7th Grade

The Respiratory SystemThe 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 SystemTwo entrances—

The nasal airway 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 SystemThe Pharynx-known as the throat, around 5

inches long in an average adultNasopharynx-superior partOropharynx-middle partLaryngopharynx-inferior part

The Larynx-known as the voice boxHouses the vocal cordsAdam’s Apple

C-shaped strips of cartilage reinforce the structure

The Respiratory SystemEpiglottis-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 SystemRight 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

BreathingStarts with a deep breathMucous and Nose hairs filter the airVeins close to the skin in the nose warm the airThe 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

Breathinghttp://

kidshealth.org/kid/htbw/_bfs_RSmoviesource.html