Lecture Mosby's paramedic textbook (4th ed) - Chapter 25: Neurology

9/10/2012 1 Chapter 25 Neurology 2 Lesson 25.1 Anatomy, Physiology Pathophysiology, and Assessment 3 Copyright © 2013 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 1 9/10/2012 Learning Objectives • Describe anatomy and physiology of nervous system. • Outline pathophysiological changes in nervous system that may alter the cerebral perfusion pressure. • Describe assessment of patient with nervous system disorder. 4 Nervous System Anatomy and Physiology • Divided into two parts – Central nervous system (CNS) – Peripheral nervous system (PNS) • Ability of human body to maintain state of balance (homeostasis) is chiefly result of nervous system’s ability to coordinate and regulate body’s activities 5 6 Copyright © 2013 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 2 9/10/2012 Nervous System Anatomy and Physiology • CNS consists of brain and spinal cord – Both are encased in and protected by bone – Total of 43 pairs of nerves originate from CNS to form PNS – 12 pairs of cranial nerves originate from brain – 31 pairs of spinal nerves originate from spinal cord 7 Nervous System Cells • Cells of nervous system – Neurons • Basic units of nervous system • Connective tissue cells – Neuroglia • Specialized cells that protect and hold functioning neurons together – Each neuron has three main parts • Cell body, which has a single, relatively large nucleus with prominent nucleolus • One or more branching projections, called dendrites • Single, elongated projection, known as axon 8 9 Copyright © 2013 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 3 9/10/2012 Nervous System Cells • Dendrites transmit impulses to cell bodies • Axons – Transmit impulses away from cell bodies – Surrounded by supportive and protective sheaths formed by cytoplasmic extensions of neuroglial cells in CNS (unmyelinated axons) – Surrounded by Schwann cells in PNS (myelinated axons) 10 Nervous System Cells • White matter – Bundles of parallel axons with their associated sheaths are white • Action potential – Initiated in neuron body – Propagated through axons via conduction pathways or nerve tracts from one area of CNS to another • In PNS, bundles of axons and their sheaths are called nerves 11 Nervous System Cells • Gray matter – Collections of nerve cells – Grayer in color – Site of integration in nervous system – Outer surface of cerebrum and cerebellum consists of gray matter • Forms cerebral cortex and cerebellar cortex 12 Copyright © 2013 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 4 9/10/2012 Neuron Types • Neurons are classified as – Sensory neurons – Motor neurons – Interneurons • Based on direction in which they transmit impulses 13 Neuron Types • Sensory neurons – Transmit impulses to spinal cord and brain from all parts of body – Also called afferent neurons • Motor neurons – Transmit impulses in opposite direction, away from brain and spinal cord – Transmit impulses only to muscle and glandular epithelial tissue – Also called efferent neurons 14 Neuron Types • Interneurons – Conduct impulses from sensory neurons to motor neurons – Also called central or connecting neurons 15 Copyright © 2013 by Jones & Bartlett Learning, LLC, an Ascend Learning Company 5 ... - tailieumienphi.vn