CNS-9 Pons And Medulla oblongata

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Pons And Medulla Oblongata:

Pons And Medulla Oblongata Husan Bano Associate Professor Department of Physiology Al- Tibri Medical College,ISRA University ,




Pons Pons is derive from metencephlon of hind brain. It lies above the medulla oblongata. It has various nuclei and tracts i.e nuclei of 5 th . and 8 th . cranial nerve


Pons A respiratory centre present in pons ,called “ Pneumotaxic centre” . This respiratory centre gives the inhibitory signals continuously to the inspiratory centre , and limits the duration of inspiration.


Pons Another respiratory centre is called “ Apneaustic Centre” lies at the junction of pons and medulla oblongata. It gives stimulatory signals to inspiratory neuron and increases the depth of respiration . Apneaustic Centre” pneumotaxic Centre

Functions of Pons:

Functions of Pons The basal portion of pons ( cerebellar peduncle) act as relay station for motor nerve fibers from cerebrum to cerebellum. It regulates the rate of respiration.

Clinical Consideration.:

Clinical Consideration . Damage of cerebral peduncle causes deficits of motor impulses i.e motor impulses from cerebral cortex do not reaches into the spinal cord and effectors organ in proper way .

Medulla Oblongata:

Medulla Oblongata

Medulla Oblongata:

Medulla Oblongata It is derive from myelencephlon of hind brain. It is upward continuation of spinal cord. The medulla oblongata joins the spinal cord at the level of Foramen Magnum of skull .

Medulla Oblongata:

Medulla Oblongata Internally the medulla have extensive arrangement of “ascending and descending tracts” It also have the “Vital and Non Vital Centers” Medulla also have “cranial nerve 9 and 12”

Vital Centers:

Vital Centers Respiratory centers. Cardiac Centers. Vaso -motor centers.

Vital Centers:

Vital Centers Respiratory Centers: Inspiratory center Expiratory center Chemo-sensitive area.

Vital Centers (Respiratory center):

Vital Centers (Respiratory center) INSPIRATORY AREA Lies on dorsal aspect of medulla oblongata. Whenever it is stimulated ,it give the signals to diaphragm and inspiratory muscle and causes inspiration.

Vital Centers ( Respiratory center):

Vital Centers ( Respiratory center) EXIRATORY AREA Lies on ventral aspect of medulla oblongata. During normal quiet respiration, this area becomes dormant or silent.

Vital Centers (Cardiac center):

Vital Centers (Cardiac center) Cardio-acceleratory center Cardio-inhibitory center These centers receive the fibers from the blood vessels , heart , lungs , cerebrum . These centers control the heart rate according to the body activity.

Vital Centers (Vaso-motor center):

Vital Centers ( Vaso -motor center) Vaso -constrictor center Vaso -dilator centers. These centers reflexly control the diameter of blood vessels and hence control the blood pressure.

Non-vital centers:

Non-vital centers Swallowing center Vomiting centers Sneezing centers Coughing centers.

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