cular branches to tibialis anticus, extensor longus digitorum, peroneous tertius, extensor proprius pollicis, and extensor brevis digitorum, articular to tarsal and metatarsal joints, and cutaneous to skin of adjacent sides of great and second toes ;

Musculo-cutaneous, giving off muscular branches, to peroneus longus and brevis, and cutaneous, to skin of lower part of leg, and dorsum of foot and toes, except outer side of little and adjoining sides of great and second toes.

Describe the sacral and coccygeal nerves.

They are five in number, their long roots forming the cauda equina in the spinal canal; each divides into an anterior (see page 209) and posterior division, the latter escaping by the posterior sacral foramina, except the fifth, which emerges between sacrum and coccyx, and supplies multifidus spinæ muscle and skin of posterior gluteal region; a branch goes from third nerve to bladder; the two lower nerves join with coccygeal, forming loops, which supply skin over coccygeal region and coccygeus, levator, and sphincter ani muscles.

The Sympathetic Nerve.

What is the sympathetic nerve or system?

It consists of a series of ganglia with intervening commissural bands, forming two cords on either side of spinal column connected above by ganglion of Ribes on the anterior cerebral communicating artery, and below by ganglion impar, in front of coccyx; they also communicate with the spinal system of nerves.

Locate and briefly describe the connections of the cranial and facial ganglia.

Ganglion of Ribes, on anterior communicating artery, connected with cavernous and carotid plexuses.

Carotid ganglion (Laumonier's) on under surface of vessel. Selumar-Gasserian, on fifth nerve (infra).

Orbital
Prenyy, Rol

Ciliary or ophthalmic, in orbit (infra).

Spheno-palatine (Meckel's), in spheno-maxillary fossa (infra). Otic (Arnold's), on inner side of inferior maxillary nerve below Aforamen ovale (infra).

(Ganglia are occasionally found on middle meningeal, lingual,

temporal, and pharyngeal arteries, receiving the name of their discoverer, as Bidder, Cloquet, etc.

Ganglion of Bochdalek is situated at point of junction of one of the nasal branches of Meckel's ganglion and anterior dental nerve. Submaxillary lies above deep portion of submaxillary gland

Situated in the orbit between the optic nerve and external rectus muscle, its roots are, sensory, from nasal branch of ophthalmic (fifth pair); motor, third nerve; sympathetic, cavernous plexus; its branches are,

Short ciliary to ciliary muscle and iris.

Describe the spheno-palatine ganglion.

Deeply placed in spheno-maxillary fossa, its roots are, sensory, from superior maxillary; motor, facial, through Vidian; sympathetic, from carotid plexus; its branches are,

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Describe the otic ganglion.

It lies immediately beneath foramen ovale on the inner surface of inferior maxillary nerve; its roots are, sensory, from auriculotemporal; motor, internal pterygoid branch of inferior maxillary, also facial and glosso-pharyngeal through continuation of small petrosal nerve; sympathetic, from middle meningeal plexus; its branches supply tensor tympani and tensor palati muscles.

Describe the submaxillary ganglion.

Situated above deep portion of submaxillary gland, its roots are, sensory, from gustatory branch of inferior maxillary; motor, facial, through chorda tympani; sympathetic, from facial plexus; its branches go to mucous membrane of mouth, to submaxillary gland and to its duct.

Describe the petrosal nerves.

The great petrosal (large superficial petrosal) is usually described as a branch of the spheno-palatine ganglion passing through the

Vidian canal, distributing twigs to mucous membrane of back part of nose, septum, and end of Eustachian tube, entering skull through foramen lacerum medium, where it divides into the large superficial petrosal, which enters hiatus Fallopii, receives a twig from Jacobson's nerve, and terminates in the geniculate ganglion of facial nerve, and the carotid (large deep petrosal) joining the carotid plexus. Small petrosal (small superficial petrosal) connects geniculate ganglion of seventh nerve with otic ganglion.

External petrosal (external superficial petrosal) passes between geniculate ganglion of seventh nerve to middle meningeal plexus. More correctly, the great petrosal and carotid branches may be said to form the Vidian nerve, which runs forward through the same named canal to join the spheno-palatine ganglion, supplying it with motor and sympathetic fibres. According to this description, the twigs said to be given off by the Vidian nerve to the nasal mucous membrane must be considered branches of the ganglion running back in the same sheath.

Describe the cervical ganglia.

There are three on either side, viz., the

Superior cervical ganglion. It is placed opposite second and third cervical vertebræ behind carotid sheath, and gives off a Superior branch, to internal carotid artery, forming by its division the cavernous plexuses and carotid plexus (with its subdivisions); Descending branch, connecting superior with middle ganglion; External branches to cranial and spinal nerves, and anterior branches forming plexuses on external carotid and its branches; Pharyngeal, forming with branches from pneumogastric, glossopharyngeal, and external laryngeal nerves, the pharyngeal plexus; Laryngeal, uniting with superior laryngeal nerve and its branches;

Superior cardiac, connected with other branches of sympathetic, and with some of pneumogastric, passes to back of aorta, the right joining the deep, and the left (usually) the superficial cardiac plexus. Middle cervical ganglion is placed opposite fifth cervical vertebra; by its

Superior and inferior branches it communicates respectively with superior and inferior cervical ganglia; the external filaments join

fifth and sixth spinal nerves, the internal are the thyroid to inferior thyroid artery and gland, and the middle or great cardiac nerve, communicating with other sympathetic branches and recurrent laryngeal, to terminate in the deep cardiac plexus.

Inferior cervical ganglion is placed between base of transverse process of seventh cervical vertebra and neck of first rib on inner side of superior intercostal artery; its superior and inferior branches connect it respectively with middle cervical, and first thoracic ganglia; the external branches join the spinal nerves, others form a plexus or vertebral artery; its chief branch is the

Inferior cardiac nerve, communicating with recurrent laryngeal and middle cardiac nerves, terminating in the deep cardiac plexus. What is the carotid plexus?

It is a plexus situated on the outer side of the internal carotid artery communicating with the Gasserian and sphenopalatine ganglia, the sixth nerve, and tympanic branch of glosso-pharyngeal; it supplies the carotid artery and dura mater

What is the cavernous plexus?

It is one situated below and internal to that part of the internal carotid artery running alongside of the sella turcica, in the cavernous sinus; it communicates with third, fourth, fifth, and sixth nerves, and ophthalmic ganglion, and supplying carotid, it, with the carotid plexus, forms plexuses embracing the cerebral and ophthalmic arteries.

What are the other ganglia of the sympathetic system?

Usually twelve thoracic, four lumbar, four or five sacral, one coccygeal (ganglion impar), and numerous ganglia connected with the various viscera, whence plexuses are formed named from their locality, or the organ.

What are the branches of the thoracic portion?

Communicating, with one another and the dorsal spinous nerves, filaments to aorta and its divisions and to posterior pulmonary plexus, and

The Great Splanchnic nerve, formed by internal branches from thoracic ganglia between sixth and tenth, with filaments from

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upper six; it perforates crus of diaphragm to terminate in semilunar ganglion, sending branches to renal plexus and suprarenal capsule.

The Lesser Splanchnic, springing from tenth and eleventh ganglia and cord between and communicating with great splanchnic, it pierces diaphragm with preceding, to join the cœliac plexus.

Smallest, or Renal Splanchnic, arises from last ganglion, occasionally communicates with preceding, pierces diaphragm, and terminates in renal and lower part of coeliac plexus.

Describe the solar plexus.

It supplies all the abdominal viscera, consisting of a network of nerves and ganglia lying in front of the aorta and crura of diaphragm, surrounding the coeliac axis and root of the superior mesenteric artery, extending below to the pancreas, laterally to the suprarenal capsules. The great and part of lesser splanchnic

nerves of both sides and termination of the right pleumogastric (ANT

form this plexus, in conjunction with the two semilunar ganglia, these latter being large, irregular gangliform masses, composed of smaller ganglia with interspaces between, placed by side of cœliac axis and superior mesenteric artery, close to suprarenal capsules, that on the right lying beneath the vena cava. From this are derived the following plexuses accompanying the same-named arteries to the various organs:

Name some of the more important.

Tympanic (see p. 316).

Inferior mesenteric.

Great, or deep, cardiac is placed in front of bifurcation of trachea, and above that of pulmonary artery, behind aortic arch, and is formed by all sympathetic cardiac nerves (except left superior), and, cardiac branches of recurrent laryngeal and pneumogastric (except left superior cardiac and left inferior cardiac of pneumogastric). Superficial cardiac lies beneath aortic arch in front of right pul-

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