Anatomi Fisiologi - Sistem Syaraf

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ANATOMI DAN FISIOLOGI ANATOMI DAN FISIOLOGI SISTEM SYARAF SISTEM SYARAF (NERVOUS SYSTEM) (NERVOUS SYSTEM) Dr . Halinda Sari Lubis, MKKK Dr . Halinda Sari Lubis, MKKK FKM - USU FKM - USU

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Nervous system

Transcript of Anatomi Fisiologi - Sistem Syaraf

  • Sistem saraf adalah pemula kegiatan otot tubuh & pengatur fungsi mental dan fisik Sistem saraf bekerja berdasarkan impuls elektrokimia

  • SISTEM SARAFTermasuk sistem pengendaliMerupakan rangkaian organ yang kompleks membentuk sistem terdiri dari jaringan saraf. Jaringan saraf tersebar di seluruh jaringan tubuh.Sistem informasi yang terintegrasi, berfungsi menerima data, mengolahnya, menentukan respon dan memberi perintah ke setiap organ tubuh untuk melakukan tindakan yang penting demi keadaan homeostasis

    Homeostasis : Pengaturan ketenangan internal dan pemelihara-an kondisi dalam tubuh meskipun terjadi perubahan pada lingkungan sekitarnya.

  • Tanpa sistem saraf manusia tidak mampu berkomunikasi, berinteraksi, beradaptasi terhadap perubahan lingkungan (internal & eksternal)

    StimulusSetiap perubahan yang terjadi di luar dan di dalam tubuh yang memicu pengiriman pesan ke sistem sarafMis: huruf mata

  • 3 FUNGSI SISTEM SARAF Fungsi kewaspadaan Membantu mengetahui perubahan-perubahan yang terjadi di sekitar untuk disampaikan ke alat indera. Pada alat indera terdapat saraf sensorik yang befungsi khusus sebagai penginput dataFungsi intergrasi Menerima pesan (input data) sensorik dari lingkungan luar, interpretasi oleh CNS, mengatur informasi dan mengintegrasikan dengan informasi yang telah ada untuk menentukan jenis respon yang akan diberikanFungsi koordinasi Setelah dari otak informasi yang sudah terintegrasi untuk mengirimkan pesan/perintah pada otot2 dan kelenjar2, menghasilkan gerak dan sekresi terorganisasi

  • Fungsi : Koordinasi beberapa Aktivitas Tubuhberbicaragerakan ototpendengaranpengecapanpenglihatanberfikir Sekresi hormonRespon terhadap bahayaPerasaan nyeri sentuhaningatandll.

  • Sistem SyarafDibagi dalam dua bagian :Central Nervous System (CNS)/Sistem Syaraf Pusat (SSP) :Brain (otak)Spinal Cord (medula spinalis)Peripheral Nervous System (PNS)/Sistem Syaraf Tepi (SST) :12 pasang syaraf Kranial & 31 pasang syaraf Spinal Somatic Nervous System (Voluntary Movement)/ Sistem Syaraf Sadar (gerakan Sadar)skeletal muscles (otot rangka)Autonomic Nervous System (Involuntary)/Sistem Syaraf Tak Sadar (gerakan Tak Sadar)viscera, otot polos & kelenjar eksokrin(sal. cerna, jantung & paru, kelenjar adrenal)

  • Sistem SyarafUnit Fungsional Sistem Syaraf adalah Sel Syaraf (NEURON) :Dasar yg membangun sistem sarafMembawa impuls listrik/informasiTerdiri dari:Cell body (membangkitkan impuls)Axon (memindahkan impuls)Dendrites (menerima impuls)

    SYNAPSE : hubungan antara neuron dengan neuron

  • NEURONS

  • Tipe NeuronSensory Neurons (neuron sensorik)Membawa informasi ke CNSMotor Neurons (neuron motorik)Membawa informasi dari CNS ke otot & kelenjarInter NeuronsNeuron yang menghubungkan antara sensory input dan motor output.

  • Neuro-transmitters (Nts)Zat Kimia yg digunakan Neuron utk berhubungan satu dgn lainnyaContoh :Dopamine (gerakan, perhatian, emosi)Serotonin (mood, lapar, tidur, arousal)Norepinephrine/adrenaline (waspada, arousal)Acetylcholine (otot, belajar, ingatan)Endorphins (menghilangkan nyeri, meningkatkan mood)

  • Central Nervous System (CNS)Sistem Syaraf Pusat (SSP)

  • BRAIN (OTAK)

  • The Brain (Otak)BentukMengandung lebih 100 Milyard sel-sel syaraf2% dari berat badan, menggunakan 30% energiTerdiri dari : 2 hemispheres

    FungsiBeberapa fungsi disebarkan keseluruh otak, lainnya lebih terlokalisir.Hubungan antar sel-sel saraf membuat otak begitu khusus (& us so smart)

  • Cerebral Cortex (Cerebrum)Mengandung lebih 30 Milyar neuronMerupakan lembaran berkerut menutupi otakDibagi atas Hemisphere (Left & Right)Informasi dari satu sisi crosses over/menyilangSuara dari telinga kanan diproses di hemisphere kiriGerakan lengan kiri dilakukan hemisphere kananFungsiMotor - Mengendalikan gerakan sadarSensory - Mengenal dan memproses sensasiAssociation Fungsi Higher mentalLanguage - memadukan dan menghasilkan

  • Cerebral HemipsheresKiri dan KananDihubungkan oleh corpus callosumDibagi dalam beberapa lobes :Frontalberbicara, gerakan otot, merencanakan, keputusanTemporalProses pendengaran, bahasa, memori, emosiParietalProses sensori (body sensations)OccipitalProses penglihatan (vision)

  • Struktur di bawah otakBrainstem (batang otak)termasuk medulla, pons, reticular formationbernapas, arousal, denyut jantung, dll.Thalamus Menyebarkan SensoriCerebellum Belajar nonverbal & ingatan.Limbic System Amygdala - emosiHypothalamus - mengawasi (lapar, haus, dll.)Pituitary Gland pelepasan hormonHippocampus - memori

  • SPINAL CORD (MEDULA SPINALIS)Jalur yg menghubungkan otak dan Sistem saraf tepiAscending : impuls sensori menuju otakDescending : impuls motor ke synaps dgn motor neurons yg akan mempengaruhi effectors

    Pusat Reflex Respon cepat tanpa melalui otaksomatic reflexes (otot rangka dan kulit)stretch reflexdeep tendon reflexflexor reflexcrossed extensor reflexvisceral reflexes (kelenjar & otot polos)Fungsi :

  • Letak :Di dalam saluran tulang belakang (vertebral canal) dimulai dari batang otak (medulla) hingga 1st or 2nd lumbar vertebraSegmen ;31 pairs of nerves : cervical (8 pair)thoracic (12 pair)lumbar (5 pair)sacral (5 pair)coccygeal (1 pair)

  • Autonomic Nervous SystemPeran sistem saraf simpatetik dan parasimpatetik adalah saling berlawanan. Umumnya sisytem saraf simpatetik berpengaruh sebagai perangsang dan mempersiapkan tubuh untuk kerja.Sedangkan system parasimpatetik mengembalikan fungsi tubuh ke keadaan normal.

  • sympatheticparasympatheticPupil dilatasiProduksi air mata tak dipengaruhiPupil konstriksi Produksi airmata dipengaruhiFrekuensi denyut jantung meFrekuensi denyut jantung meBronkodilatasiBronkokonstriksi Aktifitas lambung+pankreas meAktifitas lambung+pankreas meGlikogen dirobah menjadi glukosaGlukosa dirobah menjadi glikogenPelepasan adrenalin+noradrenalin mePelepasan adrenalin+noradrenalin mePeristalsis mePeristalsis meRelaksasi Kandung KemihKomtraksi Kandung Kemih

  • SimpatetikThoracolumbar (asal serabut saraf : antara T1 L1)

  • ParasimpatietikCraniosacral(asal serabut saraf : otak & sakrum

  • *****The brain is not particularly large. It weighs a few pounds and has the consistency of ripe avocado. It floats in a bath of Cerebro-spinal fluid (its unable to support its own weight unaided), and is protected by membranes (called "dura") to prevent damage. Also its pretty well armoured being inside the skull. It also consumes large amounts of energy (30% of our energy requirement goes to the brain). Its constantly active (even in psychology lectures). It can be roughly divided into two hemispheres (left and right) and four lobes (frontal, temporal, parietal and occipital).

    Some functions (like vision, motor control etc.) are distributed throughout the brain. Some functions (like creating dopamine) are highly localized. Mostly cognitive functions work by having a number of distributed "components" in the brain - areas which are "mostly" concerned with a particular function - such as Broca's area which is concerned with speech production.

    Note that the brain is basically split into two halves - the left and right hemispheres. Information from the left side of the body goes into the right hemisphere, and information from the left side goes into the left hemisphere. The major connection between the two hemispheres is the "corpus callosum", a broad band of fibers connecting the two halves.*The cerebral cortex is the area of our brain which is mosty developed in humans. It is a "wrinkled sheet" about the area of 4 letter sized pages. It wont fit in the skull unless you "crumple it up".The Cerebral Cortex (like the rest of the brain) can be divided into two "hemispheres" - left and right. Information from one side of the body crosses over into the other side. The cortex is mostly concerned with "higher functions" and things we have conscious control over. These include thoughts, voluntary movements, language and vision.*The cerebral hemispheres (left and right) are connected by the corpus callosum. This broad band of fibers joins the two halves, allowing the two halves of the brain to communicate.

    The Hemispheres can also be divided into lobes. These lobes are divisions based on certain "landmarks" sulci (fissures) and gyri (ridges) and also on functions. Very roughly they can be divided as follows:

    Frontal lobeSpeaking, muscle movements, plans, judgmentsTemporal lobeAuditory processing, Language, memory, emotionnote that language is normally located in the left hemisphere, in Broca's and Wernicke's areas. Parietal lobeSensory processing (body sensations)Occipita lobelVisual processing (vision)

    Damage to any one of these lobes causes defecits (or problems) with regard to those functions. In all cases (except language), damage to one side of the brain shows up as problems on the other side of the body.*You can divide the brain a number of ways. One way is to break it down into Higher Structures (Cerebral Cortex) and Lower level structures which are concerned with a variety of basic functions.Note that the brain evolved "bottom up" so that in primitive animals the "lower level" structures are present, but the cortex is not particularly large.

    Brainstem (including Medulla and reticular formation) is concerned with functions like breathing, basic arousal etc. Damage to medulla (oblongata) tends to cause death. Damage to reticular formation can result in coma.

    Thalamus is the sensory switchboard. Major neural pathways run from sensory systems (sight, hearing, touch etc.) through here before being routed to other parts of the brain. Damage here is bad since it messes up your sensory system.

    Cerebellum ("little brain") is a small cauliflower like structure on the back of the brain. It is used for motor control, coordination and learning movements. If this gets damaged your ability to walk, move your hands etc. is compromised.