Transcript The Respiratory System

7th Grade
The Respiratory System
 The system that
exchanges oxygen
and carbon dioxide
 You take 20 breaths
per minute
 The lungs are very
big organs but way
relatively very little
The Respiratory System
 Two entrances—
 The nasal airway
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Nostrils or nares
Nose hairs
The nasal cavity
 Lined with mucous membranes
Sinuses
 Secrete more mucous
 Make skull lighter
 The oral airway

Mouth
The Respiratory System
 The Pharynx-known as the throat, around 5 inches
long in an average adult
 Nasopharynx-superior part
 Oropharynx-middle part
 Laryngopharynx-inferior part
 The Larynx-known as the voice box
 Houses the vocal cords
 Adam’s Apple

C-shaped strips of cartilage reinforce the structure
The Respiratory System
 Epiglottis-a flap of elastic cartilage,
makes sure only air enters the larynx,
forces food and liquids to travel down
the esophagus
 Trachea-this is the windpipe, also has
c-shaped cartilage for protection in
the front.
The Respiratory System
 Right and Left Bronchi-the trachea breaks into two
pathways, one to the right lung and one to the left
lung.
 Bronchioles-The bronchi (think trunk of tree) fork
into many different branches called bronchioles.
 Alveoli-The bronchioles continue to branch and
eventually end at microscopic air sacs, gas is
exchanged between the blood and these grape-like
structures---there are at least 600 million alveoli in our
lungs!!
The Respiratory System
Breathing
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Starts with a deep breath
Mucous and Nose hairs filter the air
Veins close to the skin in the nose warm the air
The diaphragm-a narrow, dome-shaped muscle positioned
immediately below the lungs contracts with a breath
(flattens)
 The intercostal muscles-between each rib, the lower ribs
push out just enough so air may fill up the lungs
 The lungs are literally “stuck” to the inside of the chest so
they expand with the chest (two types of pleura)
 Gases move from high pressure to low pressure
Breathing
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