Test: Respiratory Organs (NCERT) - NEET MCQ

Larynx is a cartilaginous box containing nine pieces of cartilages.

Line in NCERT: "Larynx is a cartilaginous box which helps in sound production and hence called the sound box."

Epiglottis is a leaf shaped cartilage that closes the glottis (opening leading into tarachea) to cheak the entry of food into it during swallowing. If during eating epiglottis remains open, then food particles may center the trachea (wind pipe) lending to reflex action of couhing. This removes the food particles from traches so that breathing does not get obstructed.

Line in NCERT: "During swallowing glottis can be covered by a thin elastic cartilaginous flap called epiglottis to prevent the entry of food into the larynx."

• Insects respire using an organ called trachea.
• Several tubes are present for trachea that is uniformly distributed inside the body of the organism.
• The trachea divides into tracheoles through which the oxygen is supplied to the body parts.

Line in NCERT: "Insects have a network of tubes (tracheal tubes) to transport atmospheric air within the body."

In the given figure depicting the human larynx, the unidentified parts are as follows: (A) Epiglottis, (B) Cartilaginous rings of trachea, (C) Trachea, and (D) Larynx.

Line in NCERT: "During swallowing glottis can be covered by a thin elastic cartilaginous flap called epiglottis to prevent the entry of food into the larynx."

In the given figure depicting the respiratory passage in man, the unidentified parts are as follows: (A) Alveolar sac, (B) Secondary bronchus, (C) Alveoli, (D) Bronchioles, and (E) Trachea.

Line in NCERT: Not Found

• Since aquatic arthropods and mollusks are mainly in water, they use gills for respiration.
• These gills are present as outgrowths to their skin, which is covered by the exoskeleton.
• The exchange of gases takes place through these gills.

Line in NCERT: "Special vascularised structures called gills (branchial respiration) are used by most of the aquatic arthropods and molluscs."

The number of alveoli in the human lungs has been estimated to be approximately 300 million. This enormous number of alveoli are meant to increase surface area of lungs for diffusion of gases.

Line in NCERT: "Exchange part is the site of actual diffusion of O2 and CO2 between blood and atmospheric air."

The lungs are covered in a membrane called pleural membrane. The outer covering is called parietal pleura and the inner covering is called visceral pleura.

Line in NCERT: "We have two lungs which are covered by a double layered pleura, with pleural fluid between them."

In the given figure depicting the human respiratory system, the unidentified parts are as follows: A-Epiglottis, B-Alveoli, C- Bronchus, D-Diaphragm.

Line in NCERT: "Diagrammatic view of human respiratory system (sectional view of the left lung is also shown)"

The diffusion membrane is made up of three major layers (Figure 17.4) namely, the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries and the basement substance (composed of a thin basement membrane supporting the squamous epithelium and the basement membrane surrounding the single layer endothelial cells of capillaries) in between them.

Line in NCERT: "The diffusion membrane is made up of three major layers namely, the thin squamous epithelium of alveoli, the endothelium of alveolar capillaries and the basement substance (composed of a thin basement membrane supporting the squamous epithelium and the basement membrane surrounding the single layer endothelial cells of capillaries) in between them."