cranial nerves based on medical science

anatomy

1. Cranial & Spinal Nerves

2. NERVOUS SYSTEMNERVOUS SYSTEM
CENTRAL
BRAIN
SPINAL CORD
PERIPHERAL
CEREBROSPINAL
AUTONOMIC

4. PERIPHERAL NERVOUS SYSTEM
•Cerebrospinal nerves
12 pairs of cranial nerves
31 pairs of spinal nerves
•Autonomic nervous system
Sympathetic system
Parasympathetic system

5. Oculomotor nerve
Emerges from mid brain on medial side of the crus
cerebri.
Enters cavernous sinus by piercing posterior part of its
roof on lateral side.
Descends in lateral wall of sinus where it lies above
the trochlear nerve.
In anterior part of sinus nerve divides into a superior
and inferior division.
2 divisions of nerve enters the orbit through middle
part of supra orbital fissure.

6. Names of cranial nerves
•I Olfactory nerve
•II Optic nerve
•III Oculomotor nerve
•IV Trochlear nerve
•V Trigeminal nerve
•VI Abducent nerve
•VII Facial nerve
•VIII Vestibulocochlear nerve
•IX Glossopharyngeal nerve
•X Vagus nerve
•XI Accessory nerve
•XII Hypoglossal nerve

7. Olfactory (I) Nerve
•Sensory nerve.
•Sense of smell.
•Olfactory cells converge
to become olfactory
nerve.

8. Optic (II) Nerve
•Sensory nerve.
•Ganglion cells in the
retina of each eye join
to form an optic nerve.
•Nerve of vision.

9. Oculomotor (III) Nerve
•Motor cranial nerve.
•Originates in the
midbrain.
•Supply extrinsic eye
muscles to control
movements of the
eyeball and upper
eyelid.

10. Trochlear (IV) Nerve
•Motor cranial nerve.
•Smallest of the 12
cranial nerves.
•Origin: midbrain.
•Controls movement of
the eyeball.

11. Trigeminal (V) nerve
•Largest cranial nerve.
•Mixed nerve.
•Three branches:
opthalmic, maxillary and
mandibular. Deal with
sensation of touch, pain
and temperature.
•Motor axons supply
muscles of mastication.

12. Abducens (VI) Nerve
•Motor cranial nerve.
•Originates from the
pons.
•Cause abduction of the
eyeball (lateral
rotation).

13. Facial (VII) Nerve
•Mixed cranial nerve.
•Sensory portion extends
from the taste buds of
the anterior two-thirds
of the tongue.
•Motor portion arises
from the pons and deal
with facial expression.

14. Vestibulocochlear (VIII) Nerve
•Sensory cranial nerve.
•Originates in the inner
ear.
•Vestibular branch
carries impulses for
equilibrium.
•Cochlear branch carries
impulses for hearing.

15. Glossopharyngeal (IX) Nerve
•Mixed cranial nerve.
•Sensory axons carry
signals from the taste
buds of the posterior
one-third of the tongue.
•Motor neurons arise
from the medulla and
deal with the release of
saliva.

16. Vagus (X) Nerve

17. Vagus (X) Nerve
•Mixed cranial nerve.
•Distributed from the head and neck into the
thorax and abdomen.
•Sensory neurons deal with a variety of
sensations such as proprioception, and
stretching.
•Motor neurons arise from the medulla and
supply muscles of the pharynx, larynx, and
soft palate that are involved in swallowing and
vocalization.

18. Accessory (XI) Nerve
•Motor cranial nerve.
•Divided into cranial
accessory and spinal
accessory nerves.
•Supplies
sternocleidomastoid
and trapezius muscles
to coordinate head
movements.

19. Hypoglossal (XII) Nerve
•Motor cranial nerve.
•Conduct nerve impulses
for speech and
swallowing.

20. –31 Pairs of Spinal Nerves.
» 8 Cervical
» 12 Thoracic
» 5 Lumbar
» 5 Sacral
» 1 Coccygeal

22. –Spinal Nerves are attached by
– Ventral Root.
– Dorsal Root.
–The 2 roots unite to form a
trunk.
–This short trunk divides in to
– Ventral Ramus.
– Dorsal Ramus.

23. Picture1.jpg

25. •Dorsal ramus divides into the
lateral and medial branches
which supply the skin and
muscles of the back
•Ventral ramus supplies the
muscles and skin of the front and
the extremities by forming
plexuses

26. Thank you