1.
HUMAN RESPIRATORY
SYSTEM
LETS BEGIN
SONALI NIRALA

2.
What do you understand by RESPIRATION
 Respiration is the process in which the cells of an organism obtain energy
By combining oxygen and glucose, resulting in the release of carbon dioxide
,water and ATP(Energy).

3.
What is Respiratory System
 The respiratory system refers to the mechanism of series of organs responsible for
gas exchange in the body.

4.
Nasal Cavity
 The process of respiration begins with Nasal Cavity.
 When we breathe air flows to the nostrils and enter the nasal cavity.
 It consists of such cells which release mucus.
 Mucus is a salty and sticky substance which helps in killing bacteria.
 It has guard hairs which block the inhalation of large particles.
 It also warms and humidifiers the inhaled air.

5.
Pharynx
 It is also called throat.
 It is a muscular funnel extending 13 cm long.
 It us further divided into three parts:
1.Nasopharynx
2.Oropharynx
3.Laryngopharynx
 Upto this point (pharynx) food,drink and air share a common path.

6.
Larynx
 Its basic function is to keep food and drink out of the airways.
 At the top of the larynx is a spoon shaped flap of cartilage called Epiglottis.
(Epiglottis directs food and drink into the oesophagus)
 Larynx also has an additional function of producing sound.
(That is why it is also called voice box)

7.
Trachea
 It is also called the wind pipe.
 It is a rigid tube,12cm in length.
 It is surrounded by ‘c’ shaped cartilage rings.
 These rings provide flexibility and strength to trachea.
 In respiratory system tracheas main job is to transfer the air to next junction
/passage called primary bronchi.

8.
Primary Bronchi
 It is also called Bronchi.
 It is divided into two parts:
(a) Right Mainstem Bronchus
(b) Left Mainstem Bronchus
 These bronchi enter into our lungs and further divides
into several branches
and sub- branches

9.
Lungs
 The lungs are all elastic bags resembling rubber baloons
 Lungs has the property to float on water.
 Lungs are divided into two parts:
(1) Ring lung
(2) left lung
 Right lung is larger than left lung.
 Both lungs weights approximately 1.3 kg.

10.
Bronchial Tree
 The branches and sub-branches of primary bronchi are
called Bronchules
 Bronchules are root like structure which again,divide into
further branches
and sub-branches which is called Bronchial tree.
 The air passes through bronchial tree to the next and final
junction of the
respiratory system Alveoli.

11.
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.
 It looks like bunch of grapes.
 A single spherical ball like structure of alveoli is called
Alveolus.
 Alveoli is a group of several Alveolus.

12.
Alveolus
 It is very thin and composed of a single cell ,membrane.
 It has blood capillaries.
 The extremely thin membrane helps in very easy exchange of gases between the
Alveolus and RBCs flowing through the capillaries.
 The process of gas exchange occurs by a diffusion.