Tag: gas exchange and smoking

Questions Related to gas exchange and smoking

Choose the correct answer from the alternatives given.
What are the tiny clusters of chambers for diffusion of gases in lungs?

zoology gas exchange and smoking respiration in human beings respiration and associated structures respiration in humans respiratory organs in humans

  1. Pleura

  2. Alveolar sacs

  3. Bronchioles

  4. Lobes

Show answer
Correct Option: B
Explanation:

The pleura are membranes that secrete a lubricating fluid, which allows free movement of the lungs against the chest wall while breathing. The alveolar sacs are sacs of many alveoli (clusters of chambers), that help exchange oxygen and carbon dioxide in the lungs. The bronchioles are the passageways by which air passes through the nose or mouth to the alveoli (air sacs) of the lungs. Each lobe of the lung has the same physiologic function, bringing oxygen into the bloodstream and removing carbon dioxide. So, the correct option is 'alveolar sacs'.

What is the approximate normal composition of alveolar air? 

zoology gas exchange and smoking respiration in human beings respiration and associated structures respiration in humans respiratory organs in humans

  1. 14% oxygen, 6% carbon dioxide, 80% nitrogen

  2. 21 % oxygen, 2% carbon dioxide, 77% nitrogen

  3. 16% oxygen, 3% carbon dioxide, 81 % nitrogen

  4. 10% oxygen, 8% carbon dioxide, 82% nitrogen

Show answer
Correct Option: A
Explanation:

The air present inside the alveoli or the alveolar air usually has a higher amount of oxygen than carbon dioxide. The approximate composition of alveolar air under normal condition is 14% oxygen, 6% carbon dioxide, and 80% nitrogen.

So, the correct answer is '14% oxygen, 6% carbon dioxide, 80% nitrogen'.


Membrane separating air in pulmonary alveoli from blood capillaries.

zoology gas exchange and smoking respiration in human beings respiration and associated structures respiration in humans respiratory organs in humans

  1. Alveolar epithelium

  2. Cardiac epithelium

  3. Endothelium of blood capillaries

  4. Both $'1'$ and $'3'$

Show answer
Correct Option: A
Explanation:
Here option (D) is the correct answer as-
Outermost Layer Of pulmonary alveolitis alveolar epithelium while that of blood capillaries is endothelium. Thus, both alveolar epithelium and endothelium of blood capillaries separate air in pulmonary alveoli from blood capillaries.

Lungs made up of which structures 

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

  1. Branching network of Bronchi

  2. Bronchioles

  3. Alveoli

  4. All of the above

Show answer
Correct Option: D
Explanation:

Lungs are the main respiratory organs of the human respiratory system. The windpipe or trachea divides into two branches called bronchi, entering into each lung. Each bronchus in the lung further divides to form many bronchioles. These bronchioles end up in a sac-like structure called the alveoli.  Hence, the lungs are made up of bronchi, bronchioles and alveoli.

Hence, the correct answer is 'All of the above'.

The lungs are protected by two membranes called ________

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

  1. Pleural membrane

  2. Meninges

  3. Mucous membrane

  4. None of the above

Show answer
Correct Option: A
Explanation:

The lungs are protected by two membranes called the pleural membranes. The outer pleural membrane is called the pleura and the inner one is called the visceral or pulmonary layer. There is a space between the two layers called the intrapleural space. It is filled with fluid to keep the lungs protected from the shocks and injuries.

A. Pleural membranes are present around the lungs.
B. Meninges are present around the brain and spinal cord.
C. Mucous membranes are present around he visceral organs.
Hence, the correct answer is 'Pleural Membrane'.

Read the following statements (A to D)
(A) Rib is a flat bone connected vertebral column and dorsally to the sternum.
(B) First seven pairs of ribs are called true ribs.
(C) 8$^{th}$ ,9$^{th}$ and 10$^{th}$  pairs of the ribs are called vertebro sternal ribs.
(D) 10$^{th}$ and 11$^{th}$ pairs of ribs are not connected dorsally and are therefore called floating ribs.
How many statements are correct?

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

  1. One

  2. Two

  3. Three

  4. None

Show answer
Correct Option: A
Explanation:

A. Ribs are attached to sternum with their anterior ends.

B. First seven pair of ribs are called true ribs because their anterior are directly attached to the sternum.
C. The 8th, 9th and 10th pair of ribs are called false ribs.
D. 11tth and 12th pair of ribs are called floating ribs because their anterior ends are not attached to the sternum.
Hence only statement B is correct.
So, the correct answer is 'One'.

What do the trachea and bronchi possess in their wall  of the respiratory tract in man?

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

  1. C-shaped cartilagenous rings

  2. C-shaped bony rings

  3. V-shaped bony rings

  4. V-shaped cartilagenous rings

Show answer
Correct Option: A
Explanation:

The trachea, primary, secondary and tertiary bronchi, and initial bronchioles are supported by incomplete cartilaginous rings. 


So, the correct answer is 'C-shaped cartilaginous rings'

The mucus produced by the goblet cells 
(I) Moistens the incoming air
(II) Traps the finest dust particles
(III) Filter out largest dust particles
(IV) Warm the incoming air

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

  1. I and II

  2. II and III

  3. Only IV

  4. All of these

Show answer
Correct Option: B
Explanation:

A column-shaped cell found in the respiratory and intestinal tracts, which secretes the main component of mucus. The mucus produced by the goblet cells traps the finest dust particles and filter out largest dust particles.

So, the correct option is 'II and III'.

The alveoli contain specialized cells that secrete a phospholipoprotein complex known as pulmonary surfactant. The function of pulmonary surfactant is ________________________.

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

  1. to provide some rigidity to the alveoli to prevent lung collapse

  2. to decrease the surface tension of the alveoli, making it easier to expand them

  3. to facilitate the diffusion of $O _2$ and $CO _2$ by providing protein channels through which these gases flow

  4. to provide a sticky surface upon which dust and microbes are trapped and disposed of

Show answer
Correct Option: B
Explanation:

Alveoli is the region in the lungs where exchange of gases takes place.According to histology of alveolar wall ,it contain 2types of cell

 I.e. 1-Type-1 cell 
            2.Type -2 cell which secret  DPPP(DIPAMITOYL PHOSPHATIDOYL CHOLINE OR LECITHINE) which acts as a surfactant and help in preventing collapsing of lungs.

When there is no air in initial bronchioles, they do not collapse. It is due to the presence of _________________.

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

  1. Lecithin

  2. Complete cartilaginous rings

  3. Incomplete cartilaginous rings

  4. Transformed elastic cartilage

Show answer
Correct Option: D
Explanation:

This is due to the presence of transformed elastic cartilage which gives support to the initial bronchioles and prevents it from collapsing. The incomplete cartilaginous rings that are present in the trachea and bronchi are absent in the bronchioles. They are supported by the transformed elastic cartilage.

So, the correct option is 'transformed elastic cartilage'.