Aim: the aim is to dissect the brain and identify all the different parts of it. Equipment: a semi –frozen sheep’s brain, dissecting board, dissecting instruments (scalpel, forceps, scissors), plastic ruler, paper towel and gloves. Method:
* We placed the brain so that the cerebral hemispheres are at the top of the board and the brain stem is at the bottom. * My group identified the external features of the brain: the cerebral hemispheres, cerebellum and brain stem. * We also used the forceps and tried to lift the meninges (membranes protecting the brain). We then observed the cerebral fluid between these membranes and the hemispheres. * My group carefully observed the overall appearance of each structure and, using a plastic ruler, measure its size (length, width and height). Include this information in a table. * The group and I drew a diagram of the sheep’s brain, labelling the external features. * On our diagram we identified and labelled the part of the brain that controls the sheep’s: (a) Heart rate
(b) Balance required for walking
(c) Ability to locate it’s lamb
* We used the scalpel, to cut the brain in half between the right and left hemispheres, and separate the two cerebral hemispheres. * After we drew a cross-section of the brain.
Be sure to label it!
* Then we made a second cut down through the back of one of the hemispheres to see inside the cerebellum and brain stem. Results:
Brain Structure| Colour| Texture| Other Features| Size| Cerebrum| Pink| Slimy| Smell| Length 11.8|
Cerebellum| Pink/Red| Smooth| Smell| Width 7.7|
Brain Stem| White| Hard| Smell| Height 2.3|
1. Which structures contain the grey and white matter?
The structures that contain grey and white matter are (the cells body of interneuron’s) and a little white matter (the myelin sheath that protects axons).
2. Which part of the sheep’s brain is the biggest?