Transcript Internal Respiration

The Breath of Life
Respiration


Most organisms on Earth are aerobic.
Meaning, they require oxygen to
survive.
The basic function of the respiratory
system is to take in oxygen and
release carbon dioxide
Two Conditions


There must be a surface
to carry out the gas
exchange:
Skin, Gills or Lungs
Gas exchange must occur
in a moist environment.
Respiration – Subdivided
into 4 categories




Breathing – the physical act of taking in a
releasing air.
External respiration – the exchange of
oxygen and carbon dioxide between the air and
blood.
Internal respiration – exchange of gases
between blood and cells.
Cellular respiration – chemical reactions
taking place within the cells.
Gas Exchange



Gases diffuse due to a concentration
gradient. Oxygen present in air and water
move from an area of high concentration
to an area of low concentration.
Question 1 - what is the gradient?
Question 2 - what causes the gradient?
How gas exchange works?

Gills, skin and lungs have many things
in common.
– all must be moist
– have a large thin surface area
– a special blood supply.


Why are these requirements of a
respiratory system?
Answers???? ……
Surface area!!!

All gas exchangers increase their
effectiveness by increasing their surface
area. This often involves folds, wrinkles or
sacs - anything that will increase area (but
stay thin).
Examples
Anatomy of the Respiratory
System











nose (nostrils)
nasal passages
Pharnyx
Glottis and epiglottis
larnyx
trachea (windpipe)
bronchi
bronchiole tubes
bronchioles
alveoli
diaphragm
End of show


Review the names
for each part of the
respiratory system.
Read pages 332 –
337 Do #1,2,3 & 5
Mechanics of Breathing
Four Physical Stages of
Gas Exchange




breathing - the movement of air in and
out of the lungs
external respiration - the exchange of
O2 and CO2 between air and the blood in
the lungs
internal respiration - exchange of O2
and CO2 between blood in capillaries
Cellular respiration - cellular process.
Breathing



inhale and exhale
lungs are elastic - no muscles - they
don’t move on their own
lungs expand and contract as a result
of pressure changes from movements
of the diaphragm, ribs and rib muscles
Bulk Flow: Air into Lungs
• Diaphragm allows inspiration
• Intercostal muscles allow forceful expiration
Inhale




External intercostal muscles contract
pulling the ribs up
diaphragm contracts and pulls down
this increases the chest cavity size
causing the pressure in the lungs to
decrease.
outside air then rushes inside as lungs
expand
Inspiration
Exhale




A passive activity due to the elastic,
spongy nature of lung tissue
Diaphragm relaxes moving upward
Intercostals relax causing ribs to drop
chest cavity size decreases causing
lung pressure increases causing air to
be forced out of the lungs
Expiration
Gas Exchange
External Respiration
External Respiration
the exchange of O2 and CO2 in air
and lungs
 O2 dissolves in moist lining of
alveoli
 CO2 diffuses out of alveoli
 ! Gases diffuse down a
concentration gradient !

Gas Exchange
Internal Respiration
Internal Respiration



Cells are constantly using oxygen
The concentration of oxygen in the cell
is less than that in the blood.
Therefore oxygen will leave the blood
and diffuse into the cell
- Remember substances diffuse from
areas of high concentration to areas of
low concentration.
Internal Respiration ( Continued)



Cells produce carbon dioxide as a
waste product
The cellular concentration of carbon
dioxide is higher than the blood
concentration.
Therefore, carbon dioxide will diffuse
out of the cell into the blood where it
is taken to the lungs to be expelled
Gas Exchange
Blood Flow


Blood flow to an organ of respiration can
greatly increase the amount of gases
exchanged.
Transporting away oxygen and bringing
carbon dioxide to the gas exchanger.
Respiration Review
Air bulk flow
caused by lungs
From air in lungs
to red blood cells
Blood bulk flow
caused by heart
From red blood
cells to body cells
Transport of Gases in Blood


Oxygen is bound to hemoglobin in
RBC’s.
Some carbon dioxide is transported
bound to hemoglobin and some
dissolves in plasma
- Most carbon dioxide is transported in
the form of bicarbonate ions
- once in the lungs the bicarbonate is
converted back to carbon dioxide
Bulk Flow: Blood carries
O2 to Body Cells
End of Show
Respiratory Health
Carbon Monoxide Poisoning



Binds to hemoglobin very strongly
and doesn’t let go easily. This
prevents oxygen from binding
This decreases the amount of
oxygen reaching cells
If severe you get tired, feel like
sleeping, lie down and DIE!!!!
Diseases of the Respiratory System
Pneumonia  a disease of the
lungs where the alveoli become
inflamed and fill with liquids. This
prevents oxygen adsorption so the
body becomes starved for oxygen.
 Still one of the leading causes of
death amongst the elderly.
 2 types: Lobar and Bronchial

Bronchitis  bacterial or viral
infections that cause increased
mucus production in lungs
 Asthma  allergic reaction,
swelling of the bronchioles

Emphysema  lungs loose their
elasticity and there is increased
resistance to airflow through the
bronchioles
 Lung Cancer – an uncontrollable
growth of cells within the lung.
Causes most problem when the
cells break free and move

Lung Cancer