The Respiratory System Mrs. Hasson Ms. Golden Mrs. Lattanzio Mrs. Hopkins 7 th Science

The Respiratory System The purpose of the Respiratory System is to bring needed Oxygen to the cells and remove the waste product Carbon Dioxide! Remember: The cells use Oxygen to release energy from food in a process called Cellular Respiration. Carbon Dioxide and water are the waste created during this process.

Where Does the Respiratory System Begin? The respiratory system begins at the nose and nasal cavity. The nose and nasal cavity are lined with small hairs called cilia, capillaries and mucus. These 3 items help to warm, moisten, and clean the air before it enters the lungs.

The Trachea The trachea is the cartilage lined tube that travels down the neck, after your voice box, or larynx. It will branch before it gets to the lungs. The cartilage gives it support, helping it to remain open. Feel your neck, the bumps you feel are the cartilage rings.

The Branches or Bronchioles The Trachea branch into the bronchi and then the bronchioles. If you look carefully it appears to look like an upside-down tree.

Tiny little air sacs! At the end of the bronchioles are millions of tiny little air sacs or alveoli. These alveoli are where gas exchange takes place! They are covered with tiny blood vessels called capillaries. If you recall, capillaries are the blood vessels where gas exchange or diffusion takes place!

Oxygen in and Carbon Dioxide out! At the alveoli, oxygen will go into the capillaries, being picked up by the Red Blood Cells. The blood will then release the Carbon Dioxide into the alveoli, where it will be exhaled into the atmosphere!

Inhalation and Exhalation! The diaphragm is a smooth muscle that controls the movement of the lungs. When the diaphragm contracts, it pulls down, causing the chest to expand and the air to rush into the lungs. When it relaxes, the chest becomes smaller and air is exhaled.

Relax and contract! Remember: – When the diaphragm contracts, or pulls down, air rushes into the lungs! – When the diaphragm relaxes or bowls upward the chest relaxes and the air rushes out of the lungs expelling waste!

Very Short VIDEO on the Respiratory System!

Why do we need oxygen? Cellular Respiration! Remember: The cell is taking in Oxygen and nutrients. It releases energy from the nutrients using the oxygen. Carbon dioxide is the waste product produced. We need to get rid of that waste. The gases that are exchanges is Oxygen and Carbon Dioxide!