Cranial Nerves

1. Olfactory Nerve (I)

• Function: Sensory

• Role: Smell

• Key Details:

  • Located in the nasal cavity.

  • Detects odors and sends information to the brain.

2. Optic Nerve (II)

• Function: Sensory

• Role: Vision

• Key Details:

  • Carries visual information from the retina to the brain.

3. Oculomotor Nerve (III)

• Function: Motor

• Role: Eye movement, pupil constriction

• Key Details:

  • Controls most of the eye's movements.

  • Adjusts the size of the pupil and focuses the lens.

4. Trochlear Nerve (IV)

• Function: Motor

• Role: Eye movement

• Key Details:

  • Controls the superior oblique muscle, which moves the eye downward and laterally.

5. Trigeminal Nerve (V)

• Function: Both sensory and motor

• Role: Facial sensation and chewing

• Key Details:

  • Largest cranial nerve.

  • Has three branches:

    1. Ophthalmic (V1) – Sensation from the upper face.

    2. Maxillary (V2) – Sensation from the middle face.

    3. Mandibular (V3) – Sensation from the lower face and motor control of chewing.

6. Abducens Nerve (VI)

• Function: Motor

• Role: Eye movement

• Key Details:

  • Controls the lateral rectus muscle, which abducts (moves laterally) the eye.

7. Facial Nerve (VII)

• Function: Both sensory and motor

• Role: Facial expressions, taste, saliva, and tear production

• Key Details:

  • Provides motor control to facial muscles.

  • Detects taste from the front two-thirds of the tongue.

8. Vestibulocochlear Nerve (VIII)

• Function: Sensory

• Role: Hearing and balance

• Key Details:

  • Vestibular branch – Maintains balance and equilibrium.

  • Cochlear branch – Processes sound signals.

9. Glossopharyngeal Nerve (IX)

• Function: Both sensory and motor

• Role: Taste, swallowing, and saliva production

• Key Details:

  • Detects taste from the back one-third of the tongue.

  • Aids in swallowing and controls some saliva glands.

10. Vagus Nerve (X)

• Function: Both sensory and motor

• Role: Autonomic control of heart, lungs, digestion, and speech

• Key Details:

  • Extends beyond the head and neck to the thorax and abdomen.

  • Plays a vital role in parasympathetic nervous system regulation.

11. Accessory Nerve (XI)

• Function: Motor

• Role: Shoulder and neck movement

• Key Details:

  • Controls the sternocleidomastoid and trapezius muscles, which move the neck and shoulders.

12. Hypoglossal Nerve (XII)

• Function: Motor

• Role: Tongue movement

• Key Details:

  • Controls muscles of the tongue for speech and swallowing.