Respiratory System

Functions of the Respiratory System

• The main function is respiration– The exchange of gasses between the body and the

environment.

• The process of respiration can be divided into two parts– External Respiration– Internal Respiration

• External Respiration– The exchange of oxygen and carbon dioxide that

takes place between air and blood in the lungs.

– Oxygen moves from the lungs into the blood, and carbon dioxide moves from the blood into the lungs.

• Internal Respiration– Is the exchange of gasses between blood and body

cells.

– Oxygen moves from the blood to the cells, and carbon dioxide moves from the cells into the blood.

Structure of the Respiratory System

• Consist of the lung and a series of passageways through which air travels.

• The nose and throat make up the upper respiratory system.

• The lower respiratory system contains the larynx, trachea, bronchi and lungs.

The Lungs

• Are the principal organs of the respiratory system and the site of external respiration.

• They are found in the chest cavity and are protected by the ribs.

• The diaphragm is the muscle that separates the chest from the abdominal cavity.

• Air moves into the lungs through the trachea, or the windpipe.

• The trachea branches out into the bronchi, the main airways that reach each lung.

• The airways that lead into the lungs divide and subdivide to form a network of tubes called bronchioles.

• At the end of each bronchiole are groups of microscopic structures called alveoli, thin-walled air sacs covered with capillaries.

• Gas exchange takes place as oxygen and carbon dioxide diffuse across capillary and alveolar walls.

The Breathing Process

• The breathing process is made possible by creating a pressure between the lungs and the outside of your body.

• When you inhale– The diaphragm and muscles between your ribs

contract and expands your chest cavity and your lungs– When your lungs expand the pressure inside them

become lower than the pressure outside your body.– Air naturally flows into your lungs to equalize the

pressure.

The Breathing Process cont…

• When you exhale– The same muscles relax and the volume in your

chest cavity decreases, making the pressure in your lungs higher then the pressure outside your body.

– Air naturally flows out of your lungs to the area of lower pressure.

Other Respiratory Structures

• The upper respiratory system includes structures such as the nose and mouth.

• Air enters and exits your body through the nose and mouth.

• The membranes of the nose are lined with hair like structures called cilia and with cells that produce mucus.

• Why would you want these two extras?

• The mucus and cilia filter the air you breath to trap and remove foreign particles.

• In addition to being filter, air is warmed and moistened as it moves through the nasal passages.

• Air continues through the respiratory system to the pharynx (throat) and into the trachea (windpipe).

• As the trachea reaches the lungs, it branches into two tubes called bronchi- the airway that connects the trachea and lungs.

Larynx and Epiglottis

• Larynx- voice box– Connects the throat and trachea – produces sound

• Epiglottis– Flap of cartilage located above the larynx– Folds down when you swallow to prevent food or

liquid from entering the respiratory system.– When eating too fast or swallowing too quickly

food can go down the wrong path and you cough to expel it

Assignment

• Using your notes answer the following questions

• 1. What is the function of the respiratory system?

• 2. Explain the relationships among the trachea, the pharynx and larynx. – How are they interconnected?

• 3.What role does the diagram play in respiration?

Warm UP

• What is the function of the respiratory system?

• What is the pharynx?

• What are bronchi?

• What's the name of the voice box?

Activity for 10/14• On your warm up paper:

– Complete the AYR on page 431

– You have about 20 minutes

– You will be using this to study from

• When done:– Grab a coloring worksheet from Ms. Shockley’s desk– Have worksheet done by the end of the class period

Entry Task: a. What is the function of the respiratory system?

b. What is the pharynx?c. What are bronchi? d. What's the name of the voice box?

GLE:

Objective: Students will be able to explain what the function of the Respiratory system is, and be able to list the organs involved in respiration.