RESPIRATION: THE EXCHANGE OF
GASES
RESPIRATION: THE EXCHANGE OF
GASES
• OVERVIEW: GAS EXCHANGE INVOLVES
BREATHING, THE TRANSPORT OF GASES, AND
THE SERVICING OF TISSUE CELLS
RESPIRATION: THE EXCHANGE OF
GASES
• 3 PHASES OF GAS EXCHANGE
– BREATHING
– TRANSPORT
– ABSORPTION/SECRETION
RESPIRATION: THE EXCHANGE OF
GASES
• ANIMALS EXCHANGE O2 AND CO2 THROUGH
MOIST BODY SURFACES
– RESPIRATORY SURFACE
• THE PART OF AN ANIMAL WHERE O2 DIFFUESES INTO
THE ANIMAL AND WHERE CO2 DIFFUSES OUT TO THE
SURROUNDING ENVIRONMENT
• TYPES OF RESPIRATORY SURFACES INCLUDE
–
–
–
–
SKIN
GILLS
TRACHAE
LUNGS
RESPIRATION: THE EXCHANGE OF
GASES
• RESPIRATORY SURFACES
– SKIN
– GILLS  EXTENSIONS,
OR OUT-FOLDINGS, OF
THE BODY SURFACE
SPECIALIZED FOR GAS
EXCHANGE
– TRACHEA
– LUNGS
RESPIRATION: THE EXCHANGE OF
GASES
• SKIN
– EXAMPLE : EARTHWORM
RESPIRATION: THE EXCHANGE OF
GASES
• GILLS
– ARE ADAPTED FOR GAS EXCHANGE IN AQUATIC
ENVIRONMENTS
– VENTILATION
• REFERS TO ANY MECHANISM THAT INCREASES
CONTACT BETWEEN SURROUNDING WATER OR AIR
AND THE RESPIRATORY SURFACE
– WHY IS THERE NO PROBLEM KEEPING THE GILLS
MOIST?
RESPIRATION: THE EXCHANGE OF
GASES
• GILLS
– UTILIZE COUNTERCURRENT FLOW TO ENHANCE
O2 TRANSFER
• THE TRANSFER OF SOMETHING FROM A FLUID MOVING
IN ONE DIRECTION TO ANOTHER FLUID MOVING IN THE
OPPOSITE DIRECTION
RESPIRATION: THE EXCHANGE OF
GASES
• TRACHEA
– THE TRACHEAL SYSTEM OF INSECTS PROVIDES DIRECT
EXCHANGE BETWEEN THE AIR AND BODY CELLS
– TRACHEOLES
• THE
NARROWEST
TUBES, THEY
EXTEND TO
NEARLY EVERY
CELL IN THE
INSECT’S BODY
– SPIRACLES
• OPENINGS ON THE SURFACE OF SOME
ANIMALS THAT LEAD TO RESPIRATORY
SURFACES (SYSTEMS)
RESPIRATION: THE EXCHANGE OF
GASES
• LUNGS
– FOUND IN TERRESTRIAL VERTEBRATES
RESPIRATION: THE EXCHANGE OF
GASES
• RESPIRATORY SYSTEM INCLUDES
– DIAPHRAGM
• BINDS THE CHEST CAVITY AT THE BOTTOM; A SHEET OF MUSCLE
– NASAL CAVITY
• AIR ENTERS THROUGH NOSTRILS; FILTERED AND HUMIDIFIED
– PHARYNX
– LARYNX
• “VOICE BOX”; HOUSES THE VOCAL CORDS
– AIR RUSHING PASSED THEM CAUSES VIBRATIONS AND SOUND
– TRACHEA
– BRONCHI
• TUBES FORKING OFF TRACHEA THAT LEAD TO EACH LUNG
– BRONCHIOLES
• REPEATED BRANCHES OFF THE BRONCHI
– ALVEOLI
• GRAPE-LIKE CLUSTERS OF AIR SACS, COVERED IN CAPILLARIES; THIS IS THE SITE OF
OXYGEN/CARBON DIOXIDE EXCHANGED WITH CIRCULATING BLOOD
RESPIRATION: THE EXCHANGE OF
GASES
• SMOKING IS ONE OF THE DEADLIEST
ASSAULTS ON OUR RESPIRATORY SYSTEM
– INCREASED RISK OF LUNG CANCER
– EMPHYSEMA
• LOSS OF LUNGS ELASTICITY, REDUCTION OF GAS
EXCHANGE DUE TO LOSS OF ALVEOLI
RESPIRATION: THE EXCHANGE OF
GASES
• BREATHING VENTILATES THE LUNGS
– BREATHING
• THE ALTERNATION OF INHALATION AND EXHALATION
RESPIRATION: THE EXCHANGE OF
GASES
• BREATHING VENTILATES THE LUNGS
– NEGATIVE PRESSURE BREATHING
• AIR TRAVELS FROM A REGION OF HIGH PRESSURE TO A
REGION OF LOW PRESSURE
– VITAL CAPACITY
• THE MAXIMUM VOLUME OF AIR THAT WE CAN INHALE
AND EXHALE
– AS AGE INCREASES, RESIDUAL VOLUME (AMOUNT
OF DEAD AIR LEFT IN ALVEOLI) INCREASES; SO THE
VITAL CAPACITY DECREASES
RESPIRATION: THE EXCHANGE OF
GASES
• BREATHING IS
AUTOMATICALLY
CONTROLLED
– BREATHING
CONTROL
CENTERS
• LOCATED IN THE
PARTS OF THE
BRAIN KNOWN AS
THE PONS AND
MEDULLA
OBLANGATA
RESPIRATION: THE EXCHANGE OF
GASES
• BREATHING IS AUTOMATICALLY CONTROLLED
– HYPERVENTILATING
• EXCESSIVELY TAKING RAPID, DEEP BREATHS
– THE AMOUNT OF CO2 IN THE BLOOD IS WHAT
CONTROLS BREATHING
RESPIRATION: THE EXCHANGE OF
GASES
• BLOOD TRANSPORTS THE
RESPIRATORY GASES, WITH
HEMOGLOBIN CARRYING THE
OXYGEN
– PARTIAL PRESSURE
• EACH KIND OF GAS IN A MIXTURE
ACCOUNTS FOR A PORTION OF
THE MIXTURES’ TOTAL PRESSURE
– HEMOGLOBIN
• PROTEIN THAT CARRIES THE O2
IN THE BLOOD AND THROUGHOUT
THE BODY
RESPIRATION: THE EXCHANGE OF
GASES
• BLOOD TRANSPORTS THE RESPIRATORY
GASES, WITH HEMOGLOBIN CARRYING THE
OXYGEN
– VIDEO 1
– VIDEO 2
– VIDEO 3
– VIDEO 4
RESPIRATION: THE EXCHANGE OF
GASES
• HEMOGLOBIN HELPS TRANSPORT CO2 AND
BUFFER THE BLOOD
RESPIRATION: THE EXCHANGE OF
GASES
• HEMOGLOBIN HELPS TRANSPORT
CO2 AND BUFFER THE BLOOD
– HEMOGLOBIN HAS 3 FUNCTIONS
• CARRYING O2
• CARRYING CO2
• BUFFERING THE BLOOD
– HELPING TO CONTROL THE PH
RESPIRATION: THE EXCHANGE OF
GASES
• THE HUMAN FETUS EXCHANGES GASES WITH THE MOTHER’S
BLOODSTREAM
– HUMAN FETUS’ LUNGS
ARE FILLED WITH FLUID
AND ARE NONFUNCTIONAL
– FETAL HEMOGLOBIN HAS A
HIGHER AFFINITY FOR O2
– THE FETUS GETS GAS
EXCHANGE VIA THE
PLACENTA AND
UMBILICAL CORD
• SMOKING CAN HURT THE
FETUS SEVERELY
BECAUSE THE AMOUNT
O2 DROPS BY ABOUT 25%
RESPIRATION: THE EXCHANGE OF
GASES
• SO WE’VE TALKED ABOUT HOW WE INGEST FOOD,
AND HOW WE INHALE OXYGEN…BUT HOW DO THESE
SUBSTANCES
GET TO ALL OF
THE CELLS IN
THE BODY??
• ANSWER…
COME BACK TO
FIND OUT!!
BUT UNTIL THEN,
HERE IS A HINT 