Respiratory centers

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. 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 FUNCTION: CO-ORDICATES THE TRANSITION BETWEEN INHALATION AND EXHALATION

7. 2. APNEUSTIC AREA FUNCTION: CO-ORDICATES THE TRANSITION BETWEEN INHALATION AND EXHALATION