Tag: respiratory system of human

Questions Related to respiratory system of human

Which of the following is true for $CO _2$ concentration?

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. More in alveolar air than in expired

  2. More in expired air than in alveolar air

  3. More in inspired air than in alveolar air

  4. More in inspired air than in expired air

Show answer
Correct Option: A
Explanation:

In the alveoli, the oxygen is continuously absorbed by the blood and CO$ _{2}$ is continuously added by the blood. So, the alveolar air has more CO$ _{2}$ concentration than the expired air.

Hence, the correct answer is 'More in alveolar air than in expired air'

The gas which we breath out precipitates ______ into milky white.

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Sodium Chloride solution

  2. Calcium Carbonate solution

  3. Potassium Permanganate solution

  4. Potassium Bicarbonate solution

Show answer
Correct Option: B
Explanation:

The gas which we exhale or breath out is carbon-dioxide. 

When this gas passes through calcium carbonate solution there occurs precipitation reaction between the solution, as a result, the color of the solution turns to milky white.
When CO$ _2$ is passed through lime water which is a diluted solution of Ca(OH)_2, it turns milky due to the formation of calcium carbonate $CaCO _3$.

So the option B is correct.

Inspiration occurs when

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Pressure inside lungs is lower than atmospheric pressure

  2. Pressure inside lungs is higher than atmospheric pressure

  3. Pressure inside lungs is same as atmospheric pressure

  4. Pressure has no effect

Show answer
Correct Option: A
Explanation:

Air can be forced to move from one place to another by creating a pressure gradient. In the human body, the contraction of the diaphragm allows it to move down to abdomen cavity slightly. This increases the area in the thoracic cavity and the lungs expand. The intercostal muscles between the ribs also contract and allow the rib bones o come upwards and outward. Due to this, volume in the lungs increases and the pressure decreases. The pressure in the lungs is less than that of atmospheric pressure, so the air is drawn in and inspiration occurs.

Hence, the correct answer is 'Pressure inside lungs is lower than atmospheric pressure'

Lungs become empty after forceful expiration.

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Lungs are never empty even after forceful expiration. There is always a certain amount of air present in the lungs which is known as residual volume which amounts to 1500 ml. 

Thus, the correct answer is option B. 

Maximum contraction of diaphragm causes maximum expiration.

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

When the intercostal muscles and the diaphragm contract they increase the size of the thoracic cavity, causing negative pressure in the lungs, causing inspiration.
So, the correct answer is option B.

The width of the chest during inspiration :

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Decreases

  2. Does not change

  3. Increases

  4. None of these

Show answer
Correct Option: B
Explanation:

  • When you breathe in, or inhale, your diaphragm contract and move downward. This increases the space in the chest cavity into which lungs expand.
  • The intercostal muscles between ribs also help enlarge the chest cavity.
So, the correct option is 'Does not change'.

Which respiratory associated muscles would be contracted if you blow up a balloon?

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Diaphragm contracts and internal intercostal muscles would relax

  2. External intercostal muscle contract and phrenic muscles would contract

  3. Internal intercostal and abdominal muscle would contract

  4. Internal intercostal muscles are external intercostal muscles would contract

Show answer
Correct Option: B
Explanation:

Intercostal and abdominal muscle would contract if we blow up a balloon. When this occurs, you are interrupting the natural rhythm of breathing. The inhalation process is blowing up a balloon. As you this movement is facilitated by the contraction of the external intercostal muscles.

So the correct answer is' Internal intercostal and abdominal muscle would contract'.

Volume of thoracic chamber increases in the anteroposterior and dorsoventral axis in the human by?

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Contraction of diaphragm and external intercostal muscles

  2. Relaxation of diaphragm and external intercostal muscles

  3. Relaxation of diaphragm and abdominal muscles

  4. None of these

Show answer
Correct Option: A
Explanation:

Volume of thoracic chamber increases in anteroposterior and dorso-ventral axis in human by contraction of diaphragm and external intercostal muscles.

During expiration the diaphragm becomes

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Oblique

  2. Dome-shaped

  3. Flattened

  4. Normal

Show answer
Correct Option: B
Explanation:

During inspiration, the diaphragm contracts and moves downward and when the diaphragm relaxes it becomes dome shaped and moves upward during expiration. 

Conditioning of inspiratory air in mammals occurs in 

zoology respiratory system of human mechanism of respiration respiratory cycle breathing and exchange of gas

  1. Trachea

  2. Larynx

  3. Bronchioles

  4. Nasal chambers

Show answer
Correct Option: D
Explanation:

Nasal cavity opens to outside through external nares or nostrils. Nasal cavity occurs between palate and cranium. Nasal cavity is divisible into two nasal chambers by a nasal septum. Each nasal chamber has three parts - (a) Vestibule- It has hairs to filter out the dust particles, (b) Conditioner - respiratory region. It has bony projections and sinuses. It is abundant in blood capillaries, (c) Olfactory region- perceives sense of smell. The two nasal cavities condition the air to be received by the other areas of the respiratory tract.