Respiratory

The respiratory system: 

includes the lungs , system of passages (airways) and structures of ventilating mechanism, that link the site of gas exchange with the external environment. It is customary to divide the respiratory system into 

3 principle regions:

1.a conducting portion, consisting of the nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles.

2. a respiratory portion, consisting of respiratory bronchioles, alveolar ducts, atria, alveolar sacs and alveoli.

ventilating mechanism , which creates pressure differences that move air. It includes the diaphragm, rib cage, intercostal  muscles, abdominal muscles and elastic connective tissue in the lungs.
Conducting Portion
vSystem of ducts

vConducts air to all parts of the lungs

nNose

nNasopharynx

nLarynx

nTrachea

nBronchi

nBronchioles

nPreterminal bronchioles

nTerminal bronchioles

vConditioning of the air .



Trachea:-


n20 C-shaped cartilaginous rings

nParies membranaceus

Connective tissue that fills 

gap between the two 

posterior ends

n

Neighbouring rings

Connected by regular dense 

connective tissue

Continuous with 

perichondrium of 

cartilaginous rings.