Dissection of the Frog Brain and Spinal Cord

Review the skeleton of the frog on demonstration before commencing the dissection. Try to visualize where the brain and spinal cord are within the cranium and vertebral column. This dissection is done from the dorsal side. When the disection is complete you should be able to see the olfactory nerve, olfactory bulb, cerebrum, optic lobes, cerebellum, medulla oblongata, spinal cord with two slightly enlarged regions, the brachial and lumbar enlargements. These enlargements are due to the large number of neurons required for forelimb and hindlimb functions. With care, you may see the dorsal roots of spinal nerves.

Dorsal View of the Brain

Ventral View of the Brain

A ventral view of the brain and spinal cord should reveal in order, the olfactory nerve, olfactory lobe, cerebrum, optic nerves, optic chiasma, infundibulum immediately behind the chiasma, pituitary gland just behind the infundibulum, optic lobes, medulla oblongata and the spinal cord.