It is the group of tissues and organs in your body that allow you to breathe.
This system includes the airways , lungs, blood vessels, and muscles attached to them that work together to enable you to breathe.
Respiratory system function
The main function of the respiratory system is to supply oxygen to all parts of your body. You do this by breathing – inhaling oxygen-rich air and exhaling air filled with carbon dioxide, which is a waste gas.
The respiratory system is made up of airways (your nose, mouth, voice box, windpipe, and bronchial tubes), the lungs, muscles, and blood vessels connected to them.
Through breathing, inhalation and exhalation, the respiratory system facilitates the exchange of gases between the air and the blood and between the blood and the cells of the body. The respiratory system also helps us smell and create sound. The following are the five key functions of the respiratory system:
Inhalation and exhalation form lung ventilation, that is respiration
The respiratory system assists in breathing, also called lung ventilation. In pulmonary ventilation, air is inhaled through the nasal and oral cavities (the nose and mouth). It moves through the pharynx, larynx, and windpipe into the lungs.
Then the air is exhaled and flows back the same way. Changes in the volume and pressure of the air in the lungs trigger pulmonary ventilation. During normal inhalation, the diaphragm and external intercostal muscles contract and the rib cage rises.
As the volume of the lungs increases, the air pressure decreases and the air enters quickly. During normal exhalation, the muscles relax. The lungs become smaller, the air pressure increases, and the air is expelled.
External respiration exchanges gases between the lungs and the bloodstream
Inside the lungs, oxygen is exchanged for carbon dioxide waste through a process called external respiration. This respiratory process takes place through hundreds of millions of microscopic sacs called alveoli.
Oxygen from the inhaled air diffuses from the alveoli into the surrounding pulmonary capillaries. It binds to the hemoglobin molecules in red blood cells and is pumped through the bloodstream. Meanwhile, the carbon dioxide in the deoxygenated blood diffuses from the capillaries into the alveoli and is expelled by exhalation.
Internal respiration exchanges gases between the bloodstream and body tissues.
The blood stream supplies oxygen to cells and removes residual carbon dioxide through internal respiration, another key function of the respiratory system. In this respiratory process, red blood cells carry oxygen that is absorbed from the lungs around the body through the vasculature.
When the oxygenated blood reaches the narrow capillaries, the red blood cells release the oxygen. It diffuses through the capillary walls into the tissues of the body. Meanwhile, carbon dioxide diffuses from tissues to red blood cells and plasma. Deoxygenated blood carries carbon dioxide to the lungs for release.
The air that vibrates the vocal cords creates the sound.
Phonation is the creation of sound by structures in the upper respiratory tract of the respiratory system. During exhalation, air passes from the lungs through the larynx or ” voice box .” When we speak, the muscles of the larynx move the arytenoid cartilages.
The arytenoid cartilages push the vocal cords. When the cables are brought together, the air passing between them causes them to vibrate, creating sound. Greater tension on the vocal cords creates faster vibrations and higher pitched sounds. Lower tension causes slower vibration and lower pitch.
Smell or odor is a chemical sensation
The olfaction process begins with olfactory fibers that line the nasal cavities within the nose. As air enters the cavities, some chemicals in the air bind and activate the receptors of the nervous system in the cilia.
This stimulus sends a signal to the brain: neurons take the signal from the nasal cavities through openings in the ethmoid bone, and then to the olfactory bulbs. The signal travels from the olfactory bulbs, along cranial nerve 1, to the olfactory area of the cerebral cortex.