There are 12 pairs of cranial nerves that originate directly from the brain or inside the cranium. The first two cranial nerves, the olfactory and optic nerves, originate from the forebrain. Cranial nerves 3 through 12 arise from the brainstem, with nerves 3-4 originating from the midbrain, nerves 5-8 from the pons, and nerves 9-12 from the medulla oblongata. The cranial nerves consist of sensory nerves, motor nerves, or mixed nerves and are involved with functions like vision, facial movements, hearing, balance, taste, and internal organ control.

1. CRANIAL NERVES
PRESENTED BY : DR CHITRANSHA

2. INTRODUCTION
1. Olfactory nerve
2. Optic nerve
3. Oculomotor nerve
4. Trochlear nerve
5. Trigeminal nerve
6. Abducens nerve
7. Facial nerve
8. Vestibulocochlear nerve
9. Glossopharangial nerve
10. Vagus nerve
11. Accessory nerve
12. Hypoglossal nerve
There are 12 pairs of cranial nerves in our body.
These are called as cranial nerve because the originated directly from
the brain or inside the cranium.
There names are:

3. ORIGIN OF THE CRANIAL NERVES
 The olfactory nerve (CN I) and optic nerve (CN II) originate
from the cerebrum (forebrain).
 Cranial nerves III – XII arise from the brain stem.
 1, 2 - Forebrain
 3,4 – Midbrain
 5,6,7,8 – Pons
 9,10,11,12 – Medulla oblogata
 All cranial nerves arise from ventral surface except 4th
(trochlear nerve) which arises dorsaally.

4. ORIGIN
 1, 2 - Forebrain
 3,4 – Midbrain
 5,6,7,8 – Pons
 9,10,11,12 – Medulla oblogata

7. both motor and
sensory fibres
(mixed nerve).
sensory fibres
(sensory nerve) or
motor fibres (motor
nerve) or
Cranial nerve consist of:

8. SENSORY/
AFFERENT
OLFACTORY
OPTIC
VESTIBULO
COCHLEAR
MOTOR/
EFFERENT
OCCULOMOTOR
TROCHLEAR
ABDUCENT
ACCESSORY
HYPOGLOSSAL
MIXED
TRIGEMINAL
FACIAL
GLOSSO
PHARYNGEAL
VAGUS
S- 1,2,8
M- 3,4,6,11,12
MIXED-5,7,9,10,

9. Functional Component of Cranial Nerves

11.  Motor (efferent) Components:
 General somatic efferent (GSE) – skeletal muscles which develop
from somites.
 Special visceral efferent (SVE) – muscles derived from pharyngeal
arches.
 General visceral efferent (GVE) – glands, smooth muscles of gut &
vessels.
 Sensory (afferent) Components:
 General somatic afferent (GSA) – general sensation from skin.
(pain, touch, temperature, vibration)
 General visceral afferent (GVA) – general sensation from viscera.
 Special visceral afferent (SVA) – special sensations of taste from
tongue.
 Special somatic afferent (SSA) – special sensations of sight,
sound, balance

14. OLFACTORY NERVE
Olfactory tract

15. OPTIC NERVE