Question

Describe the parts of the human respiratory system.

Answer 1

Respiratory system:

It is a system in which a group of organs and tissues together are involved in:

1. The movement of fresh air into the body.
2. Removal of waste gases from the body

Respiratory organs:

1. Nose: The air enters through the nose. It consists of two parts i.e., nostril and nasal cavity (form two nasal passages). The nasal chambers are lined with hair to filter air entering it. In addition, mucus is secreted within the nasal passage to trap germs and dust particles that enter the nose during breathing.
2. Pharynx: It is the tube-like structure that allows food and air to pass through it to their respective ducts. It is situated behind the nasal cavity and mouth.
3. Trachea: It is commonly called the windpipe, a way to bronchi from the larynx.
   1. It starts from the neck region and ends up in the thoracic cavity.
   2. It is on the front side of the throat.
   3. It possesses C-shaped cartilaginous rings on the front that support and prevent it from collapsing.
   4. Function: Carries air into the lungs and releases waste air out.
4. Bronchi and bronchioles: Both are distributed in the lungs.
   1. The bronchus (plural: bronchi) is the respiratory tube that connects the trachea to the bronchiole. Two branches emerged from the trachea to form bronchi.
   2. The bronchioles appear like tree branches in the thoracic cavity which is formed from several branching of bronchi.
   3. Bronchioles are the terminal air passage tubules present in the lungs.
   4. Function: Both help in gaseous exchange as well as moisturize and filter the air.
5. Alveoli: Alveolus (plural: alveoli) is a tiny sac or bag-like structure that is present on the terminal bronchioles.
   1. Function: It performs diffusion of gases in capillaries. Oxygen diffused to the capillaries whereas carbon dioxide diffused from the capillaries to the alveoli.
6. Lungs: Lungs are paired, spongy, balloon-like respiratory organs present in the thoracic or chest cavity on either side of the sternum.
   1. The lung is covered with a thin layer of tissue called pleura. It protects the lungs and cushions them. Pleura also secretes lubricants that maintain smooth movement of the cavity.
   2. Lungs are enclosed inside the ribcage which is formed by ribs and sternum.
   3. A strong, large, muscular diaphragm protects it from the bottom side.