Download Mammals

Mammals
Respiratory System
Purpose:
• To transports O2 and CO2 from
atmosphere to the cells
• Two types
– External: use lungs to exchange
gases from the air to our blood
– Internal: to exchange gases
between our blood and our cells
• Respiratory system is located in the
thoracic cavity.
– Lies above the diaphragm
– The diaphragm is a large
sheet-like muscle that
divides the thoracic and
abdominal cavities.
Respiratory System
1. As you breathe in the air should enter via
your nostrils/nares.
• Nasal hairs filter air
• Nasal chambers moistens and warms the air.
2. Air then passes through the pharynx
Back of throat area/behind uvula
A common passage for food & air
3. The pharynx directs air into the larynx.
-Larynx is referred to as the Adam’s Apple or Voice Box
-Inside the larynx is the vocal cords
-As air passes through the vocal cords these thin bands
of tissue vibrate allowing you to make sounds.
• 4. The larynx has a flap of tissue protecting
its opening called the epiglottis.
• When you swallow this flap closes making
a slight sound.
– Purpose of the epiglottis is to prevent food
from entering and blocking the respiratory
pathway.
• 5.From the larynx the air passes into the
trachea.
– Known as the windpipe
– Approximately 4 ½ inches long
– Protected by rings of cartilage
that prevents it from collapsing as
air moves in and out.
• 6. The trachea branches to make two
smaller tubes called bronchi
– Bronchi direct the air into the lungs
– Bronchi divide into smaller branches called
bronchioles.
– Bronchioles keep dividing
up to 20 times and eventually
becoming the air ducts.
-Bronchioles, bronchi and trachea are all
lined with small hair like structures called
cilia.
– Cilia trap foreign particles and push
them back towards the throat area.
-Air ducts empty into our air sacs or alveoli.
7. -Alveoli is where our gases are exchanged
-Average human has 300,000,000 alveoli.
Respiratory System
•
•
•
•
Trachea
Bronchi
Bronchioles
Alveoli
• The lungs are surrounded by a double
membrane known as the pleura.
– Keeps the lungs pressurized so air can move in
and out.
– Secretes a slippery fluid which reduces friction
• Mammal lungs are made up of several
lobes.
– 3 lobes on right side
– 2 lobes on left side
• Inspiration:
– Air moves into the lungs from the
atmosphere.
• Air we breathe is 21% oxygen and .03% carbon
dioxide
• Expiration:
– Air moves out of the lungs into the
atmosphere
• Air we exhale is 14% oxygen and 5.6% carbon
dioxide.
• Lets examine how this
happens……………………………..
• Inspiration/Inhaling:
– Air moves into lungs
• Chest expands
– Ribcage moves up and
out / expands space
– Diaphragm flattens and pushes
down
– Abdominal muscles relax.
• Increase volume of thoracic cavity
• Pressure inside the cavity is lower than outside
the cavity
• Air moves from high to low causing air to move
into the lungs.
Expiration/Exhaling:
Air moves out of lungs
-Chest decreases in size
-Ribcage relaxes and moves in
-Diaphragm moves up into a
concaved shape.
-Abdominal muscles contract.
Decrease volume of thoracic cavity
Pressure inside the cavity is higher than
outside the cavity
Air moves from high to low causing air to move
out the lungs.
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