Respiratory system in human being consists of two components: – Respiratory tract & Respiratory organs.
The respiratory tract acts as a passage way for fresh air to flow from outside to the lungs and produced air from lungs to the exterior. Respiratory tract includes external nostrils nasal cavities, pharynx larynx & trachea. Respiratory tract is not concerned with the gaseous exchange. Trachea has rings of cartilage that prevent collapse of trachea.
Respiratory organs are lungs which provide surface for exchange of gases. Lungs are pair in number, and lies in thoracic cavity. Lungs remain enclosed by pleura. In lungs major bronchi further divide into secondary bronchi which in tertiary bronchi and finally into bronchioles. Each bronchioles divides into smaller alveolar ducts that enter in air sac
Respiratory system is closely surrounded by the network of blood capillaries.
It is also called larynx. It is an enlarged upper part of trachea, before puberty, it is similar in both series. In males it protrudes out and often called Adam’s apple, Vibration in vocal cord result in production of sound which is converted into speech by help of tongue.