Human Respiratory System

Definition of Respiration

Respiration is the process of gas exchange between organisms and their environment, where oxygen (O₂) is taken in and carbon dioxide (CO₂) is released. Oxygen is used to produce energy in cells through the process of cellular respiration.

Organs of the Human Respiratory System

 

 

 

 

pic taken from detikedu 

1. Nose – The entry point of air. The nose filters dust with nose hairs and moistens air with mucus.

2. Pharynx – A passageway for both air and food.

3. Larynx – Contains the vocal cords and functions in sound production.

4. Trachea (windpipe) – A tube supported by cartilage rings that carry air into the lungs.

5. Bronchi – Two branches of the trachea that lead into the left and right lungs.

6. Lungs – Contain smaller branches called bronchioles that end in alveoli, where gas exchange occurs.

Gas Exchange Process

• Occurs in the alveoli (air sacs in the lungs).

• Oxygen from inhaled air diffuses into the blood capillaries.

• Carbon dioxide from the blood diffuses into the alveoli to be exhaled.

   

The Breathing Process

1. Inhalation (Inspiration)

   • The diaphragm contracts and moves downward.

   • The rib muscles contract, causing the chest cavity to expand.

   • Air enters the lungs.

2. Exhalation (Expiration)

   • The diaphragm relaxes and moves upward.

   • The rib muscles relax, reducing the chest cavity size.

   • Air is forced out of the lungs.

Types of Breathing in Humans

• Chest (thoracic) breathing – Involves the intercostal muscles.

• Abdominal breathing – Involves the diaphragm.

   

   Differences between Chest Breathing and Abdominal Breathing

  Aspect	Chest Breathing (Thoracic)	Abdominal Breathing (Diaphragmatic)
  Main Muscle Used	Intercostal muscles (between the ribs)	Diaphragm muscle
  Movement	Chest cavity expands and contracts	Abdomen moves up and down
  Process	When inhaling, ribs are lifted upward and outward	When inhaling, diaphragm contracts and moves downward
  Air Volume	Less air enters the lungs (shallow breathing)	More air enters the lungs (deep breathing)
  Efficiency	Less efficient for gas exchange	More efficient for gas exchange
  Common Condition	Happens during light activity or rapid breathing	Happens during deep, relaxed, or sleeping states

   

Respiratory Disorders

1. Asthma – Narrowing of the bronchi causing difficulty breathing.

2. Pneumonia – Inflammation of the lungs caused by infection.

3. Tuberculosis (TB) – Caused by Mycobacterium tuberculosis.

4. Lung cancer – Abnormal growth of lung cells, often due to smoking.

5. Influenza – Viral infection that affects the respiratory tract.