Tag: gas exchange in humans

Questions Related to gas exchange in humans

Which one is the first to receive lymphatic duct from lungs

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. Right lymphatic duct

  2. Thoracic lymphatic duct

  3. Left subclavian vein

  4. Right subclavian vein.

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Correct Option: B

Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because ____________________.

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. There is a negative pressure in the lungs

  2. There is a negative intrapleural pressure pulling at the lung walls

  3. There is a positive intrapleural pressure

  4. Pressure in the lungs in higher than the atmospheric pressure

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Correct Option: A

Number of alveoli present in human lungs is?

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. $7-10$ million

  2. $70-100$ million

  3. $300-400$ million

  4. $800-1000$ million

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Correct Option: A

The ultimate end parts of the respiratory system in humans are known as

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. alveoli

  2. bronchioles

  3. tracheoles

  4. bronchi

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Correct Option: A
Explanation:

The respiratory system terminates in the alveoli which are sac-like structures and are enveloped by the capillary network for the exchange of gases.

Hence, the correct answer is 'alveoli'.

During respiration, exchange of gases take place in

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. Trachea and larynx

  2. Alveoli of lungs

  3. Alveoli and throat

  4. Throat and larynx

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Correct Option: B
Explanation:

Alveoli are the air sacs of the lungs. They have thin walls surrounded by blood capillaries (another layer of simple squamous epithelium). Gas exchange occurs in the alveoli. During inhalation, oxygen gas is in higher concentration in the alveoli than in the blood and so it diffuses into the blood through this thin layer of cells. During exhalation, carbon dioxide is in higher concentration in the blood than in the alveoli and so it diffuses into the alveoli through this thin layer of cells.

So, the correct answer is option B.

Choose the correct answer from the alternatives given.
What are the two large branches of the airway which lead off the trachea at the tracheal bifurcation?

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. Alveoli

  2. Bronchi

  3. Metavenules

  4. Bronchioles

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Correct Option: B
Explanation:

The two large branches of the airway that lead off the trachea at the tracheal bifurcation are the bronchi. They act as the main passageway into the lungs. Each bronchus enters one of the two (either the left or the right lung). Within the lungs, the bronchi branch off into smaller and smaller passageways, the smallest of which are called bronchioles and at the end of the bronchioles are tiny air sacs that are known as the alveoli. The re-oxygenized blood is sent through meta venules to the pulmonary vein. So, the correct option is 'bronchi'.

Choose the correct answer from the alternatives given.
Site of gaseous exchange in lungs is:

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. pulmonary chamber

  2. trachea

  3. bronchioles

  4. alveoli

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Correct Option: D
Explanation:

Alveoli are tiny balloon shaped structures in the respiratory system. The alveoli are only one cell thick and are surrounded by blood capillaries. This allows the relatively easy passage of oxygen and carbon dioxide (CO2) between the alveoli and the blood. Alveoli are therefore the site of gaseous exchange in the respiratory system. So, the correct option is 'alveoli'.

Choose the correct answer from the alternatives given.
The is an airway that connects the nose and mouth with the

zoology gas exchange in humans gas exchange and smoking gas exchange respiratory system in humans

  1. oral cavity; larynx

  2. trachea; pharynx

  3. pharynx; trachea

  4. pharynx; larynx

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Correct Option: D
Explanation:

The trachea or the windpipe is an airway that is a cartilaginous tube that connects the pharynx and larynx to the lungs, allowing the passage of air. It connects the nose and the mouth with the pharynx and larynx. So, the correct option is 'pharynx; larynx'.

Choose the correct answer from the alternatives given.
Which of the following constitutes the wind pipe, or the upper four inches of the airway?

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. Trachea

  2. Pharynx

  3. Larynx

  4. Bronchi

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Correct Option: A
Explanation:

The trachea is also known as the windpipe and is part of the passageway that supplies air to the lungs, it is about 4.5 inches long. The trachea branches into the bronchi that act as the passageways that enter the lungs. The larynx connects the nasal and oropharynx with the trachea and functions in air conduction and vocalization. The pharynx is the part of the throat behind the mouth and nasal cavity. The trachea connects the pharynx and the larynx to the lungs. So, the correct option is 'trachea'.

State whether the following statements are true or false.
Lungs are completely emptied and refilled with fresh air during breathing.

zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

  1. True

  2. False

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Correct Option: B
Explanation:

Even after the most forcible expiration possible some amount of air remains in the lungs. This is known as the residual volume and is about 1200 ml. So, the correct option is 'False'.