Human Biology Ch.2 Section 1

The respiratory system interacts with the environment and with other body systems.
The two main functions of respiratory system:
•It functions to get oxygen from the environment.
•It removes carbon dioxide and other waste products from your body.

The continuous process of moving & using oxygen involves mechanical movement and chemical reactions.
• * Air is transported into your lungs by mechanical movements
• * Oxygen is used during chemical reactions that release
• energy in your cells.

Exchanging Oxygen & Carbon Dioxide
Without oxygen, cells in the body die quickly.
The air that you breathe contains about 20% oxygen and less than 1% carbon dioxide. Almost 80% is nitrogen gas.
The air that you breathe out contains more carbon dioxide and less oxygen.
In order to maintain homeostasis, cells and tissues needs proper levels of both oxygen and carbon dioxide.

Cellular Respiration
Inside your cells, a process called cellular respiration uses oxygen
in chemical reactions that release energy.
•Cellular respiration requires glucose, or sugars, and oxygen to release energy. These materials are transported to every cell in your body through blood vessels.
•Carbon dioxide is a waste product of the process because they must be removed from cell.

Structures in the respiratory system function together
The respiratory system is made up of many structures that allow you to move air in and out of your body, communicate, and keep out harmful materials.

Nose, Throat, Trachea, and Lungs
-When you inhale through your nose, tiny hairs called cilia and a sticky liquid called mucus help filter air by trapping particles such as dirt. -> oxygen then passes through trachea (epiglottis keeps air from entering your stomach ) and trachea splits into two smaller tubes -> bronchial tubes-> lungs . Bronchial tubes branch throughout the lungs into smaller tubes. At the end out the smallest tubes, air enters tiny and thin air sacs called alveoli.
-Oxygen passes from inside the alveoli through the thin walls

Ribs and Diaphragm
-The rib cage encloses a space inside your body called thoracic cavity.
-The diaphragm stretches across the floor of the thoracic cavity.
When you inhale, it contracts and pulls downward.
When the diaphragm and other muscles relax, the process reverses and you exhale.

Speaking and other respiratory movements.
•Air moving over your vocal cords (folds of tissue in the larynx or the voice box) allows you to produce sound.
• When you speak, the vocal cords become tight, squeeze together, and force air from the lungs to move between them.
•The air causes the vocal cords to vibrate and produce sound