Breathing And Exchange Of Gasses

Question 1

How does lower invertebrates like sponges coelenterates and flatworms etc exchange O2 with CO2?

Answer 1

By simple diffusion

Question 2

What does earthworm use for respiration?

Answer 2

Moist cuticle

Question 3

What does insects use for respiration

Answer 3

Tracheal tubes

Question 4

What do arthropods and molluscs use for respiration??

Answer 4

Gills (branchial respiration)

Question 5

What does terrestrial forms use for respiration??

Answer 5

Lungs ( pulmonary respiration)

Question 6

What does frog use for respiration?

Answer 6

Moist skin ( cutaneous respiration)

Question 7

Explain the whole passage of respiration in humans

Answer 7

At first the air goes from the nasal passage then goes to the pharynx and the pharynx opens through the larynx region into the trachea then bronchi and then bronchioles.

Question 8

What is the sound box

Answer 8

Larynx

Question 9

What is epiglottis and glottis

Answer 9

Epiglottis is an elastic cartilage flap which acts as a door for food and air, and glottis is the area where epiglottis is located

Question 10

What is mid thoracic cavity

Answer 10

It’s the chest cavity and trachea extends till here

Question 11

Trachea is supported by complete or incomplete cartilaginous rings

Answer 11

Incomplete

Question 12

What is pleura and what does it do

Answer 12

Pleura reduces the surface friction in movement of lungs , it is present in the lining of lungs

Question 13

Explain five steps of human respiration

Answer 13

1. Breathing
2. Diffusion of gases
3. Transport of gases
4. Diffusion of O2 and CO2 between blood and tissues
5. Utilisation

Question 14

Breathing

Answer 14

Involves two stages - inspiration (drawing in atmospheric air) and expiration (releasing alveolar air). The movement of air is facilitated by a pressure gradient between the lungs and the atmosphere.

Question 15

Inspiration

Answer 15

Initiated by the contraction of the diaphragm and external inter-costal muscles, leading to an increase in thoracic and pulmonary volumes. It occurs when intra-pulmonary pressure is less than atmospheric pressure.

Question 16

Expiration

Answer 16

Occurs when intra-pulmonary pressure is higher than atmospheric pressure. It involves the relaxation of the diaphragm and inter-costal muscles, leading to a decrease in thoracic and pulmonary volumes.

Question 17

Respiratory Muscles

Answer 17

The diaphragm and a specialized set of muscles, including external and internal intercostals, play a crucial role in creating pressure gradients for breathing.

Question 18

Spirometer

Answer 18

A device used to estimate the volume of air involved in breathing movements, aiding in the clinical assessment of pulmonary functions.

Question 19

Tidal Volume (TV)

Answer 19

Volume of air inspired or expired during a normal respiration, approximately 500 mL. A healthy individual can breathe in or out around 6000 to 8000 mL of air per minute.

Question 20

Inspiratory Reserve Volume (IRV)

Answer 20

Additional volume of air a person can inspire by a forcible inspiration, averaging between 2500 mL to 3000 mL.

Question 21

Expiratory Reserve Volume (ERV)

Answer 21

Additional volume of air a person can expire by a forcible expiration, averaging between 1000 mL to 1100 mL.

Question 22

Residual Volume (RV)

Answer 22

Volume of air remaining in the lungs after a forcible expiration, averaging between 1100 mL to 1200 mL

Question 23

Inspiratory Capacity (IC)

Answer 23

Total volume of air a person can inspire after a normal expiration, including tidal volume and inspiratory reserve volume (TV+IRV).

Question 24

Expiratory Capacity (EC)

Answer 24

Total volume of air a person can expire after a normal inspiration, including tidal volume and expiratory reserve volume (TV+ERV).

Question 25

Functional Residual Capacity (FRC)

Answer 25

Volume of air that remains in the lungs after a normal expiration, including expiratory reserve volume and residual volume (ERV+RV).

Question 26

Vital Capacity (VC)

Answer 26

The maximum volume of air a person can breathe in after a forced expiration, including expiratory reserve volume, tidal volume, and inspiratory reserve volume (ERV+TV+IRV).

Question 27

Total Lung Capacity (TLC)

Answer 27

Total volume of air accommodated in the lungs at the end of a forced inspiration, including residual volume, expiratory reserve volume, tidal volume, and inspiratory reserve volume (RV+ERV+TV+IRV) or vital capacity + residual volume.

Question 28

Exchange of Gases

Answer 28

Alveoli are the primary sites for gas exchange, occurring between blood and tissues. Oxygen (O2) and carbon dioxide (CO2) are exchanged through simple diffusion based on pressure/concentration gradients.

Question 29

Partial Pressure

Answer 29

The pressure contributed by an individual gas in a mixture, represented as pO2 for oxygen and pCO2 for carbon dioxide.

Question 30

Solubility and Diffusion

Answer 30

Solubility of gases and the thickness of diffusion membranes influence the rate of gas diffusion. CO2, with higher solubility than O2, diffuses more efficiently.

Question 31

Diffusion Membrane of alveoli

Answer 31

Composed of the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries, and the basement substance. Despite its thinness, it facilitates efficient gas exchange

Question 32

Factors Favorable for Diffusion

Answer 32

The overall structure of the diffusion membrane and the concentration gradients in the body favor the diffusion of O2 from alveoli to tissues and CO2 from tissues to alveoli.

Question 33

Concentration Gradient

Answer 33

1. Alveolar air
   O - 104
   CO2– 40 mmhg
2. Carrying deoxygenated blood
   O—40
   CO2— 45
   3.carrying oxygenated blood
   O—95
   CO2—40

Question 34

Transport of Gases

Answer 34

Blood serves as the medium for the transport of oxygen (O2) and carbon dioxide (CO2). Approximately 97% of O2 is carried by red blood cells (RBCs), and the remaining 3% is dissolved in the plasma.

Question 35

Oxygen Transport

Answer 35

RBCs are the primary carriers, transporting about 97% of oxygen, while the remaining 3% is in a dissolved state in the plasma.

Question 36

Carbon Dioxide Transport

Answer 36

RBCs transport about 20-25% of carbon dioxide, 70% is carried as bicarbonate, and the remaining 7% is dissolved in the plasma.

Question 37

Bicarbonate

Answer 37

A significant form in which carbon dioxide is transported in the blood, constituting 70% of its transport.

Question 38

Dissolved Gases in Plasma

Answer 38

A small percentage (3% for O2, 7% for CO2) of gases is transported in a dissolved state through the plasma.

Question 39

Transport of Oxygen

Answer 39

Haemoglobin, a red-colored iron-containing pigment in RBCs, binds with oxygen (O2) to form reversible oxyhaemoglobin. Each haemoglobin molecule can carry up to four molecules of O2.

Question 40

Haemoglobin Structure

Answer 40

Haemoglobin is a pigment in RBCs capable of reversible binding with O2. It plays a crucial role in oxygen transport.

Question 41

Oxygen Dissociation Curve

Answer 41

The Oxygen Dissociation Curve is obtained by plotting the percentage saturation of haemoglobin with O2 against partial pressure of O2 (pO2). It is useful in studying the effects of factors like pCO2, H+ concentration, etc., on O2 binding.

Question 42

Factors Affecting O2 Binding

Answer 42

The binding of O2 with haemoglobin is primarily related to the partial pressure of O2. Other factors influencing this binding include partial pressure of CO2, hydrogen ion concentration, and temperature

Question 43

Oxygen Binding in Alveoli and tissues

Answer 43

In the alveoli, conditions are favorable for the formation of oxyhaemoglobin due to high pO2, low pCO2, lesser H+ concentration, and lower temperature. In the tissues, conditions favor the dissociation of oxygen from oxyhaemoglobin due to low pO2, high pCO2, high H+ concentration, and higher temperature.