Lesson 2 Chapter 16 – Cranial Nerves

Lesson 2 Chapter 16 – Cranial Nerves Unit 5 Study Guide There are 12 pairs of cranial nerves. Each nerve attaches to the brain near the associated sensory or motor nuclei on the ventrolateral surface of the brain. Dirty Mnemonics for the nerves Oh, Oh, Oh, Tiny Tits And Furry Vaginas Give Victor A Hardon There is another mnemonic that gives the second letter of each word. It can be utilized after writing the first letter of each word with any of the above mnemonics.  large pricks can really ream butts and extra large asses, called yards!" Utilizing this mnemonic in conjunction with the above will result in: Ol, Op, Oc, Tr, Tr, Ab, Fa, Ve, Gl, Va, Ac, Hy Mnemonics for the type of nerve S = Sensory, M = Motor, B = Both Some Say Marry Money, But My Brother Says Big Business Makes Money 1 Lesson 2 Chapter 16 – Cranial Nerves 2 Olfactory Nerve I The olfactory nerve I is a fully sensory nerve that originates in the telencephalon, the largest division of the human brain. These nerves have anterior olfactory nucleus. The functions of this cranial nerve include sense of smell. This nerve reaches the cerebral cortex, however, it does not enter the thalamus. Optic Nerve II The optic nerve II is also a fully sensory nerve. It originates from the diencephalon region of the brain and includes the ganglion cells of the retina. The functions of this nerve include sense of light. They help one see and if these nerves are damaged, it leads to temporary or permanent blindness. Oculomotor Nerve III This is also a fully sensory nerve that originates from the midbrain. These nerves help in controlling the pupil constriction and eye movements. It helps the eyes respond to external stimuli and accordingly constrict or dilate the pupils as and when the light conditions change. Trochlear Nerve IV The trochlear nerve is a mostly a motor nerve that originates from the trochlear nucleus. This nerve has an important function in the movement of the eyeball. It helps one look down and look towards a midline object. Trigeminal Nerve V The trigeminal nerve functions both as a sensory as well as a motor nerve. It originates from the pons and has a role in controlling the muscles of the face. This nerves helps in chewing, provides sensation of pain and touch to the face as well as head region. Abducens Nerve VI This motor nerve originates from the posterior margin of Pons. This nerve helps in movement of the eye to move away from the midline of the face. It works in association with cranial nerves III and IV. This helps one see normally. If there is any difference in the function of these nerves, one tends to have double vision. Facial Nerve VII The facial nerve VII has both sensory as well as motor functions. It originates from the Pons just above the olive. This nerve helps provide the facial muscles the ability to smile, frown and form other facial expressions. This nerve also helps two third region of the tongue to develop taste. The facial nerve also provides the sensation of touch and pain to the ear. Lesson 2 Chapter 16 – Cranial Nerves 3 Vestibulocochlear Nerve VIII This is a sensory nerve that has a role in the sense of sound. It also helps in maintain balance (gravity) and movement of the body. This means it plays a role in the acoustic and vestibular functions. Glossopharyngeal Nerve IX The glossphrayngeal nerve IX has sensory and motor functions and arises from the medulla. It helps one develop taste in the back of the tongue. It also provides the sense of touch as well as pain on the tongue and tonsils. This nerve also has a role in controlling the muscles of the mouth during swallowing. Vagus Nerve X The vagus nerve also works as a sensory and motor nerve. It has one of the most important functions in the human body. This cranial nerve helps in controlling the sensory as well as motor functions of the heart and glands. This nerve also has a role in digestion. Accessory Nerve XI The cranial accessory nerve XI is a motor nerve. It is also called spinal accessory nerve or accessory nerve. This nerve helps in controlling the trapezius muscle and the sternocleidomastoid muscle that are involved with the movements of the head. Hypoglossal Nerve XII The hypoglossal nerve XII is the 12th cranial nerve that is a motor nerve. This nerve helps in the proper movement of the tongue. Lesson 2 Chapter 16 – Cranial Nerves Please watch this extremely useful YouTube video. This will help you memorize the functions of the cranial nerves! http://www.youtube.com/watch?v=kqNFmBGHs2I 4