Railway Science (Biology – Respiratory System)

Lung Volumes:- Residual volume is the volume of air remaining in the lungs after maximum forceful expiration. Tidal volume is the amount of air that moves in or out of the lungs with each respiratory cycle.
Inspiratory reserve volume is the additional volume of air that can be inspired at the end of a normal or tidal inspiration. Expiratory reserve volume is the additional amount of air that can be exhaled after a normal exhalation.

The exchange of gases like Oxygen and Carbon dioxide occurs in the alveoli of the lungs. They are the smallest structures in the respiratory system. Bronchi are large tubes that connect to our trachea (windpipe) and direct the air we breathe to our right and left lungs. Trachea: The airway that leads from the larynx to the bronchi.

Smoking can harm the organs in the body and negatively impact our overall health. Smoking damages the airways, air sacs (alveoli) in the lungs and cilia (which are tiny hair-like structures that prevent dirt and mucus from entering the lungs).

Ring of cartilage - A strong and flexible C-shaped tissue present in the trachea. It supports the trachea and prevents it from collapsing when less air is present in it. Parts of the human respiratory system - Nose, Mouth, Throat (pharynx), Voice box (larynx), Windpipe (trachea), Large airways (bronchi), Small airways (bronchioles), and Lungs. Tendon is a cord of strong, flexible tissue.

Cellular respiration - The process by which individual cells break down food molecules, such as glucose (C₆H₁₂O₆) and release energy.
Reaction - C₆H₁₂O₆ + 6O₂⟶ 6CO₂ + 6H₂O + Energy.

Aerobic respiration (aerobic metabolism) - process in which oxygen is used to make energy from carbohydrates. In a cell, the glucose is broken down into carbon dioxide and water using oxygen, C₆H₁₂O₆ (Glucose ) + 6O₂ (Oxygen) → 6CO₂ (Carbon dioxide) + 6H₂O (Water) + ATP (Energy).

The equation - Glucose (C₆H₁₂O₆) + Oxygen(O₂) → Carbon dioxide (CO₂) + Water (H₂O) + Energy. Plants use oxygen for the breakdown of food and to release energy. Intake of oxygen takes place through Stomata (in leaves), lenticels (in stems) and root cells (in root). Respiration in most plants occurs under dark conditions (no light).

Pharynx: The muscle-lined space that connects the nose and mouth to the larynx and esophagus (eating tube). Larynx (voice box): It is a cylindrical grouping of cartilages, muscles and soft tissue that contains the vocal cords. The trachea is a tube-like structure within the neck and upper chest.
It transports air to and from the lungs when a person breathes. When a person inhales, air travels through the nose or mouth, down the trachea, and into the lungs.

Breathing: Process by which the air enters and leaves the human body. One inhalation and exhalation constitutes a breathing cycle. The number of breathing cycles per minute is the called breathing rate.
Respiratory rate increases while performing intense physical exercise. Spirometry: Process of recording the changes in the volume and movement of air in and out of the lungs and the instrument used for this purpose is called a spirometer or respirometer.

Aerobic respiration is a chemical process in which oxygen is used to make energy from carbohydrates (sugars). It is also called aerobic metabolism, cell respiration, and oxidative metabolism.
Anaerobic Respiration takes place in the absence of oxygen. Aerobic respiration produces around 18 times more energy compared to anaerobic respiration.