1. 1 Chapter 2c CNS Gross Anatomy Chris Rorden University of South Carolina Norman J. Arnold School of Public Health Department of Communication Sciences and Disorders University of South Carolina

2. 2 What is a Fasciculi In anatomy, a Fasciculi refers to a A.Volume of Cerebral Spinal Fluid B.White matter fiber tract C.Gray matter nuclei D.Set of cells that support neurons

3. 3 What is a Fasciculi What is a fascio? A.A Flag B.Bundle of rods, sometimes with an axe C.A spoon D.A shaft of wheat, used as an ancient straw

4. 4

5. 5 Spinal Cord Same Meningeal Layers as the Brain About 45cm long Diameter of 1 cm. Root filaments Dorsal Ventral Mixed spinal nerve Dura mater Arachnoid mater Pia mater

6. Spinal Nerve Components Dorsal Division: sensory part of nerve, sensory information enters spinal cord through dorsal root fibers Ganglion: cell bodies of these nerves come together to create the dorsal root ganglion Dorsal Horn or Column: information enters the spinal column at the dorsal horn

7. Spinal Nerve Components Ventral Division: motor commands, leave the ventral root and go to muscles Ventral Horn or Column: information passed from brain to spinal cord then from the ventral root to the extremities

8. Transverse view of spinal cord "Copyright © 2005 by Thompson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED"

9. Segmental Spinal Reflex Arc A stimulus/response system that maintains a constant state of muscular tone Works by: –muscles spindles sense stretching and send information through gamma nerves to dorsal root of spinal cord –a signal is sent back from the ventral root for the muscle to contract

10. 10 Spinal Cord Dorsal root fibers form ganglion Connect to ventral fibers to form peripheral spinal nerves. Attached by Filum Terminale

11. 11 Internal Spinal Cord Gray Matter Two Dorsal Horns (Sensory Info) Two Ventral Horns (Motor Info) White Matter Three Myelinated Fasciculi Dorsal, Lateral and Ventral

12. 12 Spinal Cord Segments & Nerves Lumbar 5 Coccygeal 1 31 Spinal Segments and Nerves Cervical 8 Thoracic 12 Sacral 5

13. 13 Ventricles Lateral Ventricles Connected by interventricular foramen Collateral trigone area Posterior and inferior horns Connects to Third Ventricle through Monro’s foramen

14. 14 Ventricles Birds Eye View –Usually symmetrical in healthy people

15. 15 Other ventricles… Third Ventricle Ventral to the corpora quadrigemina Surrounded by central gray area Connects to fourth ventricle through Cerebral Aqueduct Fourth ventricle –Near Pons / Medulla

16. 16 Multiple choice You are in bed and hear a loud crash – your heart pounds. What part of your CNS is dominant? A.Parasagittal B.Sympathetic C.Parasympathetic D.Local

17. 17 Ventricles

18. 18 Ventricles in clinical setting Hydrocephalus –E.G. cyst

19. 19 White matter fibers from the cortex Brain stem connects to cortex

20. 20 Medullary Centers Interhemispheric (between) Connections Intrahemispheric (within) Connections Three types of fibers –Projection: Project through internal capsule –Association: Within a hemisphere i.e. Arcuate fasciculus –Commissural: Between hemispheres i.e. Corpus callosum

21. 21 Meninges Three Basic Levels Extensions of Dura mater Falx Cerebri: Vertical partition dipping into cranial space (Refection) Tentorium Cerebri: Houses the cerebellum Falx Cerebelli: Separates two cerebellar hemispheres

22. 22 Multiple choice What view of the brain is this? A.Sagittal B.Axial C.Coronal D.Sympathetic

23. 23 Meninges Arachnoid Trabeculae –Connects Pia and Arachnoid –Inside subarachnoid space Arachnoid Villi –Specialized protrusions through which Cerebrospinal Fluid (CSF) leaves the brain

24. Peripheral Nervous System (PNS) 12 pairs of cranial nerves- –Sensory, motor, or mixed “On Old Olympus Towering Top A Famous Vocal German Viewed Some Hops.” 31 pairs of spinal nerves

25. Cranial Nerves (12 pair) I.Olfactory: sensory for smell II.Optic: sensory for vision III.Oculomotor: motor for vision IV.Trochlear: motor for vision V.Trigeminal: sensory to eyes, nose, face and meningies; motor to muscles of mastication and tongue

26. Cranial Nerves I.Abducen: motor to lateral eye muscles II.Facial: sensory to tongue and soft palate, motor to muscles of the face and stapes III.Vestibulocochlear: sensory for hearing and balance (aka Acoustic) IV.Glossopharyngeal: sensory to tongue, pharynx, and soft palate; motor to muscles of the the pharynx and stylopharyngeus

27. Cranial Nerves I.Vagus Nerve: sensory to ear, pharynx, larynx, and viscera; motor to pharynx, larynx, tongue, and smooth muscles of the viscera, 2 parts: superior laryngeal branch and recurrent laryngeal branch II.Spinal Accessory Nerve: motor to pharynx, larynx, soft palate and neck III.Hypoglossal Nerve: motor to strap muscles of the neck, intrinsic and extrinsic muscles of the tongue