basic topography of the brain

Question 1

What are the landmarks of the medulla?

Answer 1

• Pyramids
  
  • Olive
  • Decisidation of the pyramids
  • Cranial nerves IX, X, XI, XII
  • Inferior cerebellar peduncle

Question 2

What are the landmarks of the pons?

Answer 2

• Cranial nerves V, VI, VII, VIII

* Middle cerebellar peduncle

Question 3

What are the landmarks of the midbrain?

Answer 3

• Cranial nerves III, IV
  
  • Superior cerebellar peduncle
  • Cerebral peduncle (motor fibres)
  • Cerebral aqueduct
  • Substantia nigra
  • Colliculi: superior (visual reflex), inferior (auditory reflex)

Question 4

What are the landmarks of the cerebellum?

Answer 4

• Anterior lobe
	• Posterior lobe
	• Floculonodular node
	• Cerebellar tonsil
	- Sits on top of the foramen magnum
	- If there is a sudden change in intercranial pressure there could be herniation of the cerebellum and the tonsil will be the first part to be herniated 
	• Vermis 
	• Sulci and folia

Question 5

What are the functions of the cerebellum

Answer 5

• Posture maintenance

- Fine tuning motor activity (makes autocorrections to movements depending on where we are in space)

Question 6

Where does the cerebellum get information from|?

Answer 6

• The pyramidal tracts (via the cerebellar peduncles)
  
  • The ipsilateral proprioceptors
  • The vestibular nuclei for balance and posture

Question 7

What are the components of the diencephalon, what are their functions?

Answer 7

• Thalamus: sensory relay centre

* Hypothalamus: pituitary and endocrine

Question 8

Describe the venous drainage of the skull

Answer 8

• Venous sinuses lie between layers of dura

* Internal occipital perturbance is the part of the skull where the confluence of the sinuses is

Question 9

Describe the blood supply to different areas of the brain and understand how cerebral arterial occlusion would affect these areas

Answer 9

• The circle of Willis is a compensatory mechanism so that if one or two of the major blood supply to the brain is occluded then there will still be a blood supply to the brain
  
  • The anterior, middle and posterior cerebral arteries are end arteries
  • The basilar artery supplies the midbrain, pons, medulla and cerebellum
  • The anterior cerebrum artery supplies the medial aspect of the cerebral hemispheres excluding the occipital lobe
  • The middle cerebrum artery supplies the lateral part of the cerebral hemispheres and very key areas like the internal capsule
  • The posterior cerebrum artery supplies the inferior aspects of the cerebral hemispheres and the occipital lobe