1. Brain Dissection

2. How to perform a successful brain dissection Perform each step of the lab, referring to this power point for guidance. Carefully study each structure and think about what it does. Discuss the details of each structure with your partner and develop cues that will help you during the test. Label each structure on the brain diagrams. Take a picture of each word underlined in the lab making note of it’s name.

3. STEP 1 Use a scissors to cut away the covering around the brain known as the dura mater. Be careful on the anterior side of the brain. Nerves (white, cord-like structures) should remain attached to the brain. A skilled dissector can remove it in one piece. Answer questions 1-5.

4. Use a forceps to gently pull on the surface of the brain. You may be able to grab hold of the arachnoid mater. Answer question 6.

5. STEP 2 Find the cerebrum, cerebellum and brain stem. What is the function of each structure? How can you remember each structure for the test? Label diagram 7-9 and answer questions 10-12. cerebrum cerebellumBrain stem

6. Study the shape, size and texture of the total structure. Compare the photos of a human brain to your sheep brain. Complete the Venn diagram (13-15).

7. STEP 3 Notice the ridges and grooves in the cerebrum. What scientific names are given to these structures? What is their purpose? Answer questions 16-18.

8. Find the longitudinal fissure on the dorsal side of the brain? What is a fissure? Complete 19-21.

9. STEP 4 Observe the ventral side of the brain and begin at the anterior end. You will see some of the major nerves associated with your senses. Find the olfactory bulbs. Use your text to find out the sense associated with the olfactory bulbs. What is a tract? (See page 232 in your text) Answer questions 22-24.

10. Observe the optic nerves. What sense are these nerves associated with? The optic nerves cross as the optic chiasma. Use the internet to find out the importance of the crossing of optic fibers. Answer questions 25-28. Oculomotor nerve Optic nerve

11. Observe some of the other anterior structures. You will need to find the function of the mammillary body on the internet. Answer questions 29-32. -mammillary body -the pons

12. STEP 5 Now make a midsagittal cut through the brain.

13. Find and label the corpus callosum. What is its function? Label the corpus callosum (33) and answer question 34.

14. Find the ventricles: This is a picture of the lateral ventricle. What is the function of a ventricle? Label the lateral ventricle (35) and answer questions 36-37.

15. The 4 th ventricle is connected to the 3rd ventricle by the cerebral aqueduct. How do you think the cerebral aqueduct got its name? Label the 4 th ventricle (38) and answer question 39. 4 th ventricleCerebral aqueduct

16. Find the thalamus and label it on your diagram (40). Describe its position in the brain. Answer question 41.

17. Find the structures of the brain stem: label the medulla oblongata, pons and midbrain and label them on your diagram (42-44). Spinal cord

18. STEP 6 Make a coronal (frontal) section perpendicular to the longitudinal fissure.

19. Find the gray matter and white matter. The gray matter (also called the cortex) gets its colors from what neuron structure? How does the white matter get its color? Answer questions 45-47.

20. Can you figure out the name of these openings? Answer question 48.

21. STEP 7 Explore!!!!! Myelinated axons

22. Nick and Colton’s brain was attached to the nasal bone. Note how the nasal cavities fit over the olfactory bulbs in real life. Nasal cavitiesOlfactory bulbs

23. STEP 8 Save your brain parts in a plastic bag just in case you need them tomorrow. Place the bag in the tray of your cabinet. Wash and dry your dissection tray and tools.