Transport of Carbon Dioxide

Q.

The partial pressures (in mm Hg) of oxygen (O₂) and carbon dioxide (CO₂) at alveoli (the site of diffusion) are:

1. pO₂ = 159 and pCO = 0.3

2. pO₂ = 104 and pCO₂ = 40

3. pO₂ = 40 and pCO₂ = 45

4. pO₂ = 95 and pCO₂ = 40

Q.

What is the difference between oxygenated and deoxygenated blood?

Q.

What are the main factors that affect normal breathing?

Q. Which of the following statement is not true?

1. Every $100ml$ of oxygenated blood can deliver $20ml$ of $O_2$ to the tissues
2. Every $100ml$ of deoxygenated blood delivers approximately $4ml$ of $C{O}_2$ to the alveoli
3. None of these
4. Transport of carbon dioxide is carried by haemoglobin in the form of carbaminohaemoglobin

Q.

Carbon dioxide dissociates from carbaminohaemoglobin when

1. pCO2 and pO2 are equal

2. pCO2 is high and pO2 is low.

3. pO2 is high and pCO2 is low

4. None of the above.

Q.

Approximately seventy percent of carbon­ dioxide absorbed by the blood will be transported to the lungs

1. in the form of dissolved gas molecules

2. as bicarbonate ions

3. as carbamino-haemoglobin

4. by binding to R.B.C

Q. The additional volume of air a person can expire by a forceful expiration is called

1. Expiratory Capacity
2. Inspiratory Capacity
3. Expiratory Reserve Volume
4. Total Lung Capacity

Q.

Inspiratory capacity is:

1. The total amount of air that can be inspired after a tidal expiration

2. The total amount of exchangeable air

3. Another name for functional residual capacity

4. The amount of air inspired after a tidal inspiration

Q.

Read the following statements and find out the incorrect statement$\left(s\right).$

$a.$ The binding of $C{O}_2$ with haemoglobin is related to the partial pressure of $C{O}_2.p{O}_2$ is a major factor which could affect this binding.

$b.$ When $pC{O}_2$ is low and $p{O}_2$ is high as in the alveoli, more binding of $C{O}_2$ occurs, whereas when the $pC{O}_2$ is high and $p{O}_2$ is low as in the tissues, dissolution of $C{O}_2$ from carbaminohaemoglobin takes place.

$c.$ At the tissue site, where partial pressure of $C{O}_2$ is high due to catabolism, $C{O}_2$ diffuses into blood $\left(RBCs\text{and plasma}\right)$ and forms $HC{O}_3^{-}$ and $H^{+}.$ At the alveolar site where $pC{O}_2$ is low, the reaction proceeds in the opposite direction leading to the formation of $C{O}_2$ and $H_{2}O.$

$d.$ Oxygen dissociation curve is highly useful in studying the effect of factor like $pC{O}_2,H^{+}$ concentration, etc., on binding of $O_2$ with haemoglobin.

1. $c$ and $d$
2. $b$ only
3. $a$ and $b$
4. $b$ and $c$

Q.

What are the major transport mechanisms for $C{O}_2$? Explain.

Q.

Total lung capacity is equal to:

1. Vital capacity x Tidal volume

2. Functional residual capacity + Expiratory reserve volume

3. Anatomical dead space + Alveolar dead space

4. Residual volume + Vital capacity

Q.

How does pH affect oxygen dissociation curve?

Q.

The enzyme which converts carbon dioxide in the RBCs into carbonic acid, protons and bicarbonates and its co-factor is

1. Carbonic anhydrase and magnesium

2. Carboxylase and sodium

3. Carboxylase and zinc

4. Carbonic anhydrase and zinc

Q.

Hamburger shift is also known as

1. Bicarbonate shift

2. Chloride shift

3. Potassium shift

4. All of the above

Q.

Identify the correct statement with respect to the transport of respiratory gases by blood.

1. Haemoglobin is necessary for the transport of oxygen and carbonic anhydrase for the transport of carbon dioxide.

2. Haemoglobin is necessary for the transport of carbon dioxide and carbonic anhydrase for the transport of oxygen.

3. Only oxygen is transported by blood.

4. Only carbon dioxide is transported by blood

Q. $C{O}_2$ dissociates from carbamino-haemoglobin when:

1. $pC{O}_2\text{is high and}p{O}_2\text{is low}$
2. $p{O}_2\text{is high and}pC{O}_2\text{is low}$
3. $pC{O}_2\text{and}p{O}_2\text{are equal}$
4. $\text{None of the above}$

Q. The partial pressure of $C{O}_2$ in the air inside the lungs compared to venous blood is

1. higher
2. lower
3. equal
4. variable

Q.

The chloride shift occurs in response to

1. HCO₃⁻

2. H⁺

3. Na⁺

4. K⁺

Q. Read the following statements and select the correct one.

1. The $H^{+}$ released from carbonic acid combines with haemoglobin to form haemoglobinic acid
2. Oxyhaemoglobin of erythrocytes is alkaline
3. More than 70% of carbon dioxide is transferred from tissues to the lungs in the form of carbamino compounds
4. In lungs, the oxygen from the alveolus reaches the blood through active transport

Q. Enzyme involved in $C{O}_2$ transport in blood is

Q.

$C{O}_2$ dissociates from carbamino haemoglobin when

(a) $pC{O}_2$ is high and $p{O}_2$ is low

(b) $p{O}_2$ is high and $pC{O}_2$ is low

(c) $pC{O}_2$ and $p{O}_2$ are equal

(d) None of the above

Q. ______________ is formed by the reversible combination of carbon dioxide with haemoglobin.

1. Carboxyhaemoglobin
2. Carbaminohaemoglobin
3. Oxyhaemoglobin
4. Bicarbonate ions

Q.

State the different modes of $C{O}_2$ transport in blood.

Q.

Write a note on the affinity of hemoglobin.

Q. Approximately 70% of $C{O}_2$ is absorbed by the blood and will be transported to the lungs as ___________.

1. carbamino haemoglobin
2. gaseous form
3. bicarbonate ions
4. carbon monoxide

Q.

How does high blood pressure affect gas exchange?

Q. Listed below are four respiratory capacities (A-D) in column I and four jumbled respiratory volume of a normal human adult in column II.
$\begin{array}{cccc}& \text{Column - I}& & \text{Column - II}\\ & \text{(Respiratory capacities)}& & \text{(Respiratory volumes)}\\ \text{A.}& \text{Residual volume}& \text{I.}& \text{2500 mL}\\ \text{B.}& \text{Vital capacity}& \text{II.}& \text{3500 mL}\\ \text{C.}& \text{Inspiratory reserve volume}& \text{III.}& \text{1200 mL}\\ \text{D.}& \text{Inspiratory capacity}& \text{IV.}& \text{4500 mL}\end{array}$

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

1. A – I; B – II; C – III; D – IV
2. A – IV; B – III; C – I; D – II
3. A – II; B – III; C – IV; D – I
4. A – III; B – IV; C – I; D – II

Q.

Within the blood, oxygen is primarily transported __________________ while the bulk of carbon dioxide is transported _________________.

1. in association with hemoglobin; as carbon dioxide, dissolved in the plasma

2. as oxyhemoglobin; as bicarbonate ions

3. as deoxyhemoglobin; as carbaminohemoglobin

4. dissolved in the plasma; as carbaminohemoglobin

Q. In blood, carbon dioxide is primarily carried in the form of _________.

1. potassium bicarbonate
2. carbamino haemoglobin
3. sodium bicarbonate
4. dissolved in plasma

Q.

Which of the choices below is not a functional process performed by the respiratory system?

1. pulmonary ventilation

2. transport of respiratory gases

3. pulmonary respiration

4. external respiration