THE NERVOUS AND ENDOCRINE SYSTEMS

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2 THE NERVOUS AND ENDOCRINE SYSTEMS

3 THE NERVOUS SYSTEM

4 THE NERVOUS SYSTEM CONTROLS THE BODY S ACTIVITIES IT RECEIVES AND SENDS OUT INFORMATION ABOUT ACTIVITIES WITHIN THE BODY MONITORS AND RESPONDS TO CHANGES IN THE ENVIRONMENT

5 STIMULI THE CONSTANT CHANGES TAKING PLACE AROUND YOU INVOLUNTARY NOT UNDER YOUR CONTROL VOLUNTARY UNDER YOUR CONTROL

6 REFLEX

7 NEURON MESSAGE-CARRYING CELL BASIC UNIT STRUCTURE OF THE NERVOUS SYSTEM UNLIKE MOST OTHER CELLS IT CANNOT BE REPLACED

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9 PARTS OF A NEURON CELL BODY LARGEST PART CONTAINS THE NUCLEUS WHICH CONTROLS ALL ACTIVITIES OF THE CELL

10 DENDRITE CARRIES MESSAGES TO THE CELL BODY OF THE NEURON AXON CARRIES MESSAGES AWAY FROM THE CELL BODY CAN BE 1 MILLIMETER TO MORE THAN 1 METER LONG

11 AXON TERMINAL FEATHERLIKE FIBERS AT THE END OF THE AXON PASS MESSAGE TO THE DENDRITES OF OTHER NEURONS

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13 TYPES OF NEURONS RECEPTORS RECEIVE INFORMATION FROM SURROUNDINGS SENSORY MESSAGES TRAVEL FROM RECEPTORS TO SPINAL CORD AND BRAIN THROUGH THESE

14 MOTOR MESSAGES FROM BRAIN OR SPINAL CORD ARE SENT TO MUSCLE OR GLAND EFFECTOR MUSCLE OR GLAND STIMULATED BY MOTOR NEURON

15 NERVE IMPULSE THE PATH OF THE MESSAGE ELECTRICAL ALONG NEURON 120 METER PER SECOND SYNAPSE TINY GAP BETWEEN NEURONS IMPULSE FERRIED ACROSS BY A CHEMICAL SIGNAL

16 SYNAPSE

17 DIVISIONS OF THE NERVOUS SYSTEM CENTRAL NERVOUS SYSTEM BRAIN AND SPINAL CORD PERIPHERAL NERVOUS SYSTEM ALL NERVES FOUND OUTSIDE THE CENTRAL NERVOUS SYSTEM

18 THE CENTRAL NERVOUS SYSTEM CAN DO MANY THINGS AT ONE TIME ACTIVITIES ARE COMPLEX INTERPRET INFORMATION FROM ALL PARTS OF THE BODY ISSUE COMMANDS TO THE SAME PARTS

19 PATH OF IMPULSE

20 THE BRAIN

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22 MAIN CONTROL CENTER OF THE CENTRAL NERVOUS SYSTEM TRANSMITS AND RECEIVES MESSAGES THROUGH THE SPINAL CORD

23 GRAY MATERIAL CELL BODIES OF BILLIONS OF NEURONS WHITE MATERIAL UNDERNEATH BUNDLES OF AXONS

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25 MASS OF BRAIN 1.4 KILOGRAMS SKULL PROTECTS THE BRAIN

26 WRAPPED IN THREE LAYERS OF CONNECTIVE TISSUE WHICH NOURISH AND PROTECT IT INNER LAYER CLINGS TO SURFACE OF THE BRAIN AND FOLLOWS IT S MANY FOLDS MIDDLE LAYER WATERY FLUID THAT CUSHIONS AGAINST SUDDEN IMPACT OUTER LAYER THICKER AND TOUGHER THAN THE OTHER TWO LAYERS

27 PARTS OF THE BRAIN

28 CEREBRUM LARGEST AND MOST NOTICIBLE LINED WITH DEEP WRINKLED GROOVES INCREASE AREA ALLOWING FOR MORE ACTIVITIES TO OCCUR

29 LEARNING, INTELLIGENCE, AND JUDGEMENT CONTROLS VOLUNTARY ACTIVITIES OF THE BODY SHAPES ATTITUDES, EMOTIONS, AND PERSONALITY

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31 DIVIDED INTO HALVES EACH CONTROLS A DIFFERENT KIND OF MENTAL ACTIVITY RIGHT ARTISTIC LEFT MATHEMATICAL EACH CONTROLS THE OPPOSITE SIDE OF THE BODY

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34 CEREBELLUM LOCATED TO THE REAR AND BELOW THE CEREBRUM COORDINATES ACTIONS OF MUSCLES MAINTAINS BALANCE

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36 MEDULLA OBLONGATA LOCATED BELOW THE CEREBELLUM CONNECTS BRAIN TO SPINAL CORD CONTROLS INVOLUNTARY ACTIONS

37 MEDULLA OBLONGATA

38 SPINAL CORD RUNS THE ENTIRE LENGTH OF THE NECK AND BACK CONNECTS THE BRAIN WITH THE REST OF THE NERVOUS SYSTEM THROUGH A SERIES OF 31 PAIRS OF NERVES THESE NERVES CARRY IMPULSES TO AND FROM THE SPINAL CORD

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40 REFLEX A SIMPLE RESPONSE TO STIMULUS AUTOMATIC NERVE IMPULSES TRAVEL ONLY TO THE SPINAL CORD BYPASSING THE BRAIN

41 THE PERIPHERAL NERVOUS SYSTEM LINK BETWEEN THE CENTRAL NERVOUS SYSTEM AND THE REST OF THE BODY CONSISTS OF 43 PAIRS OF NERVES THAT ARISE FROM THE BRAIN AND SPINAL CORD AND LEAD TO ORGANS THROUGHOUT THE BODY

42 MANY ARE UNDER DIRECT CONTROL OF THE CONSCIOUS MIND

43 AUTONOMIC NERVOUS SYSTEM NOT UNDER CONTROL OF THE CONSCIOUS MIND CONTROLS BODY S ACTIVITIES THAT ARE INVOLUNTARY CONTRACTIONS OF THE HEART, DIGESTIVE SYSTEM, ETC.

44 TWO GROUPS TRIGGERS AN ACTION STOPS AN ACTION

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46 THE SENSES STRUCTURES THAT CARRY MESSAGES ABOUT YOUR SURROUNDINGS TO THE CENTRAL NERVOUS SYSTEM MOST RESPOND TO STIMULI FROM BODY S EXTERNAL ENVIRONMENT

47 OTHERS KEEP TRACK OF ENVIRONMENT INSIDE THE BODY

48 SENSE ORGANS RESPOND TO LIGHT, SOUND, HEAT, PRESSURE, AND CHEMICALS THEY DETECT CHANGES IN BODY POSITION

49 VISION EYES ARE DESIGNED TO FOCUS LIGHT RAYS TO PRODUCE IMAGES OF OBJECTS THE BRAIN RECEIVES AND INTERPRETS THE MESSAGES THAT CORRESPOND TO THESE IMAGES VISION CENTER BACK OF THE BRAIN

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51 EYE EYEBALL SHAPED LIKE A BALL SLIGHTLY LONGER THAN WIDE COMPOSED OF THREE LAYERS OF TISSUE

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53 OUTER LAYER SCLERA WHITE OF THE EYE CORNEA TRANSPARENT AREA OF SCLERA CENTER FRONT OF EYEBALL PART THROUGH WHICH LIGHT ENTERS INSIDE CHAMBER IS FILLED WITH FLUID (AQUEOUS HUMOR)

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55 MIDDLE LAYER CHROID CONTAINS BLOOD VESSELS IRIS BACK OF CHAMBER COLORED PORTION OF EYE PUPIL MIDDLE OF IRIS SMALL OPENING SIZE OF OPENING IS CONTROLLED BY MUSCLE OF THE IRIS

56 LENS BEHIND THE IRIS FOCUSES LIGHT RAYS COMING INTO THE EYE SMALL MUSCLE ENABLES IT TO CHANGE SHAPE TO SEE CLOSE OR FAR RELAXED FLATTENS LENS SEE FAR CONTRACT NORMAL SEE CLOSE

57 INNER LAYER VITREOUS HUMOR JELLYLIKE FLUID BEHIND LENS RETINA BACK SURFACE OF EYE 130 MILLION LIGHT-SENSITIVE RECEPTORS

58 RODS DIM LIGHT BUT NOT COLORS CONES COLOR BUT STOP WORKING IN DIM LIGHT

59 THE RETINA

60 BOTH RODS AND CONES PRODUCE NERVE IMPULSES THAT TRAVEL FROM THE RETINA TO THE OPTIC NERVE FROM THE OPTIC NERVE THE IMPULSES TRAVEL TO THE VISUAL CENTER OF THE BRAIN

61 GLAUCOMA

62 THE BRAIN INTERPRETS THE IMPULSE THE IMAGE ON THE RETINA IS UPSIDE DOWN THE BRAIN TURNS IT RIGHT SIDE UP THE BRAIN COMBINES THE TWO IMAGES FROM THE TWO EYES TO CREATE A 3-D IMAGE

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64 HEARING AND BALANCE SOUND SOURCES VIBRATE THROUGH THE AIR IN WAVES HEARING BEGINS WHEN THE SOUND WAVES ENTER THE EXTERNAL EAR THE FUNNELLIKE SHAPE OF THE EXTERNAL EAR ENABLES IT TO GATHER SOUND WAVES

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66 EARDRUM TIGHTLY STRETCHED MEMEBRANE THAT SEPARATES THE EAR CANAL FROM THE MIDDLE EAR AS SOUND WAVES STRIKE THE EARDRUM IT VIBRATES VIBRATIONS FROM THE EARDRUM ENTER THE MIDDLE EAR

67 MIDDLE EAR COMPOSED OF THE THREE SMALLEST BONES IN THE BODY HAMMER ANVIL STIRRUP

68 THE STIRRUP VIBRATES AGAINST A THIN MEMEBRANE COVERING THE OPENING INTO THE FLUID-FILLED INNER EAR VIBRATIONS PASS THROUGH THE FLUID AND ARE CHANNELED INTO A SNAIL-SHAPED TUBE CALLED THE COCHLEA

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70 THE COCHLEA CONTAINS NERVES THAT ARE STIMULATED BY THE VIBRATIONS THE NERVES PRODUCE AN IMPULSE THAT IS CARRIED FROM THE COCHLEA TO THE BRAIN BY THE AUDITORY NERVE ONCE IN THE BRAIN, THE IMPULSE IS INTERPRETED AND YOU HEAR

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72 BALANCE SEMICIRCULAR CANALS RESPONSIBLE FOR BALANCE THREE TINY CANALS LOCATED WITHIN THE INNER EAR JUST ABOVE THE COCHLEA TINY SACS FILLED WITH FLUID AND ARE LINED WITH HAIRLIKE CELLS

73 THESE HAIRLIKE CELLS ARE EMBEDED IN A JELLYLIKE SUBSTANCE THAT CONTAINS TINY GRAINS CALLED HEARING STONES WHEN YOUR HEAD MOVES, THE HEARING STONES ROLL BACK AND FORTH BENDING THE HAIRLIKE CELLS

74 THE CELLS RESPOND BY SENDING NERVE IMPULSES TO THE BRAIN THE BRAIN SIGNALS MUSCLES TO CONTRACT IF IT INTERPRETS THE SIGNAL TO MEAN THAT YOU ARE LOSING YOUR BALANCE

75 SMELL CHEMICALS AFFECT THE SENSE RECEPTORS IN YOUR NOSE THEY PRODUCE IMPULSES THAT ARE CARRIED TO YOUR BRAIN AND INTERPRETED

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77 TASTE TASTE IS ALSO A CHEMICAL SENSE CHEMICALS ARE CARRIED IN LIQUIDS IN YOUR MOUTH

78 TASTE BUDS ON YOUR TONGUE ARE THE CHEMICAL RECEPTORS BITTER, SOUR, SWEET, AND SALT COMBINED WITH 80 BASIC ODORS PRODUCE FLAVORS

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80 TOUCH THE SENSE OF TOUCH IS FOUND IN ALL AREAS OF THE SKIN NEAR THE SURFACE ARE TOUCH RECEPTORS THAT ALLOW YOU TO FEEL THE TEXTURES OF OBJECTS LOCATED DEEPER WITHIN THE SKIN ARE RECEPTORS THAT SENSE PRESSURE

81 THERE ARE ALSO THE RECEPTORS TO HEAT AND COLD AND ARE SCATTERED DIRECTLY BELOW THE SURFACE PAIN RECEPTORS ARE FOUND ALL OVER THE SKIN

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83 EXOCRINE GLANDS GIVE OFF CHEMICALS THROUGH DUCTS OR TUBES INTO NEARBY ORGANS DO NOT PRODUCE HORMONES PRODUCE TEARS, SWEAT, OIL, AND DIGESTIVE JUICES

84 ENDOCRINE SYSTEM GLANDS THAT PRODUCE CHEMICAL MESSENGERS CALLED HORMONES RELEASED DIRECTLY INTO THE BLOOD

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86 HORMONES TURN ON OR OFF SPEED UP OR SLOW DOWN DIFFERENT ACTIVITIES OF ORGANS DELIVERED BY CIRCULATORY SYSTEM TISSUE CELLS ARE PROGRAMMED TO ACCEPT CERTAIN HORMONES AND REJECT OTHERS

87 THE HUMAN BODY HAS EIGHT ENDOCRINE GLANDS THAT RELEASE DIFFERENT HORMONES

88 HYPOTHALAMUS LOCATED AT BASE OF BRAIN MAJOR LINK BETWEEN THE NERVOUS SYSTEM AND ENDOCRINE SYSTEM CONTROLS THE SEVEN OTHER ENDOCRINE GLANDS

89 MESSAGES TRAVELING TO AND FROM THE BRAIN PASS THROUGH THE HYPOTHALAMUS

90 PITUITARY CENTER OF SKULL BEHIND BRIDGE OF NOSE TALKS TO HYPOTHALAMUS THROUGH CHEMICALS AND NERVE IMPULSES BLOOD PRESSURE, GROWTH, METABOLISM, SEXUAL DEVELOPMENT, AND REPRODUCTION

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92 THYMUS BEHIND STERNUM GETS SMALLER AS YOU GROW BY ADULTHOOD SIZE OF THUMB DEVELOPMENT OF IMMUNE SYSTEM INFANCY PRODUCES WHITE BLOOD CELLS

93 THYROID IN NECK CONTROLS HOW QUICKLY FOOD IS BURNED UP BY THE BODY (METABOLISM)

94 PARATHYROIDS EMBEDED IN THYROID CONTROLS THE LEVEL OF CALCUIM IN THE BLOOD

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96 ADRENALS ON TOP OF KIDNEYS REACTION TO A DANGEROUS SITUATION PRODUCES ADRENALINE THE BODY S EMERGENCY ACTION TEAM

97 ADRENAL GLAND

98 PANCREAS LOCATED BY SMALL INTESTINE INSULIN KEEPS BLOOD SUGAR LEVELS UNDER CONTROL HELPS THE BODY ABSORB IT AND USE IT FOR ENERGY CHANGES SUGAR INTO GLYCOGEN FOR STORAGE

99 DIABETES MELLITUS DROP IN INSULIN PRODUCTION INSULIN PRODUCED BY SMALL GROUP OF CELLS CALLED ISLETS OF LANGERHAUS ISLETS ALSO PRODUCE GLUCAGON OPPOSITE EFFECT OF INSULIN INCREASES BLOOD SUGAR LEVEL

100 OVARIES FEMALE REPRODUCTIVE GLANDS

101 TESTES MALE REPRODUCTIVE GLANDS

102 NEGATIVE FEEDBACK MECHANISM AUTOMATICALLY CONTROLS THE LEVELS OF HORMONES IN THE BODY PRODUCTION OF A HORMONE IS CONTROLLED BY THE AMOUNT OF ANOTHER HORMONE IN THE BLOOD THEREBY KEEPING THE BODY S INTERNAL ENVIRONMENT STABLE

103 EXAMPLE: THE PITUITARY IS SENTITIVE TO THYROXINE (PRODUCED BY THE THYROID) IF TOO LOW TSH (THYROID STIMULATING HORMONE) IS RELEASED