Download Respiratory System - County Central High School

Respiratory System
Air
The air around you is composed
of nitrogen, oxygen, carbon
dioxide, and trace gases
These gases are taken into your
body with every breath you take
Air
Oxygen is so essential to humans that we would be dead
without out in only a few minutes.
In comparison:
- we can live for days without water
- we can live for weeks without food
Respiration and Breathing
Breathing
- the movement of air between the external environment
and the body
- exchange of oxygen and carbon dioxide takes place
across a respiratory membrane
Respiration
- oxygen is supplied to cells and carbon dioxide is
transported to the lungs to be expelled
Respiration and Breathing
Oxygen is used for cellular respiration
The concentration of oxygen is cells is much lower than the
environment because it is continuously being used
Oxygen needs to be constantly replenished for a cell to
survive
Nasal Cavity
Filled with tiny hairs to block particles from entering the
system
Filled with mucous to also block particles
Warm and moisten incoming air
Pharynx
Air filled cavity at the back of the mouth
Trachea
Also called the windpipe
Covered in cartilage rings to provide structure
Lined with mucous producing cells that carry debris using
cilia (hair like structures) back to the pharynx
Epiglottis
The larynx is an enlarged segment of cartilage that supports
the epiglottis
This flap structure covers the glottis (opening of the
trachea) blocks food from entering the lungs
When food is chewed, a reflex is sent closing the epiglottis
Choking
The feeling of choking is when the epiglottis has not closed
quickly enough and food or liquid has entered the trachea
The resulting coughing is your body’s response and is trying
to expel the substance from your trachea to allow breathing
to continue
Larynx
The larynx is also called the voice box - contains two thin
sheets of elastic ligaments
When air enters, it causes the vocal cords to vibrate
Different sounds are caused by change in tension of the
chords
Protected by thick cartilage called the Adam’s apple
Larynx
Larger voice boxes lead to deeper voices
When you get sick, there is an inflammation of the vocal
cords and this causes lower frequency vibrations which
causes your voice to lower
Laryngitis is extreme swelling and may result in temporary
loss of voice
Bronchi
Air moves from the trachea to the bronchi
These branch into the left and right lungs
Contain bands of cartilage for structure
Bronchioles
Smaller branches of the bronchi
Do not contain cartilaginous bands
Muscles in the walls can decrease diameter
Closing of these structures slows air movement leading to a
wheezing sound
Alveoli
Air moves from the bronchioles to the alveoli (sg: alveolus)
Each alveolus is surrounded by capillaries
Gas exchange occurs here
Oxygen and CO2 move from areas of high concentration to
low concentration → O2 moves into blood and CO2 moves
into alveolus
Alveoli
The lung contains about 150 million alveoli
During inhalation, alveoli look bulb shaped but during
exhalation, they collapse
The membranes do not stick together because there is a
film of fat called lipoprotein that allows them to pop open
during inhalation
Pleural Membrane
A thin membrane that surrounds the outer surface of the
lung and lines the inner wall of the chest cavity
The space between pleural membranes is filled with a small
amount of fluid that reduces the friction between the lungs
and the chest cavity
Sometimes fluid can build up between these membranes
making it very hard to breathe
Breathing & the Diaphragm
Pressure differences between the air and the chest cavity
determines the movement of air into and out of the lungs
Atmospheric pressure is relatively constant but the
pressure in the chest cavity may vary
Gases move from areas of high pressure to areas of low
pressure
Breathing & the Diaphragm
When you inhale, the pressure inside the lungs is less than
the atmosphere
When you exhale, the pressure inside your lungs is greater
than the atmosphere
The diaphragm is a dome shaped muscle that separates the
thoracic (chest) cavity from the abdominal cavity
Breathing & the Diaphragm
This muscle contracts during
inhalation and expands
during exhalation
The diaphragm is assisted by
the intercostal muscles that
cause the ribs to move
Breathing & the Diaphragm
A pneumothorax occurs when there is an accumulation
(build up) of air inside the chest space between the pleural
membranes and this causes the lung to collapse
Air must be removed so that the lung can re-expand and
this is sometimes accomplished by piercing the side with a
needle
Questions
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