山东大学：《医学生理学 Medical Physiology》课程教学资源（PPT课件讲稿，人体生理学 Human Physiology）Chapter 5 Respiratory Physiology Part 5 Control of Respiration

Part 5 ControveRt Respiration

1 Part 5 Control of Respiration

1. Respiratory Center and Formation of the Respiratory rhythm 1 Respiratory Center

2 I. Respiratory Center and Formation of the Respiratory Rhythm 1 Respiratory Center

Copyright e The McGraw-Hill Companies, Inc. Permission required for reproduction o The human brain corpus callosum skull meninges CEREBRUM lateral ventricle third ventricle THALAMUS HYPOTHALAMUS pituitary gland MIDBRAIN fourth ventricle pons CEREBELLUM MEDULLA vertebra OBLONGATA spinal cord

3

Normal breathing Pons Brain stem is cut below pons but above medulla Medulla Spinal co p d severed pinal cor d

4

Respiratory Centers w Pneumotaxic center Apneustic center Respiratory orsal respiratory control Medullary group center in respiratory ventral respiratory brain stem center group 5

5 Respiratory Centers

Two respiratory nuclei in medulla oblongata Inspiratory center(dorsal respiratory gtOupR more frequently they fire, more deeply you, inhale longer duration they fire, breath is prolonged slow rate Expiratory center(ventral respiratory group, VRG involved in forced Pneumotaxic center expiration pneustic center Respiratory Dorsal respiratory Medullary group center in brain stem center group

6 Two respiratory nuclei in medulla oblongata Expiratory center (ventral respiratory group, VRG) •involved in forced expiration Inspiratory center (dorsal respiratory group, DRG) • more frequently they fire, more deeply you inhale • longer duration they fire, breath is prolonged, slow rate

Respiratory Centers in pons Pneumotaxic center (upper pons) Sends continual inhibitory impulses to inspirator center of the medulla oblongata As impulse frequency rises. breathe faster and Shallower Apneustic center (lower pons Stimulation causes apneusis Integrates inspiratory cutoff information Pneumotaxic center Apneustic center Dorsal respiratory Medullary group in respiratory ventral respiratory brain stem center

7 Respiratory Centers in Pons Apneustic center (lower pons) •Sends continual inhibitory impulses to inspiratory center of the medulla oblongata, •As impulse frequency rises, breathe faster and shallower •Stimulation causes apneusis •Integrates inspiratory cutoff information Pneumotaxic center (upper pons)

Respiratory Structures in Brainstem Cerebri H potharamus Pneumotaxic center cHEM。 RECEPTORS Pons Apneustic center medulla ngata chearorsce carotid and aortic sinuses N D。sa aspirate。n Respirat。r Spinal Ventral rhythmicity enters respirator notor neurons controlling diaphragm Stimulati。n Inhibition Motor neurons Diaphragm Phrenic nerve

8 Respiratory Structures in Brainstem

2. Rhythmic Ventilation (Inspiratory Off Switeh)- Starting inspiration Medullary respiratory center neurons/are continuously active(spontaneous) Center receives stimulation from Peripheral and central receptors brain concerned with voluntary respiratory movements and emotion Combined input from all sources causes action potentials to stimulate respiratory muscles

9 2. Rhythmic Ventilation (Inspiratory Off Switch) • Starting inspiration – Medullary respiratory center neurons are continuously active (spontaneous) – Center receives stimulation from –Peripheral and central receptors –brain concerned with voluntary respiratory movements and emotion – Combined input from all sources causes action potentials to stimulate respiratory muscles

Increasing inspiration More and more neurons are activated Stopping inspiration -Neurons receive input from pontine group and stretch receptors in lungs -Inhibitory neurons activated and relaxation of respiratory muscles results in expiration Inspiratory off switch 10

10 •Increasing inspiration –More and more neurons are activated •Stopping inspiration –Neurons receive input from pontine group and stretch receptors in lungs. –Inhibitory neurons activated and relaxation of respiratory muscles results in expiration. –Inspiratory off switch