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NERVOUS SYSTEM

NERVOUS SYSTEM

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NERVOUS SYSTEM

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  1. NERVOUS SYSTEM

  2. NERVOUS SYSTEM • NERVOUS SYSTEMS RECEIVE SENSORY INPUT, INTEPRET IT, AND SENT OUT APPROPRIATE COMMANDS • NERVOUS SYSTEMS • MOST INTRICATELY ORGANIZED DATA PROCESSING SYSTEM ON EARTH • NEURON • FUNCTIONAL UNIT; SPECIALIZED NERVE CELL FOR CARRYING SIGNALS FROM ONE LOCATION IN THE BODY TO ANOTHER

  3. NERVOUS SYSTEM • NERVOUS SYSTEMS RECEIVE SENSORY INPUT, INTEPRET IT, AND SENT OUT APPROPRIATE COMMANDS • NERVOUS SYSTEM HAS 3 INTERCONNECTED FUNCTIONS

  4. NERVOUS SYSTEM • NERVOUS SYSTEMS RECEIVE SENSORY INPUT, INTEPRET IT, AND SENT OUT APPROPRIATE COMMANDS • NERVOUS SYSTEM HAS 3 INTERCONNECTED FUNCTIONS • SENSORY INPUT  CONDUCTION OF SIGNALS FROM SENSORY RECEPTORS TO INTEGRATION CENTERS • INTEGRATION  INTERPRETATION OF THE SENSORY SIGNALS AND THE FORMULATION OF RESPONSES • MOTOR OUTPUT  THE CONDUCCTION OF SIGNALS FROM THE INTEGRATION CENTERS TO EFFECTORS • MUSCLES OR GLANDS THAT PERFORM BODY FUNCTIONS

  5. NERVOUS SYSTEM • NERVOUS SYSTEMS HAVE TWO MAIN DIVISIONS • CENTRAL NERVOUS SYSTEM (CNS) • WHERE MOST INTEGRATION OCCURS; CONSISTS OF THE BRAIN AND SPINAL CORD (IN VERTEBRATES) • PERIPHERAL NERVOUS SYSTEM (PNS) • MADE UP OF COMMUNICATION LINES CALLED NERVES THAT CARRY SIGNALS IN AND OUT OF THE CNS • NERVE • A CABLE-LIKE BUNDLE OF NEURON EXTENSIONS TIGHTLY WRAPPED IN CONNECTIVE TISSUE • GANGLIA • CLUSTERS OF NEURON CELL BODIES IN THE NERVES

  6. NERVOUS SYSTEM • THREE FUNCTIONAL TYPES OF NEURONS

  7. NERVOUS SYSTEM • THREE FUNCTIONAL TYPES OF NEURONS • SENSORY NEURONS • INTERNEURONS • MOTOR NEURONS

  8. NERVOUS SYSTEM • NEURONS ARE THE FUNCTIONAL UNITS OF NERVOUS SYSTEMS • STRUCTURE OF A NEURON

  9. NERVOUS SYSTEM • STRUCTURE OF A NEURON • CELL BODY  HOUSES THE NUCLEUS AND OTHER ORGANELLES • DENDRITES  SHORT, MANY BRANCHES; RECEIVE INCOMING MESSAGES AND DIRECT THEM TOWARD CELL BODY • AXON USUALLY A SINGLE FIBER; CONDUCTS SIGNAL TOWARDS ANOTHER NEURON OR EFFECTOR

  10. NERVOUS SYSTEM • STRUCTURE OF A NEURON • SUPPORTING CELLS  PROTECT, INSULATE, AND REINFORCE THE NEURONS • SHCHWANN CELLS • MYELIN SHEATH • NODES OF RANVIER • INCREASE SPEEDAT WHICH SIGNAL TRAVELS

  11. NERVOUS SYSTEM • STRUCTURE OF A NEURON • SYNAPTIC KNOB (TERMINAL BRANCH) • ENDS THE NEURON; RELAYS SIGNALS TO ANOTHER NEURON OR EFFECTOR • SYNAPSE • THE JUNCTION, OR RELAY POINT, BETWEEN TWO NEURONS OR BETWEEN A NEURON AND AN EFFECTOR CELL

  12. NERVOUS SYSTEM • A NEURON MAINTAINS A MEMBRANE POTENTIAL ACROSS ITS MEMBRANE • RESTING POTENTIAL • THE VOLTAGE ACROSS THE PLASMA OF A RESTING NEURON • SODIUM-POTASSIUM (NA+ / K+) PUMPS • ACTIVELY TRANSPORT NA+ OUT OF THE CELL AND K+ IN

  13. NERVOUS SYSTEM • A NERVE SIGNAL BEGINS AS A CHANGE IN THE MEMBRANE POTENTIAL

  14. NERVOUS SYSTEM • A NERVE SIGNAL BEGINS AS A CHANGE IN THE MEMBRANE POTENTIAL • STIMULUS • ANY FACTOR THAT CAUSES A NERVE SIGNAL TO BE GENERATED • ACTION POTENTIAL • THE TECHNICAL NAME FOR THE NERVESIGNAL • THRESHOLD POTENTIAL • THE MINIMUM CHANGE THAT MUSTOCCUR TO GENERATE AN ACTIONPOTENTIAL • **CYCLIC PROCESS**

  15. NERVOUS SYSTEM • THE ACTION POTENTIAL PROPAGATES ITSELF ALONG THE NEURON • ALL-OR-NONE EVENTS • DIFFERENT INTENSITIES RESULT FROM FREQUENCY OF POTENTIALS

  16. NERVOUS SYSTEM • NEURONS COMMUNICATE AT SYNAPSES • SYNAPSE • THE JUNCTION, OR RELAY POINT, BETWEEN TWO NEURONS OR BETWEEN A NEURON AND AN EFFECTOR CELL • SYNAPSES CAN BEEITHER ELECTRICALOR CHEMICAL • ELECTRICAL SYNAPSES TRANSFER SIGNALSFASTER

  17. NERVOUS SYSTEM • NEURONS COMMUNICATE AT SYNAPSES • SYNAPSE • THE JUNCTION, OR RELAY POINT, BETWEEN TWO NEURONS OR BETWEEN A NEURON AND AN EFFECTOR CELL • SYNAPSES CAN BEEITHER ELECTRICALOR CHEMICAL • CHEMICAL SYNAPSES HAVEA NARROW GAPCALLED ASYNAPTIC CLEFT

  18. NERVOUS SYSTEM • NEURONS COMMUNICATE AT SYNAPSES • SYNAPSE • THE JUNCTION, OR RELAY POINT, BETWEEN TWO NEURONS OR BETWEEN A NEURON AND AN EFFECTOR CELL • SYNAPSES CAN BEEITHER ELECTRICALOR CHEMICAL • SYNAPTIC CLEFT • SEPARATESSYNAPTIC KNOBSFROM RECEIVINGNEURON

  19. NERVOUS SYSTEM • CHEMICAL SYNAPSES MAKE COMPLEX INFORMATION PROCESSING POSSIBLE • MULTIPLE SIGNALS CAN BE SENT TO THE SAME RECEIVING NEURON • NEUROTRANSMITTER • CHEMICAL SIGNAL • NERVOUS SYSTEM EQUIVALENT TO A HORMONE

  20. NERVOUS SYSTEM • A VARIETY OF SMALL MOLECULES FUNCTION AS NEUROTRANSMITTERS • ACETYLCHOLINE • IMPORTANT IN THE BRAIN; MAY BE EXCITATORY OR INHIBITORY • BIOGENIC AMINES • NITROGEN CONTAINING NEUROTRANSMITTERS DERIVED FROM AMINO ACIDS • EXAMPLES INCLUDE EPINEPHRINE, NOREPINEPHRINE, SEROTONIC, DOPAMINE • ENDORPHINS ARE PEPTIDES THAT DECREASE PAIN PERCEPTION • DISSOLEVD GASES LIKE NO (NITROUS OXIDE) ACT AS NEUROTRANSMITTERS

  21. NERVOUS SYSTEM • MANY DRUGS ACT AT CHEMICAL SYNAPSES • EFFECT US BY ACTING AT SYNAPSES OR CHANGING THE NEUROTRANSMITTER

  22. NERVOUS SYSTEM • NERVOUS SYSTEM ORGANIZATION USUALLY CORRELATES WITH BODY SYMMETRY

  23. NERVOUS SYSTEM • NERVOUS SYSTEM ORGANIZATION USUALLY CORRELATES WITH BODY SYMMETRY • NERVE NET • WEB-LIKE SYSTEM OFNEURONS EXTENDINGTHROUGHOUT THEBODY • CEPHALIZATION • CONCENTRATION OFNERVOUS SYSTEM AT HEAD END • CENTRALIZATION • THE PRESENCE OF A CNSDISTINCT FROM A PNS

  24. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED

  25. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS IS MADE UP OF THE SPINAL CORDAND BRAIN • SPINAL CORD • LIES INSIDE THE VERTEBRAL COLUMN, ORSPINE, RECEIVES SENSORY INFORMATION FROM THE SKIN AND MUSCLES ANDINTEGRATES SIMPLE RESPONSES TO CERTAIN KINDS OF STIMULI

  26. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS IS MADE UP OF THE SPINAL CORDAND BRAIN • BRAIN • MASTER CONTROL CENTER; INCLUDESHOMEOSTATIC CENTERS THAT KEEP THE BODYFUNCTIONING SMOOTHLY; SENSORY CENTERSTHAT INTEGRATE DATA FROM THE SENSE ORGANS; IN HUMANS, CENTERS OF EMOTIONS AND INTELLIGENCE; ALSO SEND OUT MOTOR COMMANDS TO MUSCLES

  27. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS IS MADE UP OF THE SPINAL CORDAND BRAIN • BLOOD-BRAIN BARRIER • MAINTAINS A STABLE CHEMICAL ENVIRONMENT IN THE BRAIN; ONLY ESSENTIAL NUTRIENTS AND OXYGEN PASS FREELY INTO THE BRAIN

  28. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS IS MADE UP OF THE SPINAL CORDAND BRAIN • VENTRICLES AND CENTRAL CANAL • FLUID-FILLED SPACES IN BRAIN ANDSPINAL CORD, RESPECTIVELY • CEREBROSPINAL FLUID • FLUID THAT CUSHIONS THE CNS AND HELPS SUPPLY IT WITH NUTRIENTS, HORMONES, AND WHITE BLOOD CELLS • MENINGES • LAYERS OF CONNECTIVE TISSUE, ALSO SUPPLY CUSHION

  29. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS HAS 2 DISTINCT AREAS

  30. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • CNS HAS 2 DISTINCT AREAS • WHITE MATTER • MAINLY AXONS • WITH WHITISH MYELIN SHEATH • GRAY MATTER • MAINLY NERVE BODIES AND DENDRITES; IN MAMMALS IT IS THE AREA OF HIGHER BRAIN FUNCTION

  31. NERVOUS SYSTEM • VERTEBRATE NERVOUS SYSTEMS ARE HIGHLY CENTRALIZED AND CEPHALIZED • PNS HAS • CRANIAL NERVES • CARRY SIGNALS TO OR FROM THE BRAIN • SPINAL NERVES • CARRY SIGNALS TO OR FROM THE SPINAL CORD

  32. NERVOUS SYSTEM • THE PERIPHERAL NERVOUS SYSTEM OF VERTEBRATES IS A FUNCTIONAL HIERARCHY

  33. NERVOUS SYSTEM • OPPOSING ACTIONS OF SYMPATHETIC AND PARASYMPATHETIC NEURONS REGULATE THE INTERNAL ENVIRONMENT • AUTONOMIC NERVOUS SYSTEM HAS 2 DIVISIONS

  34. NERVOUS SYSTEM • OPPOSING ACTIONS OF SYMPATHETIC AND PARASYMPATHETIC NEURONS REGULATE THE INTERNAL ENVIRONMENT • AUTONOMIC NERVOUS SYSTEM HAS 2 DIVISIONS • PARASYMPATHETIC DIVISION • PRIMES THE BODY FOR DIGESTING FOOD AND RESTING • SYMPATHETIC DIVISION • PREPARES THE BODY FOR INTENSE,ENERGY-CONSUMING ACTIVITIES, SUCH AS FIGHTING, FLEEING, OR COMPETING IN A STRENUOUS GAME

  35. NERVOUS SYSTEM • THE VERTEBRATE BRAIN DEVELOPS FROM THREE ANTERIOR BULGES OF THE NEURAL TUBE

  36. NERVOUS SYSTEM • THE VERTEBRATE BRAIN DEVELOPS FROM THREE ANTERIOR BULGES OF THE NEURAL TUBE • 3 ANCESTRAL REGIONS • FOREBRAIN  LEADS TO CEREBUM (DOMINANT PART OF FOREBRAIN) • MIDBRAIN • HINDBRAIN

  37. NERVOUS SYSTEM • THE STRUCTURE OF A LIVING SUPERCOMPUTER: THE HUMAN BRAIN

  38. NERVOUS SYSTEM • THE STRUCTURE OF A LIVING SUPERCOMPUTER: THE HUMAN BRAIN • MAJOR STRUCTURES • CEREBRUM • CEREBELLUM • MEDULLA OBLONGATA • PONS • CORPUS COLLOSUM

  39. NERVOUS SYSTEM • THE CEREBRAL CORTEX IS A MOSAIC OF SPECIALIZED, INTERACTIVE REGIONS • CEREBRAL CORTEX • ACCOUNTS FOR 80% OF BRAINS TOTAL MASS; INVOLVED IN REASONING AND MATHEMATICAL ABILITIES, LANGUAGE SKILLS, IMAGINATION, ARTISTIC TALENT, AND PERSONALITY TRAITS

  40. NERVOUS SYSTEM • THE CEREBRAL CORTEX IS A MOSAIC OF SPECIALIZED, INTERACTIVE REGIONS • LATERALIZATION • AREAS IN THE TWO HEMISPHERES BECOME SPECIALIZED FORDIFFERENT FUNCTIONS

  41. NERVOUS SYSTEM • INJURIES AND BRAIN OPERATIONS HAVE PROVIDED INSIGHT INTO BRAIN FUNCTION • “BROKEN BRAINS” HAVE GIVEN INSIGHT INTO NORMAL BRAIN FUNCTION • LACK OF NERVES ON THE BRAIN ALLOW NEUROSURGEONS TO OPERATE AND DISCERN SPECIFIC ASPECTS OF BRAIN FUNCTION

  42. NERVOUS SYSTEM • SEVERAL PARTS OF THE BRAIN REGULATE SLEEP AND AROUSAL • RETICULAR FORMATION • SYSTEM OF NEURONS THAT EXTENDS THROUGH THE CORE OF THE BRAINSTEM; RECEIVES DATA FROM SENSORY RECEPTORS, FILTERS AND SENDS USEFUL DATA TO CEREBRAL CORTEX

  43. NERVOUS SYSTEM • SEVERAL PARTS OF THE BRAIN REGULATE SLEEP AND AROUSAL • ELECTROENCEPHALOGRAM (EEG) • MEASURES BRAIN WAVE ACTIVITY • REM SLEEP • RAPID EYE MOVEMENT • UNIQUE BRAIN-WAVE PATTERN DURING DEEP SLEEP; TIME WHEN DREAMS OCCUR

  44. NERVOUS SYSTEM • THE LIMBIC SYSTEM IS INVOLVED IN EMOTIONS, MEMORY, AND LEARNING • LIMBIC SYSTEM • INCLUDES PARTS OF THALMAMUS; HYPOTHALAMUS, PORTIONS OF CEREBRAL CORTEX; AMYGDALA AND HIPPOCAMPUS PLAY KEY ROLES IN MEMORY, LEARNING, AND EMOTION

  45. NERVOUS SYSTEM • THE LIMBIC SYSTEM IS INVOLVED IN EMOTIONS, MEMORY, AND LEARNING • LIMBIC SYSTEM • AMYGDALA • CENTRAL IN RECOGNIZING THE EMOTIONAL CONTENT OF FACIAL EXPRESSIONSAND LAYING DOWNEMOTIONAL MEMORIES • HIPPOCAMPUS • INVOLVED IN FORMATION OF MEMORIES ANDTHEIR RECALL

  46. NERVOUS SYSTEM • WE NEED TO SPRINKLE IN A FEW MORE PIECES OF INFO ON THE HUMAN BODY • SENSES • MUSCLES