Transcript Respiratory System

Respiratory System
Respiration Overview
 All of your body’s cells
require oxygen
(remember, oxygen and
glucose are used by your
cells during cellular
respiration to make ATP
or energy)
 The respiratory system
supplies oxygen and
removes carbon dioxide
from your body
Overview cont.
 The respiratory system is
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made up of:
Nasal passages
Pharynx (upper throat)
Larynx (voice box),
Epiglottis (a flap of tissue that
keeps food from getting into the
windpipe/trachea)
Trachea
lungs,
Bronchi
Bronchioles
Alveoli
Diaphragm
The Path of Air
 First, air enters the mouth or
nose. Hairs in the nose filter out
dust and other large particles in
the air
 Hair-like structures called cilia
line the nasal passage (and other
respiratory tubes), and trap
foreign particles from the air and
sweep them toward the throat so
that they don’t enter the lungs.
 Mucous membranes beneath the
cilia in the nasal massage warm
and moisten the air while
trapping foreign materials
Path of Air cont.
 The filtered air now passes
through the upper throat (the
pharynx). A flap of tissue
called the epiglottis prevents
food particles from entering
the respiratory tubes (like the
larynx)
 The epiglottis allows air to
pass from the larynx to a long
tube in the chest called the
trachea (or windpipe)
Path of air cont.
 The trachea branches into two
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large tubes, called bronchi
(singular is bronchus), which lead
to the lungs
The lungs are the largest organs in
the respiratory system, and this is
where gas exchange takes place
Each bronchus branches into
smaller tubes called bronchioles
Bronchioles branch into even
smaller passageways which end in
an individual air sac called an
alveoli (alveolus singular)
Each alveolus has a thin wall –
only one cell thick – and is
surrounded by capillaries
Gas Exchange in the Lungs
 Air travels to individual
alveoli, where oxygen
diffuses across the thin
capillary walls and into the
blood cells
 The oxygen is then taken to
cells in the body
 Carbon dioxide in the
blood crosses the capillary
walls and diffuses into the
alveoli to be exhaled
Breathing
 The brain controls the rate of
breathing by responding to internal
stimuli that tell how much oxygen the
body needs.
 When you have lots of CO2 in your
blood, your breathing rate increases
(because your cells need more oxygen)
 During inhalation (taking in oxygen),
your diaphragm contracts, which
causes the chest cavity to expand as
the diaphragm moves down. This
allows air to move into the lungs
 In exhalation, the diaphragm relaxes,
reduces the size of the chest cavity and
air naturally flows out from the greater
pressure of the lungs
Assignment:
 Draw a Venn Diagram that illustrates THREE
differences and similarities between the respiratory
system and circulatory system
 Fill in Venn diagram as we watch the following video:
http://www.youtube.com/watch?v=9fxm85Fy4sQ
“I Can” Quiz - Respiration
 I Can Quiz:
 1. Explain the function of the respiratory system
 2. What are at least 5 organs found in the respiratory
system?
 3. What is the function of the alveoli?
 4. Draw the path that air takes through the respiratory
system.
Answers:
 1. The respiratory system provides oxygen to the body
and helps remove carbon dioxide
 2. nasal cavity, pharynx, larynx, epiglotis, trachea,
bronchi, bronchioles, alveoli, lungs, diaphram
 3. alveoli are the site of gas exchange between the
respiratory and circulatory systems
 4.