Mammalian Brain Dissection Purpose: The purpose of dissecting the sheep brain is to learn the structure of the brain.
We must learn a brains structure to help us learn its functions, because they are very important and part of the Central Nervous System. We must learn the Central Nervous System to learn how it communicates between different parts of the body and the body’s interactions with the environment because it is a California standard. ? Analysis Questions: 1. ) What observable features of the brain helped you determine Dorsal from Ventral…front from back?I was able to determine the front from the back of the sheep brain because the spinal cord leads from the end of the brain down the body. I was able to tell the top from the bottom of the sheep brain because I was able to identify the left and right hemisphere.
2. ) When locating the pairs of the cranial nerves what structures would they have been close to if the entire head were present? If the head of the sheep were actually present the cranial nerves would be close to the nose because they are made for smelling. 3. Upon opening the brain what four observable characteristics supported the idea that the brain is complex, with multiple functions and special regions for each task? When the brain was cut open I first noticed the long white strips throughout the brain known as the corpus callosum. I also noticed the spinal cord and the inside of the medulla oblongata there were white branched out root like lines present. ? Procedure: 1.
Identify the way the sheep brain should be facing if body was present. 2. Remove the meninges, (three outer layers that protect the brain and spinal cord. 3. Turn over the brain and look for the “T” that is formed between sulcus and deep grove that runs across the front third of the brain.
4. Now locate the cranial nerves. Try to locate the following cranial nerves: •Olfactory bulbs-two flaps of tissue located near the front of the brain. Used for smell •Optic chiasm-structure behind olfactory bulbs, shaped like an X 5. Take one of the two brains and cut down the middle.
6. Try to locate different neutral structures between real brain and pictures that are provided.