Question

Air is breathed through:
A) Trachea$\to$Lungs$\to$Larynx$\to$Pharynx$\to$Alveoli
B) Nose$\to$Larynx$\to$Pharynx$\to$Bronchus$\to$Alveoli$\to$Bronchioles
C) Nostril$\to$Pharynx$\to$Larynx$\to$Trachea$\to$Bronchi$\to$Bronchioles$\to$Alveoli
D) Nose$\to$Mouth$\to$Lungs

Answer 1

The flowchart represents a step by step process involved in the passing of the air through the body starting from the very first point to the end and how the exchange of gases takes place.

Complete step by step answer: The in and out of the air is simply known as breathing. It is the very first step involved in the process of respiration. Normal Breathing is called ‘Eupnoea’. The air is firstly taken in by the nostrils of the nose to filter the dirt. Breathing involves two main processes: inspiration (inhale) and expiration (exhale). Next, the air goes into the windpipe or trachea in the throat which filters the air. The trachea branches into two bronchi which leads to the lungs. When air goes into the lungs, oxygen is moved into the bloodstream. Blood carries oxygen to different parts of the body where it is needed. RBCs(Red blood cells) take carbon dioxide from the cells and give it back to the lungs. Alveoli are small structures where the exchange of oxygen and carbon dioxide takes place. After this, the carbon dioxide is exhaled and this cycle is repeated again.
Hence, the correct answer is option C.

Note: The diaphragm is a dome-shaped muscle present below the lungs that controls breathing. The diaphragm flattens out and pulls forward, drawing air into the lungs for inhalation. During exhalation, the diaphragm expands to force air out of the lungs. Adults generally take 12 to 20 breaths/min. Strenuous exercise drives the breath rate up to 45 breaths/min.