Presentation on theme: "Brainstem David A. Morton, Ph.D. Jan 10 th, 2013 Midbrain and Pons."— Presentation transcript:
Brainstem David A. Morton, Ph.D. Jan 10 th, 2013 Midbrain and Pons
Objectives Explain how spinal nerves differ from cranial nerves Name all the cranial nerves and know their components and functions Identify and locate the CN’s associated with the medulla, pons and midbrain Recognize the major internal and external landmarks on the dorsal and ventral surface of the brain stem, so that you can determine if a gross or stained cross section is medulla, pons or midbrain. Identify on a typical cross section all the brain stem nuclei containing motor neurons that end on striated muscle. List the cranial nerves that contain parasympathetic fibers, the location of their nuclei, and their function Explain why cranial nerves are so important in localizing lesions. Name reflexes that test these nerves and brain stem levels. Relate branches of the vertebrobasilar blood supply to the medulla and pons explaining the deficits that would occur with vascular occlusion.
Corpus callosum Lateral ventricle 3 rd ventricle Cerebral aqueduct 4 th ventricle Brain Overview 4 Corpus callosum 3 LV aq
Spinal Cord and Spinal Nerve Review Alar Basal Sulcus limitans Spinal cord Som S VS VM SM Spinal nerve anatomy Dorsal root Somatic sensory neurons Visceral sensory neurons Ventral root Visceral motor neurons Somatic motor neurons
Internal anatomy of brainstem Alar Basal Sulcus limitans Spinal cord Som S VS VM SM Alar Basal Sulcus limitans Medulla Som S VS VM SM BM The fate of the alar and basal laminae Why are brain stem sensory nuclei lateral to motor nuclei in brainstem?
External anatomy: Quadrigeminal plate Superior colliculus Inferior colliculus Cerebral peduncles CN IV Midbrain (mesencephalon) SC CP IC IV Dorsal view of brainstem
External anatomy: Quadrigeminal plate Superior colliculus Inferior colliculus Cerebral peduncles CN III (arrows) Midbrain (mesencephalon) Rostral midbrain Caudal midbrain SC IC CP Dorsal view of midbrain CP Ventral
4 th Ventricle Motor nucleus of V Tegmentum R.F. Pons Proper Axons of the sensory part of V Axons of the motor part of V Pons (Rostral/Mid) Internal anatomy Trigeminal motor nucleus Functional significance
Pons (caudal) Facial nucleus Branchial motor nucleus Innervate muscles of face
Pons (caudal) Superior salivatory nucleus Visceral motor (Para) Origin of preganglionic parasympathetic neurons
Pons (caudal) Abducens nucleus Origin of Abducens n. (CN VI) Homolog to ventral horn