Inter brain

INTER BRAIN 

  • The thalamus and the third ventricle are now exposed
  • The Thalamus is a large ovoid mass of grey matter situated below the hippocamous and over the cerebral peduncle. Note a band of white matter the Stria semicircularis separating the thalamus from the caudate nucleus.
  • The lateral geniculate body is an indistinct prominence blended with the thalamus at the point of entrance of the optic tract. At the angle between the thalamus and the cerebral peduncle is the meidal geniculate body.
  • The Epiphysis cerebri is situated between the thalamus and the corpora quadrigemina, attached by a hollow stalk into which extends a small recess of the third ventricle.
  • The third ventricle is an annular space around the thalamus, the roof of which is formed by the fornix and on either side ofwhich it communicates with the lateral ventricles through the interventricular foramen of Munro.
  • In a sagittal section of the brain, study the recesses of the third ventricle into the stalk of the Epiphysis, into the infundibulum of the pituitary gland and the extension of third ventricle just above the optic chiasma.
  • The third ventricle communicates with the fourth ventricle throught the cerebral aqueduct, which passes through the midbrain under the corpora quadrigemina.
  • The corpora quadrigemina, which are four rounded eminences behind the thalamus should now be studied.
  • The posterior peduncle connceting the medial geniculate body to the posterior colliculus is seen on the lateral aspect. Behind the coliculi note the trochlear nerves emerging after decusation in the anterior medullary velum.
  • The cerebral peduncles, which are at the ventral aspect of the midbrain below the corpora qadrigemina, should now be studied.
Last modified: Thursday, 3 May 2012, 6:23 AM