Exchange of Gases

Q.

How are oxygen and carbon dioxide transported in human beings?

Q.

What will be the $p{O}_2$ and $pCO2$ in the atmospheric air compared to those in the alveolar air?

Q. What is the $P{o}_2$ and $Pc{o}_2$ in the systemic arteries?

1. $P{o}_2$ 40 mm Hg; $Pc{o}_2$ 45 mm Hg
2. $P{o}_2$ 95 mm Hg; $Pc{o}_2$ 40 mm Hg
3. $P{o}_2$ 40 mm Hg; $Pc{o}_2$ 40 mm Hg
4. $P{o}_2$ 45 mm Hg; $Pc{o}_2$ 40 mm Hg
5. $P{o}_2$ 104 mm Hg; $Pc{o}_2$ 159 mm Hg

Q.

What will be the pO₂ and pCO₂ in the atmospheric air compared to those in the alveolar air?

(i) pO₂ lesser, pCO₂ higher

(ii) pO₂ higher, pCO₂ lesser

(iii) pO₂ higher, pCO₂ higher

(iv) pO₂ lesser, pCO₂ lesser

Q. Exchange of gases in lungs occurs through

1. Simple diffusion
2. Active transport
3. Osmois
4. Plasmolysis

Q. Which of the following statement(s) regarding respiration in humans is/are not correct?

1. Exchange of gases takes place in alveoli region
2. All are incorrect
3. Exchange of gases takes place by the process of diffusion
4. Oxygen is transported only by RBC

Q.

Why do capillaries have only endothelium lining?

Q.

What is the role of the lungs in blood circulation?

Q.

What are alveoli made up of ?

Q. The RBCs in our body perform a vital role of oxygen transporration. But they do not possess nucleus, mitochondria to co ordinate any cellular activities. But it lives for 120 days. How does it get energy? Does it perform anaerobic respiration?

Q. Why is alveolar air not of the same composition as that of atmospheric air?

1. Moisture dilutes ${\mathrm{pO}}_2$ of alveolar air
2. ${\mathrm{pO}}_2$ in alveolar air is less than atmospheric air
3. Moisture increases ${\mathrm{pO}}_2$ of alveolar air
4. ${\mathrm{pO}}_2$ in atmospheric air is less than atmospheric air

Q. What is the site for respiratory gas exchange in the human body?

1. Alveoli
2. Lungs
3. None of the above
4. RBC

Q. About 70% of $C{O}_2$ in blood is transported in the form of

1. dissolved $C{O}_2$
2. bicarbonates
3. carbaminohaemoglobin
4. carboxyhaemoglobin

Q.

Which cells are the main sites of gas exchange?

Q.

What is the partial pressure of oxygen and carbon dioxide in atmospheric air?

1. 160 mmHg and 0.23 mmHg

2. 104 mmHg and 40 mmHg

3. 40 mmHg and 45 mmHg

4. 95 mmHg and 40 mmHg

Q.

The nephrons discharge their urine at the

1. urinary bladder

2. urethra

3. renal pelvis

4. renal pyramid

Q.

For completion of respiration process, write the given steps in sequential manner.

(a) Diffusion of gases $\left(O_{2}andC{O}_2\right)$ across alveolar membrane.

(b) Transport of gases by blood.

(c) Utilisation of $O_2$ by the cells for catabolic reactions and resultant release of $C{O}_2$.

(d) Pulmonary ventilation by which atmospheric air is drawn in and $C{O}_2$ rich alveolar air is released out.

(e) Diffusion of $O_{2}andC{O}_2$ between blood and tissues.~

Q.

If the partial pressures of oxygen and carbon dioxide in the alveoli are 104 and 40 and in the blood reaching the alveoli at that moment it is 40 and 45 respectively, then oxygen and carbon dioxide will diffuse from

1. There will be no exchange of gases

2. Both oxygen and carbon dioxide will diffuse from blood into alveoli

3. Oxygen will diffuse from alveoli into blood and carbon dioxide will diffuse from blood into alveoli

4. Oxygen will diffuse from blood into alveoli and carbon dioxide will diffuse from alveoli into blood

Q. How do we breathe?

Q.

The correct pathway of movement of gases in the body is

1. Oxygen from alveoli – pulmonary vein – left atrium – left ventricle – systemic arteries – tissues – carbon dioxide from tissues – systemic veins – right atrium – right ventricle – pulmonary artery – alveoli.

2. Oxygen from alveoli – pulmonary artery – left atrium – left ventricle – systemic arteries – tissues – carbon dioxide from tissues – systemic veins – right atrium – right ventricle – pulmonary vein – alveoli.

3. Oxygen from alveoli – pulmonary vein – left atrium – left ventricle – systemic veins – tissues – carbon dioxide from tissues – systemic arteries – right atrium – right ventricle – pulmonary artery – alveoli.

4. Oxygen from alveoli – pulmonary vein – right atrium – right ventricle – systemic arteries – tissues – carbon dioxide from tissues – systemic veins – left atrium – left ventricle – pulmonary artery – alveoli

Q.

In humans, which among these is not a step in respiration?

1. Transport of gases by blood

2. Diffusion of O2 and CO2 between blood and tissues

3. Utilisation of CO2 by cells for catabolic reactions

4. Alveolar diffusion of O2 and CO2

Q. Which one of the following statements is incorrect?

1. Birds and land snails are uricotelic animals.
2. Aquatic amphibians and aquatic insects are ammonotelic animals
3. Mammals and frogs are ureotelic animals
4. Birds and reptiles are ureotelic

Q. Match the following
$\begin{array}{cccc}\text{(a)}& \text{Bohr effect}& \text{(i)}& \text{Increase in}{O}_2\text{causes release of}C{O}_2\text{from Hb into lungs}\\ \text{(b)}& \text{Haldane effect}& \text{(ii)}& \text{Increase in}C{O}_2\text{causes release of}{O}_2\text{from Hb into tissues}\\ \text{(c)}& \text{Diffusion}& \text{(iii)}& \text{Movement of solvent through semi permeable membrane to the region of higher solute concentration.}\\ \text{(d)}& \text{Osmosis}& \text{(iv)}& \text{Movement of solute from high concentration to low concentration}\end{array}$

1. a-iv, b-i, c-iii, d-ii
2. a-i, b-ii, c-iii, d-iv
3. a-ii, b-i, c-iv, d-iii
4. a-iii, b-ii, c-i, d-iv

Q. Fill in the blanks.

a. Breathing involves two stages:
......1...... during which atmospheric air is drawn in and
......2...... by which alveolar air is released out.

b. The movement of air into and out of the lungs is carried out by ......3...... gradient between the lungs and the atmosphere.

c. Inspiration can occur if the pressure within lungs is ....4.... than the atmospheric pressure i.e., there is a ....5..... pressure in the lungs with respect to atmospheric pressure.

d. Expiration takes place when the intrapulmonary pressure is ....6.... than atmospheric pressure.

1. 1-inspiration, 2-expiration, 3-pressure, 4-higher, 5-positive, 6-lower
2. 1- inspiration, 2- expiration, 3- pressure, 4-lower, 5-negative, 6-higher
3. 1-inspiration, 2-expiration, 3-pressure, 4-higher, 5-negative, 6- lower
4. 1-expiration, 2-inspiration, 3-concentration, 4-lower, 5- positive, 6- higher

Q. Explain the process of external respiration.

Q.

Stomata are mostly present on the

1. upper surface of the leaf.

2. lower surface of the leaf.

3. tip of the leaf.

4. point of attachment of the leaf to its petiole.

Q.

The Respiratory system and Circulatory system meet here

1. alveoli

2. diaphragm

3. mouth

4. brain

Q. During sleep the rate of RBC formation increases or decreases .Explain.

Q. Discuss the transport of gases ($O_2$ and $C{O}_2$) in the blood.

Q. How oxygen enters in blood from alveoli of lungs?

1. Pressure of $C{O}_2$
2. Simple diffusion
3. By Haemoglobin
4. None of the above