[医学]cranial nerves颅神经lecture 3a.ppt

Cranial nerves andcranial nerve nuclei Key points Important cranial nuclei and nerves CN V, VII, X, XII nerve supply of tongue Master the name and role of 12 pairs of cranial nerves. Introduction to Cranial Nerves Classification of Nerves Sensory (afferent) – carry impulse to the CNS Motor (efferent) – carry impulses from CNS Mixed– sensory and motor ( somatic and autonomic) fibers carry impulses to and from CNS; most common type of nerve Peripheral Nerves Each spinal nerve contains four type of fibers: Somatic sensory and somatic motor Visceral sensory and visceral motor All cranial nerve contain: ( The seven types of fibers in the cranial nerves): Motor: General somatic motor: CN III, IV, VI, XII General visceral motor : CN III, VII, IX, X Special visceral motor: CN V, VII, IX, X, XI Sensory: General Somatic sensory: CN V, VII, X Special Somatic sensory : CN II, VIII General Visceral sensory: CN IX, X Special Visceral sensory: CN I ,V The cranial nerves are composed of twelve pairs of nerves that emanate from the nervous tissue of the brain.??In order reach their targets they must ultimately exit/enter the cranium through openings in the skull.?? ?The function of the cranial nerves is for the most part similar to the spinal nerves, but the cranial nerves have some special characters, e.g. each spinal nerve is mixed nerve, and some cranial nerves are mixed nerves, somejust have one type of fiber (motor or sensory). There are 7 type of fibers in the cranial nerves. ?? The motor components of the cranial nerves are derived from nuclei that are located in the brain. These nuclei send their axons out of the cranium where they will ultimately control muscle (e.g., eye movements) , glandular tissue (e.g., salivary glands) or specialized muscle (e.g., heart or stomach). The sensory components of cranial nerves originate from collections of?neurones (sensory ganglion) that are located outside the brain. The?sensory ganglia are essent