Anatomy Of The Lungs

The respiratory system is vital to human life. They have many different functions and are composed of many important organs that allow us to inhale oxygen and exhale carbon dioxide.

The respiratory system supplies RBC’s with oxygen and allows it to deliver the oxygen throughout the body. Oxygen enters the oral and nasal cavities, and then flows through the larynx and trachea (windpipe), into the bronchi. The bronchi form into two small tubes (bronchus), then eventually forms into the bronchial tubes, which allows the oxygen to enter the lungs. The bronchial tubes divide into smaller tubes and attach to the 600 million, spongy alveoli (small sacs contain air) that are located throughout the lungs. The alveoli allow inhaled oxygen to pass through them and diffuse through capillaries into arterial blood. During this time, the carbon dioxide blood from the veins, releases the waste product into the alveoli. This waste follows the same tract to exit the lungs, when you exhale. 

Respiratory System
  • Oral Cavity (mouth) allows oxygen to enter the respiratory tract
  • Nasal Cavity (nostrils) allows oxygen to enter the respiratory tract
  • Trachea (windpipe) is a long narrow tube
  • Lungs are the main organs in the respiratory system
  • Larynx filters warm, moistened air and channels it into the lungs
  • Diaphragm is a large dome shaped sheet of muscle that expands on inhalation. It is situated in the thoracic cavity and separates the chest from the abdomen. The ribs form a cage around the lungs and sides of the diaphragm. It contracts and flattens, then stretches the lungs downward, while the intercostal muscles contract and pull the ribcage upward and outward, which also helps the lung to stretch. 
  • Intercostal muscles make up the chest wall and are situated between the ribs. 
  • Thorax situated between the neck and diaphragm and is partially surrounded by the ribs
The diaphragm and intercostal muscles help to change the thorax’s size, which causes air to enter and exit the lungs. 

Conducting Zone
The main function of the conducting zone is to filter warm, moistened air and channel it into the lungs.
  • Nose
  • Pharynx (throat)
  • Larynx (voice box)
  • Trachea
  • Bronchi and bronchioles
The bronchioles contain cilia (tiny hairs) and are lined with mucous secreting cells, which trap dust, pollen, and viruses and prevent it from entering the lungs. The cilia are continuously beating and waving in an upward flow, which pushes the mucus up toward the esophagus. 

Unconscious Control

Breathing is controlled by is an unconscious control, which basically means that we do not have to tell our respiratory system to inhale and exhale (passive process), because it automatically does it, without thought.  The brain stem regulates and maintains the breathing pattern. When the brain nerve cells detect carbon dioxide, it will send electrical signals to the muscles of breathing, until the carbon dioxide level is back to normal.