The pons is located ventral to the midbrain and connects the medulla to the midbrain. It is approximately 2.5 cm long and contains motor and sensory tracts as well as nuclei that control cranial nerves V, VI, VII, and VIII. The pons can be divided into a ventral basal portion containing pontocerebellar fibers that connect to the cerebellum and a dorsal tegmental portion traversed by ascending and descending tracts and cranial nerve nuclei.

1. Dr Chintan Bhatt

2. External features
 2.5 cm long
 Location
 Rest on clivus

3.  Ventral surface
 Ventral longitudinal sulcus basilaris
 Motor and sensory roots of trigeminal nerve
 Middle cerebellar peduncle
 Transverse ridges
 Pontomedullary junction

5. Dorsal surface
 Upper part of floor of the fourth ventricle

8. Internal features
 Two parts ventral basilar part
 Posterior tegmental part

9. Pons
 The pons may be divided into ventral or
basal portion and a dorsal portion, also
known as tegmentum
 The ventral portion is marked by
numerous transversely oriented
fascicles of pontocerebellar fibres that
originate from scattered cell groups
called pontine nuclei

11. Basal part Pons
 The pontocerebellar fibres pass to the
contralateral side of the cerebellum
through the massive middle cerebellar
peduncle
 Corticospinal fibres appear as small and
separate bundles running longitudinally
between the fascicles of transverse
pontine fibres

12. Tegmental part
 Traversed by ascending and descending
tract, decussation of trapazoid body,
nuclei of 6,7,8 CN

14. Pons
These nuclei include:
 Abducens nucleus for lateral rectus muscle
 Facial motor nucleus for muscles of facial
expression
 Trigeminal motor nucleus for muscles of
mastication

16.  Spinal lemniscus
 Trigeminal lemniscus
 Medial lemniscus
 Lateral lemniscus

18. Neurobiotaxis

20.  Trigeminal nucleus: (GSA)
Main sensory: touch pressure
Spinal : pain and thermal
Mesencephalic nucleus of trigeminal

23.  cochlear nucleus:
first order neuron: cochlea-
Second order neuron: ventral and
dorsal cochlear nucleus
3rd order: superior olivery complex