Respiratory System Of Human
Respiratory system

The respiratory system also called ventilatory system is the biological system that introduces respiratory gases to the interior and performs gas exchange.

Breathing is the process that delivers oxygen to where it is needed in the body and removes carbon dioxide. Another important process involves the movement of blood by the circulatory system.

Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood. This exchange process occurs in the alveolar region of the lungs.

Ventilation or ventilation rate is the rate at which gas enters or leaves the lung.

The breathing rate increases with the concentration of carbon dioxide in the blood and exercise also increases respiratory rate. Respiratory rate can increase due to increased inflation in the lungs.
respiratory tract
The organs used for breathing are the pharynx, larynx, bunghole, bronchi, lungs and diaphragm.
Essential organs of the human respiratory system

The human pharynx is the part of the throat situated immediately inferior to below the mouth and nasal cavity, and superior to the esophagus and larynx.

The human pharynx is conventionally divided into three sections: the nasopharynx (epipharynx), the oropharynx (mesopharynx), and the laryngopharynx (hypopharynx). The pharynx is part of the digestive system and also the respiratory system; it is also important in vocalization.

The larynx commonly called the voice box, is an organ in the neck involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume.

Sound is generated in the larynx, and that is where pitch and volume are manipulated. The strength of expiration from the lungs also contributes to loudness.

The trachea or windpipe, is a tube that connects the pharynx and larynx to the lungs, allowing the passage of air. The mucus lines the cells of the trachea to trap inhaled foreign particles The trachea has an inner diameter of about 25 millimetres (1.0 in) and a length of about 10 to 16 centimetres (4 to 6 in).A flap-like epiglottis closes the opening to the larynx during swallowing to prevent swallowed matter from entering the trachea.

The human trachea or windpipe divides into two main bronchi.


The bronchi is the passage of airway in the respiratory tract that conducts air into the lungs. The bronchus branches into smaller tubes, which in turn become bronchioles. No gas exchange takes place in this part of the lungs.

The right main bronchus is wider, shorter, and more vertical than the left main bronchus.The right main bronchus subdivides into three lobar bronchi, while the left main bronchus divides into two.

The lobar bronchi divide into tertiary bronchi, also known as segmentalinic bronchi. The segmental bronchi divide into many primary bronchioles which divide into terminal bronchioles, each of which then gives rise to several respiratory bronchioles, which go on to divide into two to 11 alveolar ducts. There are five or six alveolar sacs associated with each alveolar duct. The alveolus is the basic anatomical unit of gas exchange in the lung.

The alveolar ducts and alveoli consist primarily of simple squamous epithelium, which permits rapid diffusion of oxygen and carbon dioxide. Exchange of gases between the air in the lungs and the blood in the capillaries occurs across the walls of the alveolar ducts and alveoli.

The human lungs are the organs of respiration in humans. Humans have two lungs, a right lung and a left lung. The right lung consists of three lobes while the left lung is slightly smaller consisting of only two lobes.

Together, the lungs contain approximately 2,400 kilometres of airways and 300 to 500 million alveoli, having a total surface area of about 70 square metres (8,4 x 8,4 m) in adults — roughly the same area as one side of a tennis court. Each lung weighs 1.1 kilograms, therefore making the entire organ about 2.3 kilograms.

It has two zones The conducting zone contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the alveoli. The conducting zone and the respiratory stuffers (but not the alveoli) are made up of airways. The conducting zone has no gas exchange with the blood, and is reinforced with cartilage in order to hold open the airways. The conducting zone warms the air to 37 °C (99 °F) and humidifies the air. It also cleanses the air by removing particles via cilia located on the walls of all the passageways. The lungs are surrounded by the rib cage. The respiratory zone is the site of gas exchange with blood.
The diaphragm performs an important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs.The diaphragm is a sheet of internal skeletal muscle that extends across the bottom of the rib cage.

The diaphragm functions in breathing. During inhalation, the diaphragm contracts and moves in the inferior direction, thus enlarging the volume of the thoracic cavity which creates suction that draws air into the lungs.

The diaphragm is also involved in non-respiratory functions, helping to expel vomit, feces, and urine from the body by increasing intra-abdominal pressure.

respiratory system


Change in state of water
Water and it's states
Spheres of the earth
Nutrients & Deficiency Of Nutrients & It's Effect
Interesting Facts About Human Organs
Circulatory system
Digestive system
Endocannabinoids system
Endocrine system
Excretory system
Integumentary system
Immune system
Lymphatic system
Nervous system
Respiratory system
Musculoskeletal system
Vestibular system

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