Human Respiratory System

Overview

• The respiratory system is a complex biological system that brings oxygen into the body and removes carbon dioxide.
• It consists of the upper and lower respiratory tracts, lungs, and breathing muscles.

Upper Respiratory Tract

• Includes the:
  • Nose and mouth (entry points for air)
  • Pharynx (throat)
  • Larynx (voice box)
  • Epiglottis ( flap that separates the trachea and esophagus)
• Functions:
  • Warms, humidifies, and filters the air we breathe
  • Contains small hair-like structures called cilia that help remove dust and debris

Lower Respiratory Tract

• Includes the:
  • Trachea (windpipe)
  • Bronchi (tubes that branch off from the trachea)
  • Bronchioles (smaller tubes that branch off from the bronchi)
  • Alveoli (tiny air sacs where gas exchange occurs)
• Functions:
  • Conducts air to the lungs
  • Allows for gas exchange between the air we breathe and the bloodstream

Lungs

• Located in the chest cavity, protected by the rib cage
• Functions:
  • Exchange oxygen and carbon dioxide through the process of respiration
  • Regulate pH levels by removing excess hydrogen ions

Breathing Muscles

• Includes the:
  • Diaphragm (main muscle of breathing, located below the lungs)
  • Intercostal muscles (muscles between the ribs)
  • Accessory muscles (neck, back, and abdominal muscles that assist with breathing)
• Functions:
  • Contract and relax to expand and deflate the lungs
  • Allow for inhalation and exhalation

Gas Exchange

• Occurs in the alveoli, where oxygen diffuses into the bloodstream and carbon dioxide diffuses out
• Oxygen-rich blood is transported to the heart and then to the rest of the body
• Carbon dioxide-rich blood is transported to the lungs, where it is exhaled out of the body

Regulation of Breathing

• Controlled by the:
  • Brainstem (regulates automatic breathing)
  • Cerebral cortex (regulates voluntary breathing)
• Influenced by factors such as:
  • Carbon dioxide levels
  • Oxygen levels
  • pH levels
  • Emotional state (e.g. anxiety, excitement)

Respiratory System

• Complex biological system that brings oxygen into the body and removes carbon dioxide

Upper Respiratory Tract

• Includes nose and mouth as entry points for air
• Includes pharynx (throat), larynx (voice box), and epiglottis (flap that separates trachea and esophagus)
• Functions: warms, humidifies, and filters the air we breathe
• Contains small hair-like structures called cilia that help remove dust and debris

Lower Respiratory Tract

• Includes trachea (windpipe), bronchi (tubes that branch off from trachea), bronchioles (smaller tubes that branch off from bronchi), and alveoli (tiny air sacs where gas exchange occurs)
• Functions: conducts air to the lungs and allows for gas exchange between the air we breathe and the bloodstream

Lungs

• Located in the chest cavity, protected by the rib cage
• Functions: exchange oxygen and carbon dioxide through the process of respiration, and regulate pH levels by removing excess hydrogen ions

Breathing Muscles

• Includes diaphragm (main muscle of breathing, located below the lungs), intercostal muscles (muscles between the ribs), and accessory muscles (neck, back, and abdominal muscles that assist with breathing)
• Functions: contract and relax to expand and deflate the lungs, allowing for inhalation and exhalation

Gas Exchange

• Occurs in the alveoli, where oxygen diffuses into the bloodstream and carbon dioxide diffuses out
• Oxygen-rich blood is transported to the heart and then to the rest of the body
• Carbon dioxide-rich blood is transported to the lungs, where it is exhaled out of the body

Regulation of Breathing

• Controlled by the brainstem (regulates automatic breathing) and cerebral cortex (regulates voluntary breathing)
• Influenced by factors such as carbon dioxide levels, oxygen levels, pH levels, and emotional state