Chapter 12: Nervous Tissue

Size: px
Start display at page:

Download "Chapter 12: Nervous Tissue"

Transcription

1 Chapter 12: Nervous Tissue --controls and integrates all body actvities within limits that maintain life --3 Basic Functions a. Sensing changes with sensory receptors (fullness of stomach or sun on face) b. interpreting and remembering those changes c. reacting to those changes with effetors (muscular contractions, glandular excretions) --Organization of the Nervous Sysme *CNS is brain and spinal cord *PNS is everything else a. consists of cranial and spinal nerves that contain both sensory and motor fibers b. connects CNS to muscles, glands, and all sensory receptors c. 3 subdivisions i. Somatic/voluntary nervous system (SNS) ~sensory neurons from cutaneous, skeletal muscle, and tendons, and special sensory receptors to the CNS ~motor neurons to skeletal muscle tissue ii. Autonomic/involuntary nervous system (ANS) ~sensory neurons from visceral organs to CNS ~motor neurons to smooth and cardiac muscle and glands --symapthetic division (speeds up heart rate) --parasympathetic division (slow down heart rate) iii. Enteric nervous system (ENS) ~involuntary sensory and motor neurons control GI tract ~neurons fuction independently of ANS and CNS --Neurons *functional unit of nervous system *have capacity to produce action potentials electrical excitability (muscles too) *Cell body a. single nucleus with prominent nucleolus b. rough ER (Nissl bodies) c. free ribosomes for protein synthesis d. neurofilaments give cell shape and support e. microtubules move material inside cell f. lipofuscin pigment clumps (harmless aging) *Dendrites a. conduct impulses towards the cell body b. Typically: numberous, short, highly branched, unmyelinated c. surfaces specialized for contact with other neurons (synapse) d. contain neurofibrils *Axons a. conduct impulses away form cell body b. single, long, thin cylindrical process of cell, may be myelinated c. arises at axon hillock d. impulses arise from initial segment (trigger zone) e. side branches (collaterals) f. end in fine processes called axon terminals g. swollen tips called synaptic end bulbs contain vesicles filled with NTs

2 --Axonal Transport *cell body is location for most protein synthesis NTs and repair proteins *Axonal transport system moves substances a. slow axonal flow: movement in one direction only away from cell body = anterograde, movement at 1-5mm per day b. fast axonal flow: moves organelles and materials along surface of microtubules at mm/day --transports in either direction (anterograde and retrograde) --for use or for recycling in cell body *Fast axonal transport route by which toxins or pathogens reach neuron cell bodies a. tetanus (Clostridium tetani bacteria) b. disrupts motor neurons causing painful muscle spasms *Bacteria enter the body through a laceration or puncture injury a. more serious if wound is in head or neck because of shorter transit time --Summary of Neuronal Structure and Function Structure Dendrites Cell Body Junction of axon hillock and initial segment of axon Axon Axon terminals and synaptic end bulbs (or varicosities) Functions -Receive stimuli through activation of ligand-gated or mechanically gated channels -In sensory neurons, produce generator or receptor potentials -In motor neurons and interneurons, produce excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) -Receives stimuli and produces EPSPs and IPSPs throught activation of ligand-gated and mechanically gated ion channels -Trigger zone in many neurons; integrates EPSPs and IPSPs and if sum is a depolarization that reaches threshold, initiates AP Propagates nerve impulses from initial segment or from dendrites of sensory neurons to axon terminals in a self-reinforcing manner; impulse amplitude does not change as it propagates along the aon -have voltage gated Na + and K + channels -Inflow of Ca++ caused by depolarizing phase of nerve impulse triggers exocytosis of NT from synaptic vesicles -Voltage gated Ca++ channels --Functional Classification a. Sensory/afferent neurons: transport sensory information from skin, muscles, joints, sense organs and viscera to CNS (arriving) b. Motor/efferent neurons: send motor nerve impulses to muscles and glands (exiting) c. Interneurons/association neurons: connect sensory to motor neurons, 90% of neurons in the body (exclusively in CNS) most are multipolar --Structural Classification a. Multipolar: several dendrites and one axon *most common cell type b. Bipolar: one main dendrite and one axon *found in retina, inner ear, and olfactory c. Unipolar: one process only (develops from a bipolar) *are always sensory neurons

3 --Neuroglial Cells *half of the volume of the CNS *smaller cells than neurons *50x more numerous *cells can divide: rapid mitosis in tumor formation (gliomas) *4 cell types in CNS a. astrocytes ~star-shaped cells ~their processes extend into the basement membrane of capillaries and pia mater ~Functions: i. form blood brain barrier by covering blood capillaries ii. metabolize NTs iii. regulate K + balance iv. provide nutrients and structural support b. oligodendrocytes ~most common glial cell type ~analogous to Schwann cells of PNS provide electrical insulation ~each oligodendrocyte wraps around more than one axons in PNS c. microglia ~small cells found near blood vessels ~phagocytic role: clear away dead cells (brain macrophages) ~derived from cells that also gave rise to macrophages and monocytes d. ependymal ~form epithelial membrane lining cerebral cavities (ventricles) and central canal ~produce CSF (cerebrospinal fluid) *2 cell types in PNS a. Schwann cells ~cells encircling PNS axons ~each cell produces part of the myelin sheath surrounding an axon (only 1) in the PNS b. satellite cells ~flat cells surrounding neuronal cell bodies in peripheral ganglia ~support neurons in the PNS ganglia --Axon Coverings in the PNS *axons surrounded by a lipid and protein covering (myelin sheath) produced by Schwann cells *Neurolemma is cytoplasm and nucleus of Schwann cell: gaps called nodes of Ranvier *Myelinated fibers appear white a. jelly roll like wrappings made of lipoprotein = myelin b. acts as electrical insulator c. speeds conduction of nerve impulses *Unmyelinated fibers a. slow, small diameter fibers b. only surrounded by neurilemma but no myelin sheath wrapping *Myelination in PNS a. Schwann cells myelinate axons in the PNS during fetal development

4 b. Schwann cell cytoplasm and nucleus forms outermost layer of neurolemma with inner portion being the myelin sheath c. Tube guides growing axons that are repairing themselves --Myelination in the CNS *oligodendrocytes myelinate axons in the CNS *broad, flat cell processes wrap around CNS axons, but the cell bodies d/n surround the axons *no myelin sheath is formed, no neurolemma *little regrowth after injury is possible due to the lack of a distinct tube or neurolemma --Gray and White Matter *white matter: myelinated processes (white in color) *gray matter: nerve cell bodies, dendrite, axon terminals, bundle o unmyelinated axons and neuroglia (gray color) a. in the spinal cord: gray matter forms an H shaped inner core surrounded by white matter (centrally located) b. In the brain: a thin outer shell of gray matter covers the surface and is found in clusters called nuclei inside the CNS (outer location) --Electrical Signals in Neurons *neurons are electrically excitable due to the voltage difference across their membrane *communicate with 2 types of electric signals a. action potentials that can travel long distances (always depolarizing) b. graded potentials that are local membrane changes only (proportionate to strength of stimulus, can be depolarizing and hyperpolarizing, found in dendrites and cell bodies) *in living cells, a flow of ions occurs through ion channels in the cell membrane --2 Types of Ion Channels a. Leakage (nongated) channels: always open *nerve cells have more K+ than Na+ leakage channels *as a result, membrane permeability to K+ is higher *explains resting membrane potential of -70mV in nerve tissue b. Gated channels: open and close in response to a stimulus and play role in neuron excitability *Voltage-gated: open in response to change in voltage *Ligand-gated: open and close in response to particular chemical stimuli (hormone, NT, ion) *Mechanically-gated: open with mechanical stimulation --Resting Membrane Potential *Negative ions along inside of cell membrane and positive ions along outside a. potential energy difference at rest is -70mV b. cell is polarized *Resting potential exists because a. concentration of ions is different inside and outside ~extracellular fluid rich in Na+ and Cl- ~cytosol full of K+, organic phosphate and amino acids b. membrane permeability differs for Na+ and K+ ~ greater permeability for K+ than for Na+ ~inward flow of Na+ can t keep up with outward flow of K+ ~Na+/K+ pump removes Na+ as fast as it leaks

5 --Graded Potentials *Small deviations from resting potential of -70mV a. hyperpolarization: membrane has become more negative b. depolarization: membrane has become more positive c. occur most often in dendrites and cel body of a neuron *source of stimuli a. Mechanical stimulation of membranes with mechanical gated ion channels (pressure) b. Chemical stimulation of membranes wit ligand gated ion channels (NT) c. Voltage change: graded/postsynaptic/receptor or generator potential *Characterisitics of graded potentials: a. ions flow through ion channels and change membrane potential locally b. amount of change varies with strength of stimuli (not so for APs), aplitude expains strength c. Potential amplitude decreases over distance, dies out (no so for APs) --Action Potentials a. series of rapidly occurring events that change and then restore the membrane potential of a cell to its resting state b. Ion channels open, Na+ rushes in (depolarization), K+ rushes out (repolarization) c. All or none principal: with stimulation, either happens one specific way or not at all (lasts 1/1000 of a second) d. travels (spreads) over surface of cell without dying out --Phases of Action Potential a. Depolarizing Phase *Chemical or mechanical stimulus caused a graded potential to reach at least -55mV or threshold *Voltage-gated Na+ channels open and Na+ rushes into cell: ~in resting membrane, inactivation gate of sodium channel is open and activation gate is closed (Na+ c/n get in) ~when threshold (-55mV) is reached, both are open and Na+ enters ~inactivation gate closes in few ten-thousandths of a second ~only a total of 20,000 Na+ actually enter the cell, but they change the membrane potential considerably (up to +30mV) *positive/viscous feedback process b. Repolarizing Phase *when threshold potential of -55mV is reached, voltage-gated K+ channels open *K+ channel opening is much slower than Na+ channel opening *When K+ channels finally do open, the Na+ channels have already closed (Na+ inflow stops) *K+ outflow returns membrane potential to -70mB (repolarization) *If enough K+ leaves the cell, it will reach a -90mV membrane potential and enter the after-hyperpolarizing phase *K+ channels close and the mem potential returns to the resting potential of -70mV c. Refractory Period *Period of tiem during which neuron can not generate another AP *Absolute refractory period ~even very strong stimulus will not initiate another AP ~inactivated Na+ channels must return to the resting state before they can

6 be reopened ~large fibers have absolute refractory period of 0.4 msec and up to 1000 impulses per second are possible *Relative refractory period ~a suprathreshold stimulus will be able to start an AP ~K+ channels are still open, but Na+ channels have closed --Local Anesthetics *Prevent opening of voltage-gated Na+ *Nerve impulses c/n pass the anesthetize region *Ex: novocaine and lidocaine --Propagation of Action Potential *An action potential spreads/propagates over the surface of the axon membrane a. as Na+ flows into the cell during depolarization, the voltage of adjacent areas is affected and their voltage-gated Na+ channels open b. self-propagating along the membrane (unlike graded potential) c. AP travels at constant speed and its magnitude is constant (same size regardless of stimulus strength, unlike graded potential) *The traveling action potential is called a nerve impulse --Continuous versus Saltatory Conduction a. Continuous conduction: unmyelinated fibers *step-by-step depolarization of each portion of the length of the axolemma b. Saltatory conduction: jumping, myelinated fibers *depolarization only at nodes of Ranvier where there is a high density of voltage- gated ion channels *current carried by ions flows through extracellular fluid from node to node *faster speed of propagation --Comparison of Graded and Action Potentials Trait Graded Potentials Action Potentials Origin Arise on dendrites and cell bodies Arise only at trigger zone on axon hillock Types of Channels Produced by ligand or mechanicallygated Produced by voltage-gated ion channels channels Conduction Localized (not propagated, die out Conduct over the entire length of axon with distance) Amplitude Vary depending upon stimulus Constant, nondecremental Polarity of potentials Depolarizing or hyperpolarizing Only depolarizing Duration As long as the stimulus lasts, thus Have refractory period, no summation summation is possible Refractory period None Refractory period due to the nature of the noltage-gated channels --Encoding of Stimulus Intensity *How do we differentiate a light touch from a firmer touch? a. frequency of impulses: firm pressure generates impulses at a higher frequency b. number of sensory neurons activated: firm pressure stimulates more neurons than does a light touch --Speed of Impulse Propagation

7 to *The propagation speed of a nerve impulse (AP) is not related to stimulus strength ~larger, myelinated fibers conduct impulses faster due to sie and salutatory conduction (recall form physics that resistance is inversely proportional diameter) *Fiber types a. A fibers: largest and fastest (5-20 um and 130 m/sec), myelinated, somatic sensory and motor to skeletal muscle b. B fibers: medium (2-3 um and 15 m/sec), myelinated, visceral sensory and autonomic preganglionic c. C fibers smallest ( um and 2 m/sec), unmyelinated, sensory and autonomic postganglionic motor Fiber Type Speed (m/sec) Function A α (I) Motor neurons, afferents form muscle spindles and tendon organs A β (II) 60 Tactile from skin A γ 40 Efferent to muscle spindles and from mechanoreceptors A δ (III) 20 Temperature, pain (in skin, fast) B 10 Preganglionic autonomic C (IV) 1 Postganglionic autonomic, visceral afferents (temp, pain, slow) --Action Potentials in Nerve and Muscle *Entire muscle cell membrane versus only the axon of the neuron is involved *Resting membrane potential a. nerve is -70mV b. skeletal and cardiac muscle is closer to -90mV (SA node is -60mV) c. smooth muscle varies but often around -60mV *Duration a. nerve impulse is ½ to 2 msec b. muscle action potential lasts 1-5 msec for skeletal and msec for cardiac and smooth *Fastest nerve conduction velocity is 18x faster than velocity over skeletal muscle fiber --Signal Transmission at Synapses *2 types of synapses a. Electrical: ~ionic current spreads to next cell through gap junctions ~faster ~two way transmission and capable of synchronizing groups of neurons b. Chemical: ~one-way information transfer from a presynaptic neuron to a postsynaptic neuron ~slower ~neurotransmitter released: axodendritic, axosomatic, axoaxonic --Chemical Synapses *Action potential reaches end bulb and voltage-gated Ca++ channels open *Ca++ flows inward triggering release of NT *NT crosses synaptic cleft and binds to ligand-gated receptors (the more NT released the

8 greater the change in potential of the postsynaptic cell) *Synaptic delay is 0.5 msec *one way information transfer --Excitatory and Inhibitory Postsynaptic Potentials (EPSP, IPSP) *the effect of a NT can be either excitatory or inhibitory a. a depolarizing postsynaptic potential is called an EPSP ~it results from the opening of ligand-gated Na+ channels ~the postsynaptic cell is more likely to reach threshold b. an inhibitory postsynaptic potential is called an IPSP ~it results from the opening of ligand-gated Cl- or K+ channels ~it causes the postsynaptic cell to become more negative or hyperpolarized ~the postsynaptic cell is less likely to reach threshold --Removal of Neurotransmitter a. Diffusion: move down concentration gradient b. Enzymatic degradation: acetylcholinesterase c. Uptake by neurons or glia cells: NT transporters (prozac serotonin reuptake inhibitors) --Integration of information at single neuron level a. multiple inputs on a single neuron, both excitatory or inhibitory b. amount of neurotransmitter released and length of its presence c. timing of arriving stimuli d. summation of incoming information e. integration f. decision for outcome (to fire or not) --Spatial summation *summation of effects of neurotransmitters simultaneously released from several end bulbs onto one neuron (graded potential) --Temporal Summation *summation of effect of neurotransmitters released from 2 or more firings of the same end bulb in rapid succession onto a second neuron (looking at 1 synapse) *a single neuron receives numerous, excitatory and inhibitory, inputs. It integrates the information (sums it up) and decides whether to respond or not --Three Possible responses a. EPSP occurs: potential reaches -56mV only (below threshold)-no AP generated b. An impulse is generated: threshold was reached, membrane potential of at least -55mV c. IPSP occurs: membrane hyperpolarized, potential drops below -70mV --Strychnine Poisoning *In spinal cord, Renshaw cells normally release an inhibitory NT (glycine) onto motor neurons preventing excessive muscle contraction *Strychnine binds to and blocks glycine receptors in the spinal cord *Massive titanic contractions of all skeletal muscles are produced: when the diaphragm contracts and remains contracted, breathing c/n occur --Neurotransmitter Effects *NT effects can be modified: a. synthesis can be stimulated or inhibited b. release can be blocked or enhanced c. removal can be stimulated or blocked d. receptor site can be blocked or activated

9 *Agonist: anything that enhances a transmitters effects *Antagonish: anything that blocks the action of a NT Neurotransmitters --Neurotransmitters 2classes: 1. Small Molecules a. ACh b. Amino acids: GABA, gly, glu, asp c. Amines: (nor)epinephrine, dopamine, serotonin, histamine d. NO 2. Neuropeptides a. hypothalamic-releasing hormones b. pituitary peptides c. dual location/action peptides d. from other tissues --Characteristics of small molecule transmitters a. fast acting b. involved in transmission of acute signals/responses c. synthesized in cytosol of neuron terminal d. released within a ms or less e. vesicles are recycled containing all the machinery for synthesis/uptake/concentration of new NT f. interact with post-synaptic neuron within a msec g. most often activated an ion channel in the post-synaptic memebrane, occasionally activate a receptor h. most often cause excitation/inhibition, rarely may affect cellular metabolic pathways --Characteristics of neuropeptides a. larger molecules b. sites of synthesis and release different anatomical sites c. synthesized in cell body, processed (precursors split to smaller peptides and packaged into vesicles in Golgi) d. transported to terminal by axonal streaming = slow flow of cytoplasm (few cm/day) e. vesicles are autolyzed (not reused) f. lower amounts relased (potent chem. messenger) g. much more potent than small molecule h. activate a receptor on target cell (rarely open ion channels) i. cause prolonged action: change cell metabolism, gene expression; effects last from days to years --Small Molecule NTs a. Acetylcholine (ACh): released by many PNS and some CNS *PNS: 1. all motor neurons activating skeletal muscle 2. all preganglionic neurons of the ANS 3. postganglionic fibers of the parasympathetic ANS (and some postganglionic sympathetic neurons) *CNS:

10 1. at synapses involved in the acquisition of short-term memory. Drugs that enhance ACh levels are used in elderly patients with failing memory) 2. excitatory on NMJ but inhibitory at others 3. inactivated by acetylcholinesterase b. Amino Acids *Glutamate 1. released by nearly all EXCITATORY neurons in the BRAIN 2. inactivated by glutamate specific transporters 3. essential for loner term potentiation (long term memory pathways) 4. leads to depolarization by binding to: --ligand gated Na+ channels (FAST) --receptors that activate second messengers which open Na+ channels (SLOW) *GABA 1. Is INHIBITORY for 1/3 of all BRAIN synapses (Valium is a GABA agonist enhancing its inhibitory effect) 2. GABA hyperpolarizes the postsynaptic membrane by binding to: --GABAA receptors on the postsynaptic neuron opens up ligand- gated Cl- channels (FAST, about 1 ms) --GABAB receptors activates G protein and a second messenger that leads to the opening of K+ channels (SLOW, as long as 1 sec) *Glycine 1. is INHIBITORY 2. mainly in the SPINAL CORD (CNS) c. Biogenic Amines (modified amino acids) *Norepinephrine 1. regulates mood, dreaming, awakening from deep sleep 2. mostly EXCITATORY in BRAIN STEM and hypothalamus 3. found in postganglionic sympathetic neurons *Dopamine 1. in CNS 2. usually INHIBITORY 3. regulates skeletal muscle tone **Norepinephrine, epinephrine, and dopamine are derived from tyrosine and are collectively known as catecholamines *Serotonin 1. mostly INHIBITORY 2. precursor is tryptophan 3. control of mood, temperature regulation, and induction fo sleep 4. removed from synapse and recycled or destroyed by enzymes (monoamine oxidase MAO or catechol-o-methyltransferase COMT) d. ATP and other purines (ADP, AMP, and adenosine) 1. EXCITATORY in BOTH PNS AND CNS 2. released with other NTs (ACh and NE) e. Gases: Nitric Oxide (NO) 1. formed from the amino acid arginine 2. formed on demand and acts immediately: produced on demand, not sotored in

11 presynaptic vesicles, diffuses out of cell that produced it, diffuses into neighboring cells, changes metabolism (not mem. potential) 3. first recognized as vasodilator that helps lower blood pressure --Neuropeptides *3-40 amino acids linked by peptide bonds a. Substance P: enhances our perception of pain (originally found in GI) b. Pain Relief 1. enkephalins: pain-relieving effect by blocking the release of substance P 2. acupuncture, meditation may produce loss of pain sensation b/c of release of opioids-like substances such as endorphins or dynorphins c. Comparison of Neuropeptides Substance Substance P Enkephalins Endorphins Dynorphins Description Found in sensory neurons, spinal cord pathways, and parts of brain associated with pain; ENHANCES PERCEPTION OF PAIN INHIBIT PAIN IMPULSES BY SUPPRESSING RELEASE OF SUBSTANCE P, may have a role in memory and learning, control of body temp, sexual activity, and mental illness INHIBIT PAIN BY BLOCKING RELASE OF SUBSTANCE P, may have a role in memory and learning, sexual activity, control of body temp, and mental illness May be related to controlling pain and registering emotions Hypothalamic releasing and Produced by the hypothalamus; regulate the release of hormones by the inhibiting hormones anterior pituitary Angiotensin II STIMULATES THIRST; MAY REGUALTE BLOOD PRESSURE IN THE BRAIN as a hormone causes vasoconstriction and promotes release of aldosterone, which increases the rate of salt and water reabsorption by the kidneys CCK FOUND IN THE BRAIN AND SMALL INTESTINE, may regulate feeding as a stop eating signal, as a hormone regulates pancreatic enzyme secretion during digestion and contraction of smooth muscle in the GI tract --Neuron Circuits *neurons in the CNS are organized into neuronal networks *a neuronal network may contain thousands or even millions of neurons *neuronal circuits are involved in may important activities (breathing, short term memory, waking up) *Types: a. Diverging: single cell stimulates many others (motor units) ~Divergence into a single tract: amplication of signal output (corticospinal tract a single pyramidal cell can excite up to 10,000 muscle fibers) ~Divergence into multiple tracts: send info to several areas (dorsal columns diverge into cerebellum and to the thalamus) b. Converging: one cell stimulated by many others (detect weak stimuli) ~spacial summation from a single source or from multiple sources (where the inputs can be both excitatory and inhibitory interneurons in the spinal cord receive info form afferents, proprio, motor cortex)

12 ~can be temporal summation too c. Reverberating: impulses from later cells repeatedly stimulate early cells in the circuit (short term memory) d. Parallel-after-discharge: single cell stimulates a group of cells that all stimulate a common postsynaptic cell (math problems) --Organization of Neuronal Pools (More than 1 neuron and their connections) * input and output * stimulatory field : neuronal area stimulated by each incoming nerve fiber *excitation: a postsynaptic neuron fires only if enough excitatory stimuli are present (temporally or spatially summated) = reach threshold *facilitation: signals that d/n add up to threshold but still depolarize the postsynaptic membrane are subthreshold a. dischard/excited/liminal zone: excite b. facilitated/subthreshold/subliminal zone: inhibitory c. threshold-excitation and subthreshold-facilitation *a single discharge from a presynaptic neuron almost never cause an AP in a postsynaptic neuron --Continuous Signal Output a. intrinsic neuronal excitability b. continuous signal emitted from a reverberating circuit c. rhythmical signal output (respiration, scratching reflex of a dog/cat hind leg; almost all are reverberating circuits; can change frequency and amplitude of signal output) --circuit s output lasts longer than the stimulus prolongation of a signal: 1. Synaptic after-discharge: as long as graded depolarization is at threshold (as with some long lasting NTs), the neuron will discharge APs 2. Reverberatory/oscillatory circuits a. one neuron only b. several neurons longer delay c. both, facilitatory and inhibitory feedback d. reverberatory circuit with many parallel fibers can have gradations b/w weak and strong reverberating signal depending on how many of the parallel fibers are involved e. reverberation stops suddenly when a component drops below a critical level --Most neurons have basal rate of discharge and thus, can signal both excitatory and inhibitory information a. excitatory input greatly increases signal output b. inhibitory input decreases output, thus decrease in output intensity is in itself a signal output --Inhibitory circuits as a mechanism for stabilizing nervous system function a. Types 1. Inhibitory feedback: from circuit termini to initial excitatory neurons 2. Synaptic fatigue *Short term: depletion of limited NT *Long term: up/down regulation of synaptic receptor --Epilepsy: second most common neurological disorder (affects 1% of population) *characterized by short, recurrent attacks initiated by electrical discharges in the brain a. lights, noise, or smells may be sensed triggers

13 b. skeletal muscles may contract involuntarily c. loss of consciousness *epilepsy has many causes including brain damage at birth, metabolic disturbances, infections, toxins, vascular disturbances, head injuries, and tumors --Regeneration and Repair *Plasticity maintained throughout life (sprouting of new dendrites, synthesis of new proteins, changes in synaptic contacts with other neurons) *Limited ability for regeneration (repair) a. PNS can repair damaged dendrites or axons b. CNS no repairs are possible --Neurogenesis in the CNS *formation of new neurons from stem cells was not thought to occur in humans a. 1992: a growth factor was found that stimulates adult mice brain cells to multiply b. 1998: new neurons found to form within adult human hippocampus *factors preventing neurogenesis in CNS a. inhibition by neuroglial cells, absence of growth stimulating factors, lack of neurolemmas, and rapid formation of scar tissue --Repair within the PNS *axons and dendrites may be repaired if: a. neuron cell body remains intact b. Schwann cells remain active and form a tube c. scar tissue does not form too rapidly *Chromatolysis: a hours after injury, Nissl bodies break up into fine granular masses b. 3-5 days: wallerian degeneration occurs 9breakdown of axon and myelin sheath distal to injury), retrograde degeneration occurs back one noe c. within several months, regeneration occurs: neurolemma on each side of injury repairs tube (Schwann cell mitosis), axonal buds grow down the tube to reconnect (1.5 mm/day) --Multiple Sclerosis (MS) *Autoimmune disorder causing destruction of myelin sheaths in CNS a. sheaths become scars or plaques b. ½ million people in US c. appear b/w ages of 20 and 40 d. females twice as often as males *symptoms include muscular weakness, abnormal sensations or double vision *remissions and relapses result in progressive, cumulative loss of function

Major Structures of the Nervous System. Brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses and sensory receptors

Major Structures of the Nervous System. Brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses and sensory receptors Major Structures of the Nervous System Brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses and sensory receptors Nervous System Divisions Central Nervous System (CNS) consists

More information

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1 Chapter 12 Nervous Tissue Copyright 2009 John Wiley & Sons, Inc. 1 Overview of the Nervous System The nervous system, along with the endocrine system, helps to keep controlled conditions within limits

More information

Biology 218 Human Anatomy

Biology 218 Human Anatomy Chapter 17 Adapted form Tortora 10 th ed. LECTURE OUTLINE A. Overview of the Nervous System (p. 537) 1. The nervous system and the endocrine system are the body s major control and integrating centers.

More information

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1 Chapter 12 Nervous Tissue Copyright 2009 John Wiley & Sons, Inc. 1 Overview of the Nervous System The nervous system, along with the endocrine system, helps to keep controlled conditions within limits

More information

Nervous System. Electrical Signals.III Signal Transmission at Synapses Neurotransmitters.V Neural Circuits.VI

Nervous System. Electrical Signals.III Signal Transmission at Synapses Neurotransmitters.V Neural Circuits.VI Nervous System Overview.I Histology.II Electrical Signals.III Signal Transmission at Synapses Neurotransmitters.V Neural Circuits.VI Repairs.VII Pathology.VIII.IV 1 Controls and integrates all body activities

More information

BIOH111. o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system

BIOH111. o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system BIOH111 o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system Endeavour College of Natural Health endeavour.edu.au 1 TEXTBOOK AND REQUIRED/RECOMMENDED

More information

The Nervous System. Nervous System Functions 1. gather sensory input 2. integration- process and interpret sensory input 3. cause motor output

The Nervous System. Nervous System Functions 1. gather sensory input 2. integration- process and interpret sensory input 3. cause motor output The Nervous System Nervous System Functions 1. gather sensory input 2. integration- process and interpret sensory input 3. cause motor output The Nervous System 2 Parts of the Nervous System 1. central

More information

Chapter 11: Nervous System and Nervous Tissue

Chapter 11: Nervous System and Nervous Tissue Chapter 11: Nervous System and Nervous Tissue I. Functions and divisions of the nervous system A. Sensory input: monitor changes in internal and external environment B. Integrations: make decisions about

More information

Chapter 11 Introduction to the Nervous System and Nervous Tissue Chapter Outline

Chapter 11 Introduction to the Nervous System and Nervous Tissue Chapter Outline Chapter 11 Introduction to the Nervous System and Nervous Tissue Chapter Outline Module 11.1 Overview of the Nervous System (Figures 11.1-11.3) A. The nervous system controls our perception and experience

More information

Chapter 11: Functional Organization of Nervous Tissue

Chapter 11: Functional Organization of Nervous Tissue Chapter 11: Functional Organization of Nervous Tissue I. Functions of the Nervous System A. List and describe the five major nervous system functions: 1. 2. 3. 4. 5. II. Divisions of the Nervous System

More information

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1

Chapter 12 Nervous Tissue. Copyright 2009 John Wiley & Sons, Inc. 1 Chapter 12 Nervous Tissue Copyright 2009 John Wiley & Sons, Inc. 1 Terms to Know CNS PNS Afferent division Efferent division Somatic nervous system Autonomic nervous system Sympathetic nervous system Parasympathetic

More information

10.1: Introduction. Cell types in neural tissue: Neurons Neuroglial cells (also known as neuroglia, glia, and glial cells) Dendrites.

10.1: Introduction. Cell types in neural tissue: Neurons Neuroglial cells (also known as neuroglia, glia, and glial cells) Dendrites. 10.1: Introduction Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cell types in neural tissue: Neurons Neuroglial cells (also known as neuroglia, glia, and glial

More information

Outline. Neuron Structure. Week 4 - Nervous System. The Nervous System: Neurons and Synapses

Outline. Neuron Structure. Week 4 - Nervous System. The Nervous System: Neurons and Synapses Outline Week 4 - The Nervous System: Neurons and Synapses Neurons Neuron structures Types of neurons Electrical activity of neurons Depolarization, repolarization, hyperpolarization Synapses Release of

More information

Nervous System. Master controlling and communicating system of the body. Secrete chemicals called neurotransmitters

Nervous System. Master controlling and communicating system of the body. Secrete chemicals called neurotransmitters Nervous System Master controlling and communicating system of the body Interacts with the endocrine system to control and coordinate the body s responses to changes in its environment, as well as growth,

More information

Unit Three. I. General Functions of the Nervous System. I. General Functions of the Nervous System

Unit Three. I. General Functions of the Nervous System. I. General Functions of the Nervous System 10 Refer to the following URLs. It is a good idea to print them and bring them to class. Be sure to study these along with your book. http://www.sirinet.net/~jgjohnso/nervous.html http://faculty.washington.edu/chudler/ap.html

More information

Principles of Anatomy and Physiology

Principles of Anatomy and Physiology Principles of Anatomy and Physiology 14 th Edition CHAPTER 12 Nervous Tissue Introduction The purpose of the chapter is to: 1. Understand how the nervous system helps to keep controlled conditions within

More information

NEURAL TISSUE (NEUROPHYSIOLOGY) PART I (A): NEURONS & NEUROGLIA

NEURAL TISSUE (NEUROPHYSIOLOGY) PART I (A): NEURONS & NEUROGLIA PART I (A): NEURONS & NEUROGLIA Neural Tissue Contains 2 kinds of cells: neurons: cells that send and receive signals neuroglia (glial cells): cells that support and protect neurons Neuron Types Sensory

More information

Zoology 142 Nervous Tissue Ch 12 Dr. Bob Moeng. Nervous Tissue

Zoology 142 Nervous Tissue Ch 12 Dr. Bob Moeng. Nervous Tissue Nervous Tissue Homeostatic Control Nervous system and endocrine system are basis of homeostasis Nervous system responds rapidly (in msec) Endocrine system responds slowly Three major components of control

More information

Biology 201-Worksheet on Nervous System (Answers are in your power point outlines-there is no key!)

Biology 201-Worksheet on Nervous System (Answers are in your power point outlines-there is no key!) Bio 201 Tissues and Skin 1 March 21, 2011 Biology 201-Worksheet on Nervous System (Answers are in your power point outlines-there is no key!) 1. The study of the normal functioning and disorders of the

More information

The Nervous System -The master controlling and communicating system of the body

The Nervous System -The master controlling and communicating system of the body The Nervous System -The master controlling and communicating system of the body Functions: -Sensory input -Integration -Motor output Organization of the Nervous System Central nervous system (CNS) -Brain

More information

Collin County Community College BIOL Week 5. Nervous System. Nervous System

Collin County Community College BIOL Week 5. Nervous System. Nervous System Collin County Community College BIOL 2401 Week 5 Nervous System 1 Nervous System The process of homeostasis makes sure that the activities that occur in the body are maintained within normal physiological

More information

sensory input receptors integration Human Anatomy motor output Ch. 7 effectors Structural classification

sensory input receptors integration Human Anatomy motor output Ch. 7 effectors Structural classification Human Anatomy Ch. 7 I. The Nervous System A. General characteristics 1. body s control & communication center a. 3 overlapping functions 1) sensory input: receptors monitor stimuli 2) integration: processes,

More information

Nervous System. Chapter 9 Pages

Nervous System. Chapter 9 Pages Nervous System Chapter 9 Pages 211-257 Chapter 9 Wordbytes 1. af- = toward 11. -ferrent = carried 2. arachn- = spider 12. gangli- = swelling 3. astro- = star 13. -glia = glue 4. auto- = self 14. mening-

More information

Warm-Up. Label the parts of the neuron below.

Warm-Up. Label the parts of the neuron below. Warm-Up Label the parts of the neuron below. A B C D E F G Warm-Up 1. One neuron transmits a nerve impulse at 40 m/s. Another conducts at the rate of 1 m/s. Which neuron has a myelinated axon? 2. List

More information

BIOH111. o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system

BIOH111. o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system BIOH111 o Cell Module o Tissue Module o Integumentary system o Skeletal system o Muscle system o Nervous system o Endocrine system Endeavour College of Natural Health endeavour.edu.au 1 Textbook and required/recommended

More information

BIOLOGY 2050 LECTURE NOTES ANATOMY & PHYSIOLOGY I (A. IMHOLTZ) FUNDAMENTALS OF THE NERVOUS SYSTEM AND NERVOUS TISSUE P1 OF 5

BIOLOGY 2050 LECTURE NOTES ANATOMY & PHYSIOLOGY I (A. IMHOLTZ) FUNDAMENTALS OF THE NERVOUS SYSTEM AND NERVOUS TISSUE P1 OF 5 P1 OF 5 The nervous system controls/coordinates the activities of cells, tissues, & organs. The endocrine system also plays a role in control/coordination. The nervous system is more dominant. Its mechanisms

More information

1. Name the two major divisions of the nervous system and list the organs within each. Central Nervous System Peripheral Nervous System

1. Name the two major divisions of the nervous system and list the organs within each. Central Nervous System Peripheral Nervous System CHAPTER 10: NERVOUS SYSTEM I OBJECTIVES 1. Name the two major divisions of the nervous system and list the organs within each. Central Nervous System Peripheral Nervous System Brain Spinal Cord Cranial

More information

Functions of the Nervous System

Functions of the Nervous System Chapter 11 Functional Organization of Nervous Tissue 11-1 Functions of the Nervous System 1. Sensory input. Monitor internal and external stimuli 2. Integration. Brain and spinal cord process sensory input

More information

Portions from Chapter 6 CHAPTER 7. The Nervous System: Neurons and Synapses. Chapter 7 Outline. and Supporting Cells

Portions from Chapter 6 CHAPTER 7. The Nervous System: Neurons and Synapses. Chapter 7 Outline. and Supporting Cells CHAPTER 7 The Nervous System: Neurons and Synapses Chapter 7 Outline Neurons and Supporting Cells Activity in Axons The Synapse Acetylcholine as a Neurotransmitter Monoamines as Neurotransmitters Other

More information

MOLECULAR AND CELLULAR NEUROSCIENCE

MOLECULAR AND CELLULAR NEUROSCIENCE MOLECULAR AND CELLULAR NEUROSCIENCE BMP-218 November 4, 2014 DIVISIONS OF THE NERVOUS SYSTEM The nervous system is composed of two primary divisions: 1. CNS - Central Nervous System (Brain + Spinal Cord)

More information

Nerve Cell Flashcards

Nerve Cell Flashcards 1. What does the word innervates mean? Refers to a nerve supplying a muscle or organ. For example, The phrenic nerve innervates the diaphragm muscle. 2. 3 parts of the Nervous System 1. Central Nervous

More information

BIOL241 - Lecture 12a

BIOL241 - Lecture 12a Cranial Nerves, source: training.seer.cancer.gov Nervous System Overview BIOL241 - Lecture 12a 1 Topics Divisions of the NS: CNS and PNS Structure and types of neurons Synapses Structure and function of

More information

Nervous Tissue and Neurophysiology

Nervous Tissue and Neurophysiology Nervous Tissue and Neurophysiology Objectives Describe the two major divisions of the nervous system and their characteristics. Identify the structures/functions of a typical neuron. Describe the location

More information

Chapter 4 Neuronal Physiology

Chapter 4 Neuronal Physiology Chapter 4 Neuronal Physiology V edit. Pg. 99-131 VI edit. Pg. 85-113 VII edit. Pg. 87-113 Input Zone Dendrites and Cell body Nucleus Trigger Zone Axon hillock Conducting Zone Axon (may be from 1mm to more

More information

Functions of the Nervous System. Fundamentals of the Nervous System & Nervous Tissue

Functions of the Nervous System. Fundamentals of the Nervous System & Nervous Tissue Fundamentals of the Nervous System & Nervous Tissue Overview Structure cell types & structures Neurophysiology membrane potential Synapse, neurotransmitters & receptors Functions of the Nervous System

More information

The Nervous System 7PART A. PowerPoint Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College

The Nervous System 7PART A. PowerPoint Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College PowerPoint Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College The Nervous System 7PART A Functions of the Nervous System Sensory input gathering information To monitor

More information

Nervous System Dr. Naim Kittana Department of Biomedical Sciences Faculty of Medicine & Health Sciences An-Najah National University

Nervous System Dr. Naim Kittana Department of Biomedical Sciences Faculty of Medicine & Health Sciences An-Najah National University Nervous System Department of Biomedical Sciences Faculty of Medicine & Health Sciences An-Najah National University Declaration The content and the figures of this seminar were directly adopted from the

More information

Functions of Nervous System Neuron Structure

Functions of Nervous System Neuron Structure Chapter 10 Nervous System I Divisions of the Nervous System Cell Types of Neural Tissue neurons neuroglial cells Central Nervous System brain spinal cord Peripheral Nervous System nerves cranial nerves

More information

NERVOUS SYSTEM 1 CHAPTER 10 BIO 211: ANATOMY & PHYSIOLOGY I

NERVOUS SYSTEM 1 CHAPTER 10 BIO 211: ANATOMY & PHYSIOLOGY I BIO 211: ANATOMY & PHYSIOLOGY I 1 Ch 10 A This set Ch 10 B CHAPTER 10 NERVOUS SYSTEM 1 BASIC STRUCTURE and FUNCTION Dr. Lawrence G. Altman www.lawrencegaltman.com Some illustrations are courtesy of McGraw-Hill.

More information

Overview of the Nervous System A. Subdivisions of the Nervous System: 1. The two major subdivisions of the nervous system:

Overview of the Nervous System A. Subdivisions of the Nervous System: 1. The two major subdivisions of the nervous system: BIO 211: ANATOMY & PHYSIOLOGY I 1 Ch 10 A This set Ch 10 B CHAPTER 10 NERVOUS SYSTEM 1 BASIC STRUCTURE and FUNCTION Dr. Lawrence G. Altman www.lawrencegaltman.com Some illustrations are courtesy of McGraw-Hill.

More information

The Nervous System PART A

The Nervous System PART A 7 The Nervous System PART A PowerPoint Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY EIGHTH EDITION ELAINE N. MARIEB Structural Classification

More information

Neurons, Synapses and Signaling. Chapter 48

Neurons, Synapses and Signaling. Chapter 48 Neurons, Synapses and Signaling Chapter 48 Warm Up Exercise What types of cells can receive a nerve signal? Nervous Organization Neurons- nerve cells. Brain- organized into clusters of neurons, called

More information

Mohammad Tarek. Wahab Al-tekreeti Tamer Barakat. Faisal Mohammad

Mohammad Tarek. Wahab Al-tekreeti Tamer Barakat. Faisal Mohammad 15 Mohammad Tarek Wahab Al-tekreeti Tamer Barakat Faisal Mohammad Things to remember Types of synapse: Neuron types and neurotransmitters When it happens between an axon and dendrites it is called axodendritic

More information

A. Subdivisions of the Nervous System: 1. The two major subdivisions of the nervous system:

A. Subdivisions of the Nervous System: 1. The two major subdivisions of the nervous system: BIO 211: ANATOMY & PHYSIOLOGY I 1 Ch 10 A Ch 10 B CHAPTER 10 NERVOUS SYSTEM 1 BASIC STRUCTURE and FUNCTION Dr. Lawrence G. Altman www.lawrencegaltman.com Some illustrations are courtesy of McGraw-Hill.

More information

Learning expectations for BIOL 131. Chapters 11, Nervous System Overview Read Chapter 11. You should be able to:

Learning expectations for BIOL 131. Chapters 11, Nervous System Overview Read Chapter 11. You should be able to: NOTE The quiz will have question ONLY from the material we get through on Tuesday. The first midterm will cover all material from day one until the lecture before the second midterm. Learning expectations

More information

Neural Tissue. Chapter 12 Part B

Neural Tissue. Chapter 12 Part B Neural Tissue Chapter 12 Part B CNS Tumors - Neurons stop dividing at age 4 but glial cells retain the capacity to divide. - Primary CNS tumors in adults- division of abnormal neuroglia rather than from

More information

Fundamentals of the Nervous System and Nervous Tissue. Nervous System. Basic Divisions of the Nervous System C H A P T E R 12.

Fundamentals of the Nervous System and Nervous Tissue. Nervous System. Basic Divisions of the Nervous System C H A P T E R 12. C H A P T E R 12 Fundamentals of the Nervous System and Nervous Tissue Nervous System Sensory input Integration Motor output Figure 12.1 Basic Divisions of the Nervous System Brain CNS Spinal cord Nerves

More information

3) Most of the organelles in a neuron are located in the A) dendritic region. B) axon hillock. C) axon. D) cell body. E) axon terminals.

3) Most of the organelles in a neuron are located in the A) dendritic region. B) axon hillock. C) axon. D) cell body. E) axon terminals. Chapter 48 Neurons, Synapses, and Signaling Multiple-Choice Questions 1) A simple nervous system A) must include chemical senses, mechanoreception, and vision. B) includes a minimum of 12 ganglia. C) has

More information

Nervous tissue, charachteristics, neurons, glial cells

Nervous tissue, charachteristics, neurons, glial cells Nervous tissue, charachteristics, neurons, glial cells Functional Organization of Nervous Tissue The Nervous System Components Brain, spinal cord, nerves, sensory receptors Responsible for Sensory perceptions,

More information

Functional Organization of Nervous Tissue. Nervous tissue, charachteristics, neurons, glial cells. The Nervous System. The Nervous System 21/12/2010

Functional Organization of Nervous Tissue. Nervous tissue, charachteristics, neurons, glial cells. The Nervous System. The Nervous System 21/12/2010 Nervous tissue, charachteristics, neurons, glial cells Functional Organization of Nervous Tissue The Nervous System Components Brain, spinal cord, nerves, sensory receptors Responsible for Sensory perceptions,

More information

Overview of Nervous System

Overview of Nervous System Nervous Tissue Overview of the nervous system Nerve cells (neurons) Supportive cells (neuroglia) Electrophysiology of neurons Synapses Neural integration 12-1 Overview of Nervous System Endocrine and nervous

More information

2401 : Anatomy/Physiology

2401 : Anatomy/Physiology Dr. Chris Doumen Week 5 2401 : Anatomy/Physiology Introduction Neural Tissue TextBook Readings Pages 388 through 397. Make use of the figures in your textbook ; a picture is worth a thousand words! Work

More information

Chapter 9. Nervous System

Chapter 9. Nervous System Chapter 9 Nervous System Central Nervous System (CNS) vs. Peripheral Nervous System(PNS) CNS Brain Spinal cord PNS Peripheral nerves connecting CNS to the body Cranial nerves Spinal nerves Neurons transmit

More information

The Nervous System: Neural Tissue Pearson Education, Inc.

The Nervous System: Neural Tissue Pearson Education, Inc. 13 The Nervous System: Neural Tissue Introduction Nervous System Characteristics Controls and adjust the activity of the body Provides swift but brief responses The nervous system includes: Central Nervous

More information

2/27/2019. Functions of the Nervous System. Nervous Tissue and Neuron Function. Fundamentals Of The Nervous System And Nervous Tissue

2/27/2019. Functions of the Nervous System. Nervous Tissue and Neuron Function. Fundamentals Of The Nervous System And Nervous Tissue Nervous Tissue and Neuron Function Fundamentals Of The Nervous System And Nervous Tissue Learn and Understand 1. Like muscle cells, neurons use membrane polarity upset (AP) as a signal therefore keeping

More information

CHAPTER 12 LECTURE OUTLINE I. OVERVIEW OF THE NERVOUS SYSTEM 1. The nervous system, along with the endocrine system, helps to keep controlled

CHAPTER 12 LECTURE OUTLINE I. OVERVIEW OF THE NERVOUS SYSTEM 1. The nervous system, along with the endocrine system, helps to keep controlled CHAPTER 12 LECTURE OUTLINE I. OVERVIEW OF THE NERVOUS SYSTEM 1. The nervous system, along with the endocrine system, helps to keep controlled conditions within limits that maintain health and helps to

More information

Neurons Chapter 7 2/19/2016. Learning Objectives. Cells of the Nervous System. Cells of the Nervous System. Cells of the Nervous System

Neurons Chapter 7 2/19/2016. Learning Objectives. Cells of the Nervous System. Cells of the Nervous System. Cells of the Nervous System Learning Objectives Neurons Chapter 7 Identify and describe the functions of the two main divisions of the nervous system. Differentiate between a neuron and neuroglial cells in terms of structure and

More information

Chapter 2: Cellular Mechanisms and Cognition

Chapter 2: Cellular Mechanisms and Cognition Chapter 2: Cellular Mechanisms and Cognition MULTIPLE CHOICE 1. Two principles about neurons were defined by Ramón y Cajal. The principle of connectional specificity states that, whereas the principle

More information

NERVOUS SYSTEM CELLS. a. afferent division CHAPTER 12 ORGANIZATION OF THE NERVOUS SYSTEM. Student Name

NERVOUS SYSTEM CELLS. a. afferent division CHAPTER 12 ORGANIZATION OF THE NERVOUS SYSTEM. Student Name Student Name CHAPTER 12 NERVOUS SYSTEM CELLS T he nervous system organizes and coordinates the millions of impulses received each day to make communication with and enjoyment of our environment possible.

More information

Neurobiology. Cells of the nervous system

Neurobiology. Cells of the nervous system Neurobiology Cells of the nervous system Anthony Heape 2010 1 The nervous system Central nervous system (CNS) Peripheral nervous system (PNS) 2 Enteric nervous system (digestive tract, gall bladder and

More information

Neurophysiology scripts. Slide 2

Neurophysiology scripts. Slide 2 Neurophysiology scripts Slide 2 Nervous system and Endocrine system both maintain homeostasis in the body. Nervous system by nerve impulse and Endocrine system by hormones. Since the nerve impulse is an

More information

Chapter 7. The Nervous System: Structure and Control of Movement

Chapter 7. The Nervous System: Structure and Control of Movement Chapter 7 The Nervous System: Structure and Control of Movement Objectives Discuss the general organization of the nervous system Describe the structure & function of a nerve Draw and label the pathways

More information

Chapter 7. Objectives

Chapter 7. Objectives Chapter 7 The Nervous System: Structure and Control of Movement Objectives Discuss the general organization of the nervous system Describe the structure & function of a nerve Draw and label the pathways

More information

The Nervous System & Nervous tissue. Dr. Ali Ebneshahidi

The Nervous System & Nervous tissue. Dr. Ali Ebneshahidi The Nervous System & Nervous tissue Dr. Ali Ebneshahidi Functions of the Nervous System 1. Nervous system and endocrine system are the chief control centers in maintaining body homeostasis. 2. Nervous

More information

Chapter 12 Nervous Tissue

Chapter 12 Nervous Tissue 9/12/11 Chapter 12 Nervous Tissue Overview of the nervous system Cells of the nervous system Electrophysiology of neurons Synapses Neural integration Subdivisions of the Nervous System 1 Subdivisions of

More information

BI 232: Human Anatomy & Physiology

BI 232: Human Anatomy & Physiology BI 232: Human Anatomy & Physiology Roster Business Course Introduction and Syllabus Notecard Name E-mail Why you are taking the course Something interesting you did over break Lecture Tips Use the Study

More information

Hole s Human Anatomy and Physiology Eleventh Edition. Chapter 10

Hole s Human Anatomy and Physiology Eleventh Edition. Chapter 10 PowerPoint Lecture Outlines to accompany Hole s Human Anatomy and Physiology Eleventh Edition Shier Butler Lewis Chapter 10 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction

More information

anatomic divisions central nervous system peripheral nervous system Anatomic Divisions of the PNS afferent or sensory division

anatomic divisions central nervous system peripheral nervous system Anatomic Divisions of the PNS afferent or sensory division Chapter 12 Functional Organization of the Nervous System I. Two anatomic divisions: CNS and PNS A. central nervous system (CNS) 1. consists of the brain and spinal cord and is encased in bone. 2. Surrounded

More information

Human Anatomy & Physiology

Human Anatomy & Physiology PowerPoint Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College Ninth Edition Human Anatomy & Physiology C H A P T E R 11 Annie Leibovitz/Contact Press Images 2013 Pearson Education,

More information

Chapter 7. The Nervous System

Chapter 7. The Nervous System Chapter 7 The Nervous System General overview of the nervous system functions Sensory input (info travels in along afferent pathways) Integration (information is processed) Sensory neurons Spinal cord

More information

Chapter 2. The Cellular and Molecular Basis of Cognition Cognitive Neuroscience: The Biology of the Mind, 2 nd Ed.,

Chapter 2. The Cellular and Molecular Basis of Cognition Cognitive Neuroscience: The Biology of the Mind, 2 nd Ed., Chapter 2. The Cellular and Molecular Basis of Cognition Cognitive Neuroscience: The Biology of the Mind, 2 nd Ed., M. S. Gazzaniga, R. B. Ivry, and G. R. Mangun, Norton, 2002. Summarized by B.-W. Ku,

More information

LECTURE STRUCTURE ASC171 NERVOUS SYSTEM PART 1: BACKGROUND 26/07/2015. Module 5

LECTURE STRUCTURE ASC171 NERVOUS SYSTEM PART 1: BACKGROUND 26/07/2015. Module 5 LECTURE STRUCTURE PART 1: Background / Introduction PART 2: Structure of the NS, how it operates PART 3: CNS PART 4: PNS Why did the action potential cross the synaptic junction? To get to the other side

More information

Neurons. Pyramidal neurons in mouse cerebral cortex expressing green fluorescent protein. The red staining indicates GABAergic interneurons.

Neurons. Pyramidal neurons in mouse cerebral cortex expressing green fluorescent protein. The red staining indicates GABAergic interneurons. Neurons Pyramidal neurons in mouse cerebral cortex expressing green fluorescent protein. The red staining indicates GABAergic interneurons. MBL, Woods Hole R Cheung MSc Bioelectronics: PGEE11106 1 Neuron

More information

THE NERVOUS SYSTEM. Neurons & Impulses

THE NERVOUS SYSTEM. Neurons & Impulses THE NERVOUS SYSTEM Neurons & Impulses Organization of the Nervous System: Two Major Portions: The central nervous system (CNS) and the peripheral nervous system (PNS). CNS = Brain/Spinal Cord PNS = Nerves-provide

More information

Omar Ismail. Dana Almanzalji. Faisal Mohammad

Omar Ismail. Dana Almanzalji. Faisal Mohammad 11 Omar Ismail Dana Almanzalji Faisal Mohammad Neuronal classification: Neurons are responsible for transmitting the action potential to the brain. The speed at which the action potential is transmitted

More information

Organization of the nervous system. [See Fig. 48.1]

Organization of the nervous system. [See Fig. 48.1] Nervous System [Note: This is the text version of this lecture file. To make the lecture notes downloadable over a slow connection (e.g. modem) the figures have been replaced with figure numbers as found

More information

Chapter 17. Nervous System Nervous systems receive sensory input, interpret it, and send out appropriate commands. !

Chapter 17. Nervous System Nervous systems receive sensory input, interpret it, and send out appropriate commands. ! Chapter 17 Sensory receptor Sensory input Integration Nervous System Motor output Brain and spinal cord Effector cells Peripheral nervous system (PNS) Central nervous system (CNS) 28.1 Nervous systems

More information

! BIOL 2401! Week 5. Nervous System. Nervous System

! BIOL 2401! Week 5. Nervous System. Nervous System Collin County Community College! BIOL 2401! Week 5 Nervous System 1 Nervous System The process of homeostasis makes sure that the activities that occur in the body are maintained within normal physiological

More information

Chapter 2. The Cellular and Molecular Basis of Cognition

Chapter 2. The Cellular and Molecular Basis of Cognition Chapter 2. The Cellular and Molecular Basis of Cognition Cognitive Neuroscience: The Biology of the Mind, 2 nd Ed., M. S. Gazzaniga,, R. B. Ivry,, and G. R. Mangun,, Norton, 2002. Summarized by B.-W. Ku,

More information

Sheet: microscopic structures of the ns Done by: Rasha Rakan and Nisreen Obiedat

Sheet: microscopic structures of the ns Done by: Rasha Rakan and Nisreen Obiedat Sheet: microscopic structures of the ns Done by: Rasha Rakan and Nisreen Obiedat Lecture Objectives Classify the types of neurons. Describe the structure of the different parts of neurons. Describe the

More information

Hole s Human Anatomy and Physiology Tenth Edition. Chapter 10

Hole s Human Anatomy and Physiology Tenth Edition. Chapter 10 PowerPoint Lecture Outlines to accompany Hole s Human Anatomy and Physiology Tenth Edition Shier Butler Lewis Chapter 10 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or

More information

5-Nervous system II: Physiology of Neurons

5-Nervous system II: Physiology of Neurons 5-Nervous system II: Physiology of Neurons AXON ION GRADIENTS ACTION POTENTIAL (axon conduction) GRADED POTENTIAL (cell-cell communication at synapse) SYNAPSE STRUCTURE & FUNCTION NEURAL INTEGRATION CNS

More information

Axon Nerve impulse. Axoplasm Receptor. Axomembrane Stimuli. Schwann cell Effector. Myelin Cell body

Axon Nerve impulse. Axoplasm Receptor. Axomembrane Stimuli. Schwann cell Effector. Myelin Cell body Nervous System Review 1. Explain a reflex arc. 2. Know the structure, function and location of a sensory neuron, interneuron, and motor neuron 3. What is (a) Neuron Axon Nerve impulse Axoplasm Receptor

More information

Endocrine System Nervous System

Endocrine System Nervous System Cells Endocrine System Nervous System Tissues Controls Organs Nervous System vs Endocrine System Electrical signals (graded potentials and action potentials) and chemical signals (neurotransmitters) Fast

More information

Chapter 11: Fundamentals of the Nervous System and Nervous Tissue

Chapter 11: Fundamentals of the Nervous System and Nervous Tissue Chapter 11: Fundamentals of the Nervous System and Nervous Tissue Objectives: 1. List the basic functions of the nervous system. 2. Explain the structural and functional divisions of the nervous system.

More information

Endocrine System Nervous System

Endocrine System Nervous System Cells Endocrine System Nervous System Tissues Controls Organs Nervous System vs Endocrine System Electrical signals (graded potentials and action potentials) and chemical signals (neurotransmitters) Fast

More information

Summarized by B.-W. Ku, E. S. Lee, and B.-T. Zhang Biointelligence Laboratory, Seoul National University.

Summarized by B.-W. Ku, E. S. Lee, and B.-T. Zhang Biointelligence Laboratory, Seoul National University. Chapter 2. The Cellular l and Molecular Basis of Cognition Cognitive Neuroscience: The Biology of the Mind, 3 rd Ed., M. S. Gazzaniga, R. B. Ivry, and G. R. Mangun, Norton, 2008. Summarized by B.-W. Ku,

More information

Introduction to Nervous Tissue

Introduction to Nervous Tissue Introduction to Nervous Tissue Nervous Tissue Controls and integrates all body activities within limits that maintain life Three basic functions 1. sensing changes with sensory receptors 2. interpreting

More information

NEURONS Chapter Neurons: specialized cells of the nervous system 2. Nerves: bundles of neuron axons 3. Nervous systems

NEURONS Chapter Neurons: specialized cells of the nervous system 2. Nerves: bundles of neuron axons 3. Nervous systems NEURONS Chapter 12 Figure 12.1 Neuronal and hormonal signaling both convey information over long distances 1. Nervous system A. nervous tissue B. conducts electrical impulses C. rapid communication 2.

More information

Na + K + pump. The beauty of the Na + K + pump. Cotransport. The setup Cotransport the result. Found along the plasma membrane of all cells.

Na + K + pump. The beauty of the Na + K + pump. Cotransport. The setup Cotransport the result. Found along the plasma membrane of all cells. The beauty of the Na + K + pump Na + K + pump Found along the plasma membrane of all cells. Establishes gradients, controls osmotic effects, allows for cotransport Nerve cells have a Na + K + pump and

More information

NERVOUS SYSTEM C H A P T E R 2 8

NERVOUS SYSTEM C H A P T E R 2 8 NERVOUS SYSTEM C H A P T E R 2 8 CAN AN INJURED SPINAL CORD BE FIXED? Injuries to the spinal cord disrupt communication between the central nervous system (brain and spinal cord) and the rest of the body

More information

25 Things To Know. Neurons

25 Things To Know. Neurons 25 Things To Know Neurons Neurons receive & transmit to other cells Neurons Many last your whole life Neurons Many last your whole life Other cells die and are replaced Most aren t replaced Neurons Hippocampus

More information

PARTS central nervous system brain and spinal cord nerve bundle of neurons wrapped in connective tissue

PARTS central nervous system brain and spinal cord nerve bundle of neurons wrapped in connective tissue NEUROPHYSIOLOGY Electrical Properties of Nerve cells (neurons) Electro physiology of neurons lie in Membrane Physiology Model organisms is Squid Giant Axon (SGA) diversity of Nervous systems NERVOUS SYSTEM

More information

NERVOUS SYSTEM. Somatic (SNS) Fibers - transmit impulses from CNS to control voluntary action of skeletal muscle

NERVOUS SYSTEM. Somatic (SNS) Fibers - transmit impulses from CNS to control voluntary action of skeletal muscle NERVOUS SYSTEM The master controlling and communicating system of the body --- cells communicate via electrical and chemical signals. Signals are rapid, specific and cause almost immediate responses. Functions

More information

Physiology of synapses and receptors

Physiology of synapses and receptors Physiology of synapses and receptors Dr Syed Shahid Habib Professor & Consultant Clinical Neurophysiology Dept. of Physiology College of Medicine & KKUH King Saud University REMEMBER These handouts will

More information

NEURONS COMMUNICATE WITH OTHER CELLS AT SYNAPSES 34.3

NEURONS COMMUNICATE WITH OTHER CELLS AT SYNAPSES 34.3 NEURONS COMMUNICATE WITH OTHER CELLS AT SYNAPSES 34.3 NEURONS COMMUNICATE WITH OTHER CELLS AT SYNAPSES Neurons communicate with other neurons or target cells at synapses. Chemical synapse: a very narrow

More information

Human Anatomy & Physiology I Dr. Sullivan Unit X Nervous Tissue Chapter 12

Human Anatomy & Physiology I Dr. Sullivan Unit X Nervous Tissue Chapter 12 Human Anatomy & Physiology I Dr. Sullivan Unit X Nervous Tissue Chapter 12 I. Two main functions of the Nervous System a) Maintain homeostasis (keep controlled conditions within limits that maintain life)

More information

Neural Tissue. PowerPoint Lecture Presentations prepared by Jason LaPres. Lone Star College North Harris Pearson Education, Inc.

Neural Tissue. PowerPoint Lecture Presentations prepared by Jason LaPres. Lone Star College North Harris Pearson Education, Inc. 12 Neural Tissue PowerPoint Lecture Presentations prepared by Jason LaPres Lone Star College North Harris An Introduction to the Nervous System Organs of the Nervous System Brain and spinal cord Sensory

More information

Chapter 2 The Brain or Bio Psychology

Chapter 2 The Brain or Bio Psychology Chapter 2 The Brain or Bio Psychology 1 2 3 1 Glial Cells Surround neurons and hold them in place Make Myelin (covering for neurons) Manufacture nutrient chemicals neurons need Absorb toxins and waste

More information