pons

Examples of pons in the following topics:

• Pons

  • The pons is a structure located on the brainstem, named after the Latin word for "bridge."
  • The pons measures about 2.5 cm in length in adults.
  • These connect the cerebellum to the pons and midbrain.
  • A number of cranial nerve nuclei are present in the pons:
  • Describe the role and location of the pons region of the brainstem

• Neural Mechanisms (Respiratory Center)

  • The medulla and the pons are involved in the regulation of the ventilatory pattern of respiration.
  • The pons is the other respiratory center and is located underneath the medulla.

• Abducens (VI) Nerve

  • The abducens nerve leaves the brainstem at the junction of the pons and the medulla, medial to the facial nerve.
  • It runs upward between the pons and the clivus, and then pierces the dura mater to run between the dura and the skull.
  • Mass lesions that push the brainstem downward can damage the nerve by stretching it between the point where it emerges from the pons and the point where it hooks over the petrous temporal bone.

• Trigeminal (V) Nerve

  • Its name, "trigeminal," meaning "three twins," is derived from the fact that each nerve, one on each side of the pons, has three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3) .
  • From the trigeminal ganglion, a single large sensory root enters the brainstem at the level of the pons.
  • Immediately adjacent to the sensory root, a smaller motor root emerges from the pons at the same level.
  • Motor fibers pass through the trigeminal ganglion on their way to peripheral muscles, but their cell bodies are located in the nucleus of the trigeminal nerve, deep within the pons.

• Functions of the Brain Stem

  • The three components of the brainstem are the medulla oblongata, midbrain, and pons.
  • Its upper part is continuous with the pons.
  • The pons (part of metencephalon) lies between the medulla oblongata and the midbrain.
  • Structures of the brainstem are depicted on these diagrams, including the midbrain, pons, medulla, basilar artery, and vertebral arteries.

• Reticular Formation

  • The reticular formation is a region in the pons involved in regulating the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli.
  • A cross section of the lower part of the pons showing the pontine reticular formation labeled as #9.
  • Describe the functions of the reticular formation region of the pons

• Facial (VII) Nerve

  • It emerges from the brainstem between the pons and the medulla and controls the muscles of facial expression.
  • The motor part of the facial nerve arises from the facial nerve nucleus in the pons while the sensory part of the facial nerve arises from the nervus intermedius.

• Chemoreceptor Regulation of Breathing

  • For the respiratory rate, the chemoreceptors are the sensors for blood pH, the medulla and pons form the integrating center, and the respiratory muscles are the effector.
  • The chemoreceptors are the sensors for blood pH, the medulla and pons form the integrating center, and the respiratory muscles are the effector.

• Parts of the Cerebellum

  • Anatomists classify the cerebellum as part of the metencephalon, which also includes the pons, and all its connections with other parts of the brain travel through the pons.

• Midbrain

  • Caudally (posteriorly) the mesencephalon adjoins the pons (metencephalon), and rostrally it adjoins the diencephalon (eg., thalamus, hypothalamus).
  • Brainstem anatomy showing the location of the midbrain in relation to the midbrain, pons, medulla, basilar artery, and vertebral arteries.