NEURAL CONTROL OF NEURAL CONTROL OF BREATHINGBREATHING

MEDULLAMEDULLAPONSPONS

Respiratory CenterRespiratory Center

The respiratory center is composed of several groups of neurons located bilaterally in the medulla oblongata and pons of the brain stem.

It is divided into :

1.Dorsal Respiratory Group2.Ventral Respiratory Group3.Pneumotaxic Center4.Apneustic Center

To larynx and bronchiTo respiratory muscles

Pontine center

Dorsal Respiratory Group

Brainstem Respiratory Centres

Pons

Medulla

Ventral respiratory group

- Nucleus ambiguus

- Nucleus retroambigualis

DORSAL RESPIRATORY DORSAL RESPIRATORY GROUPGROUP

The dorsal respiratory group of neurons extends along most of the length of the medulla. Most of its neurons are located within the nucleus of the tractus solitarius.

This group of neurons emits repetitive bursts of inspiratory neuronal action potentials.

The basic rhythm of respiration is generated mainly in the dorsal respiratory group of neurons.

VENTRAL RESPIRATORY VENTRAL RESPIRATORY GROUPGROUP

The Ventral respiratory group of neurons is found in the nucleus ambiguus rostrally and the nucleus retroambiguus caudally.

The VRG contains both inspiratory and expiratory neurons.

The neurons of the ventral respiratory group remain almost totally inactive during normal quiet respiration.

The VRG is responsible for motor control of inspiratory and expiratory muscles during exercise.

They are especially important in providing the powerful expiratory signals to the abdominal muscles during very heavy expiration

Pontine Respiratory Pontine Respiratory Center Center

Pons contains 2 centres for control of respiration:

1.Pneumotaxic Center2.Apneustic Center

INTEGRATION

Inhibitory Signal

HERRING-BRUER’S REFLEX

To larynx and bronchiTo respiratory muscles

Pontine center

Dorsal Respiratory Group

Brainstem Respiratory Centres

Pons

Medulla

Ventral respiratory group

- Nucleus ambiguus

- Nucleus retroambigualis

Pons

Medulla

Produces apneustic effect – long, powerful inspirations.

Stops breathing since no automated output to respiratory system – cause of death in hanging.

LESIONS

Irregular but Rhythmic Breathing

ABNORMAL RESPIRATORY ABNORMAL RESPIRATORY PATTERNSPATTERNS

ApneusisBiot BreathingCheyne Stroke BreathingVagal Breathing