The nervous system presentation dawn part 1
•Download as PPTX, PDF•
3 likes•1,600 views
Nervous system part 1
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Similar to The nervous system presentation dawn part 1
Similar to The nervous system presentation dawn part 1 (20)
More from DAWN V TOMY
More from DAWN V TOMY (20)
Recently uploaded
Recently uploaded (20)
The nervous system presentation dawn part 1
- 1. THE NERVOUS SYSTEM Part -1 DAWN V TOMY M.Pharm Asst.Professor Dept. Of Pharmacology St.JOSEPH’S COLLEGE OF PHARMACY, CHERTHALA.
- 2. 2 Divisions of the Nervous System • Central Nervous System (CNS) • Brain. • Spinal cord. • Peripheral Nervous System (PNS) consists of the cranial nerves and spinal nerves. The 3 divisions of PNS are: 1. Somatic Nervous System (SNS) 2. Autonomic Nervous System (ANS) and 3. Enteric Nervous System.
- 3. 3 Divisions of Peripheral Nervous System • Sensory Division • Picks up sensory information and delivers it to the CNS • Motor Division • Carries information to muscles and glands • Divisions of the Motor Neurons: • Somatic Neurons – carries information to skeletal muscle. • Autonomic Neurons – carries information to smooth muscle, cardiac muscle, and glands.
- 5. 5 Divisions Nervous System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Sensory division Sensory receptors Motor division Skeletal muscle Brain Cranial nerves Spinal cord Spinal nerves Central Nervous System (brain and spinal cord) (a) (b) Peripheral Nervous System (cranial and spinal nerves) Smooth muscle Cardiac muscle Glands Somatic Nervous System Autonomic Nervous System
- 7. Nuclei of neuroglia 7 Histology of Nerve cells • Cell types in neural tissue: • Neurons • Neuroglial cells (also known as neuroglia, glia, and glial cells) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dendrites Cell body Axon © Ed Reschke
- 8. 8 The Neurons • Neurons may vary in size and shape. • They may differ in length and size of their axons and dendrites. • Neurons share certain features: • Dendrites • A cell body • An axon
- 9. 9 Neuron Structure Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chromatophilic substance (Nissl bodies) Cell body Nucleus Dendrites Impulse Nodes of Ranvier Myelin (cut) Axon Axon Axonal hillock Axon collateral Schwann cell Synaptic knob of axon terminal
- 12. 12 Classification of Neurons and Neuroglia • Neurons vary in function • They can be sensory, motor, or integrative neurons • Neurons vary in size and shape, and in the number of axons and dendrites that they may have • Due to structural differences, neurons can be classified into three (3) major groups: • Bipolar neurons • Unipolar neurons • Multipolar neurons
- 13. 13 Classification of Neurons: Structural Differences • Bipolar neurons • Two processes • Eyes, ears, nose • Unipolar neurons • One process • Ganglia of PNS • Sensory • Multipolar neurons • 99% of neurons • Many processes • Most neurons of CNS Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Dendrites Axon Axon Axon Direction of impulse (a) Multipolar Peripheral process Central process (b) Bipolar (c) Unipolar
- 15. Sensory receptor 15 Classification of Neurons: Functional Differences • Sensory Neurons • Afferent • Carry impulse to CNS • Most are unipolar • Some are bipolar • Interneurons • Link neurons • Aka association neurons or internuncial neurons • Multipolar • Located in CNS • Motor Neurons Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Central nervous system Peripheral nervous system Cell body Interneurons • Multipolar • Carry impulses away from CNS • Carry impulses to effectors Dendrites Axon Axon Sensory (afferent) neuron Motor (efferent) neuron Cell body Axon (central process) Axon (peripheral process) Effector (muscle or gland) Axon terminal
- 16. 16 Types of Neuroglial Cells in the CNS 2) Astrocytes • CNS • Scar tissue • Mop up excess ions. • Induce synapse formation • Connect neurons to blood vessels •Part of Blood Brain Barrier 3) Oligodendrocytes • CNS • Myelinating cell 4) Ependyma or ependymal • CNS • Ciliated • Line central canal of spinal cord • Line ventricles of brain 1) Microglia • CNS • Phagocytic cell
- 18. 18 Types of Neuroglial Cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Microglial cell Axon Oligodendrocyte Astrocyte Fluid-filled cavity of the brain or spinal cord Capillary Neuron Myelin sheath (cut) Node of Ranvier Ependymal cell
- 19. 19 Types of Neuroglial Cells in the PNS 1) Schwann Cells • Produce myelin found on peripheral myelinated neurons • Speed up neurotransmission 2) Satellite Cells • Support clusters of neuron cell bodies (ganglia)
- 21. 21 Regeneration of A Nerve Axon Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Axon Site of injury Schwann cells Changes over time (a) (b) (c) (d) (e) Motor neuron cell body Distal portion of axon degenerates Proximal end of injured axon regenerates into tube of sheath cells Schwann cells degenerate Schwann cells proliferate Former connection reestablished Skeletal muscle fiber
- 22. 22 General Functions of the Nervous System • The three general functions of the nervous system: • Receiving stimuli = sensory function • Deciding about stimuli = integrative function • Reacting to stimuli = motor function
- 23. 23 Functions of Nervous System • Sensory Function • Sensory receptors gather information • Information is carried to the CNS • Integrative Function • Sensory information used to create: • Sensations • Memory • Thoughts • Decisions • Motor Function • Decisions are acted upon • Impulses are carried to effectors
- 24. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 24 Myelination of Axons •White Matter • Contains myelinated axons • Considered fiber tracts • Gray Matter • Contains unmyelinated structures • Cell bodies, dendrites Dendrite Myelinated region of axon Node of Ranvier Axon (a) Unmyelinated region of axon Neuron cell body Neuron nucleus (c) Enveloping Schwann cell Schwann cell nucleus Unmyelinated axon Longitudinal groove
Editor's Notes
- SLIDE.NO.:
- SLIDE.NO.: MAJOR STRUCTURES OF THE NERVOUS SYSTEM – Brain and cranial nerves, spinal cord and spinal nerves, ganglia, enteric plexuses and sensory receptors.
- SLIDE.NO.: HISTOLOGY OF NEURONS -
- SLIDE.NO.:
- Unipolar neurons have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body. Bipolar neurons have one main dendrite and one axon. They are found in the retina of the eye, in the inner ear, and in the olfactory (olfact to smell) area of the brain. Multipolar neurons usually have several dendrites and one axon. Most neurons in the brain and spinal cord are of this type.
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.:
- SLIDE.NO.: