CHAPTER 11NERVOUS SYSTEM II

DIVISIONS OF THE NERVOUS SYSTEM

CENTRAL NERVOUS SYSTEMPARTS:

BRAINSPINAL CORD

MENINGESDURA MATER

TOUGH, WHITE, DENSE WHITE CONNECTIVE TISSUEPERIOSTEUM OF SKULL BONESBLOOD VESSELSSOME AREAS PENETRATE BETWEEN BRAIN LOBESDURAL SINUSES (VENOUS BLOOD)CONTINUES DOWN AROUND SPINAL CORDEPIDURAL SPACE: BLOOD VESSELS, CONNECTIVE TISSUE, ADIPOSE TISSUE

ARACHNOID MATERTHIN, WEB-LIKENO BLOOD VESSELSON BRAIN BUT DOESN’T DIP INTO BRAINSUBARACHNOID SPACE: CEREBROSPINAL FLUID

PIA MATERTHINMANY NERVES AND BLOOD VESSELS TO NOURISH BRAIN & SPINAL CORD CELLS

VENTRICLES4 INTERCONNECTED CAVITIES IN BRAIN AND BRAIN STEM•CONNECT TO CENTRAL CANAL IN SPINAL CORD•OPENS TO SUBARACHNOID SPACE•CHOROID PLEXUSES:

•SPECIALIZED CAPILLARIES OF PIA MATER THAT SECRETE CSF •COVERED BY EPENDYMAL CELLS WHICH FORM A BLOOD-CSF BARRIER•REGULATES CSF COMPOSITION BY FACILLITATED DIFFUSION AND ACTIVE TRANSPORT

CSF• 140 ML FILLS SPACE•PRODUCE 500ML/DAY ????•REABSORBED AT ARACHNOID GRANULATIONS•CLEAR, VISCID•HAS MORE SODIUM AND LESS POTASSIUM & GLUCOSE THAN OTHER EXTRACELLULAR FLUIDS•FUNCTIONS:

•PROTECTION: ABSORBS FORCE; •NUTRITION; •HOMEOSTASIS: IONIC CONCENTRATION; •REMOVAL OF WASTE; •PROBABLY TELLS AUTONMOMIC SYSTEM WHAT IS HAPPENING

SPINAL CORD•FROM FORAMEN MAGNUM TO 1ST/2ND LUMBAR VERTEBRAE• 31 SEGMENTS WITH PAIR OF SPINAL NERVES•THICKENINGS: WHERE? FOR?

•CEVICAL ENLARGEMENT•LUMBAR ENLARGEMENT

•CONUS MEDULARIS•FILUM TERMINALE TO COCCYX•CAUDA EQUINA•GROOVES:

•ANTERIOR MEDIAN FISSURE: DEEP•POSTERIOR MEDIAN SULCUS: SHALLOW

•WHITE MATTER ON OUTSIDE/ GREY MATTER ON INSIDE•GREY MATTER: MOSTLY INTERNEURONS, SOME MOTOR NEURONS•WHITE MATTER: 3 DIVISIONS:

•ANTERIOR, LATERAL, POSTERIOR FUNICULI: MAJOR NERVE TRACTS

SPINAL CORDFUNCTIONS:

REFLEX CENTERTRANSFER NERVE IMPULSES

REFLEX ARCS•SIMPLEST: 2 NEURONS

•SENSORY RECEPTOR ON DENDRITE OF SENSORY NEURON: AFFERENT•INTERNEURON: CNS: TO OTERH INTERNEURONS OR MOTOR NEURON•MOTOR NEURON: EFFERENT: TO EFFECTOR•EFFECTOR: SPINAL REFLEXES ARE SIMPLEST RESPONSE

REFLEX•FUNCTIONS:

•MAINTAIN HOMEOSTASIS•AUTOMATIC ACTIONS: SWALLOWING, SNEEZING, COGHING, & VOMITTING•AUTOMATIC RESPONSES TO CHANGE IN STIMULI•SENSORY RECEPTOR SENSORY NEURON CNS: INTERNEURONS MOTOR NEURON EFFECTOR

•AFFERENT NEURON INTERNEURON EFFERENT NEURON

•SPINAL REFLEXES: SIMPLESTREST TO BRAIN

PATELLAR REFLEX/KNEE-JERK•MONOSYNATPTIC REFLEX: 2 NEURONS: SENSORY-MOTOR•STRIKING PATELLAR LIGAMENT•KEEPS UPRIGHT POSITION WHEN KNEE SAGS

WITHDRAWAL REFLEX•PAIN STIMULI•SENSORY INTERNEURON MOTOR•SIGNAL TO ONE SET OF MUSCLES TO CONTRACT AND TO ANOTHER SET OF MUSCLES TO RELAX ??•IPSILATERAL FLEXOR CONTRACT/ CONTRALATERAL FLEXOR INHIBITED AND CONTRALATERAL EXTENDER CONTRACT TO TAKE SHIFT IN WEIGHT: CROSSED EXTENSOR REFLEX•ALSO SENDS MESSAGE TO BRAIN ??•FUNCTION??

ASCENDING/DESCENDING TRACTS

•USUALLY ALL AXONS IN SAME TRACT ORIGINATE IN SAME PLACE AND TRAVEL TO SAME PLACE

ASCENDING TRACTS•FASCICULUS GRACILUS & FASCICULUS CUNEATUS: POSTERIOR FUNICULI; SENSORY IMPULSES FROM SKIN, MUSCLES, JOINTS, BONES; INFO FOR TOUCH, PRESSURE AND BODY MOVEMENT; MOST CROSS ??•SPINOTHALAMIC: LATERAL AND ANTERIOR FUNICULI; FROM DIFFERENT BODY REGIONS TO BRAIN; TOCU AND PRESSURE; CROSS OVER•SPINOCEREBELLAR: LATERAL FUNICULI; POSTERIOR UNCROSSED; ANTERIOR CROSSED; FROM LOWER LIMBS AND TRUNK TO CEREBELLUM FOR COORDINATION

DESCENDING TRACTS•CORTICOSPINAL: LATERAL AND ANTERIOR FUNICULI; CROSS OVER; VOLUNTARY MUSCLE MOVEMENTS (SKELETAL MUSCLES); PYRAMIDAL TRACTS•RETICULOSPINAL: LATERAL AND ANTERIOR FUNICULI; SOME LATERAL CROSS, ANTERIOR UNCROSSED; CONTROL MUSCLE TONE AND SWEAT GLANDS; EXTRAPYRAMIDAL TRACTS•RUBROSPINAL: LATERAL FUNICULI; CROSS; MUSCLE COORDINATION AND MAINTENANCE OF POSTURE; EXTRAPYRAMIDAL TRACTS

BRAIN•FUNCTIONS??

•OVERSEES FUNCTIONS OF ENTIRE BODY•MEMORY; SENSES/PERCEPTION; HIGHER THINKING•PERSONALITY; EMOTIONS; YOU!!

•CEREBRUM; BRAIN STEM; CEREBELLUM

CEREBRUM•LARGETS; 2 HEMISPHERES; •CORPUS COLLOSUM•GYRI; SULCHI/FISSURES: DIFFERENT IN DIFFERENT PEOPLE

•LONGITUDINAL FISSURE•TRANSVERSE FISSURE

•LOBES: SAME AS SKULL BONES•FRONTAL: ANTERIOR PORTION; INFRONT OF CENTRAL SULCHUS; ABOVE LATERAL SULCHUS•PARIETAL: BEHIND CENTRAL SULCHUS•TEMPORAL: BELOW LATERAL SULCHUS•OCCIPITAL: POSTERIOR; NO DISTINCT BOUNDARY IN

FRONT; TENTORIUM CEREBELLI: DURA MATER BETWEEN CEREBELLUMINSULA: DEEP UNDER LATERAL SULCHUS; SEPARATED BY CIRCULAR SULCHUS

CEREBRUM•CEREBRAL CORTEX: THIN LAYER OF GRAY

MATTER ; OUTERMOST LAYER OF CORTEX??

•75% OF ALL CELL BODIES

•REST: WHITE MATTER: MYELINATED NEURONS; SENSORY/MOTOR/INTERNEURON: PASSING BETWEEN HEMISPHERES OR AREAS OF CEREBRUM

FUNCTIONS•HIGHER BRAIN FUNCTIONS: INTERPRETING SENSORY STIMULI; INITIATING VOLUNTARY MOVEMENT; MEMORY; REASONING (USING MEMORY); INTELLIGENCE; PERSONALITY•FUNCTIONAL REGIONS:

•SENSORY: INTERPRET SENSORY INFO PRODUCING FELLINGS•ASSOCIATION AREAS: ANALYZE AND INTERPRET

SENSORY INFO AND PROVIDE MEMORY, REASONING, VERBALIZING, JUDGEMENT

AND EMOTIONS•MOTOR: CARRY INFO TO EFFECTORS FOR PROPER RESPONSE TO SENSORY INFO

SENSORY•POSTCENTRAL GYRI OF ANTERIOR PORTION OF PARIETAL LOBE ALONG CENTRAL SULCHUS: TEMPERATURE; TOUCH; PRESSURE; PAIN; •POSTERIOR PORTION OF OCCIPITAL: VISION•BASE OF CENTRAL AND LATERAL SULCHI: TASTE•DEEP: SMELL•INFO CROSSES SO???•SIGHT AND HEARING GO TO BOTH SIDES ????•WENICKE’S AREA/SENSORY SPEECH AREA IN PARIETAL LOBE BEHIND LATERAL SULCHUS USUALLY IN LEFT HEMISPHERE: FROM VISUAL AND AUDITORY CORTEX FOR UNDERSTANDING WRITTEN AND SPOKEN LANGUAGE

ASSOCIATION•FRONTAL LOBES: HIGHER INTELLECTUAL PROCESSES: CONCENTRATING, PLANNING, COMPLEX PROBLEM SOLVING•PREFRONTAL AREAS: EMOTIONAL BEHAVIOR, AWARENESS OF CONSEQUENCES•PARIETAL LOBES: HELP INTERPRET SENSORY INFO, UNDERSTANDING SPEECH, CHOOSING WORDS OF THOUGHT AND FEELING EXPRESSION, AWARENESS OF THE FORM OF OBJECTS•TEMPORAL LOBES: COMPLEX SENSORY EXPERIENCES TO UNDERSTAND SPEECH AND FOR READING, STORE MEMORIES OF VISUAL SCENES, MUSIC, OTHER COMPLEX PATTERNS•OCCIPITAL LOBES: ANALYZING VISUAL PATTERNS, RECOGNIZING THINGS (PEOPLE)•GENERAL INTERPRETIVE AREA: (WHERE TEMPORAL, PARIETAL AND OCCIPITAL MEET) PROCESSES SENSOPRY INFO FROM ALL 3 ASSOCIATION AREAS, INTEGRATING VISUAL, AUDITORY AND OTHER SENSES FOR INTREPRETATION

MOTOR AREAS•FRONTAL LOBES: PRIMARY MOTOR AREAS IN THE CORTEX WITH MANY LARGE PYRAMIDAL CELLS CONTROL MOST OF MOTOR ACTIVITY,

•BROCA’S AREA: USUALLY LEFT HEMISPHERE, COMPLEX MUSCLE ACTION FOR SPEECH,•FRONTAL EYE FIELD: VOLUNTARY MOVEMENT OF EYES AND EYELIDS

•SEND IMPULSES TO DESCENDING TRACTS

HEMISPHERE DOMINANCE•BOTH INVOLVED IN BASIC FUNCTIONS: RECEIVING AND ANALYZING SENSORY INFO, CONTROLING MUSCLE MOVEMENT ON OPPOSITE SIDE, STORING MEMORIES•ONE SIDE (IN MOST: LEFT) DOMINANT FOR: SPEECH, WRITING, READING, COMPLEX INTELLECTUAL FUNCTIONS: VERBAL, ANALYTICAL, COMPUTATIONAL•NON-DOMINANT: NONVERBAL FUNCTIONS: ORIENTATION OF BODY SPACIALLY, UNDERSTANDING MUSICAL PATTERNS, VISUAL EXPERIENCES, EMOTIONAL AND INTUITIVE THOUGHT PROCESSES,

MEMORY•PERSISTENCE OF LEARNING•WORKING/SHORT TERM MEMORY: ELECTRICAL, ONLY THERE AS LONG AS NEURONS ARE CONNECTED•LONG TERM: CHANGES STRUCTURE OR FUNCTION OF NEURONS TO ENHANCE TRANSMISSION, CAN MAKE LIMITLESS SYNATIC CONNECTIONS, SOME OF WHICH REMAIN UNCHANGED FOR YEARS

MEMORY CONSOLIDATION•TURNING SHORT TERM INTO LONG TERM•LONG TERM SYNAPTIC POTENTIATION: REPEATED STIMULATION STRENGTHENS CONNECTION•HIPPOCAMPUS•AMYGDALA: ASSIGNS VALUE TO MEMORY

BASAL NUCLEI•MASSES OF GREY MATTER DEEP IN CEREBRUM•CAUDATE NUCLEUS, PUTAMEN, GLOBUS PALLIDUS•PRODUCE DOPAMINE: INHIBITORY NEUROTRANSMITTER•FACILITATE VOLUNTARY MOVEMENT BY INTERACTING WITH MOTOR CORTEX, THALAMUS AND CEREBELLUM

DIENCEPHALON•BETWEEN HEMISPHERES ABOVE BRAINSTEM•GREY MATTER•THALAMUS, HYPOTHALAMUS, OPTIC TRACTS AND CHIASMA, INFUNDIBULUM, POSTERIOR PITUITARY GLAND, MAMMILARY BODIES, PINEAL GLAND

THALAMUS•SELECTIVE GATEWAY FOR SENSORY IMPULSES (ALL BUT SMELL) TO APPROPRIATE AREAS OF CORTEX•CAN RECEIVE INFO FROM ANY PART OF CORTEX•SELECTS WHICH INFO TO SEND BASED ON SYNCHRONIZED ACTION POTENTIALS

HYPOTHALAMUS•CONNECTED TO CEREBRAL CORTEX, THALAMUS, AND BRAINSTEM•MAINTAINS HOMEOSTASIS BY LINKING NERVOUS AND ENDOCRINE SYSTEMS:

•HEART RATE•ATERIAL BLOOD PRESSURE•BODY TEMPERATURE•WATER & ELECTROLYTE BALANCE•HUNGER•BODY WEIGHT•MOVEMENTS AND SECRETIONS OF STOMACH & INTESTINES•PRODUCTION OF NUEROSECRETORY SUBSTANCES TO TELL PITUITARY GLAND TO REGULATE GROWTH, GLANDS AND REPRODUCTIVE PHYSIOLOGY•SLEEP AND WAKEFULNESS

LIMBIC SYSTEM•CEREBRAL CORTEX, HYPOTHALAMUS, THALAMUS, BASAL NUCLEI, DEEP NUCLEI= LIMBIC SYSTEM•CONTROLS EMOTIONAL EXPERIENCE AND EXPRESSION•CAUSING PLEASANT OR UNPLEASANT FEELINGS ABOUT EXPERIENCES AND GUIDES BEHAVIOR FOR SURVIVAL•ALSO INTERPRETS SMELL: WHICH IS WHY SMELL INFLUENCES EMOTIONS

BRAINSTEM•CONNECTS BRAIN TO SPINAL CORD•HAS MANY NERVE TRACTS AND NUCLEI (GREY MATTER)•PARTS:

•MIDBRAIN•PONS•MEDULAR OBLONGATA•RETICULAR FORMATION*

MIDBRAIN•BETWEEN DIENCEPHALON AND BRAINSTEM•MYELINATED NERVE FIBERS AND GREY MATTER FOR REFLEX CENTER•CEREBRAL PENDUNCLES: NOTOR PATHWAYS•SENSORY BUNDLES TO THALAMUS•CORPORA QUADRIGEMINA: 4 NUCLEI: REFLEX CENTERS FOR VISUAL REFLEXES (SUPERIOR) AND AUDITORY REFLEXES (INFERIOR) •RED NUCLEUS: COMMUNICATES WITH CEREBELLUM & SPINAL CORD CENTERS: REFLEXES FOR POSTURE

PONS•BETWEEN MIDBRAIN AND PONS•DORSAL: NERVES TO AND FROM MEDULA AND CEREBRUM•VENTRAL: MESSAGES FROM CEREBRUM TO CEREBELLUM•CENTER WHICH WORKS WITH MEDULLA FOR BASIC RHYTHM OF BREATHING

MEDULLA OBLONGATA•BETWEEN PONS AND MAGNUM FORAMEN•FLOOR OF FOURTH VENTRICLE•NERVES TO CEREBELLUM•ALL ASCENDING AND DESCENDING NERVE FIBERS PASS THROUGH•WHITE MATTER ON OUTSIDE; GREY MATTER IN CENTER FORMING NUCLEI: PASS SENSORY INFO, CROSSOVER

•CARDIAC CENTER: INCREASE/DECREASE HEART RATE•VASOMOTOR CENTER: VASOCONSTRICTION: INCREASE BLOOD PRESSURE OR OPPOSITE ACTION•RESPIRATORY CENTER: ADJUSTS RATE AND DEPTH OF BREATHING, WITH PONS CONTROLS BASIC RHYTHM•COUGHING, SNEEZING, SWALLOWING AND VOMITTINGINJURIES TO MEDULLA: ??•FATAL

RETICUALR FORMATION•IN MEDULLA, PONS AND MIDBRAIN: NETWORK CONNECTS HYPOTHALAMUS, BASAL NUCLEI, CEREBELLUM AND CEREBRUM•WHEN STIMULATED WAKES UP CEREBRAL CORTEX •DECREASED ACTIVITY= SLEEP•INJURY= COMA•FILTERS SENSORY INFO: KEEPS CORTEX FROM DEALING WITH UNIMPORTANT STIMULATIONREGULATE MOTOR ACTIVITIES SO MUSCLES MOVE EVENLY•INHIBITS/ENHANCES SOME SPINAL REFLEXES•INTENSE CEREBRAL CORTEX ACTIVITY KEEPS PERSON AWAKE

SLEEP•SLOW-WAVE: NON-REM: DECREASING ACTIVITY OF RETICULAR FORMATION•RESTFUL, DREAMLESS, REDUCED BLOOD PRESSURE AND RESPIRATORY RATE; LIGHT TO HEAVY: 4 STAGES: 70-90 MINUTES•REM: PARADOXICAL SLEEP: SOME BRAIN AREAS ARE ACTIVE; DREAM SLEEP; 5-15 MINUTES; HEART AND RESPIRATORY RATES VARY

CEREBELLUM•BELOW OCCIPITAL LOBES•TWO LATERAL HEMISPHERES: SEPARATED BY FALX CEREBELLI CONNECTED BY VERMIS•WHITE MATTER: ARBOR VITAE WITH GREY MATTER ON OUTSIDE•CEREBELLAR PENDUNCLES: NERVE TRACTS

•INFERIOR: SENSORY INFO ABOUT POSITION OF BODY PARTS •MIDDLE: FROM CEREBRAL CORTEX ABOUT DESIRED POSITION OF BODY PARTS•SUPERIOR: MOTOR IMPULSES TO MOVE BODY TO APPROPRIATE POSITION: INCORPORATES OTHER BRAIN AREAS

•FOR COORDINATION AND BALANCE, EQUILIBRIUM (SEMICIRCULAR CANALS)

PERIPHERAL NERVOUS SYSTEM

•NERVES THAT BRANCH FROM CNS•CRANIAL NERVES•SPINAL NERVES

•2 PARTS:•SOMATIC:

•CNS TO SKIN, & SKELETAL MUSCLES: CONCIOUS

•AUTONOMIC:•CNS TO VISCERA: SUBCONCIOUS

PERIPHERAL NERVES•FASCIA

•EPINEURIUM:•AROUND WHOLE NERVE; DENSE; COLLAGENOUS FIBERS

•PERINEURIUM:•SURROUNDS FASCICLE; LOOSER CONNECTIVE TISSUE

•ENDONEURIUM:•LOOSER CONNECTIVE TISSUE; INDIVIDUAL NEURON

•BLOOD VESSELS IN EPINEURIUM AND PERINEURIUM BECOME CAPPILLARIES IN ENDONEURIUM ??

NERVE CLASSIFICATION•SENSORY•MOTOR•MIXED

•CRANIAL NERVES•SPINAL NERVES

SUBDIVISIONS OF NERVE FIBERS

•IN BRAIN OR SPINAL NERVES:•GENERAL SOMATIC EFFERENT FIBERS:

•MOTOR IMPULSES TO SKELETAL MUSCLES •GENERAL VISCERAL EFFERENT FIBERS

•TO SMOOTH MUSCLES OR GLANDS•GENERAL SOMATIC AFFERENT FIBERS

•FROM SKIN OR SKELETAL MUSCLES TO CNS•GENERAL VISCERAL AFFERENT FIBERS

•FROM BLOOD VESSELS AND INTERNAL ORGANS TO CNS

SPECIALIZED CRANIAL NERVE FIBERS

•SPECIAL SOMATIC EFFERENT FIBERS: •MOTOR IMPULSES TO MUSCLES FOR CHEWING, SWALLOWING AND SPEAKING

•SPECIAL VISCERAL AFFERENT FIBERS:•SENSORY FROM OLFACTORY AND TASTE

•SPECIAL SOMATIC AFFERENT FIBERS:•SENSORY FROM SIGHT, HEARING, AND EQUILIBRIUM

CRANIAL NERVES•HOW MANY?

•12 PAIRS•ALL BUT FIRST 2 FROM BRAINSTEM•SEE HANDOUT

http://hicheeky.files.wordpress.com/2009/10/cranial_nerves_netter.jpg?w=527

SPINAL NERVESHOW MANY:

31 PAIRSALL BUT FIRST ARE MIXED8 PAIRS OF CERVICAL NERVES: C1-C812 PAIRS OF THORACIC NERVES: TI-T125 PAIRS OF LUMBAR NERVES: L1-L55 PAIRS OF SACRAL NERVES: S1-S51 PAIR OF COCCYGEAL NERVES C0

CAUDA EQUINA•ADULT SPINAL CORD ENDS????

•L2•LUMBAR, SACRAL, AND COCYGEAL NERVES DESCEND TO THEIR EXITS BEYOND THE END

SPINAL ROOTS•EACH NERVE HAS 2 ROOTS

•DORSAL ROOT•POSTERIOR: SENSORY•DORSAL ROOT GANGLION:

•CELL BODIES•DIRECTION????

•DERMATOME: AREA OF SKIN INNERVATED BY SPINAL NERVE

•VENTRAL ROOT•ANTERIOR:MOTOR ROOT•CELL BODIES IN GREY MATTER

SPINAL NERVES•BOTH ROOTS UNITE TO FORM NERVE•4 BRANCHES

•MENINGEAL BRANCH: •BACK INTO VENTRAL CANAL TO MENINGES, BLOOD VESSELS AND INTERVERTEBRAL LIGAMENTS

•DORSAL BRANCH: •POSTERIORLY: INNERVATES SKIN AND MUSCLES OF BACK

•VENTRAL BRANCH:• MAIN BRANCH, MUSCLE AND SKIN ON FRONT, SIDES AND LIMBS

•VISCERAL BRANCH: •ONLY IN THORACIC AND LUMBAR REGIONS, TO ORGANS, PART OF AUTONOMIC NERVOUS SYSTEM

PLEXUSES•IN ALL REGIONS BUT THORACIC AREAS•NEURONS ARE RECOMBINED SO THAT ALL NEURONS GOING TO A PARTICULAR AREA TRAVEL THROUGH THE SAME NERVES EVEN IF THEY COME FROM DIFFERENT SPINAL NERVES•TYPES:

•CERVICAL: •IN NECK, BRANCHES FROM C1-C4; TO MUSCLES AND SKIN OF NECK

•BRACHIAL: • C5-8 AND T1; TO SHOULDER AREA; 10 DIFFERENT MUSCLES

•LUMBOSACRAL: •T12 TO C0; 5 NERVES; LOWER ABDOMEN TO FEET (SCIATIC NERVES: LARGEST/LONGEST)

•VENTRAL BRANCHES DON’T FORM PLEXUSES; BECOME INTERCOSTAL NERVES

AUTONOMIC NERVOUS SYSTEM

•PART OF PNS•AUTONOMOUS??•CONTROLS SMOOTH MUSCLE, CARDIAC MUSCLE AND GLANDS•HEART RATE, BLOOD PRESSURE, BREATHING RATE, BODY TEMPERATURE AND OTHER HOMEOSTASIC MECHANISMS

GENERAL CHARACTERISTICS•REFLEXES: START WITH RECEPTORS IN VISCERA AND SKIN THROUGH AFFERENT FIBERS TO NERVE CENTERS IN BRAIN OR SPINAL CORD, TRANSLATED AND INTEGRATED TO CRANIAL AND PERIPHERAL NERVES TO GANGLIA OUTSIDE CNS WHERE MESSAGE IS INTEGRATED; TO EFFERENT FIBERS TO MUSCLE AND BONE•SOME INDEPENDENCE FROM REST OF BRAIN AND SPINAL CORD

AUTONOMIC NERVE FIBERS•EFFERENT/MOTOR•UNLIKE SOMATIC NERVOUS SYSTEM HAS 2 NEURONS:

•PREGANGLIONIC: CELL BODY IN CNS•POSTGANGLIONIC: CELL BODY IN AUTONOMIC GANGLION; TO EFFECTOR

DIVISIONS•SYMPATHETIC•PARASYMPATHETIC

SYMPATHETIC DIVISION•T1-L2•PREGANGLIONIC FIBERS ENTER THE SYMPATHETIC GANGLIA•SYMPATHETIC CHAIN GANGLIA/PARAVERTEBRAL GANGLIA: BOTH SIDES OF SPINAL CORD; UNDER PARIETAL PLEURA & PERITONEUM•SYMPATHETIC TRUNKS: SYMPATHETIC GANGLIA PLUS FIBERS OF CONNECTION•COLLATERAL GANGLIA: GANGLIA CLOSER TO VISCERA

SYMPATHETIC DIVISION•FOUND IN T1-L2•PREGANGLIONIC FIBERS EXIT VENTRAL ROOT AND SYNAPSE WITH POSTGANGLIONIC FIBER IN SYMPATHETIC GANGLION NEAR SPINAL CORD, OR TRAVELS ALONG SYMPATHETIC TRUNK TO ANOTHER GANGLION OR TRAVELS TO COLLATERAL GANGLION NEARER THE ORGAN OR GLAND

PREGANGLIONIC FIBERS•MAY SYNAPSE IN PARAVERTEBRAL GANLIA, PASS THROUGH GANGLIA ALONG SYMPATHETIC TRUNKS & SYNAPSE IN OTHER GANGLIA OF TRUNK, OR TO COLLATERAL GANGLIA TO SYNAPSE

• SYMPATHETIC CHAIN GANGLION/PARAVERTEBRAL GANGLION: 2 GROUPS OF GANGLIA IN CHAINS ALONG SPINAL CORD• SYMPATHETIC TRUNKS: GANGLIA AND FIBERS OF CONNECTION• COLLATERAL GANGLIA: SYMPATHETIC GANGLIA NEARER VISCERA

http://home.comcast.net/~wnor/sympatheticchain.jpg

AUTONOMIC NEUROTRANSMITTERS

•PREGANGLIONIC FIBERS OF BOTH DIVISIONS SECRETE ACETYLCHOLINE: CHOLINERGIC FIBERS•POSTGANGLIONIC OF PARASYMPATHETIC: CHOLINERGIC•POSTGANGLIONIC OF SYMPATHETIC: RELEASE NOREPINEPHRINE: ADRENERGIC•TO SWEAT GLANDS AND SOME BLOOD VESSELS ARE CHOLINERGIC•MOST ORGANS ARE INNNERVATED BY BOTH WITH OPOSING ACTIONS•SYMPATHETIC TONE: BLOOD VESSELS ONLY INNERVATED BY SYMPATHETIC ; DECREASING STIMULATION: VASODILATION; INCREASING: VASOCONSTRICTION

AUTONOMIC NEUROTRANSMITTER ACTION

•BIND TO PROTEIN RECEPTOR: ALTERS MEMBRANE: CAUSING SMOOTH MUSCLE TO CONTRACT AND GLAND TO SECRETE•ACETYLCHOLINE BINDS TO 2 RECEPTORS:

•MUSCARINIC: IN EFFECTOR CELL MEMBRANES OF ALL POSTGANGLIONIC PARASYMPATHETIC NERVE FIBERS AND ALL CHOLINERGIC SYMPATHETIC FIBERS;•RESPONSES ARE EXCITATORY BUT SLOW•NICOTINIC: BETWEEN PREGANGLIONIC AND POSTGANGLIONIC OF BOTH; RESPONSES ARE EXCITATORY AND FAST

•NOREPINEPHRINE FROM SYMPATHETIC TO ADRENERGIC RECEPTORS

•ALPHA•BETA

•STIMULATION OF EACH IS EXCITATORY BUT DIFFERENT IN DIFFERENT ORGANS, THE OVERALL EFFECT IS DETERMINED BY HOW MANY OF EACH RECEPTOR TYPE ARE IN THE CELL MEMBRANE

ENDING NEUROTRANSMITTER ACTION

•ACETYLCHOLINE: ACETYLCHOLINESTERASE: RELEASED QUICKLY SO ACETYLCHOLINE USUALLY HAS A SHORT STIMULATION•NOREPINEPHRINE: RE-UPTAKE: ACTIVE TRANSPORT AND INACTIVATED BY MONOAMINEOXIDASE OF MITHOCHONDRIA; TAKES LONGER SO SOME MAY DIFFUSE INTO BLOODSTREAM COULD WORK UP TO 30 SECONDS

CONTROL OF AUTONOMIC ACTIVITY

•MOSTLY BRAIN AND SPINAL CORD: LIKE MEDULLA, HYPOTHALAMUS•LIMBIC SYSTEM, CEREBRAL CORTEX: CONTROL DURING STRESS•GANGLIA PROVIDE SOME INDEPENDENCE

•ALSO AUTONOMIC NERVOUS SYSTEM CAN AFFECT EMOTIONAL EXPRESSION AND BEHAVIOR

LIFE SPAN CHANGES•APOPTOSIS: PROGRAMMED CELL DEATH; BEGINS BEFORE BIRTH; CONTINUES THROUGH LIFE; WHEN IT STOPS DISEASE OCCURS

•30: APOPTOSIS INCREASES (SOME STEM CELLS STILL) •RESULTS IN 10% BRAIN SHRINKAGE OVER LIFE; AT DIFFERENT SPEEDS IN DIFFERENT AREAS: MORE IN CEREBRAL CORTEX

•DENDRITIC BRANCHES OF CEREBRAL CORTEX DECREASE; SLOWING TRANSMISSION; DECREASING NEUROTRANSMITTERS AND ENZYMES TO MAKE THEM; MAY DECREASE 5-10%; DISEASES: STROKE, DEPRESSION, ALZEIMER’S, PARKINSON’S, DEMETIA

• FADING MEMORIES• SLOWING REFLEXES AND RESPONSES• DECREASING BLOOD PRESSURE• 70: ANKLE NERVES CAN’T PICK UP

VIBRATIONS AS WELL: LOSS OF BALANCE; POOR EYESIGHT; ANEMIA; INNER EAR MALFUNCTION: POOR BALANCE: MORE FALLS• RETICULAR ACTIVATING CENTER

AFFECTED: SLEEP LESS; HARDER TO FALL ASLEEP AND STAY ASLEEP; MOVE MORE; SLOW WAVE AND REM SLEEP DECREASES: NAP MORE