a)
Simple squamous epithelium
b)
Simple cuboidal epithelium
c)
Pseudostratified epithelium
d)
Simple columnar epithelium
|
|
Dhaanya Dhaanya answered |
A later of Squamous epithelial cells is really thin... we need thin surfaces for diffusion purposes.... simple squamous epithelium serves this purpose in alveoli...
Opening to the trachea is covered by a small flap of tissues termed as the ______.- a)Glottis
- b)Trachea
- c)Epiglottis
- d)Larynx
Correct answer is option 'C'. Can you explain this answer?
Opening to the trachea is covered by a small flap of tissues termed as the ______.
a)
Glottis
b)
Trachea
c)
Epiglottis
d)
Larynx
|
|
Hridoy Mehta answered |
**Explanation:**
The opening to the trachea is covered by a small flap of tissues known as the **epiglottis**. The epiglottis is a leaf-shaped structure made of elastic cartilage located at the base of the tongue, just behind the hyoid bone. It is attached to the entrance of the larynx and acts as a valve to prevent food and liquid from entering the airway during swallowing.
**Functions of the Epiglottis:**
1. **Swallowing:** During swallowing, the epiglottis closes over the larynx, covering the opening to the trachea. This prevents food and liquid from entering the respiratory tract and ensures they are directed towards the esophagus and down into the stomach.
2. **Protecting the Airways:** The epiglottis acts as a protective mechanism for the airway. It closes off the entrance to the trachea, preventing the entry of foreign particles, such as food, liquids, or saliva, into the lungs. This helps to prevent choking and aspiration pneumonia.
3. **Respiratory Functions:** When not involved in swallowing, the epiglottis remains in an upright position, allowing air to freely flow through the larynx and into the trachea. The opening in the larynx, covered by the epiglottis, is called the glottis, through which air passes during breathing.
**Conclusion:**
The epiglottis is a crucial structure in the respiratory system as it helps in swallowing and protecting the airways. It covers the opening to the trachea, preventing the entry of food and liquid into the respiratory tract. The correct answer to the given question is **c) Epiglottis**.
The opening to the trachea is covered by a small flap of tissues known as the **epiglottis**. The epiglottis is a leaf-shaped structure made of elastic cartilage located at the base of the tongue, just behind the hyoid bone. It is attached to the entrance of the larynx and acts as a valve to prevent food and liquid from entering the airway during swallowing.
**Functions of the Epiglottis:**
1. **Swallowing:** During swallowing, the epiglottis closes over the larynx, covering the opening to the trachea. This prevents food and liquid from entering the respiratory tract and ensures they are directed towards the esophagus and down into the stomach.
2. **Protecting the Airways:** The epiglottis acts as a protective mechanism for the airway. It closes off the entrance to the trachea, preventing the entry of foreign particles, such as food, liquids, or saliva, into the lungs. This helps to prevent choking and aspiration pneumonia.
3. **Respiratory Functions:** When not involved in swallowing, the epiglottis remains in an upright position, allowing air to freely flow through the larynx and into the trachea. The opening in the larynx, covered by the epiglottis, is called the glottis, through which air passes during breathing.
**Conclusion:**
The epiglottis is a crucial structure in the respiratory system as it helps in swallowing and protecting the airways. It covers the opening to the trachea, preventing the entry of food and liquid into the respiratory tract. The correct answer to the given question is **c) Epiglottis**.
Pneumotaxic centre is present in- a)Pons
- b)Medulla
- c)Cerebrum
- d)Lungs
Correct answer is option 'A'. Can you explain this answer?
Pneumotaxic centre is present in
a)
Pons
b)
Medulla
c)
Cerebrum
d)
Lungs
|
|
Rocky Handsome answered |
¥¥The pneumotaxic center is located in the upper part of the pons. Its nuclei are the subparabrachial nucleus and the medial parabrachial nucleus.
•The pneumotaxic center controls both the rate and the pattern of breathing.
•The pneumotaxic center controls both the rate and the pattern of breathing.
Thoracic cavity is enlarged by contraction of- a)Internal Intercostal muscles
- b)Diaphragm
- c)Lungs
- d)All of above
Correct answer is option 'B'. Can you explain this answer?
Thoracic cavity is enlarged by contraction of
a)
Internal Intercostal muscles
b)
Diaphragm
c)
Lungs
d)
All of above
|
|
Rohit Shah answered |
When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.
Trachea is a straight tube extending up to the ________- a)End of pharynx
- b)Anterior of the thoracic cavity
- c)Posterior of the thoracic cavity
- d)Middle of larynx
Correct answer is option 'B'. Can you explain this answer?
Trachea is a straight tube extending up to the ________
a)
End of pharynx
b)
Anterior of the thoracic cavity
c)
Posterior of the thoracic cavity
d)
Middle of larynx
|
Stepway Academy answered |
- Trachea is a straight tube extending up to the anterior part of the thoracic cavity.
- It is also known as the windpipe.
- The trachea connects the soundbox to the bronchi.
- Also, it provides the passage for air.
Among mammals, the efficiency of ventilation of lungs as compared to reptiles and birds is better developed by the presence of
- a)Ribs & costal muscles
- b)Only ribs
- c)Only costal muscles
- d)Diaphragm
Correct answer is option 'D'. Can you explain this answer?
Among mammals, the efficiency of ventilation of lungs as compared to reptiles and birds is better developed by the presence of
a)
Ribs & costal muscles
b)
Only ribs
c)
Only costal muscles
d)
Diaphragm
|
|
Sinjini Das answered |
In the reptiles and the birds, the respiration is less efficient than the mammals. It is because in mammals they have secondary structures that will help them to breathe and respire better. In addition to the lungs, the mammals have the ribs and internal and external intercostal muscles. They help in increasing the volume and the space in the lungs and thus the respiration is way more efficient.
So, the correct option is 'Ribs & coastal muscles'
Chapter doubts & questions for Respiratory System - Biology 2025 is part of Grade 9 exam preparation. The chapters have been prepared according to the Grade 9 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Grade 9 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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