More Related Content
Cns, pns
- 1. Slide 2.1 Human AnatomyHumanAnatomy NERVOUS SYSTEMNERVOUS SYSTEM pavemedicine.compavemedicine.com
- 2. Slide 7.43a CerebellumCerebellum • Twohemispheres with convoluted surfaces • Provides involuntary coordination of body movements
- 3.
- 4. Slide 7.44a Protection ofthe Central NervousProtection of the Central Nervous SystemSystem • Scalp and skin • Skull and vertebral column Figure 7.16a
- 5. Slide 7.44a Protection ofthe Central NervousProtection of the Central Nervous SystemSystem • Meninges: • Dura mater • Arachnoid • Pia Mater Figure 7.16a
- 6. Slide 7.44b Protection ofthe Central NervousProtection of the Central Nervous SystemSystem • Cerebrospinal fluid: subarachnoid space • Blood brain barrier Figure 7.16a
- 7. Slide 7.45a MeningesMeninges • Duramater • Double-layered external covering • Periosteum – attached to surface of the skull • Meningeal layer – outer covering of the brain • Folds inward to support hemispheres
- 8. Slide 7.45b MeningesMeninges • Arachnoidlayer • Middle layer • Web-like • Pia mater • Internal layer • Clings to the surface of the brain
- 9. Slide 7.46 Cerebrospinal FluidCerebrospinalFluid • Similar to blood plasma • Formed by the choroid plexus • Forms a watery cushion to protect the brain • Circulated in subarachnoid space, ventricles, and central canal of the spinal cord
- 10. Slide 7.47a Ventricles andLocation of theVentricles and Location of the Cerebrospinal FluidCerebrospinal Fluid Figure 7.17a
- 11. Slide 7.47b Ventricles andLocation of theVentricles and Location of the Cerebrospinal FluidCerebrospinal Fluid Figure 7.17b
- 12. Slide 7.48 Blood BrainBarrierBlood Brain Barrier • The least permeable capillaries of the body + astrocyte processes • Excludes many potentially harmful substances • Useless against some substances • Fat soluble substances • Anesthetics
- 13. Slide 7.48 Blood BrainBarrierBlood Brain Barrier • “Good news”: keeps out most harmful substances • Alcohol, viruses, some drugs • “Bad news”: keeps out most helpful substances • Antibiotics, chemotherapy drugs
- 14. Slide 7.49 Traumatic BrainInjuriesTraumatic Brain Injuries • Concussion • Slight brain injury • Usually no permanent damage • Contusion • Nervous tissue destruction occurs • Nervous tissue does not regenerate • Cerebral edema • May compress and kill brain tissue
- 15. Slide 7.50 Cerebrovascular Accident(CVA)Cerebrovascular Accident (CVA) • Commonly called a stroke • The result of a ruptured blood vessel • Brain tissue supplied with oxygen from that blood source dies • Loss of some functions or death may result
- 16. Slide 7.51 Alzheimer’s DiseaseAlzheimer’sDisease • Progressive degenerative brain disease • Mostly seen in the elderly, but may begin in middle age • Structural changes in the brain due to abnormal proteins • Symptoms: memory loss, irritability, confusion, ultimately hallucinations and death
- 17. Slide 7.52 Spinal CordSpinalCord • Extends from the medulla oblongata to L-1 • Below is the cauda equina • Enlargements in the cervical and lumbar regions Figure 7.18
- 18. Slide 7.53a Spinal CordAnatomySpinal Cord Anatomy • White mater – conduction tracts • Superficially located Figure 7.19
- 19. Slide 7.53b Spinal CordAnatomySpinal Cord Anatomy • Gray matter - mostly cell bodies, deep • Dorsal (posterior) gray horns • Ventral (anterior) gray horns Figure 7.19
- 20. Slide 7.53c Spinal CordAnatomySpinal Cord Anatomy • Central canal: holds cerebrospinal fluid Figure 7.19
- 21. Slide 7.54 Spinal CordAnatomySpinal Cord Anatomy • Meninges: same as brain • Spinal Nerves attached to each spinal segment • Dorsal root: sensory • Associated with the dorsal root ganglia • Ventral root: motor
- 22. Slide 7.55 Peripheral NervousSystemPeripheral Nervous System • All structures outside CNS • Nerve = bundle of neuron fibers (usually axons) • Neuron fibers: bundled by connective tissue (like muscles)
- 23. Slide 7.56 Structure ofa NerveStructure of a Nerve • Endoneurium surrounds each fiber • Groups of fibers are fascicles • Coverd by perineurium • Fascicles bound by epineurium Figure 7.20
- 24. Slide 7.54 Nerves (PNS)vs. Tracts (CNS)Nerves (PNS) vs. Tracts (CNS) • Tract: a bundle of neuron fibers inside the CNS • Usually axons • Wrapped by CT • Continuation of “nerve” from PNS • Long tracts in spinal cord • Short tracts in brain
- 25. Slide 7.57 Classification ofPeripheral NervesClassification of Peripheral Nerves • Mixed nerves – both sensory and motor fibers • Afferent (sensory) nerves – carry impulses toward the CNS • Efferent (motor) nerves – carry impulses away from the CNS
- 26. Slide 7.58 Cranial NervesCranialNerves • Arise from brain • 12 pairs of nerves • Numbered in order, anterior to posterior • Most are mixed nerves, but three are sensory only
- 27. Slide 7.60 Cranial NervesCranialNerves • I Olfactory nerve – sensory for smell • II Optic nerve – sensory for vision • III Oculomotor nerve – motor fibers to eye muscles • IV Trochlear – motor fiber to eye muscles
- 28. Slide 7.61 Cranial NervesCranialNerves • V Trigeminal nerve – sensory for the face; motor fibers to chewing muscles • VI Abducens nerve – motor fibers to eye muscles • VII Facial nerve – sensory for taste; motor fibers to the face • VIII Vestibulocochlear nerve – sensory for balance and hearing
- 29. Slide 7.62 Cranial NervesCranialNerves • IX Glossopharyngeal nerve – sensory for taste; motor fibers to the pharynx • X Vagus nerves – sensory and motor fibers for pharynx, larynx, and viscera • XI Accessory nerve – motor fibers to neck and upper back • XII Hypoglossal nerve – motor fibers to tongue