Breathing

1. NEURAL CONTROL OF
BREATHING
MEDULLA
PONS

2. Neural
Control Of
Breathing
Voluntary
Cerebral
cortex
Autonomic
Medullary
Centers
Dorsal
Respiratory
Group
Ventral
Respiratory
Group
Pontine
Centers
Pneumotaxic
Center
Apneustic
Center

3. Respiratory 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 Group
2. Ventral Respiratory Group
3. Pneumotaxic Center
4. Apneustic Center

4. To larynx and bronchi
To respiratory muscles
Pontine center
Dorsal Respiratory Group
Brainstem Respiratory Centres
Pons
Medulla
Ventral respiratory group
- Nucleus ambiguus
- Nucleus retroambigualis

5. DORSAL RESPIRATORY
GROUP
 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.

6. VENTRAL RESPIRATORY GROUP
 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

7. Pontine Respiratory
Center
Pons contains 2 centres
for control of respiration:
1.Pneumotaxic Center
2.Apneustic Center

8. INTEGRATION

9. Inspiratory
Center
Phrenic Nerve
Diaphragm
Contracts &
Lung Expands
Stretch
Receptors on
Lungs
Activated
Vagus Nerve
Inhibitory Signal
HERRING-BRUER’S REFLEX

10. To larynx and bronchi
To respiratory muscles
Pontine center
Dorsal Respiratory Group
Brainstem Respiratory Centres
Pons
Medulla
Ventral respiratory group
- Nucleus ambiguus
- Nucleus retroambigualis

11. 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

12. ABNORMAL RESPIRATORY
PATTERNS
Apneusis
Biot Breathing
Cheyne Stroke Breathing
Vagal Breathing