Respiratory System Overview

Study Notes

The respiratory system is a biological system that brings oxygen into the body and removes carbon dioxide
It is essential for the survival of all living organisms

Nose and mouth: air enters the body through the nose or mouth
Pharynx (throat): air passes through the pharynx, which is a tube that connects the nose and mouth to the lungs
Larynx (voice box): air passes through the larynx, which contains the vocal cords
Trachea (windpipe): air passes through the trachea, which divides into two bronchi
Bronchi: air passes through the bronchi, which branch into smaller and smaller tubes like the branches of a tree
Bronchioles: air passes through the bronchioles, which lead to the alveoli
Alveoli: air reaches the alveoli, where oxygen is absorbed into the blood and carbon dioxide is removed
Diaphragm: a dome-shaped muscle that separates the chest cavity from the abdominal cavity
Rib cage: the rib cage protects the lungs and helps with breathing

Inhalation:
- Diaphragm contracts and flattens, increasing the volume of the chest cavity
- Rib cage expands, increasing the volume of the chest cavity
- Air enters the lungs through the nose or mouth
Exhalation:
- Diaphragm relaxes and rises, decreasing the volume of the chest cavity
- Rib cage descends, decreasing the volume of the chest cavity
- Air leaves the lungs through the nose or mouth

Oxygen from the air we breathe diffuses into the blood through the alveoli
Carbon dioxide from the blood diffuses into the alveoli and is exhaled out of the body
Oxygen-rich blood is transported to the body's tissues through the circulatory system
Carbon dioxide-rich blood is transported back to the lungs through the circulatory system

Oxygen diffuses into blood through alveoli
Carbon dioxide diffuses from blood into alveoli and is exhaled
Oxygen-rich blood is transported to body tissues through circulatory system
Carbon dioxide-rich blood is transported back to lungs through circulatory system