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Khusnul Mufikhah Department of Phisiology

Central Nervous System

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Page 1: Central Nervous System

Khusnul Mufikhah

Department of Phisiology

Page 2: Central Nervous System

Tujuan Pembelajaran Mahasiswa mampu menjelaskan fungsi umum

sistem saraf pusat Mahasiswa mampu menjelaskan fungsi

serebrum Mahasiswa mampu menjelaskan fungsi

masing-masing lobus / area korteks serebri Mahasiswa mampu menjelaskan fungsi

dienchepalon (thalamus dan hipotalamus) Mahasiswa mampu menjelaskan fungsi

serebelum Mahasiswa mampu menjelaskan fungsi

medulla spinalis

Page 3: Central Nervous System

Pendahuluan

Sistem Saraf : 3 % berat badan tubuh Unit fungsional dasar : NEURON Jaringan saraf menyusun organ-organ

sistem saraf : otak, medulla spinalis, reseptor di organ spesifik

Dibagi 2 : CNS (Central Nervous System) dan PNS (Peripheral Nervous System)

CNS : otak dan medulla spinalis PNS : seluruh jaringan saraf diluar CNS

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Page 5: Central Nervous System

CNS

.

Figure 8-1

• Tersusun atas:▫ Otak.▫ Medula Spinalis.

• Menerima input dari neuron sensorik .

• Mengatur aktifitas neuron motorik.• Neuron asosiasi (interneuron)

memelihara homeostasis dalam lingkungan internal.

Page 6: Central Nervous System

Fungsi CNS

Mengatur Homeostasis Koordinasi Emosi Memori Berfikir, belajar, bahasa

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Proteksi Otak

Cranium Cranial meninges Cerebrospinal fluid (CSF)

Page 9: Central Nervous System

Cerebrum

Figure 8-6

Bagian terbesar (80%).

Responsibel untuk fungsi mental yang lebih tinggi.

Corpus callosum:Axon utama yang

berfungsi menghubungkan otak kanan dan kiri.

Page 10: Central Nervous System

Korteks serebri

Figure 8-7

Lobus Frontal : Bag anterior cerebrum. Girus Precentral :

○ Neuron motorik.○ Mengatur gerakan.

Bagian tubuh yang memperoleh banyak saraf memiliki kortek motorik lebih luas.

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Lobus parietal

Figure 8-7

• Area primer persepsi sensorik somatesthetik.

• Bagian tubuh yang memiliki banyak saraf sensorik mempunyai kortek sensorik yang lebih luas.

Page 13: Central Nervous System

Corteks Cerebri (continued)

Temporal:Berisi pusat auditorik/ pendengaran.Interpretasi dan asosiasi informasi pendengaran

dan penglihatan. Oksipital:

area Primer penglihatan dan koordinasi gerak bola mata.

Insula: Proses simpan ingatan.Integrasi informasi sensorik dengan respon

visceral.Koordinasi respon cardiovascular terhadap stres.

Page 14: Central Nervous System

Ganglia basalis

Terdiri dari: Corpus striatum:

○ Nukleus kaudatus.○ Nukleus lentiformis:

Putamen dan globus palidus.

Fungsi:Mengatur gerakan

volunter.

Page 15: Central Nervous System

Lateralisasi Cerebrum

Cerebral dominan: Specialisasi oleh satu

hemisfer. Hemisfer kiri:

Kemampuan bahasa dan analitik.

kerusakan:○ Gangguan bicara berat.

Hemisfer kanan: Tugas visuospatial. Kerusakan:

○ Kesulitan menenukan jalan pulang.

Page 16: Central Nervous System

Bahasa

area Broca : Pusat artikulasi bicara.

area Wernicke:Pusat bahasa komprehensif.Jika rusak bicara cepat, tidak punya arti.

gyrus Angular :Pusat integrasi pendengaran, penglihatan, dan

informasi somatesthetik.

Page 17: Central Nervous System

Emosi dan Motivasi

Hipothalamus dan sistem limbic.

Pusat kebiasaan dan perasaan. Aggresif: Amygdala dan

hipothalamus. takut: Amygdala dan hipothalamus. Lapar:Hipothalamus Dorongan seksual: Hipothalamus

dan sistem limbic. Kebiasaan bertujuan (hadiah dan

hukuman):○ Hipothalamus dan cortex frontal.

Page 18: Central Nervous System

Memori

Jangka pendek:Ingatan hal/ kejadian yang baru terjadi.Lobus temporal Medial: Komponen utama Hippocampus.

Akuisisi informasi baru memerlukan kerja sama Lobus temporal Medial dan hippocampus.

Page 19: Central Nervous System

Memori

Jangka panjangKonsolidasi ingatan jangka pendek menjadi jangka

panjang.Memerlukan aktivasi gen, sintesis protein dan

pembentukan sinaps baru.

Corteks Cerebral menyimpan informasi faktual:Informasi Visual di hemisfer kiri.Informasi Visuospatial di hemisfer kanan.

Lobus Prefrontal :Perhitungan matematis, pemecahan masalah,

perencanaan.

Page 20: Central Nervous System

Thalamus

▫Menyusun 4/5 dienchepalon▫Membentuk sebagian besar dinding ventrikel III▫Acts as relay center through which all sensory

information (except olfactory) passes to the cerebrum. Nukleus genikulatum lateral:

Relay visual information. Nukleus genikulatum medial:

Relay auditory information. Nukleus intralaminer :

Activated by many sensory modalities. Projects to many areas.▫Promotes alertness and arousal from sleep.

Page 21: Central Nervous System

Hypothalamus

The subconscious control of skeletal muscle contractions

Contains neural centers for hunger, thirst, and body temperature.

Contributes to the regulation of sleep, wakefulness, emotions, sexual arousal, anger, fear, pain, and pleasure.

Stimulates hormonal release from anterior pituitary. Produces ADH and oxytocin. Coordinates sympathetic and parasympathetic

reflexes.

Page 22: Central Nervous System

Midbrain

Contains:Corpora quadrigemina:

○ Superior colliculi: Involved in visual reflexes.

○ Inferior colliculi:Relay centers for auditory information.

Cerebral peduncles:○ Composed of ascending and descending fiber tracts.

Substantia nigra:○ Required for motor coordination.

Red nucleus:○ Maintains connections with cerebrum and cerebellum.

Involved in motor coordination.

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Hindbrain

Metencephalon: Pons:

○ Surface fibers connect to cerebellum, and deeper fibers are part of motor and sensory tracts.

○ Contains several nuclei associated with cranial nerves V, VI, VII.

○ Contains the apneustic and pneumotaxic respiratory centerss.

Cerebellum:○ Receives input from proprioceptors.○ Participates in coordination of

movement.○ Necessary for motor learning,

coordinating different joints during movement, and limb movements.

Figure 8-23

Page 24: Central Nervous System

Hindbrain (continued)

Myelencephalon (medulla oblongata): All descending and ascending fiber tracts between spinal

cord and brain must pass through the medulla.○ Nuclei contained within the medulla include VIII, IX, X, XI, XII.○ Pyramids:

Fiber tracts cross to contralateral side. Vasomotor center:

○ Controls autonomic innervation of blood vessels. Cardiac control center:

○ Regulates autonomic nerve control of heart. Regulates respiration with the pons.

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Reticular Formation

Reticular Formation:Complex network of nuclei and nerve fibers within

medulla, pons, midbrain, thalamus and hypothalamus.

Functions as the reticular activating system (RAS).○ Non specific arousal of cerebral cortex to incoming

sensory information.

Page 26: Central Nervous System

Fungsi Medulla Spinalis•Jalur/ saluran terakhir sistem somatomotor

•Mengumpulkan informasi somatosensorik dari tubuh

•Neuron otonom

•Refleks