University:
Kentucky State University
Course:
BIO 301 | Human Anatomy
Academic year:

2019
Views:

223

Pages:

36
Author:

cinquennehgz

THE NERVOUS SYSTEM 1/4 INTRO. AND BRAIN NERVOUS SYSTEM (NS) ANATOMY • DEVELOPS FROM ECTODERM (NEURAL TUBE). • DIVIDED ANATOMICALLY INTO CENTRAL AND PERIPHERAL NS. FUNCTIONS OF THE NERVOUS SYSTEM • SENSORY FUNCTION. SENSORY RECEPTORS DETECT INTERNAL STIMULI ( INCREASE IN BLOOD PRESSURE, OR EXTERNAL STIMULI (A RAINDROP LANDING ON YOUR ARM). THEN CARRIED INTO THE BRAIN AND SPINAL CORD THROUGH CRANIAL/SPINAL NERVES. • INTEGRATIVE FUNCTION. PROCESSES SENSORY INFORMATION BY ANALYZING IT AND MAKING DECISIONS FOR APPROPRIATE RESPONSES. • MOTOR FUNCTION. ONCE SENSORY INFORMATION IS INTEGRATED, THE NERVOUS SYSTEM MAY ELICIT AN APPROPRIATE MOTOR RESPONSE BY ACTIVATING EFFECTORS (MUSCLES/GLANDS) THROUGH CRANIAL/SPINAL NERVES (CAUSES MUSCLES TO CONTRACT AND GLANDS TO SECRETE) NEURON STRUCTURE NEURON CLASSIFICATION THE BRAIN BRAIN FOUR MAJOR PARTS: • CEREBRUM (LARGEST). • DIENCEPHALON • BRAINSTEM • CEREBELLUM CEREBRUM SUBDIVIDED INTO SEVERAL LOBES: FRONTAL, PARIETAL, TEMPORAL, AND OCCIPITAL LOBES THE CENTRAL SULCUS SEPARATES THE FRONTAL LOBE FROM THE PARIETAL LOBE. PRECENTRAL GYRUS AND POSTCENTRAL GYRUS???? FUNCTION? HOMEWORK!! THE LATERAL CEREBRAL SULCUS (FISSURE) SEPARATES THE FRONTAL LOBE FROM THE TEMPORAL LOBE. THE PARIETO-OCCIPITAL SULCUS SEPARATES THE PARIETAL LOBE FROM THE OCCIPITAL LOBE. THE INSULA, CANNOT BE SEEN AT THE SURFACE OF THE BRAIN BECAUSE IT LIES WITHIN THE LATERAL CEREBRAL SULCUS, DEEP TO THE PARIETAL, FRONTAL, AND TEMPORAL LOBES CEREBRAL WHITE MATTER CONSISTS PRIMARILY OF MYELINATED AXONS IN THREE TYPES OF TRACTS • 1.ASSOCIATION TRACTS: CONDUCT NERVE IMPULSES BETWEEN GYRI IN THE SAME HEMISPHERE. • 2.COMMISSURAL TRACTS: CONDUCT NERVE IMPULSES FROM GYRI IN ONE CEREBRAL HEMISPHERE TO CORRESPONDING GYRI IN THE OTHER CEREBRAL HEMISPHERE ( CORPUS CALLOSUM , ANTERIOR COMMISSURE, AND POSTERIOR COMMISSURE.) • 3.PROJECTION TRACTS: CONDUCT NERVE IMPULSES FROM THE CEREBRUM TO LOWER PARTS OF THE CNS (THALAMUS, BRAINSTEM, OR SPINAL CORD) IN TWO DIRECTIONS. WHITE MATTER FUNCTIONAL ORGANIZATION OF THE CEREBRAL CORTEX • SENSORY AREAS RECEIVE SENSORY INFORMATION AND ARE INVOLVED IN PERCEPTION( THE CONSCIOUS AWARENESS OF A SENSATION). • MOTOR AREAS CONTROL THE EXECUTION OF VOLUNTARY MOVEMENTS. • ASSOCIATION AREAS DEAL WITH MORE COMPLEX INTEGRATIVE FUNCTIONS SUCH AS MEMORY, EMOTIONS, REASONING, WILL, JUDGMENT, PERSONALITY TRAITS, AND INTELLIGENCE SENSORY AREAS • THE PRIMARY SOMATOSENSORY AREA: AREAS 1, 2, 3 • THE PRIMARY VISUAL AREA: AREA 17. • THE PRIMARY AUDITORY AREA: AREAS 41, 42. • THE PRIMARY GUSTATORY AREA: AREA 43, (TASTE) • THE PRIMARY OLFACTORY AREA: AREA 28 MOTOR AREAS THE PRIMARY MOTOR AREA:AREA 4. • ELECTRICAL STIMULATION OF ANY POINT IN THE PRIMARY MOTOR AREA CAUSES CONTRACTION OF SPECIFIC SKELETAL MUSCLE FIBERS ON THE OPPOSITE SIDE OF THE BODY. BROCA’S SPEECH AREA: AREAS 44, 45 • SPEAKING AND UNDERSTANDING LANGUAGE ARE COMPLEX ACTIVITIES ( SEVERAL SENSORY, ASSOCIATION, AND MOTOR AREAS OF THE CORTEX) • 97% OF THE POPULATION, AREAS ARE LOCALIZED IN THE LEFT HEMISPHERE. • THE PLANNING AND PRODUCTION OF SPEECH OCCUR IN THE LEFT FRONTAL LOBE IN MOST PEOPLE. ASSOCIATION AREAS • SOMATOSENSORY ASSOCIATION AREA. • VISUAL ASSOCIATION AREA. • FACIAL RECOGNITION AREA. • AUDITORY ASSOCIATION AREA. • ORBITOFRONTAL CORTEX, • ****WERNICKE’S AREA: INTERPRETS THE MEANING OF SPEECH BY RECOGNIZING SPOKEN WORDS. (IMPORTANT) DAMAGE? HOMEWORK. • COMMON INTEGRATIVE AREA. PREFRONTAL CORTEX • IS AN EXTENSIVE AREA IN THE ANTERIOR PORTION OF THE FRONTAL LOBE. • THAT IS WELL DEVELOPED IN PRIMATES, ESPECIALLY HUMANS. • IS INVOLVED WITH THE MAKEUP OF A PERSON’S PERSONALITY, INTELLECT, COMPLEX LEARNING ABILITIES, RECALL OF INFORMATION, INITIATIVE, JUDGMENT, FORESIGHT, REASONING, CONSCIENCE, INTUITION, MOOD, PLANNING FOR THE FUTURE, AND DEVELOPMENT OF ABSTRACT IDEAS. • DAMAGE? ? HOMEWORK!! PREMOTOR AREA • DEALS WITH LEARNED MOTOR ACTIVITIES OF A COMPLEX AND SEQUENTIAL NATURE. • IT GENERATES NERVE IMPULSES THAT CAUSE SPECIFIC GROUPS OF MUSCLES TO CONTRACT IN A SPECIFIC SEQUENCE, AS WHEN YOU WRITE YOUR NAME. • THE PREMOTOR AREA ALSO SERVES AS A MEMORY BANK FOR SUCH MOVEMENTS. HEMISPHERE LOCALIZATION BRAIN STEM • MIDBRAIN • PONS • MEDULLA OBLONGATA MIDBRAIN • THE AQUEDUCT OF THE MIDBRAIN (CEREBRAL AQUEDUCT) PASSES THROUGH THE MIDBRAIN, CONNECTING 3RD AND 4TH VENTRICLES. • THE MIDBRAIN CONTAINS BOTH NUCLEI AND TRACTS • CONTAINS PAIRED BUNDLES OF AXONS KNOWN AS THE CEREBRAL PEDUNCLES (WHICH CONDUCT NERVE IMPULSES FROM MOTOR AREAS IN THE CEREBRAL CORTEX TO THE SPINAL CORD, MEDULLA, AND PONS). • COORDINATE MOVEMENTS OF HEAD, EYES, AND TRUNK IN RESPONSE TO VISUAL AND AUDITORY STIMULI . • CONTAINS NUCLEI OF ORIGIN FOR OCULOMOTOR (III) AND TROCHLEAR (IV) NERVES. PONS • SUPERIOR TO THE MEDULLA AND ANTERIOR TO THE CEREBELLUM . • CONSISTS OF BOTH NUCLEI AND TRACTS. • IS A BRIDGE THAT CONNECTS PARTS OF THE BRAIN WITH ONE ANOTHER. • PONTINE RESPIRATORY GROUP, TOGETHER WITH THE MEDULLARY RESPIRATORY CENTER, THE PONTINE RESPIRATORY GROUP HELPS CONTROL BREATHING. MEDULLA OBLONGATA • IS CONTINUOUS WITH THE SUPERIOR PART OF THE SPINAL CORD. • FORMS THE INFERIOR PART OF THE BRAINSTEM • THE MEDULLA’S WHITE MATTER CONTAINS ALL SENSORY (ASCENDING) TRACTS AND MOTOR (DESCENDING) TRACTS THAT EXTEND BETWEEN THE SPINAL CORD AND OTHER PARTS OF THE BRAIN. • CONTAINS SEVERAL NUCLEI. • THE CARDIOVASCULAR (CV) CENTER REGULATES THE RATE AND FORCE OF THE HEARTBEAT AND THE DIAMETER OF BLOOD VESSELS. • THE MEDULLARY RESPIRATORY CENTER ADJUSTS THE BASIC RHYTHM OF BREATHING • CONTROL REFLEXES FOR VOMITING, SWALLOWING, SNEEZING, COUGHING, AND HICCUPPING. CEREBELLUM • SECOND TO THE CEREBRUM IN SIZE • OCCUPIES THE INFERIOR AND POSTERIOR ASPECTS OF THE CRANIAL CAVITY. • THE CEREBELLUM HAS A HIGHLY FOLDED SURFACE (OUTER GRAY MATTER CORTEX, INNER WHITE (ARBOR VITAE)) • RESEMBLES A BUTTERFLY. THE CENTRAL CONSTRICTED AREA IS THE VERMIS, THE LATERAL “WINGS” OR LOBES ARE THE CEREBELLAR HEMISPHERES • EACH HEMISPHERE CONSISTS OF LOBES (ANTERIOR, POSTERIOR, FLOCCULONODULAR). CEREBELLUM • EVALUATE HOW WELL MOVEMENTS INITIATED BY MOTOR AREAS IN THE CEREBRUM ARE ACTUALLY BEING CARRIED OUT. • THE CEREBELLUM DETECTS THE DISCREPANCIES. • SENDS FEEDBACK SIGNALS TO MOTOR AREAS OF THE CEREBRAL CORTEX • COORDINATE COMPLEX SEQUENCES OF SKELETAL MUSCLE CONTRACTIONS. • IS THE MAIN BRAIN REGION THAT REGULATES POSTURE AND BALANCE. DIENCEPHALON • CENTRAL CORE OF BRAIN TISSUE JUST SUPERIOR TO THE MIDBRAIN. • ALMOST COMPLETELY SURROUNDED BY THE CEREBRAL HEMISPHERES. • CONTAINS NUMEROUS NUCLEI INVOLVED IN A WIDE VARIETY OF SENSORY AND MOTOR PROCESSING BETWEEN HIGHER AND LOWER BRAIN CENTERS. • SURROUNDS THE THIRD VENTRICLE • IT INCLUDES THE THALAMUS, HYPOTHALAMUS, AND EPITHALAMUS. THALAMUS • PAIRED OVAL MASSES OF GRAY MATTER ORGANIZED INTO NUCLEI (SEVEN MAJOR GROUPS) WITH INTERSPERSED TRACTS OF WHITE MATTER. • MAJOR RELAY STATION FOR MOST SENSORY IMPULSES THAT REACH THE PRIMARY SENSORY AREAS. • CONTRIBUTES TO MOTOR FUNCTIONS BY TRANSMITTING INFORMATION FROM THE CEREBELLUM AND BASAL NUCLEI TO THE PRIMARY MOTOR AREA OF THE CEREBRAL CORTEX. • RELAYS NERVE IMPULSES BETWEEN DIFFERENT AREAS OF THE CEREBRUM • PLAYS A ROLE IN THE MAINTENANCE OF CONSCIOUSNESS. HYPOTHALAMUS • SMALL PART OF THE DIENCEPHALON, INFERIOR TO THE THALAMUS. • CONTROLS AND INTEGRATES ACTIVITIES OF AUTONOMIC NERVOUS SYSTEM. • PRODUCES HORMONES (RELEASING/INHIBITING HORMONES, OXYTOCIN, ADH). • REGULATES EMOTIONAL AND BEHAVIORAL PATTERNS (TOGETHER WITH LIMBIC SYSTEM). • CONTAINS FEEDING/SATIETY CENTERS, THIRST CENTER, AND SUPRACHIASMATIC NUCLEUS (REGULATES CIRCADIAN RHYTHMS). • CONTROLS BODY TEMPERATURE BY (BODY’S THERMOSTAT) EPITHALAMUS • CONSISTS OF PINEAL GLAND: SECRETES MELATONIN PROTECTIVE COVERINGS OF THE BRAIN (MENINGES) • CONTINUOUS WITH THE SPINAL MENINGES, HAVE THE SAME BASIC STRUCTURE, AND BEAR THE SAME NAMES: • THE OUTER DURA MATER (CRANIAL IS TWO LAYERS, SPINAL ONLY ONE.) • THE MIDDLE ARACHNOID MATER • THE INNER PIA MATER. • THEY ARE FUSED TOGETHER EXCEPT WHERE TO ENCLOSE THE DURAL VENOUS SINUSES ( ENDOTHELIAL-LINED VENOUS CHANNELS FOR DRAIN VENOUS BLOOD FROM THE BRAIN). BLOOD–BRAIN BARRIER (BBB) • TIGHT JUNCTIONS THAT SEAL TOGETHER THE ENDOTHELIAL CELLS AND A THICK BASEMENT MEMBRANE THAT SURROUNDS THE CAPILLARIES. • ASTROCYTES (NEUROGLIA); PRESS UP THEIR PROCESSES AGAINST THE CAPILLARIES AND SECRETE CHEMICALS THAT MAINTAIN THE TIGHTNESS OF THE TIGHT JUNCTIONS. • LIPID-SOLUBLE SUBSTANCES (INCLUDING: O2, CO2), STEROID HORMONES, ALCOHOL, BARBITURATES, NICOTINE, AND CAFFEINE), AND WATER MOLECULES EASILY CROSS THE BBB BY DIFFUSING. • A FEW WATER-SOLUBLE SUBSTANCES (GLUCOSE) QUICKLY CROSS THE BBB BY FACILITATED TRANSPORT. CEREBROSPINAL FLUID (CSF) • A CLEAR, COLORLESS LIQUID (PRIMARILY WATER) THAT PROTECTS THE BRAIN AND SPINAL CORD. • CSF CONTINUOUSLY CIRCULATES THROUGH CAVITIES IN THE BRAIN AND SPINAL CORD. • THE TOTAL VOLUME OF CSF IS 80-150 ML. • CONTAINS SMALL AMOUNTS OF GLUCOSE, PROTEINS, LACTIC ACID, UREA, IONS (NA+, K+, CA2+, MG2+, CL− AND HCO3−), AND SOME WHITE BLOOD CELLS. • THE MAJORITY COMES FROM THE CHOROID PLEXUSES (NETWORKS OF BLOOD CAPILLARIES IN THE WALLS OF THE VENTRICLES) FUNCTIONS OF CSF • 1.MECHANICAL PROTECTION. CSF SERVES AS A SHOCK-ABSORBING MEDIUM. • 2.CHEMICAL PROTECTION. CSF PROVIDES AN OPTIMAL CHEMICAL ENVIRONMENT FOR ACCURATE NEURONAL SIGNALING. • 3.CIRCULATION. CSF IS A MEDIUM FOR MINOR EXCHANGE OF NUTRIENTS AND WASTE PRODUCTS. VENTRICLES (V.) • LATERAL V. • 3RD V. • 4TH V. Ø THE CSF OF LATERAL V. FLOWS INTO THE 3RD V. THROUGH TWO INTERVENTRICULAR FORAMINA Ø THE FLUID FLOWS THROUGH THE AQUEDUCT OF THE MIDBRAIN INTO 4TH V. Ø CSF ENTERS THE SUBARACHNOID SPACE THROUGH THREE OPENINGS IN THE ROOF OF THE 4TH V. Ø CSF THEN CIRCULATES IN THE CENTRAL CANAL OF THE SPINAL CORD. VENTRICLES CRANIAL NERVES • 12 PAIRS OF CRANIAL NERVES (I-XII) • PART OF THE PNS. • EACH CRANIAL NERVE HAS BOTH A ROMAN NUMER, AND A NAME. • THE NUMBERS INDICATE THE ORDER, FROM ANTERIOR TO POSTERIOR, IN WHICH THE NERVES ARISE FROM THE BRAIN. • THE NAMES DESIGNATE A NERVE’S DISTRIBUTION OR FUNCTION. CRANIAL NERVES • I, II, AND VIII NERVES CARRY AXONS OF SENSORY NEURONS (CALLED SPECIAL SENSORY NERVES: SMELL, VISION, HEARING ). • III, IV, VI, XI, AND XII NERVES ARE MOTOR NERVES (ONLY AXONS OF MOTOR NEURONS) • THEY LEAVE THE BRAINSTEM. • V, VII, IX, AND X NERVES ARE MIXED NERVES (AXONS BOTH OF SENSORY AND MOTOR).

The Nervous System 1-4 Intro and Brain

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