A sketch of the central nervous system and its origins G E Schneider 2009 Part 5 Differentiation of the brain vesicles MIT 9 14 Class 9a Autonomic nervous system structures Autonomic nervous system Overview of functions Schematic overview Formation of sympathetic ganglia from the neural crest REVIEW Sympathetic innervation pattern thoracico lumbar system Cf parasympathetic innervation cranio sacral system dual innervation of smooth muscles and glands Chemical mediation at synapses discovery by Otto Loewi in 1921 Closure of neural tube formation of sympathetic ganglia Neural plate Ectoderm Notochord Neural groove Neural tube and neural crest Roof plate Alar plate Basal plate Floor plate Autonomic nervous system Overview of functions Schematic overview Formation of sympathetic ganglia from the neural crest Sympathetic innervation pattern thoracico lumbar system Cf parasympathetic innervation cranio sacral system dual innervation of smooth muscles and glands Chemical mediation at synapses discovery by Otto Loewi in 1921 INTERNAL STRUCTURE OF THE SPINAL CORD Dorsal Root Fibers Nuc cornucommissuralis Posterior Fasc Substantia Gelatinosa Gracilis Nuc Posteromarginalis Internal Structure Spinal Cord Segment C1 Internal structure of spinal cord Note the lateral horn Zone of Lissauer Lat Corticospinal Tr Nuc Proprius Cornu Dorsalis Nuc Reticularis Nuc Dorsalis of Clarke Ant Spinocerebellar Tr Lat Spinothalamic Tr Nuc Motorii Lateralis Fasc Proprius Ant Spinothalamic Tr Vestibulospinal Tr Ventral Root Fibers Nuc Motorii Medialis Segment C5 Segment C8 Segment T2 II I Segment T10 III IV V Segment L1 VI X M VII VIII IX Segment L4 IX IX IX Figure by MIT OpenCourseWare Segment S4 Dorsal root ganglion Sympathetic nervous system Descending axons schematic reticulospinal section of spinal xxxxx fibers cord thoracic xxxxx xx level Spinal nerve Paravertebral ganglion To striated muscles Prevertebral ganglion e g celiac Smooth muscle Glands intestinal tract blood vessels erector pili hairs sweat glands Cardiac muscle Sympathetic Innervation P Brodal Figure by MIT OpenCourseWare Autonomic nervous system Overview of functions Schematic overview Formation of sympathetic ganglia from the neural crest Sympathetic innervation pattern thoracico lumbar system Parasympathetic innervation cranio sacral system dual innervation of smooth muscles and glands Chemical mediation at synapses discovery by Otto Loewi in 1921 Vagus nerve 10th cranial nerve MESENCEPHALON Visceral Efferent Oculomotor Nucleus Edinger Westphal Ciliary Ganglion Pupillary Sphincter Muscle Oculomotor Nerve Ciliary Muscle Superior Salivary Nucleus Maxillary Nerve Intermediate Nerve Greater Pterygopalatine Petrosal Nerve Ganglion MEDULLA OBLONGATA Chorda Tympani Mandibular Nerve GlossophaRyngeal Nerve Submandibular Ganglion Submandibular Gland Sublingual Gland Parotid Gland Parasympathetic Innervation Auriculo Temporal Nerve Tympanic Otic Ganglion Nerve MEDULLA OBLONGATA Pharynx Esophagus Trachea Bronchi Lungs Vagus Nerve MEDULLA SPINALIS S3 S4 Nasal Palatal Gland Lingual Nerve Facial Nerve Dorsal Motor Vagus Nucleus Lacrimal Gland Ganglia Plexuses Pelvic Nerve Sympathetic Trunk Figure by MIT OpenCourseWare Heart Stomach Small Intestine Large Intestine Liver Pancreas Gallbladder Large Intestine Lower Rectum Bladder Genitals P Brodal Autonomic nervous system Overview of functions Schematic overview Formation of sympathetic ganglia from the neural crest Sympathetic innervation pattern thoracico lumbar system Parasympathetic innervation cranio sacral system dual innervation of smooth muscles and glands Chemical mediation at synapses discovered by Otto Loewi in 1921 REVIEW Autonomic pathways with neurotransmitters showing accelerator decelerator nerves of the heart An advance in PNS anatomy in the late part of the 20th century The enteric nervous system The little brain in the gut A semi autonomous network that may contain as many neurons as the entire spinal cord In the wall of the intestine this network contains multiple plexi Myenteric plexus the outer plexus Submucous plexus the middle plexus Villous plexus inner plexus Periglandular plexus inner plexus Innervation by vagus nerve Cf Cardiac Ganglion Does the heart have a brain Various neurotransmitters are used in this system Levels of autonomic control The enteric nervous system shows autonomy at the lowest level in control of the alimentary tract Within the CNS there are lower levels of control of the internal environment capable of some autonomy Temperature regulation is a good example For this function each higher level adds more refinement Levels of control in the ANS the temperature regulation systems Temperature is regulated by mechanisms operating at all levels spinal hindbrain midbrain hypothalamus of the tweenbrain Each higher level adds refinements for endothermic animals this means speed and a narrower range of target temperatures See reviews by Evelyn Satinoff For other functions there is probably a similar hierarchy A sketch of the central nervous system and its origins G E Schneider 2009 Part 5 Differentiation of the brain vesicles MIT 9 14 Class 9b Differentiation of the brain vesicles Introduction to hindbrain and segmentation The encephalon brain Hindbrain rhombencephalon Midbrain mesencephalon Forebrain prosencephalon Tweenbrain diencephalon Endbrain telencephalon In the head The embryonic neural tube above the spinal cord What are the flexures in the neural tube See e g Nauta Feirtag pp 162 163 The flexures of the developing neural tube s rostral end human From Nauta Feirtag Figure by MIT OpenCourseWare Origin of the term rhombencephalon What happens to the roof plate where the pontine flexure bend forms See e g Nauta Feirtag p 162 Basic subdivisions embryonic neural tube Where is the rhombus What is it a Spinal cord a Spinal cordcord a Spinal b Hindbrain b Hindbrain rhombencephalon b Hindbrain rhombencephalon rhombencephalon Reminder Students c Midbrain c Midbrain mesencephalon c Midbrain should understand and mesencephalon mesencephalon know this figure d Tweenbrain d Tweenbrain diencephalon d Tweenbrain diencephalon diencephalon Forebrain e Endbrain e Endbrain e Endbrain telencephalon prosencephalon telencephalon telencephalon Terminology What is the obex Find it in the previous picture The hindbrain rhombencephalon topics Basic structural organization compared with spinal cord Basic functions Cell groupings origins Sensory channels and the trigeminal nerve The