University:
Missouri State University
Course:
BIO 121 | General Biology I
Academic year:

2019
Views:

104

Pages:

9
Author:

Triston Franco

Internal Structures PART 4 • Turn the brain over so the dorsal side is up to make a sagittal cut. You are going to cut the brain in half along the line of the longitudinal fissure. • Bisect the brain along the longitudinal fissure, separating right and left hemispheres. You will be cutting through the corpus callosum. Hold your scalpel like a pencil and try to cut with one smooth slice, using enough pressure to cut with one smooth pass of the blade. If you do not get identical halves, ask for help to clean up the cut. • Before taking a picture of the bisected brain, use a probe to pull the choroid plexus out of the third ventricle (Sometimes it can be found in the lateral ventricle as well. • It will be dark pink in color. • Take a picture of the bisected brain The image below shows a cleanly separated brain with the major internal structures visible. Diencephalon • You can also see the thalamus, and the hypothalamus. The thalamus integrates information and relays it to appropriate regions for processing in the cerebrum. • The hypothalamus (“hypo” means below, so below the thalamus) in involved in many functions from biological timekeeping to most homeostatic regulation. The hypothalamus also controls the pituitary gland which is attached at its base. • The hypothalamus does not appear as a distinct structure, but is a general area bounded by other structures (thalamus, optic chiasm, and mammillary bodies). • Identify the cerebellum posterior to the fourth ventricle and notice the internal treelike arrangement of its white matter called the arbor vitae.