Respiratory System
The respiratory system’s main function is gas exchange, mainly carbon dioxide to oxygen via osmosis. It also enables speech and sound, and has an extensive defense system against pathogens.
Parts Involved
The first five parts listed below make up the conducting zone, and the last four make up the respiratory zone.
- Larynx – houses the vocal chords
- Trachea – air tube connecting to the bronchi
- Bronchi – left and right tubes that carry air to and from the lungs respectively
- Bronchioles – non-cartilaginous branches of the bronchi, distribute air to alveoli
- Terminal bronchioles – branches of the bronchioles
- Respiratory bronchioles – branches of terminal bronchioles, with sporadic alveoli
- Alveolar ducts – each lung holds 1.5-2 million of them, and they are responsible for 10% of gas exchange
- Alveoli – responsible for 90% of gas exchange, sacs found sporadically on the respiratory bronchioles the alveolar ducts, within the alveolar sacs and at the end of each branch
- Diaphragm – shelf of muscle separating the thoracic cavity from the abdominal cavity (critical to making room for aspiration)
Fun Facts
Lined up end to end, the lungs’ airways would be about 1,490 miles (2,400 km) long.
The average person take 21,600 breaths per day.
70% of the body’s waste products leave through breath.
The brain uses 25% of the body’s oxygen and is only 2-3% of its mass.
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Skeletal System
Bones have two purposes. Some, like your backbone, provide the structure which enables you to stand erect instead of lying like a puddle on the floor. Other bones protect the delicate, and sometimes soft insides of your body.
Parts Involved
- Bones – adult skeletons have 206; newborns have significantly more that fuse with age
- Cartilage – tense connective tissue that serves structurally and protectively
- Ligaments – bands of fibrous connective tissue that connect bones to other bones (forming a joint)
Functions
- Structural integrity
- Protection for other systems
- Blood cell production occurs in the marrow
Fun Facts
You have over 230 movable and semi-movable joints in your body.
Humans and giraffes have the same number of neck bones; clearly they’re not the same length proportionally!
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Continued Anatomical Learning
Human Body & Mind - BBC Science & Nature
How Your Brain Works - How Stuff Works
How Sex Works - How Stuff Works
The Anatomy Coloring Book (book)
Content on this page came in part from Wikipedia article Human Anatomy and several articles accessed from links within. All Wikipedia materials are copylefted under the GNU Free Documentation License agreement.
