Human Anatomy and Physiology ILab 10 The nervous systemSheep brain dissectionLab Exercises 10-1The sheep brain is quite similar to the human brain except for proportion. The sheep has asmaller cerebrum. Also, the sheep brain is oriented anterior to posterior (more horizontally), whilethe human brain is oriented superior to interior (more vertically.)MaterialsDissection tools and tray, lab gloves, preserved sheep brain.Figure 10-11. The major structures of a sheep brain cut along the longitudinalfissure.Examining the external sheep brain.1.The tough outer covering of the sheep brain is the dura mater, the outermost meninges membranecovering the brain. Remove the dura mater to see most of the structures of the brain, but removeit carefully, so as to leave all the other structures beneath it intact. Removing the dura mater fromthe cerebellum at the back of the brain can be tricky. Look for areas on the side of the brain thatyou can snip to peel the dura mater off.
2.Note the second meninges membrane, the arachnoid mater, below the dura mater.3.The cerebrum half is missing the longitudinal fissure – which divides the brain into nearlysymmetrical left and right hemispheres. But the transverse fissure is clearly visible.4.The surface of the cerebrum is covered with large folds of tissue called gyri. The groovesbetween the gyri are sulci. The deeper sulci are often called fissures. The fissures are used as