Respiratory system in humans is composed of pharynx, bronchi, lungs, nasal passage and trachea. This is responsible for respiration process which is important for the survival of human. This is the process of obtaining and using oxygen, while eliminating carbon dioxide. This is the process where human beings inhale oxygen from environment and exhale carbon dioxide, which is produced as a result of chemical reactions in cells. This specialized system that brings about the critical process is called human respiratory system. This article gives information about the structure of respiratory system.
Structure of Respiratory System:
Human respiratory may be divided into upper respiratory tract which consists of pharynx, nasal passages and larynx. Lower respiratory system contains primary bronchi, lungs and trachea.
Nasal Passages: Air that enters from nostrils is directed to nasal passages. Nasal cavity situated behind the nose contains nasal passages which are the important part of human respiratory system. Air that is received by the nose is conditioned by the nasal cavity. The conditioning process involves cooling or warming of air received by nose, removes dust particles from air and also moistens it, before entering pharynx.
Pharynx: This is situated above larynx and behind nasal cavity. This is a part of digestive system too. Air as well as food passes through pharynx.
Larynx: This is associated with sound production. This contains two pairs of membranes. Air makes vocal cords to vibrate and hence produces sound. Larynx is located in mammals neck and plays vital role in protecting trachea.
Trachea: Trachea refers to the airway from which air travels. Cartilage rings within the walls opens up the trachea.
Bronchi: Trachea is divided into bronchi. Bronchi extends into lungs spreading in tree-like structure as bronchial tubes. Bronchial tubes subdivide and hence, the walls get thinner. This division of bronchi into thin walled tubes leads to the formation of bronchioles. Bronchioles terminate into tiny chambers that contain cavities called alveoli. These alveoli have thin walls that form respiratory surface. Gas exchange takes place between blood and air through walls of bronchioles.
Lungs: These are most important parts of respiratory system in human. They are located on the either sides of heart. These are responsible for the transportation of oxygen from atmosphere into the blood and releases carbon dioxide from the blood to atmosphere.
