The Respiratory SystemChapter 18, Section 1

Monday, April 12, 2010

Pages 566 -- 575

Objectives

• Understand the functions of the respiratory system.

• Describe the structures that are involved with the passage of air as it travels to the lungs.

• Understand the role of oxygen, carbon dioxide, and water as they move in the lungs.

• Explain the process of breathing and speaking.

Vocabulary Words

• Respiration• Cilia• Pharynx• Trachea• Bronchi

• Lungs• Alveoli• Diaphragm• Larynx• Vocal cords

Respiratory System

• Functions of the respiratory system:– Move oxygen from

the outside environment into the body.

– Removes carbon dioxide and water from the body.

Respiration

• It is the process in which oxygen and glucose undergo complex chemical reactions inside cells.– These chemical reactions release energy

that your body needs to function properly.– This process also produces carbon dioxide

and water.

Respiration vs. Breathing

• In respiration, the oxygen and glucose in your body’s cells undergo a complex series of chemical reactions.– The chemical reactions release energy that aid in

growth and regular cell function.

• Respiration also gets rid of carbon dioxide and a small of water through your lungs.

• All of these things are processes that take place as a chemical reaction inside cells.

Respiration vs. Breathing

• It is the movement of air into and out of the lungs that is referred to as breathing.

Respiration Path

• Air from the outside environment ---> nose ---> pharynx ---> trachea ---> bronchi ---> the lungs.

The Nose

• The nose is the first organ the air from the outside environment travels through.

• The inside of the nose is coated with mucus.– Mucus cleans, warms, and moistens the air

that we breathe.– The inside of the nose is lined with cilia.

The Nose -- cont’d

• Cilia in your nose are tiny hairlike extensions that can move together.

• They sweep the mucus into the throat where it is swallowed.

QuickTime™ and a decompressor

are needed to see this picture.

The Pharynx

• The pharynx is the next organ after the nose.

• The pharynx is also known as simply, the top of the throat.

QuickTime™ and a decompressor

are needed to see this picture.

The Trachea

• The trachea is also known as the windpipe.

• The trachea leads from the pharynx to the lungs.

• Walls of the trachea are made up of rings of cartilage that prevents it from collapsing.

• The trachea is lined with cilia and mucus.

QuickTime™ and a decompressor

are needed to see this picture.

Bronchi

• Air from the trachea move into the right and left bronchi (singular is bronchus).

• Bronchi are passages that direct air into the lungs.

QuickTime™ and a decompressor

are needed to see this picture.

The Lungs

• The lungs are the main organs of the respiratory system.

• Inside the lungs, each bronchus divides into smaller and smaller tubes.

• At the end of the smallest tubes are bunches of alveoli.

QuickTime™ and a decompressor

are needed to see this picture.

Alveoli (singular alveolus)

• Alveoli are tiny sacs of lung tissues.

• These tiny sacs are specialized for the movement of gases between air and blood.

• Alveoli are surrounded by capillaries.

QuickTime™ and a decompressor

are needed to see this picture.

Gas Exchange

• Air enters an alveolus ---> oxygen passes through the wall of the alveolus ---> capillary wall into the blood ---> carbon dioxide and water pass from the blood into the alveoli.

• This process is called gas exchange.

The Diaphragm

• The diaphragm is a large dome-shaped muscle at the base of the lungs.

• The diaphragm and rib muscles make the chest cavity expand when you inhale and contract when you exhale.

QuickTime™ and a decompressor

are needed to see this picture.

The Process of Breathing

• You inhale or breathe in.• Rib muscles contract and lifts the chest wall

upward and outward.• The diaphragm contacts and moves

downward.• When the rib muscles and diaphragm

contract, it lifts the chest wall and provides more space for the lungs to expand.

The Process of Breathing -- Cont’d

• At this time, that space is fully occupied and no extra air can fill it.

• This causes the pressure of the air inside the lungs to decrease.

• The pressure of the air inside the chest cavity is lower than that of the surrounding atmosphere pushing on the body.

The Process of Breathing -- Cont’d

• This difference in air pressure causes the air to rush into your chest. (Think vacuum cleaner!)

• This describes inhalation. • When you exhale or breathe out, the rib

muscles and diaphragm relaxes.• The relaxation causes the chest cavity to

become smaller, squeezing the air out of the lungs.

The Larynx• The larynx is also known

as your voicebox.• It is located at the top of

the trachea.• The vocal cords are folds

of connective tissue that stretch across the opening of the larynx.

• Vocal cords vibrate when air passes over them.– This vibration is what

produces the sound of your voice.

QuickTime™ and a decompressor

are needed to see this picture.

High and Low Tones

• The high and low pitch tones in your voices depend on the length of the vocal cords.– High pitch voices are produced by the contraction

and shortening of the vocal cords.– Low pitch voices are produced by the relaxation of

the vocal cords.– Vocal cord length changes over a person’s

lifetime.

Review

• What is the function of the respiratory system?

• Trace the path of oxygen in the respiratory system (air to alveoli).

• What is the difference between respiration and breathing?

Homework

• Workbook 18.1 (4/14)

• Vocabulary quiz 18.1 (4/14)

• Worksheet 18.1 (4/14)

• Current Science -- Free Range (4/13)

• Bring in one clean water bottle. Make sure it has a narrow neck. Remove the label.