The respiratory system is composed of organs and tissues which help us in breathing. The main parts of this system include the pair of lungs, a series of airways for air passages, blood vessels, and the muscles that facilitate in breathing.
Here are the certain special features of the human respiratory system:
- The energy is generated by the breakdown of glucose molecules in all living cells of the human body.
- Oxygen is inhaled and is transported to various parts and are used in the process of burning food particles (breaking down of glucose molecules) at the cellular level in a series of chemical reactions.
- The obtained glucose molecules are used for discharging energy in the form of ATP- adenosine triphosphate molecules by the human body to fulfill essential life processes.
The organs of respiratory system
Excluding the lungs, there are several other associated organized structures that together constitute the respiratory system. This system is strictly connected to the circulatory system as the transference of the gases takes place through the blood.
The complete respiratory tract consists of the nose, pharynx, larynx, trachea, bronchi, and bronchioles.
The air that we inhale has the following composition:
Nitrogen – 78%, Oxygen – 21%, Carbon dioxide – 0.03 – 0.04% and other traces of Hydrogen and Noble gases.
From the above list, the air contains more oxygen than carbon dioxide. The air is inhaled in with the help of nostrils and in the nasal cavity, the air is cleansed by the fine hair follicles present within them. The cavity also has a collective group of blood vessels that keep the air warm. This air then passes to the pharynx, then to the larynx and into the trachea.
The trachea and the bronchi are coated with ciliated epithelial cells and goblet cells (secretory cells) which discharges mucus to moisten the air as it passes through the respiratory tract and also traps the fine bits of dust or bacteria that have been escaped from the hairs of the nasal openings. The motile cilia strike in an ascending motion such that the mucus and other foreign particles are carried back to the buccal cavity where it might be either cough out or swallowed.
Once the air reaches bronchus it moves into the bronchioles and then into the alveoli. From the alveoli, the formation of respiratory surfaces occurs in humans.
Human Respiratory System – Parts and its Functions
The nose possesses a couple of exterior nostrils which are divided by a framework of cartilaginous structure termed as the septum. Tiny hair follicles cover the interior lining of nostrils.
Two cartilaginous chords lay the framework for the larynx. They are situated at the point of joining of the pharynx and trachea. It is also termed as Adam’s apple or the voice box. It is the portion which rises and falls during swallowing of food molecules. It generates sound as air passes through the hollow in the middle.
The nasal chambers open up into a wide void termed as pharynx. It is a common path for both air and food. It functions by preventing the entry of food molecules into the windpipe. The epiglottis is an elastic cartilage which serves as a switch between the larynx and the esophagus by allowing the passage of air into the airway to the lungs and food into the gastrointestinal tract.
Have you ever questioned Why do we get a cough while eating or swallowing?
If we talk during eating or swallowing, we get a cough. The reason behind this scenario is the epiglottis. It is forced to open for the air to exit outwards and the food to enter into the windpipe, triggering a cough.
The trachea or the windpipe rises below the larynx and moves down to the neck. The walls of trachea comprise of C-shaped cartilaginous rings which give hardness to the trachea and maintain it by completely expanding.
Lungs are the chief centers of respiration process.They are located in the thoracic cavity of the chest near the backbone and on either side of the heart. They are the pair of large, spongy organs mainly involved in the exchange of gases between the blood and the air. Compared to the left lung, the right lung is quite bigger and heavier.
The trachea splits into two tubes termed as bronchi, which enter each lung individually. The bronchi are divided into secondary, tertiary, and to bronchioles which is again further divided into small air sacs termed alveoli.
The alveoli are minute sacs of air with thin walls, and single-celled manner. They act as a crossing point for the respiratory gases to get diffused in and out of the bloodstream.
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