PNS Structure of Nerves Cranial Nerves Spinal Nerves















- Slides: 15

PNS Ø Ø Ø Structure of Nerves Cranial Nerves Spinal Nerves Sensory receptors Motor control

Structure & Classification of Nerves Classification: Sensory, Motor, Mixed, Cranial & Spinal nerves; Ganglia

Cranial Nerves • 12 pair of nerves – arise from brain – exit through foramina leading to muscles, glands and sense organs in head & neck • Input & output ipsilateral except CN II and IV

I: Olfactory Nerve II: Optic Nerve

III: Oculomotor Nerve & IV: Trochlear Nerve

V: Trigeminal Nerve VI: Abducens Nerve

VII: Facial Nerve VIII: Vestibulocochlear Nerve

IX: Glossopharyngeal Nerve X: Vagus Nerve

XI: Accessory Nerve XII: Hypoglossal Nerve

Cranial Nerve Disorders • Trigeminal neuralgia (tic douloureux) – recurring episodes of intense stabbing pain in trigeminal nerve area – pain triggered by touch, drinking, washing face – treatment may require cutting nerve • Bell’s palsy – disorder of facial nerve causes paralysis of facial muscles on one side – may appear abruptly w/ full recovery w/in 3 -5 weeks

Spinal Nerves - 31 pairs of mixed nerves - connect to cord via dorsal & ventral roots and rootlets - away from cord branch into dorsal & ventral rami - nerve plexuses - nerve damage

Dermatomes: skin segment innervated by cutaneous sensory spinal nerve

Sensory Receptors • Stimulus type: type – mechanoreceptor, thermoreceptors, nociceptors, chemoreceptors & photoreceptors • Source: Source – exteroceptors, interoceptors & proprioceptors • Structural complexity: – simple vs. complex

Organization of Somatosensory System 1. Receptor level: level sensory receptors 2. Circuit level: level ascending fiber tracts 3. Perceptual level: level cerebral cortex

Hierarchy of Motor Control
Spinal nerves labled
Spinal cord anatomy
Spinal cord layers
Figure 13-2 spinal nerves labeled
Edinger westphal nucleus function
Glossopharyngeal nerve function test
Optic nerve names
Labeling cranial nerves
Cranial nerves
Cranial nerves mnemonic
Olfactory nerve
Cranial nerves classification
Testing vestibulocochlear nerve
Cranial nerves labeled with roman numerals
Figure 14-2 cranial nerves labeled
Cranial nerves labeled with roman numerals