Neuroscience Lecture Notes: Medulla Oblongata

Introduction

• Topic: Overview of the medulla oblongata in the brainstem.
• Location: Lowest part of the brainstem, beneath the pons and above the spinal cord.
  • Gradual transition from spinal cord to medulla without clear separation.

Functions

Cardiovascular and Respiratory Regulation

• Cardiovascular Function:
  • Receives information via baroreceptors in blood vessels about blood pressure changes.
  • Nucleus of the Solitary Tract: Initiates reflex actions to regulate blood pressure.
• Respiratory Function:
  • Generates breathing movements.
  • Chemoreceptors: Detect changes in blood oxygen and carbon dioxide levels.
  • Neurons in and around the nucleus of the solitary tract and nucleus ambiguus increase respiration when oxygen is low.

Reflex Actions

• Controls reflexive actions such as:
  • Swallowing
  • Coughing
  • Sneezing
  • Vomiting

Associated Structures

• Inferior Olivary Nuclei:
  • Connected to cerebellum.
  • Involved in movement.
• Nucleus Gracilis & Nucleus Cuneatus:
  • Part of the dorsal-columns medial lemniscus sensory pathway.
• Cranial Nerve Nuclei: Present in the medulla.

Tracts and Pathways

• Corticospinal & Corticobulbar Tracts:
  • Important for movement.
  • Form the medullary pyramids on the brainstem's exterior.
  • Also known as pyramidal tracts.

Conclusion

• The medulla oblongata plays a crucial role in autonomic functions and as a pathway for various crucial neural tracts and reflex actions.