Stephanie Oblitas Honors Biology Mr. Issler April 9, 2012
Systems Objectives
The Respiratory System
1. Identify the structure and function of the parts of the respiratory system.
Nose - Inspiration and expiration usually occurs through the nose. Pharynx - Allows for separation of food and air. The epiglottis closes the trachea when we eat and opens when we breathe.
Trachea - Also called the windpipe, is a tube through which air moves. Bronchi - The trachea branches into two forks each called bronchi. Bronchioles - The smaller and smaller passageways that come off the bronchi. Branches of a bronchus. Larynx - This structure sits on top of the trachea. It is a structure in the throat containing the vocal cords. Alveoli – Tiny air sac at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur.
2. Explain the function of the ribs and diaphragm in the breathing process.
The diaphragm is a muscle. It helps to expand and contract the ribs (they are flexible). If the person inhales, the diaphragm rises and the ribs expand. If the person exhales, the diaphragm drops, and the ribs contract.
3. Explain how breathing rate is controlled.
Your medulla oblongata located in the brainstem stimulates you to breathe when the carbon dioxide levels in your blood reach a certain level. Your emotions, activity level, and thoughts can increase your breathing.

4. Describe what happens between the alveoli and the capillaries.
Inside the lungs, the bronchus split into smaller branches to form thousands of tiny sacs called alveoli (alveolus). The capillaries surround the alveolus and absorb the oxygen, which is then carried into the circulatory system. This is what happens between the alveoli and the capillaries.

5. Describe the effects of smoking on respiration.

Smoking can cause such respiratory diseases as chronic bronchitis, emphysema, and lung cancer.

Vocabulary:

Alveoli: The alveoli are tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place.
Gas exchange: Gas exchange occurs by diffusion across the membrane of an alveolus and a capillary.
Epiglottis: The flap that covers the trachea during swallowing, so that food does not enter the lungs.
Trachea: A tube-like portion of the respiratory tract that connects the larynx with the bronchial parts of the lungs. Also known as windpipe.
Bronchi: A large air tube that begins at the end of the trachea and branches into the lungs. The supporting walls of the bronchus are made up in part of cartilage.
Brochiole: The tiny branch of air tubes within the lungs that are a continuation of the bronchus. The bronchioles connect to the alveoli (air sacs).
Larynx: A tube-shaped organ in the neck that contains the vocal cords. The larynx is about 5 cm (2 in.) long. It is part of the respiratory system and is located between the pharynx and the trachea. Humans use the larynx to breathe, talk, and swallow.
Lung: The lungs are a pair of organs in the chest, which are primarily responsible for the exchange of oxygen and carbon dioxide