Tag: bio-chemistry

Questions Related to bio-chemistry

Assertion :

Inspiration occurs due to muscular relaxation.



Reason : During

inspiration, ihe diaphragm and external iniercostal muscle contract

simultaneously






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

  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

Show answer
Correct Option: E
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.





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 ______________.

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

  1. Pneumotaxic centre

  2. Apneustic centre

  3. Respiratory rhythm centre

  4. Both A and B

Show answer
Correct Option: A

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?

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

  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

Show answer
Correct Option: C
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.

Rate of breathing is controlled mainly by ________________.

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

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

  2. pH in blood

  3. $O _{2}$ level in blood

  4. $O _{2}$ level and pH in blood.

Show answer
Correct Option: A
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.

Rate of breathing is controlled mainly by

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

  1. $CO _2$ level in blood

  2. pH in blood

  3. $O _2$ level in blood

  4. $O _2$ level and pH in blood

Show answer
Correct Option: A
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.'

Which of the following is not a stimulus for breathing?

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

  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

Show answer
Correct Option: A
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'.

Types of chemoreceptors involved in respiration regulation is

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

  1. Central chemoreceptors

  2. Peripheral chemoreceptors

  3. Spinal chemoreceptors

  4. Both A and B

Show answer
Correct Option: D
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'.

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

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

  1. Increase breathing rate

  2. Decrease breathing rate

  3. Increase heart beat

  4. None of th above

Show answer
Correct Option: A
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'.

Central chemoreceptors are found in

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

  1. Pons

  2. Medulla

  3. Spinal cord

  4. Cerebrum

Show answer
Correct Option: B
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'.

Central chemoreceptors are sensitive to the

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

  1. pH of their environment

  2. Level of oxygen

  3. High blood pressure

  4. Level of sugar in blood

Show answer
Correct Option: A
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'.