Nervous System Anatomy & Physiology PDF

Nervous System Part 1 Anatomy & Physiology of Nervous Tissue Tutor Debbie Hemington Module Biomedical Sciences  GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their applica;on to pa;ent management. 1.1.6 Des...

Nervous System Part 1 Anatomy & Physiology of Nervous Tissue Tutor Debbie Hemington Module Biomedical Sciences  GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their applica;on to pa;ent management. 1.1.6 Describe relevant and appropriate physiology and explain its applica;on to pa;ent management Intended Learning Outcomes including Part 2 Students will be able to: List the characteris;cs of nervous ;ssue List and describe the cells of nervous ;ssue Explain the mechanism by which impulses are generated and their relevance in den;stry The Nervous System The nervous system detects and responds to changes inside and outside the body. Together with the endocrine system it controls important aspects of body func;on and maintains homeostasis. - State of Balance for body to & Survive1 function. Nervous system s;mula;on provides an immediate response while endocrine ac;vity is, in the main, slower and more prolonged. There are 2 divisions of the nervous system 1. Central nervous system (CNS) –brain & spinal cord into two 2. Peripheral nervous system (PNS) –all other nerves - Split · Peripheral Nervous System a Sensory division - vaunzatewenaer Motor division – voluntary- soma;c nervous system - involuntary-autonomic nervous system / \ Leg increasing sympathe;c parasympathe;c rate. heart / \ Pght or Qight rest and digest Signals. to Brain Carry Signals away ↓ - from CNS Nervous Tissue Cells of the nervous system Neurones Schwann Cells Neuroglial/Glial Cells  Neurones - Nerve cells. · contains many. · single - all body / with branching Processes. Processes · are receptive from information away in function. - carry cell body. known as dendrites , · Lots of Axen's are called newes. Neurons- different forms can appere in Location function. depending on & Key Features 1. Cell body 2. Axon 3. Schwann Cells 4. Nodes of Ranvier 5. Dendrites 6. Synap;c end bulb  seen naked · Too small to be by eye - of nervous system. · form grey matter of neuron Cell Body - care section Contains well Found Previtral · · of Brain and developed nucleus, manyorganes Chter of Spinal cord. Includingradria. · Don't contain any mitotic apparatus , so. Cont be replaced But can regenerate to a certain. extent  divide into collaterals Can · Sending information to different Axons Part of body Simultantsidy. Communica;on route between cell body & axon terminals Conducts electrical impulses away from the neurone's cell body Longer than dendrites – can be longer than 1m!! Large axons & those of the peripheral nervous system are I surrounded by a MYELIN sheath (series of Schwann cells) acts as insulator.  Sometimes · gaps in myelin Sheath which is called node of Schwann Cells ranvier & Allows rapid of transmision neve Impulses · Wrapped around axon so there are layers of Schwann cell - forming myelin sheath. Mainly provide myelin insula;on to axons in the peripheral nervous system MYELIN SHEATH: High phospholipid (fa\y) content o]ers electrical insula;on Nodes of Ranvier Exposed areas between the Schwann Cells Assist rapid transmission of ac;on poten;als in myelinated neurones. Dendrites Extensions of the cell body Provide a large surface area to receive informa;on to pass to the cell body Same structure as axons but shorter Plasma has dense chemical ion channels for impulse transmission Form synapses with other dendrites or terminate in specialised sensory receptors e.g. skin aware making you of touch ,. heat  its ProperJes of Neurones - to allow carryout functions. Irritability – ability to ini;ate nerve impulses in response to s;muli from either inside# the body or outside.. Change of CO2 in bloodIncrease eg * rate. eg · touch voluntary respiratory. movement ConducJvity- ability to transmit an impulse. Neuroglial cells- support network Three types of non-excitable glial (glue-like) cells support the neurones of the central nervous system. Unlike nerve cells, these con;nue to replicate throughout life. These are; Microglia Astrocytes - Blood Brain Barrier Oligodendrocytes  MICROGLIA- are found mainly in the area of blood vessels. They enlarge and become phagocy;c in areas of inQamma;on and cell destruc;on. ASTROCYTES- form the main suppor;ng ;ssues of the central nervous system. Star shaped with Pne branching processes, they lie in a muccopolysaccharide ground substance. Found in large numbers adjacent to blood vessels. OLIGODENDROCYTES smaller then astrocytes and are found in clusters around the neurone cell wall, and adjacent to, and along the length of many myelinated nerve Pbres in the CNS. They form and maintain myelin and have the same func;on as Schwann cells in the peripheral nerves.  important very form a sleeve & Astrocytes vessels blood is Blood-brain barrier around blood , Wall and Layer separated by Capillary of astrocytes. Is a selec;ve barrier that protects the brain from poten;ally toxic substances and chemical varia;ons in the blood eg: acer a meal. Oxygen, carbon dioxide, glucose and other lipid soluble substances such as alcohol quickly cross the barrier into the brain. Some large molecules, many drugs, inorganic ions and amino acids pass more slowly or do not pass at all from the blood to the brain  end of Dendrites. SynapJc End Bulbs - found at Important for nerve impulse conduc;on from one neurone to another or neurone to an e]ector Contain enclosed sacs called synapJc vesicles These store neurotransmiPers  and another Synapse - space between one neuron with each allow communication Pre-synap;c neurone to Pre-synap;c knob other by passing Signals. Neurotransmi\ers – acetylcholine/noradrenaline Calcium Mitochondria Neurotransmi\er receptors Post-synap;c knob Post-synap;c neurone Neuro-transmission Break Jme!