Tag: bio-chemistry

Quizzes (82) Questions (1918)

Questions Related to bio-chemistry

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Assertion :

Inspiration occurs due to muscular relaxation.



Reason : During

inspiration, ihe diaphragm and external iniercostal muscle contract

simultaneously






  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

(e) Inspiration is the result of muscular contraction. The diaphragm and external intercostal muscle contracts simultaneously. The lateral thoracic wall moves outward and upward.





Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

In response to $CO {2}$ and $H^{+}$ concentration, the chemosensitive area and, receptors associated with aortic arch and carotic artery, send necessary signals for remedial action to ______________.

  1. Pneumotaxic centre

  2. Apneustic centre

  3. Respiratory rhythm centre

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chemosensitive areas in the medulla and peripheral receptors in the aortic arch and carotid artery detect changes in carbon dioxide and hydrogen ion levels. They transmit regulatory nerve signals directly to the respiratory rhythm centre in the medulla to adjust breathing rate.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Listed below are four respiratory capacities (i-iv) and four jumbled respiratory volumes of a normal human adult.

Respiratory volumes and capacities Volume of air
(i)    Residual volume  2500 mL
(ii)   Vital capacity   3500 mL
(iii) Inspiratory reserve volume 1200 mL
 (iv) Inspiratory capacity  4500 mL

Which one of the following is the correct matching of two capacities and volumes?

  1. (ii) 2500 mL, (iii) 4500 mL

  2. (iii) 1200 mL, (iv) 2500 mL

  3. (iv)3500mL, (i) 1200 mL

  4. (i) 4500 mL; (ii) 3500 mL
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Respiratory volumes and capacities Volume of air

Residual volume 1200 mL Vital capacity 4500 mL
Inspiratory reserve volume 2500 mL Inspiratory capacity 3500 mL.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Rate of breathing is controlled mainly by ________________.

  1. $CO _{2}$ level in blood

  2. pH in blood
  3. $O _{2}$ level in blood
  4. $O _{2}$ level and pH in blood.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rate of breathing is mainly controlled by $CO _2$ level in the blood. Excess $CO _2$ decrease the pH of the blood and it mainly stimulate the respiratory centre of the brain (i.e., Medulla oblongata) and increase the inspiratory and expiratory signals to the respiratory muscles.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Rate of breathing is controlled mainly by

  1. $CO _2$ level in blood

  2. pH in blood
  3. $O _2$ level in blood
  4. $O _2$ level and pH in blood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The rate of breathing is controlled mainly by CO$ _2$ level in blood. The partial pressure of carbon dioxide (PCO$ _2$) controls the respiratory rate. The respiratory centre measures the levels of carbon dioxide, oxygen and acidosis in the arterial blood and sends message accordingly. If the carbon dioxide levels in the blood increases, the rate and depth of breathing increases.

Thus, the correct answer is 'CO$ _2$ level in blood.'

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Which of the following is not a stimulus for breathing?

  1. Rising $CO _2$ levels

  2. Rising blood pressure
  3. Arterial $pO _2$ below $60$mm of Hg

  4. Change in pH of arterial blood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

An increased concentration of carbon dioxide is the strongest stimulus to breathe more deeply and more frequently. When the carbon dioxide concentration in the blood is low, the brain decreases the frequency and depth of breath.

So the correct answer is 'Rising CO2 levels'.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Types of chemoreceptors involved in respiration regulation is

  1. Central chemoreceptors

  2. Peripheral chemoreceptors

  3. Spinal chemoreceptors

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Central and peripheral chemoreceptors involve in the regulation of respiration. They detect reduction and elevation in the concentration level of oxygen, carbon dioxide and pH in the body.
So the correct answer is 'Both A and B'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

In response to a decrease in blood pH, the respiratory center sends nervous impulses to

  1. Increase breathing rate

  2. Decrease breathing rate

  3. Increase heart beat

  4. None of th above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Respiratory centre is located in the medulla oblongata and pons. They control the rate and depth of respiratory movements of the diaphragm. The increase in CO$ _2$ level in the blood lowers the pH of the blood which in response cause respiratory center to send impulses to breath fast and increase breathing rate.
So the correct answer is 'Increase breathing rate'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Central chemoreceptors are found in

  1. Pons

  2. Medulla

  3. Spinal cord

  4. Cerebrum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Central chemoreceptors are located on the ventrolateral medullary surface in the central nervous system. There receptors act to detect the changes in pH of their environment by detecting alteration in the concentration of O$ _2$ and CO$ _2$ of nearby cerebrospinal fluid. The decrease in CO$ _2$ causes the blood to become more acidic while it's increase makes the blood alkaline
So, the correct answer is 'Medulla'.
Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

Central chemoreceptors are sensitive to the

  1. pH of their environment

  2. Level of oxygen

  3. High blood pressure

  4. Level of sugar in blood
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Central chemoreceptors are located on the ventrolateral medullary surface in the central nervous system. There receptors act to detect the changes in pH of their environment by detecting alteration in the concentration of O$ _2$ and CO$ _2$ of nearby cerebrospinal fluid. The decrease in CO$ _2$ causes the blood to become more acidic while it's increase makes the blood alkaline.
So, the correct answer is 'pH of their environment'.