Breathing And Respiration

Question 1

What is the process of exchanging O2 and CO2 called?

Answer 1

The process of exchanging O2 from the atmosphere with CO2 produced by the cells is called breathing, commonly known as respiration.

Question 2

How do lower invertebrates exchange gases?

Answer 2

Lower invertebrates like sponges and flatworms exchange O2 with CO2 by simple diffusion over their entire body surface.

Question 3

What respiratory structures do earthworms and insects use?

Answer 3

Earthworms use their moist cuticle, while insects have a network of tubes called tracheal tubes to transport atmospheric air within the body.

Question 4

What structures do aquatic arthropods and molluscs use for gas exchange?

Answer 4

Aquatic arthropods and molluscs use special vascularised structures called gills for gas exchange.

Question 5

What respiratory structures do terrestrial vertebrates use?

Answer 5

Terrestrial vertebrates, including reptiles, birds, and mammals, respire through lungs.

Question 6

What is the role of the larynx in the human respiratory system?

Answer 6

The larynx is a cartilaginous box that helps in sound production and is referred to as the sound box.

Question 7

What is the function of the epiglottis?

Answer 7

The epiglottis is a thin elastic cartilaginous flap that covers the glottis during swallowing to prevent food from entering the larynx.

Question 8

What are alveoli?

Answer 8

Alveoli are very thin, irregular-walled, vascularised bag-like structures where gas exchange occurs.

Question 9

What is the conducting part of the respiratory system?

Answer 9

The conducting part transports atmospheric air to the alveoli, clears it from foreign particles, humidifies it, and brings it to body temperature.

Question 10

What are the steps involved in respiration?

Answer 10

Respiration involves breathing, diffusion of gases across the alveolar membrane, transport of gases by blood, diffusion between blood and tissues, and utilization of O2 by cells.

Question 11

What are the two stages of breathing?

Answer 11

Breathing involves two stages: inspiration (drawing in air) and expiration (releasing air).

Question 12

What muscles are involved in inspiration?

Answer 12

The diaphragm and external intercostal muscles are involved in generating the pressure gradient for inspiration.

Question 13

What is Tidal Volume (TV)?

Answer 13

Tidal Volume (TV) is the volume of air inspired or expired during a normal respiration, approximately 500 mL.

Question 14

What is Inspiratory Reserve Volume (IRV)?

Answer 14

Inspiratory Reserve Volume (IRV) is the additional volume of air a person can inspire by forcible inspiration, averaging 2500 mL to 3000 mL.

Question 15

What is Expiratory Reserve Volume (ERV)?

Answer 15

Expiratory Reserve Volume (ERV) is the additional volume of air a person can expire by forcible expiration, averaging 1000 mL to 1100 mL.

Question 16

What is Residual Volume (RV)?

Answer 16

Residual Volume (RV) is the volume of air remaining in the lungs after a forcible expiration, averaging 1100 mL to 1200 mL.

Question 17

What is Vital Capacity (VC)?

Answer 17

Vital Capacity (VC) is the maximum volume of air a person can breathe in after a forced expiration, including ERV, TV, and IRV.

Question 18

What is the primary site of gas exchange?

Answer 18

Alveoli are the primary sites of exchange of gases.

Question 19

What is partial pressure?

Answer 19

Partial pressure is the pressure contributed by an individual gas in a mixture of gases, represented as pO2 for oxygen and pCO2 for carbon dioxide.

Question 20

How is oxygen transported in the blood?

Answer 20

About 97 percent of O2 is transported by RBCs in the blood, while the remaining 3 percent is carried in a dissolved state through the plasma.

Question 21

What is the oxygen dissociation curve?

Answer 21

The oxygen dissociation curve is a sigmoid curve that plots the percentage saturation of haemoglobin with O2 against the partial pressure of O2.

Question 22

How is carbon dioxide transported in the blood?

Answer 22

CO2 is transported by haemoglobin as carbamino-haemoglobin (about 20-25 percent), with the rest carried as bicarbonate and dissolved in plasma.

Question 23

What is the partial pressure of oxygen in mm Hg that can deliver O2 to tissues?

Answer 23

Every 100 ml of oxygenated blood can deliver around 5 ml of O2 to the tissues under normal physiological conditions.

Question 24

How is carbon dioxide (CO2) transported in the blood?

Answer 24

CO2 is carried by haemoglobin as carbamino-haemoglobin (about 20-25 percent).

Question 25

What factors affect the binding of carbon dioxide to haemoglobin?

Answer 25

The binding is related to the partial pressure of CO2 and is influenced by the levels of pO2.

Question 26

What happens to CO2 at the tissue site?

Answer 26

At the tissue site where partial pressure of CO2 is high, CO2 diffuses into blood and forms HCO3– and H+.

Question 27

What is the role of carbonic anhydrase?

Answer 27

Carbonic anhydrase facilitates the conversion of CO2 and H2O into H2CO3, which can dissociate into HCO3– and H+.

Question 28

What occurs at the alveolar site regarding CO2?

Answer 28

At the alveolar site where pCO2 is low, CO2 is released from bicarbonate and diffuses out of the blood.

Question 29

How much CO2 does deoxygenated blood deliver to the alveoli?

Answer 29

Every 100 ml of deoxygenated blood delivers approximately 4 ml of CO2 to the alveoli.

Question 30

What regulates the respiratory rhythm in humans?

Answer 30

The respiratory rhythm is primarily regulated by the respiratory rhythm centre in the medulla region of the brain.

Question 31

What is the function of the pneumotaxic centre?

Answer 31

The pneumotaxic centre in the pons region can moderate the functions of the respiratory rhythm centre.

Question 32

What activates the chemosensitive area in the medulla?

Answer 32

An increase in CO2 and hydrogen ions can activate the chemosensitive area, signaling adjustments in respiration.

Question 33

What is asthma?

Answer 33

Asthma is a difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles.

Question 34

What is emphysema?

Answer 34

Emphysema is a chronic disorder where alveolar walls are damaged, decreasing the respiratory surface.

Question 35

What can cause occupational respiratory disorders?

Answer 35

Long exposure to dust in certain industries can lead to inflammation and serious lung damage.

Question 36

What is the first step in respiration?

Answer 36

The first step in respiration is breathing, which involves inspiration and expiration.

Question 37

What muscles are involved in inspiration and expiration?

Answer 37

Inspiration and expiration are carried out by intercostal muscles and the diaphragm.

Question 38

How is the exchange of O2 and CO2 facilitated?

Answer 38

The exchange occurs by diffusion, dependent on partial pressure gradients and solubility.

Question 39

How is oxygen primarily transported in the blood?

Answer 39

Oxygen is transported mainly as oxyhaemoglobin.

Question 40

What percentage of carbon dioxide is transported as bicarbonate?

Answer 40

Nearly 70 percent of carbon dioxide is transported as bicarbonate (HCO3–).

Question 41

What is the significance of the respiratory rhythm?

Answer 41

Respiratory rhythm is maintained by the respiratory centre in the medulla, with modulation by the pneumotaxic centre.