2. The Sympathetic Nervous System.
This system consists of a cord on each side closely following the course of the systemic arches and the dorsal aorta. It has on it six ganglionic swellings, and there are connections between the ganglia and all the spinal nerves. Anteriorly each of the cords is joined to the vagus nerve; it ends posteriorly as a broad swelling on the ninth spinal nerve.
[In the Frog the system consists of a chain of ganglia on each side of the body closely following the course of the systemic arches and the dorsal aorta. The cords have connections with the spinal nerves. Anteriorly each cord ends in the Gasserian ganglion of the trigeminal nerve and posteriorly it is united with the coccygeal nerve by a varying number of branches.]
Make a complete sketch showing the spinal nerves and the sympathetic nervous system.
3. The Cranial Nerves.
Expose the brain and note the following cranial nerves:—
(a) The olfactory nerve, arising from the anterior end of the olfactory lobes, supplying the olfactory capsule.
(b) The optic nerve, arising from the ventral surface of the brain below the optic lobes, supplying the retina of the eye.
(c) The trigeminal nerve, arising just behind the optic nerve, giving rise to the following branches:—