Tag: respiratory system in humans

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Questions Related to respiratory system in humans

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

Number of alveoli in the two human lungs is?

  1. $600-800$ million
  2. $200-300$ million
  3. $1-2$ million
  4. $100,000-150,000$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Alveoli are the basic unit of ventilation. The number of alveoli is a key structural determinant of lung architecture. Alveolar number is closely related to total lung volume, with larger lungs having considerably more alveoli, ranging from 600-800 million. 
So, the correct option is '600-800 million'.
Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Lungs have a large number of alveoli for.

  1. Having spongy texture and proper shape

  2. More surface area for diffusion of gases

  3. More space for increasing volume of inspired air

  4. More nerve suply
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The large number of alveoli maximizes the surface area available for the diffusion of oxygen and carbon dioxide, which is essential for efficient respiration.

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

Air is breathed through.

  1. Trachea $\rightarrow$ lungs $\rightarrow$ larynx $\rightarrow$ pharynx $\rightarrow$ alveoli
  2. Nose $\rightarrow$ larynx $\rightarrow$ pharynx $\rightarrow$ bronchus $\rightarrow$ alveoli $\rightarrow$ bronchioles
  3. Nostrils $\rightarrow$ pharynx $\rightarrow$ larynx $\rightarrow$ trachea $\rightarrow$ bronchi $\rightarrow$ bronchioles $\rightarrow$ alveoli
  4. Nose $\rightarrow$ mouth $\rightarrow$ lungs
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Air follows the pathway: Nostrils -> Pharynx -> Larynx -> Trachea -> Bronchi -> Bronchioles -> Alveoli.

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

Presence of large number of alveoli around alveolar ducts opening into bronchioles in mammalian lungs is?

  1. Inefficient system of ventilation with little of residual air

  2. Inefficient system of ventilation with high percentage of residual air

  3. An efficient system of ventilation with no residual air

  4. An efficient system of ventilation with little residuak air
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The presence of alveoli allows for efficient gas exchange. Residual air (the air remaining in lungs after forced expiration) is a normal feature of mammalian lungs that prevents collapse.

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

Trachea is lined with incomplete rings of

  1. Fibrous cartilage

  2. Calcified cartilage

  3. Elastic cartilage

  4. Hyaline cartilage
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The trachea is also called as windpipe. It is a cartilaginous tube which connects pharynx and larynx to the lungs, allowing passage of air. The wall of the trachea is lined by C shaped incomplete cartilaginous rings to protect it from collapsing during the breathing process due to pressure exerted on its walls by the air. These incomplete rings are made up of hyaline cartilage.
So, the correct answer is 'Hyaline cartilage'.
Multiple choice zoology gas exchange and smoking gas exchange gas exchange in humans respiratory system in humans

Gases diffuse over the respiratory surface because of.

  1. $pO _2$ is more in alveoli than in blood
  2. $pO _2$ is more in blood than in tissues
  3. $pCO _2$ is more in alveoli than in blood
  4. $pCO _2$ is more in blood than in tissues
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gas diffusion occurs from areas of higher partial pressure to areas of lower partial pressure. Oxygen diffuses from the alveoli (high pO2) into the blood (low pO2).

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

Arrange the following in order of increasing volume.
$1$. Tida. volume $2$. Residual volume $3$. Expiratory reserve volume $4$. Vital capacity.

  1. $1 < 2 < 3 < 4$
  2. $1 < 4 < 3 < 2$
  3. $1 < 3 < 2 < 4$
  4. $1 < 4 < 2 < 3$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tidal volume (approx 500ml) < Expiratory reserve volume (approx 1000-1200ml) < Residual volume (approx 1200ml) < Vital capacity (approx 4600ml).

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

According to Boyle's law, the product of pressure and volume is constant, hence.

  1. If volume of lung is increased, the pressure decreases proportionately

  2. If volume of lung is increased, the pressure also increases proportionately

  3. If volume of lungs is increased, the pressure decreases disproportionately

  4. If volume of lungs is increased, the pressure remains the same
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Boyle's Law states that pressure is inversely proportional to volume (P = k/V). Thus, increasing the volume of the thoracic cavity decreases the pressure inside the lungs.