Transcript Respiratory System NOTES

Respiratory System
I. Function (job) of the
Respiratory System
A. Respiration is to provide gas exchange
between the blood and the environment.
a. Requirements for Gas exchange
at the respiratory surface:
1. Thin-walled –(so gases can freely
diffuse across)
2. Moist- (O2 and CO2 must be in
solution or dissolved)
3. In contact with O2 source-(outside
environment)
4. In contact with transport system
carrying dissolved gases (Circulatory
system/Blood)
b. Examples of gas respiratory surfaces
used for exchange
• Protists
(Amoeba/Paramecium)
– Surface: Cell
membrane
– Method: Simple
direct diffusion
through cell
membrane to water
• Earthworm
– Surface: Moist skin
– Method: Diffusion
through moist mucus
coated skin into blood
vessels
(has hemoglobin to help)
Examples of gas respiratory surfaces used for
exchange
• Fish
– Surface: Gills
– Method: Diffusion
from water to blood
vessels in the gills
• Grasshopper
– Surface: Air tubes &
Sacs
– Method: Air comes in
through spiracles,
through the air tubes,
moved by muscle
contraction (no
hemoglobin/blood
used)
c. Human Respiratory System
• Surface: Moist air
sacs (alveoli)
• Method: Diffusion
across air sacs into
blood stream (use
hemoglobin to
increase amount of
O2 that blood can
carry)
1. Oxygen is absorbed
from the atmosphere
into the body.
2. Carbon dioxide is
expelled from the
body.
3. Inhaling (breahing)
brings oxygen into the
body that cells
need for cell respiration.
4. Cellular Respiration- using oxygen carried by the red
blood to the mitochondria to break down food to create
ATP (energy) and CO2 gas as waste.
Question
1. What is the main job of the respiratory
system?
2. Why does the body need oxygen? Be
specific
3. Explain the difference between breathing
and cell respiration.
Question
1. What is the main job of the respiratory
system? provide gas exchange between
the blood and the environment.
2. Why does the body need oxygen? Be
specific.
cell respiration [breaking down food for
energy]
II. Respiratory System: Subsystems- Components that
work together to support the system:
A.
The Upper Respiratory Tract:
1. Nose (nostrils) - It is the entrance
of the respiratory tract.
2. Pharynx - It is situated behind
the mouth and is the passage to the
stomach and the lungs.
3. Larynx - It is present at the top of
trachea and contains vocal cords.
It is also known as the voice box.
4. Trachea (windpipe) - It is a tube like structure that helps in passage
of air from larynx to the bronchi.
B. The Lower Respiratory Tract:
1. Bronchi (bronchioles) - These
are the branches (tubes) of the
bronchi that conduct air into the
lungs.
one bronchi goes to each lung
and branches into
bronchioles
2. Alveoli (air sacs) - The sacs in
the lungs where gas
exchange occurs.
3. Lungs - The two inverted-cone
shaped organs present in
the chest of human beings.
C. Breathing Process
Four Stages of Gas Exchange :
1.Breathing- movement of air in and out
of the lungs
a.Inhalation - chest cavity increases
• Diaphragm contracts (flattens) and lowers
• Ribs raise up and out
• Lungs inflate because during breathing
negative pressure creates a vacuum
which “sucks” air into the lungs
Four Stages of Gas Exchange :
b. Exhalation - chest cavity is decreased
– Diaphragm relaxes and moves upward
– Ribs drop down and in
– Lungs deflate because positive
pressure pushes the air out of the
lungs
Four Stages of Gas Exchange :
2. External respiration- exchange of gases
between outside air and bloodstream in
the air sacs
– Mucus coats air sacs (alveoli) to moisten
them
– O2 diffuses across air sacs into capillaries of
air sacs and CO2 diffuses in the opposite
direction
– O2 attaches itself to hemoglobin on the red
blood cells
Four Stages of Gas Exchange :
3. Transport- movement of gases in the
blood between the cells to the lungs
(circulatory system)
4. Internal respiration- exchange of gases
between the blood stream and the cells
of the body
– At the capillaries, O2 diffuses into the
intracellular fluid and then into the body cells
& CO2 diffuses in the opposite direction
Question
1. Explain what would happen if one of the
subsystems in the respiratory system
stopped working.
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