The Respiratory System

1. The Respiratory System Teacher Version

2. The respiratory system consists of the respiratory airways and the lungs

3. The respiratory airways include: • The nasal cavity • The pharynx • The trachea • The bronchi or bronchial tubes The respiratory system has only one opening for air to flow in and out of the body

4. Nasal Cavity • The nasal cavity has: • Hair Lined Walls – to filter out the foreign particles in the air • Numerous Capillaries – to warm up the air that is inhaled • Mucous Glands – moisten this air

6. The Pharynx • The Pharynx is between the nasal cavity and the trachea (windpipe) • Serves as the crossover point between the digestive and respiratory tracts • The “epiglottis” is the switching mechanism that closes off the windpipe while swallowing food

8. The Trachea • The trachea is a tube about 12 cm long that is held open by a series of cartilage rings. • The walls of the trachea are lined with: • -Mucus Glands that capture foreign particles that have escaped nasal filtration and have entered the trachea • -Numerous Cilia (hair-like structures) that move the mucus covered particles back up the trachea so they can be swallowed down the esophagus or expelled from the respiratory tract.

9. The Larynx • The larynx is situated at the top of the trachea. It is our voice box due to its vocal cords. In the human male the larynx is called the Adam’s Apple and is more visible. The male vocal cords are longer producing a lower sound

10. The Bronchi The Bronchi Are extensions of the trachea they: • Serve as airways that carry air to the lungs • Are held open by rings of cartilage • Are lined with cilia and mucous glands

11. The Lungs • Each bronchus enters a lung and branches into smaller bronchi known as bronchioles. • The bronchioles then subdivide into millions of alveoli. • It has been estimated that there are approximately 700 million alveoli in both lungs. • The alveolus is the functional unit of the lung. Here carbon-dioxide blood is oxygenated to become oxygen-carrying blood.

12. Alveoli

14. Alveoli • Oxygen (good gas) that we breathe in enters the alveoli and is carried to the body cells. • Carbon dioxide (waste gas) leaves , following the same path as the oxygen, but in the opposite direction.

15. Diaphragm • The diaphragm is a muscular structure that supports the lungs and separates the thorax (rib cage) from the abdomen.

16. Respiration • Breathing: • Is the movement of the air into and out of the lungs. • Lungs are spongy air filled sacs. • Breathing is caused by muscle action. • In humans inspiration and expiration (the cycle) occurs from 16 to 24 times per minute.

20. The Plan Today: review questions, binder clean up Tuesday: Hand in project, open binder assignment Wednesday: MINI DAY-No class Thursday: Practice Test Monday Respiratory Test

21. Review Questions • Describe the path that oxygen would take through the respiratory system. Start at the mouth/nasal cavity and end at the body cells • Which gas is removed from the body when we exhale? Where does this gas come from? • Why is the respiratory system often called the respiratory tree? What organs make up this “tree”?

22. Describe what happens to the diaphragm and the volume of the thorax when we a) breathe in, b) breathe out. • Draw a picture of an alveoli, be sure to label the following: -capillary, oxygen, carbon dioxide, bronchiole. -Show the direction that each gas is moving

23. What are cilia? Where are they and what is their function? What is the difference between the larynx and the pharynx? Where are they located? What is their function? Describe what the trachea looks like.