how can you see in your eyes ? Of the end of this lecture you will be able to answer this question. Nerve supply (chapter 11)

Objectives: -Cranial Nerve -Innervation of Extraocular Muscles -Sympathetic and Parasympathetic Systems

Definition : Cranial nerves are the nerves that emerge indirectly from the brain (including the brainstem), in contrast to spinal (which emerge from segments of the spinal cord). Cranial nerves relay information between the brain and parts of the body, primarily to and from regions of the head and neck

Cranial nerves (mnemonic) There are many cranial nerve mnemonics that can be memorable and rude. Either way, they can be helpful for remembering the names of the twelve cranial nerves as well as remembering which nerves are sensory, motor or both. Remembering cranial nerve names in order of CN I through to CN XII: Ooh, ooh, ooh to touch and feel very good velvet. Such heaven! Remembering functional information: Some say marry money but my brother says big brains matter more.

graph to make it easy :

Olfactory Nerve (CN I) Modality : Special Sensory Function : Smell

Optic Nerve (CN II) Modality : Special Sensory Function : Vision

Oculomotor Nerve (CN III) Function : 1-Somatic Motor - Eye movement. 2-Visceral Motor - pupil constriction.

Trochlear Nerve (CN IV) Function : Eye movement (Superior oblique muscle)

Trigeminal Nerve (CN V) Modality : Somatosensory information (touch, pain) Function : Branchial Motor- Muscles of mastication General Sensory- Sensory for head/neck

Abducens Nerve (CN VI) Function : Somatic Motor-Lateral rectus muscle

Facial Nerve (CN VII) Function : Taste (anterior 2/3 of tongue). somatosensory information from ear. controls muscles used in facial expression

Vestibulocochlear Nerve (CN VIII) Modality : Special Sensory Function : Hearing and Balance

Glossopharyngeal Nerve (CN IX) Function : Taste (posterior 1/3 of tongue). Somatosensory information from tongue, tonsil, pharynx. controls some muscles used in swallowing.

Vagus Nerve (CN X) Function : Sensory, motor and autonomic functions of viscera (glands, digestion, heart rate)

Accessory Nerve (CN XI) Function : Controls muscles used in head movement. (Trapezius and (sternocleidomastoid muscles

Hypoglossal Nerve (CN XII) Function : Controls muscles of tongue except palatoglossal

There are the six extraocular muscles, which act to turn or rotate an eye about its vertical, horizontal, and antero-posterior axes: 1-medial rectus (MR) cranial nerve III (Oculomotor) 2-lateral rectus (LR) cranial nerve VI (Abducens) 3-superior rectus (SR) cranial nerve III (Oculomotor) 4-inferior rectus (IR) cranial nerve III (Oculomotor) 5-superior oblique (SO) cranial nerve IV (Trochlear) 6-inferior oblique (IO) cranial nerve III (Oculomotor)

The autonomic nervous system is divided into the sympathetic nervous system and parasympathetic nervous system. The sympathetic division emerges from the spinal cord in the thoracic and lumbar areas, terminating around L2-3. The parasympathetic division has craniosacral “outflow”, meaning that the neurons begin at the cranial nerves (specifically the oculomotor nerve, facial nerve, glossopharyngeal nerve and vagus nerve) and sacral (S2- S4) spinal cord.

parasympathetic pupil contrict sympathetic pupil dilat

This work was to provide : Salman al-Ghunime Moaz al-Zughaibi Mohammed Abalkhayl Abdallah al-Harby