RESPIRATORY CENTERS

1. CONTROL
OF
RESPIRATION
BY:
Mrs.Keerthi Samuel. K
Asst.Professor,
Vijay Marie CON

2. INTRODUCTION
• At rest about 200ml of oxygen
is used each minute by our
body.
• During strenuous breathing
oxygen use typically increases
15-20 fold in a normal healthy
adult.

3. RESPIRATORY CENTER
• The size of thorax is altered by action of respiratory muscles
which contract as a result of nerve impulses transmitted to
them from the centers in the brain and relax in the absence
of nerve impulses.
• RESPIRATORY CENTER: Nerve impulses are sent from
clusters of neurons located bilaterally in MEDULLA
OBLONGATA and PONS.
• THE THREE AREARS OF RESPIRATORY CENTER ARE:
 MEDULLARY RHYTHMICITY AREA
 PNEUMOTAXIC AREA
 APNEUSTIC AREA

4. 1.MEDULLARY RHYTHMICITY AREA
• FUNCTION: TO CONTROL THE RHYTHM OF RESPIRATION
• There are two areas: 1.INSPIRATORY 2. EXPIRATORY
• During quiet breathing – Inhalation lasts about 2 seconds
Exhalation lasts for 3 seconds
• Nerve impulses will be generated in inspiratory area to
establish the rhythm
• Activation of inspiratory area
• Generation of nerve impulse for 2 sec
• These impulses propagate to ext. Intercostals via
• INTERCOSTAL NERVES- EIM
• PHRENIC NERVES-DIAPHRAGM

5. The cycle repeats
Elastic recoil of lungs and thoracic wall
With no impulses ,the diaphragm and EIM reax for 3seconds
Inspiratory area becomes inactive inactive after 2sec and the nerve impulses cease
As the muscles contract INHALATION occurs.
1.MEDULLARY RHYTHMICITY AREA
Neurons of the Exp.area
remains inactive during quiet
breathing but during forceful
breathing impulses from
Insp.area activates the
Exp.area

6. 2. PNEUMOTAXIC AREA
Seen in upper pons which transmits
inhibitory impulses to inspiratory area
The major function of this area is to
turnoff the inspiratory area before lungs
become too full of air.
In other words the impulses shorten the
duration of inhalation.
When this area is active , breathing is
more rapid
FUNCTION:
CO-ORDICATES
THE
TRANSITION
BETWEEN
INHALATION
AND
EXHALATION

7. 2. APNEUSTIC AREA
Present in LOWER PONS
Stimulates and activates the
inspiratory area during
inhalation
Results in long deep
inhalation
FUNCTION:
CO-ORDICATES
THE
TRANSITION
BETWEEN
INHALATION
AND
EXHALATION