Transcript PT.3-UNIT 5 - cvadultcma

PT. 3
UNIT 1
LECTURE 1
OVERVIEW OF THE
RESPIRATORY SYSTEM

1. WHEN YOU
INHALE
(INSPIRATION),
AIR ENTERS THE
RESPIRATORY
SYSTEM THROUGH
THE NOSE AND
MOUTH AND
PASSES DOWN THE
THROAT (PHARYNX)
AND THROUGH THE
VOICE BOX
(LARYNX)

2. THE ENTRANCE TO THE LARYNX IS
COVERED BY A SMALL FLAP OF
MUSCULAR TISSUE (EPIGLOTTIS)
THAT CLOSES WHEN YOU SWALLOW,
PREVENTING FOOD FROM ENTERING
THE AIRWAYS

3. THE LARGEST AIRWAY IS THE
WINDPIPE (TRACHEA), WHICH
BRANCHES INTO TWO SMALLER
AIRWAYS (BRONCHI) TO SUPPLY THE
TWO LUNGS
 4.
THE BRONCHI
DIVIDES MANY
TIMES INTO EVEN
SMALLER
AIRWAYS
(BRONCHIOLES)

5. AT THE END
OF EACH
BRONCHIOLE
ARE DOZENS OF
BUBBLESHAPED, AIRFILLED
CAVITIES
(ALVEOLI)

6. EACH LUNG CONTAINS MILLIONS OF
ALVEOLI, AND EACH ALVEOLUS IS
SURROUNDED BY A DENSE NETWORK OF
CAPILLARIES
7. INHALED AIR, CONTAINING
OXYGEN, PASSES THROUGH THE
THIN WALLS OF THE ALVEOLI AND
INTO THE BLOOD IN THE
CAPILLARIES
 8. OXYGEN IS EXCHANGED FOR
CARBON DIOXIDE WHICH PASSES
FROM THE BLOOD INTO THE
ALVEOLI, AND IS EXHALED
THROUGH THE NOSE AND MOUTH
(EXPIRATION)

 PRIMARY
RESPIRATORY
FUNCTIONS:
BRING OXYGEN INTO THE LUNGS
2. TRANSFER THE OXYGEN TO THE
BLOOD
3. EXPEL THE WASTE PRODUCT –
CARBON DIOXIDE
1.
CONTROL OF BREATHING:
1. BREATHING IS USUALLY
CONTROLLED BY THE BODY’S
AUTONOMIC NERVOUS SYSTEM
 2. THE RESPIRATORY CENTERS IN THE
BRAIN THAT CONTROL YOUR RATE OF
BREATHING ARE IN THE BRAINSTEM
OR MEDULLA, AND MAY BE
INFLUENCED BY SEVERAL FACTORS:

A.
OXYGEN – SPECIALIZED
NERVE CELLS WITHIN THE
AORTA CALLED PERIPHERAL
CHEMORECEPTORS MONITOR
THE OXYGEN CONCENTRATION
OF THE BLOOD
IF THE OXYGEN
CONCENTRATION IN THE
BLOOD DECREASES, THEY TELL
THE RESPIRATORY CENTERS
TO INCREASE THE RATE AND
DEPTH OF BREATHING
B.
CARBON DIOXIDE – PERIPHERAL
CHEMORECEPTORS ALSO MONITOR
THE CARBON DIOXIDE
CONCENTRATION IN THE BLOOD
 IF
THE CARBON DIOXIDE
CONCENTRATION GETS TOO HIGH, THE
CHEMORECEPTORS SIGNAL THE
RESPIRATORY CENTERS TO INCREASE
THE RATE AND DEPTH OF BREATHING
 THE INCREASED RATE OF BREATHING
RETURNS THE CARBON DIOXIDE
CONCENTRATION TO NORMAL AND
THE BREATHING RATE THEN SLOWS
DOWN
CHEMICAL IRRITANTS – NERVE
CELLS IN THE AIRWAYS SENSE THE
PRESENCE OF UNWANTED
SUBSTANCES IN THE AIRWAYS
SUCH AS POLLEN, DUST, NOXIOUS
FUMES, WATER, OR CIGARETTE
SMOKE
C.
 THESE
CELLS THEN SIGNAL THE
RESPIRATORY CENTERS TO
CONTRACT THE RESPIRATORY
MUSCLES, CAUSING YOU TO SNEEZE
OR COUGH
 3.
IN QUIET BREATHING, THE
AVERAGE ADULT INHALES AND
EXHALES ABOUT 15-18 TIMES A
MINUTE

4. THE LUNGS
HAVE NO MUSCLES
OF THEIR OWN, SO
THE WORK OF
BREATHING IS
DONE PRIMARILY
BY THE
DIAPHRAGM AND
INTERCOSTAL
MUSCLES (THE
MUSCLES
BETWEEN YOUR
RIBS)
 A.
WHEN YOU
INHALE, THE
DIAPHRAGM AND
INTERCOSTAL
MUSCLES
CONTRACT AND
EXPAND THE CHEST
CAVITY
THIS
EXPANDS THE
LUNGS AND
ALLOWS AIR TO
ENTER THE LUNGS
 B.
WHEN YOU
EXHALE, THE
DIAPHRAGM AND
INTERCOSTAL
MUSCLES RELAX AND
THE CHEST CAVITY
GETS SMALLER
THIS
PUSHES AIR
OUT OF THE LUNGS
 C.
THIS CYCLE
REPEATS WITH EACH
BREATH
 5.
THE LUNGS ARE COVERED BY A
SLIPPERY MEMBRANE (PLEURA)
WHICH ALLOWS THE LUNGS TO
EXPAND AND CONTRACT
PARIETAL
PLEURA: ATTACHED TO THE
WALL OF THE THORACIC CAVITY
VISCERAL PLEURA: COVERS THE
LUNGS THEMSELVES
RESPIRATORY DISORDERS
 1.
DISEASES OR CONDITIONS THAT
INFLUENCE THE MECHANICS OF
BREATHING (THOSE THAT MAKE
BREATHING HARDER):
A.
ASTHMA: THE BRONCHIOLES
CONSTRICT, REDUCING THE SIZE OF
THE AIRWAYS, CUTTING DOWN ON THE
FLOW OF AIR AND MAKES THE
RESPIRATORY MUSCLES WORK
HARDER
B.
EMPHYSEMA: THE LUNGS BECOME
STIFF WITH FIBERS AND BECOME
LESS ELASTIC, WHICH INCREASES
THE WORK OF THE RESPIRATORY
MUSCLES
C. BRONCHITIS: THE AIRWAYS
BECOME INFLAMED AND NARROWER,
WHICH RESTRICTS THE FLOW OF AIR
AND INCREASES THE WORK OF THE
RESPIRATORY MUSCLES
D. CHRONIC OBSTRUCTIVE
PULMONARY DISEASE (COPD):
CAUSED BY EMPHYSEMA AND
CHRONIC BRONCHITIS
 2.
DISEASES OR CONDITIONS
THAT MINIMIZE OR PREVENT
GAS EXCHANGE (THOSE THAT
DAMAGE THE LUNGS' ABILITY TO
EXCHANGE CARBON DIOXIDE
FOR OXYGEN):
A.
PULMONARY EDEMA: FLUID
BETWEEN THE ALVEOLUS AND
PULMONARY CAPILLARY BUILDS
UP, WHICH INCREASES THE
DISTANCE OVER WHICH GASES
MUST EXCHANGE AND SLOWS
DOWN THE EXCHANGE
B.
SMOKE INHALATION: SMOKE
PARTICLES COAT THE ALVEOLI AND
PREVENT THE EXCHANGE OF GASES
C. CARBON MONOXIDE POISONING:
CARBON MONOXIDE BINDS TO
HEMOGLOBIN MORE TIGHTLY THAN
EITHER OXYGEN OR CARBON
DIOXIDE, WHICH MINIMIZES THE
DELIVERY OF OXYGEN TO ALL THE
TISSUES OF THE BODY, INCLUDING
THE BRAIN, HEART, AND MUSCLES
THE END
 THAT’S
MY
STORY AND
I’M STICKING
TO IT!!!