CRANIAL NERVES OF SCOLIODON (SHARK)

SHARK FISH (SCOLIODON) CRANIAL NERVES ORIGIN AND PHYSIOLOGICAL FUNCTION

Ten pairs of cranial nerves arise from the brain at different loca­tions to supply the anterior region of the body. In addition to them a pair of terminal or pre olfactory nerves (zero nerves) arises from the ventral surface of the cerebrum.

The ten pairs of cranial nerves are furnished below for detail study.

 

1. BRANCHIALIS X

3. LATERALIS X

4. BUCCALIS VII

5. CEREBELLUM

6. OPTIC III

7. OPHTHALMICUS SUPERFICIALIS V& VII

8.OLFACTORY LOBE

9.BUCCALIS VII

10. PALATINUS VII

11.MAXILLARIS INFERIOR V

12.MANDIBULARS V

13. MANDIBULARS EXTERNUS VIII

14. HYOMANDIBULARIS VII

15. PHARYNGEAL

16. OPHTHALMICUS PROFUNDUS V

17. POST TREMATIC PRETREMATIC IX IX

18. MANDIBULARS INTERNUS VII

 

 

 

Name of the nerve	Origin		Branches		Distribution		Physiological Nature
I. OLFACTORY	Olfactory lobe.				Olfactory epithelium of the nasal cavity.		Sensory
2. OPTIC	Optic lobe.				Retina of eye.		Sensory
3. OCULOMOTOR	Ventrolateral side ofthe midbrain.				Anterior rectus, superior rectus, inferior rectus and inferior oblique muscles of the eye. Superior oblique muscle of the eye		Motor Motor
4 TROCHLEAR	Dorsolateral aspect of the midbrain between the optic lobes and cerebrum.				Olfactory capsule and dorsal		Mixed
5 TRIGEMINAL	Dorsally from the side of medulla oblongata below the corpora restiformes.		(i) Opthalmic profundus (ii) Ophthalmicus superfi-cialis V (iii) Maxillaris V (a) Superior (b) Inferior (iv) Mandibularis		skin of the snout. Skin of the snout. Skin of upper jaw Posterior part of upper lip. Muscles of the lower jaw.		Mixed Motor Mixed
6. ABDUCENS	Midventrally from the floor of medulla oblongata				Posterior rectus muscle of the eye.		Mixed
7. FACIAL	From the side of medulla below the corpora restiformes in the form of a bundle.		(i) Opthalmicus super-ficialisVII (ii) Ramus buccalis (iii) Flyomandibularis (a) Mandibularis exte-rnus (b) Mandibularis inter-nus (c) Hyoidean (iv) Ramus palatinus		Sense organs; the lateral line system of snout. Infra-orbital lateral line canal and associated ampullae. Mandibular canal of lateral-line system. Mucous membrane of the floor of buccal cavity. Muscles of the roof of buccal cavity and pharynx. Roof of the pharyngeal and buccal cavity.		Mixed Mixed Mixed Mixed Mixed Sensory
8. AUDITORY	From the side of medulla close to the V and Vll cranial nerves.		(i) Vestibular (ii) Saccular		Membranous labyrinth of the internal ear		Sensory
9. GLOSSOPHARYN GEAL	From the ventro-lateral side of medulla. .		(i) Pre-trematic (ii) Post-trematic		Mucous membrane of the first gill-cleft and the pharynx. The muscles of the pharynx Gills.		Sensory Mixed Mixed
10. VAGUS	Side of Medulla.		(a) Branchialis (b) Visceralis (c) Lateralis		Viscera. Lateral-line system of the trunk.		Mixed Mixed Mixed