THE NEURAL TISSUE MARTINI, ANATOMY & PHYSIOLOGY, 9TH EDITION, CHAPTER # 12 LAB MANUAL, Exercise # 18 Page # 225 1 NOTE: • THIS IS A STUDY GUIDE, NOT AN ALL INCLUSIVE REVIEW. • THERE MIGHT BE THINGS NOT COVERED BY THIS STUDY GUIDE THAT MIGHT BE ASKED IN YOUR PRACTICUMS / QUIZZES. • STUDENTS ARE RESPONSIBLE FOR READING THEIR TEXBOOK (S) AND FOR ALL THE MATERIAL COVERED DURING THE LABORATORY PERIOD, AS PER THE COURSE SYLLABUS 7/25/2016 2 Competency 6: The Nervous System • Upon successful completion of this laboratory, the students will be able to demonstrate an understanding of the structural and functional features of the nervous system including the special sense organs by: – Identifying the parts of a neuron. – Explaining the structural and functional classification of the neurons. 7/25/2016 3 Competency 6: The Nervous System – Describing the structure and functions of the supporting cells of the nervous system. • – Distinguishing between neuron, nerve and track. • – Explaining the structure and functions of the central nervous system and the cranial nerves. 7/25/2016 4 NEURAL TISSUE NEURON STRUCTURE CLASSIFICATION OF NEURONS BY STRUCTURE CLASSIFICATION OF NEURONS BY FUNCTION SCHWANN CELLS GREY MATTER WHITE MATTER 7/25/2016 5 7/25/2016 ALFONSO A. PINO. MD. 6 7/25/2016 ALFONSO A. PINO. MD. 7 NEURON STRUCTURE • CELL BODY (SOMA) • NEUROFIBRILS (Black or brown lines in model) • F- intracellular transport • NISSIL BODIES- Blue in one model & blue with red dots in another model • F- protein synthesis • DENDRITES- They are short citoplasmatic • projections from cell bodies • F- to receive the nerve impulse or signal • AXON- It is a citoplasmatic projection from the • cell body • F-to carry away the nerve impulse or signal 7/25/2016 8 • AXON HILLOCK- The place where the • • • the neurofibrils converge F- trigger zone for nerve impulse AXON TERMINALS- End part of the neuron • • that connects with another neuron F- to release the neurotransmiter 7/25/2016 9 Dendrites Perikaryon Dendrite Dendritic spines Cell body Nucleus Nissl bodies (RER and free ribosomes) Axon Mitochondrion Telodendria (a) Regions of a neuron Axon hillock Initial segment of axon Axolemma Axon Telodendria Golgi apparatus Neurofilament Synaptic terminals See Figure 12-2 Nucleolus Nucleus PRESYNAPTIC CELL (b) Structural components of a neuron POSTSYNAPTIC CE 7/25/2016 ALFONSO A. PINO. MD. 11 7/25/2016 ALFONSO A. PINO. MD. 12 NEURONS BY STRUCTURE • • • • ANAXONIC BIPOLAR UNIPOLAR MULTIPOLAR 7/25/2016 13 Figure 12-3: A Structural Classification of Neurons Anaxonic neuron Bipolar neuron Unipolar neuron Dendrites Multipolar neuron Dendrites Initial segment Dendrites Axon Axon Synaptic terminals Axon Axon Synaptic terminals Synaptic terminals • SCHWANN CELLS- They surround the axon • • • • • • • • • • f- to produce the myelin sheath MYELIN SHEATH- Layers of cell membrane that surround the axon (yellow in the models f- to isolate the axon Neurilemma- outermost layer with nucleus of the Schwann cell NODES OF Ranvier- area between two Schwann cells f- to produce saltatory conduction (jumping conduction), to increase the speed of nerve impulse transmission 7/25/2016 15 7/25/2016 ALFONSO A. PINO. MD. 16 7/25/2016 ALFONSO A. PINO. MD. 17 NEURONS BY FUNCTIONS • SENSORY ( • Afferent)- it carries iformation towards the cns (central nervous system) • MOTOR ( EFFERENT)- It carries information • away from cns • ASSOCIATION NEURONES OR INTERNEURONS• They carry impulses between • sensory & motor neurons located at cns 7/25/2016 18 Anatomy of a Spinal Nerve 7/25/2016 ALFONSO A. PINO. MD. 19 • GREY MATTER- Non myelinated parts of the • • Neurons & glia (cell bodies) It forms nuclei in the cns • WHITE MATTER- Myelinated fibers • • • It forms tracs in the cns It forms nerves in pns (peripheral nerve system) 7/25/2016 20 7/25/2016 ALFONSO A. PINO. MD. 21 7/25/2016 ALFONSO A. PINO. MD. 22 GRAY MATTER & WHITE MATTER (CNS) 7/25/2016 ALFONSO A. PINO. MD. 23 WHITE MATTER (CNS) 7/25/2016 ALFONSO A. PINO. MD. 24 WHITE MATTER REMEMBER! GO TO THE TUTORING ROOM AND PRACTICE WITH MODELS. ROOM 3326. 7/25/2016 26