The document discusses the anatomy and functions of the pons. The pons is a horseshoe-shaped structure located in the brainstem between the midbrain and medulla. It relays sensory information between the cerebrum and cerebellum, regulates breathing and the sleep-wake cycle, and connects the forebrain to the hindbrain. Several cranial nerves originate from the ventral surface of the pons. Its functions include coordinating movement, controlling arousal and attentiveness, and regulating involuntary actions like respiration.

1. PONS
NAME : SAKSHI
MBBS Batch 2020 - 2021
ESIC MEDICAL COLLEGE, GULBARGA

2. Objectives
Gross anatomy
Development
Internal anatomy
Functions

3. BRAINSTEM
Consists of:
Midbrain
The pons
Medulla oblongata

4. GROSS ANATOMY
PONS
The pons is also called the pons Varolii
Extends from cranial end of Medulla oblongata to the cerebral
peduncles of midbrain
This region of the brainstem includes neural
pathways and tracts that conduct signals from the brain down to
the cerebellum and medulla, and tracts that carry the sensory
signals up into the thalamus.

5. Development
During embryonic development :
Rhombencephalon
Metencephalon
pons cerebellum

6. Anatomical Position
• The pons is a horseshoe-shaped collection of nerve fibers located in the anterior
part of the posterior cranial fossa.
• Its anatomical relations are as follows:
• Posteriorly – the cerebellum, separated by the fourth ventricle.
• Inferiorly – the medulla oblongata.
• Superiorly – the midbrain
Horizontal section
Midbrain
Pons
Medulla

7. Cranial nerves originating from the
ventral surface of the pons:
• Cranial nerve V: Trigeminal
• Cranial nerve VI: Abducens
• Cranial nerve VII: Facial
• Cranial nerve VIII: Vestibulocochlear

8. INTERNAL ANATOMY
pontine nuclei
Function: coordinating movement.
Fibers from the pontine nuclei cross the midline
and form the middle cerebellar peduncles on
their way to the cerebellum.
Contains a set of nuclei
Function: controls arousal and attentiveness.
Damage to this part of the pons may result in
anosognosia for hemiplegia, where patients are
unaware of their paralysis.
PONS
VENTRAL PONS TEGMENTUM

9. Tracts passing through the pons
• Descending corticospinal tracts
• Descending corticobulbar tracts
• Ascending medial lemniscus tracts
• Ascending spinothalamic tracts
Corticobulbar tract

10. Blood supply
1. Pontine branch of Basilar artery
2. Anterior inferior cerebellar artery
3. Posterior inferior cerebellar artery
4. Superior cerebellar artery
Venous Drainage
• Basilar plexus drains into cerebral
vein
• Inferior petrosal sinus drains into
internal jugular veins

11. FUNCTIONS
• Pons relays sensory information between the cerebrum and cerebellum
• It connects forebrain to hindbrain
• Regulates breathing
It is also called as pneumotaxic center of the brain
• Involved in control of sleep cycle
The reticular activating system operates the body’s sleep-wake cycle

12. • Regulates involuntary actions
Like respiration, bladder control etc.…
• Sensory role in hearing, equilibrium and
taste.
• Motor role in rapid eye movement, facial
expression, chewing and swallowing.
• pons has some role in secretion of saliva
and tears.
• It is a part of body’s fight-or-flight system

13. Brainstem consist of midbrain, pons and medulla
oblongata.
Pons is also called as pons varolli ; horse-shoe shaped
collection of the nerve fibers
Located in the anterior part of the posterior cranial fossa
Extends from medulla oblongata to the midbrain
Develops from metencephalon

14. Several cranial nerves originate form ventral surface of the pons { cranial
nerves V, VI, VII & VIII }
Pons is divided into ventral pons (coordinating movement) and tegmentum
(control arousal and attentiveness)
Ascending and descending tracts pass through pons
Blood supply is by Basilar artery branches
FUNCTIONS: pons relay sensory information, regulates breathing,
connects forebrain to the hindbrain, sleep control and regulates several
involuntary functions also.

15. Thank you
Resources
• Ganong’s book of medical physiology
• BD Chourasia's Human anatomy