Category: Anatomy

2. Pharynx:

• It is also called Throat.
• 12-14 Cm long tube
• Lies behind the mouth cavity and larynx
• Belongs to both the Respiratory and Digestive System.
• Passageway of air and food
• Divide into three parts:|
• 1. Nasopharynx: It is the upper part of Pharynx and associated with Nasal cavity
• 2. Oropharynx: It is the middle part of Pharynx and associated with oral cavity
• 3. Laryngopharynx: It is the lowest part of Pharynx and associated with Laryn.
• 4.Larynx:
  • Lies in the Neck
  • Length is 3.5 to 4.5 Cm
  • Formed by Cartilage
  • Its basic function is to keep food and drink out of the airway.
  • At the top of the larynx is a spoon shaped flap of cartilage called Epiglottis (Epiglottis directs food and drink into the esophagus)
  • Larynx also has an additional function of producing sound (that is why it is also called Voice Box/Sound Box)

  4.Trachea:

  • Also called Wind Pipe
  • 10-12 Cm Long
  • Surrounded by 16-20 C- Shaped rings of Hyaline Cartilage.
  • These rings provide Flexibility and Strength to trachea.
  • At the level of 5″ Thoracic vertebra, it divides into two Bronchi
  • In respiratory system trachea’s main job is to transfer the air to next junction/passage called Bronchi.5. Bronchi:
    • There are two Left Bronchi and Right Bronchi.
    • Right Bronchi is shorter and wider then left
    • Made up of complete rings of Cartilage
    • It controls air entry
    • These bronchi enter into our lungs and further divides into several branches and sub – branches

    6. Lungs:

    • Lungs reside inside Rib cage above diaphragm and inside thoracic cavity.
    • Rib cage protect lungs
    • Lungs are covered by layer called Pleura
    • Lungs are two spongy, elastic and cone shaped organ.
    • Space between two lungs is called Mediastinum
    • Right lung is larger than left lung
    • Both lungs weight approx. 1.3 Kg
    • There are two lungs:
      Right: 620 grams (contain 3 Lobes)
      Left: 560 grams (contain 2 Lobes). 7. Bronchial Tree:
      • The branches and sub-branches of bronchi are called Bronchioles
      • Bronchioles are root like structure which again divide into further branches and sub-branches which is called Bronchial

      8. Alveoli:

      • Alveoli is the actual site of gaseous exchange of oxygen and carbon dioxide between the lungs and the blood
      • Alveoli is called the Basic Unit of Respiratory System
      • Air Sacs
      • It looks like bunch of grapes

      TION U

      • A single spherical ball like structure of Alveoli is called
        Alveolus
      • Alveoli is a group of several Alveolus
      • Final termination of each Bronchi

      700 million. 9. Alveolus

      • It is very thin and composed of a single cell membrane
      • The extremely thin membrane helps in very easy exchange of gases between the Alveolus and RBC’s flowing through the capillaries.
      • The process of gas exchange occurs by a diffusion.