FISIOLOGI OTAK DAN SARAF KRANIAL

SEKOLAH TINGGI ILMU KESEHATAN KOTA SUKABUMI

Program Study S1 Keperawatan

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Thalamus

Hypothalamus

Midbrain

Pons

Medulla Oblongata

Cerebrum

Corpus callosum

Cerebellum

Area otak bagian kanan

Divisions and function of the brain

Brainstem Connect the spinal cord to the cerebrum, several important functions, location of cranial nerve nuclei

Medulla Oblongata

Pathway for ascending and descending nerve tracts; center for several important reflexes (e.g., heart rate, breathing, swallowing, vomiting)

Pons Contains ascending and descending nerve tracts; relay between cerebrum and cerebellum; reflex centers

Midbrain Contain ascending and descending nerve tracts; visual reflex centers; part of auditory pathway

Reticular formation

Scattered throughout the brainstem; controls cyclic activities such as the sleep-wake cycle

Cerebellum Control of muscles movement and tone; regulates extent of intentional movement; involved in learning motor skills

Division ……………………

Diencephalon

Thalamus Major sensory relay center; influences mood and movement

Subthalamus Contain nerve tracts and nuclei

Epithalamus Contains nuclei responding to olfactory stimulation and contains pineal body

Hypothalamus Major control center for maintaining homeostasis and regulating endocrine function

Cerebrum Conscious perception; thought, and conscious motor activity; can override most other systems

Basal Nuclei Control of muscle activity and postures; largerly inhibit unintentional movement when at rest

Limbic System Autonomic response to smell, emotion, mood, and other such functions

Brainstem ………………

Batang Otak

1. Batang otak menyambungkan medula spinalis dengan bagian otak lainya

2. Bertanggung jawab terhadap beberapa fungsi kerusakan pada area walaupun kecil dapat menyebabkan kematian

3. Batang otak terdiri dari medula oblongata, pons dan midbrain

Gambaran depan batang otak dan diencephalon

Medulla oblongata ……..

Medulla Oblongata

1. medulla oblongata bersambungan dengan medula spinalis dan terdiri dari jalur saraf asending dan desending

2. pyramids adalah jalur saraf yang berisi saraf pergerakan otot

3. olives adalah nukleus yang berfungsi dalam keseimbangan, koordinasi, dan modulasi suara dari telinga bagian dalam

4. Medullary nuclei mengatur denyut jantung, pembuluh darah, respirasi, menelan, batuk, bersin, dan sendawa . Nukleus saraf kranial V and IX – XII ada di medula

Pons …………..

Pons

1. pons ada di atas medula

2. Jalur saraf asending dan desending melewati pons

3. Mengatur tidur dan respirasi. Nukleus saraf kranial V – IX are ada di Pons

Midbrain ………

OTAK TENGAH

1. Otak tengah ada di atas PONS

2. Otak tengah terdiri dari nukleus nervus kranialis III, IV, and V

3. The substantia nigra connect to other basal nuclei and is involved with muscle tone and movement

Reticular formation ……………

FORMASI RETIKULARIS

Formasi retikularis terdiri dari nukleus pd batang otak. RAS meluas ke talamus dan cerebrum dan berfungsi mempertahankan kesadaran.

Cerebellum1. Cerebellum berkomunikasi dengan otak tengah , pons,

dan medula oblongata

2. Cerebellum 3 bagian , flocculonodular lobe, vermis, and lateral hemisphere.

3. Flocculonodular lobe merupakan bagian yang paling sederhana membantu mengontrol keseimbthe simplest part helps control balangan dan pergerakan mata

4. The vermis and medial portion of the lateral hemisphere are involved in the control of posture, pergerakan, dan koordinasi gerakan motorik halus menghasilkan gerakan yang halus

5. The major portion of the lateral hemispheres is involved, with the cerebral cortex of the frontal lobe, in planning, practicing, and learning complex movements

Diencephalon …………

Diencephalon

Diencephalon merupakan bagian dr otak dan berada diantara batang otak dan cerebrum. Komponen utamanya adalah talamus,

sub talamus, epi talamus dan hipotalamuss

Thalamus

1. Merupakan bagian terbesar dari diencephalon.

2. Ian Ruangan sekitar bagian intermediate mass disebut ventrikel ke 3 otak

3. Hampir seluruh input sensoris masuk ke thalamus

4. Thalamus mempengaruhi mood dan emosi

5. ……………..

5. Bagian ventral terlibat dalam fungsi motor dan mengkomunikasikan antara basal ganglia, cerebellum, dan motor cortex.

6. Bagaian anterior berhubungan dengan sistem limbik .

7. Bagian dorsal sisi berhubungan dengan korteks serebri dan berperan mengatur emosi

8. Bagian sisi belakang berperan dalam integrasi sensoris

Subthalamus

1. Bagian kecil dibawah talamus

2. Sebagian kecil dari nukleus dan substantia nigra di otak tengah meluas sampai ke sub talamus

3. Sel sub talamus berhubungan dengan sel basal dan berperan dalam mengontrol fungsi motorik

Epithalamus

1. Berada pada bagian atas belakang talamus terdiri dari sel habenular dan bana pineal

2. Sel Habenular dipengaruhi oleh penciuman dan terlibat dalam emosi dan respon terhadap bau

3. Badan pineal berperan dalam mulai pubertas dan juga berperan dalam siklus tudur dan terjaga

Hypothalamus …………..

Hypothalamus

1. Bagian paling bawah dari diencephalon terdiri dari beberapa sel dan jaras-jaras

2. Badan mammilary merupakan pusat refleks untuk penciuman

3. Hypothalamus mengatur beberapa fungsi endokrin (metabolisme, reproduksi, respon terhadap stress, dan produksi urin). Kelenjar pituitari menempel pada hipotalamus

4. Hipotalamus mengatus suhu tubuh, rasa lapar, haus, menelan dan juga emosi.

Hypothalamic functions

Function Description

Autonomic Helps control heart rate, urine release from the bladder, movement of food through the digestive tract, and blood vessel diameter

Endocrine Helps regulate pituitary gland secretion and influences metabolism, ion balance, sexual development, and sexual functions

Muscle tone Controls muscles involved in swallowing and stimulate shivering in several muscles

Temperature regulation

Promotes heat loss when the hypothalamic temperature increases by increasing sweat production (anterior hypothalamus) and promotes heat production when the hypothalamic temperature decreases by promoting shivering (posterior hypothalamus)

Hypothalamic functions ………………..

Regulation of food and water intake

Hunger center promotes eating and satiety center inhibits eating; thirst center promotes water intake

Emotions Large range emotional influences over body functions; directly involved in stress – related and psychosomatic illnesses and with feelings of fear and rage

Regulation of the sleep–wake cycle

Coordinates responses to the sleep-wake cycle with the other areas of brain (e.g., the reticular activating system)

Cerebrum …………

Cerebrum1. Bagian koteks dari cerebrum berlipat lipat, bagian tonjolan disebut girus

dan lipatan disebut sulci, atau fisur

2. Belahan longitudinal membagi cerebrum menjadi hemisfer kiri dan kanan. Setiap hemisfer memiliki lima lobus:

a. Lobus frontalis untuk penciuman, fungsi motorik volunter, motivasi, agresi dan mood

b. Lobus parietalis untuk area sensori utama menerima sensasi umum, rasa dan keseimbangan

c. Lobus oksipitalis merupakan pusat penglihatan

d. LObus temporalis menerima input dari olfactorius dan auditori dan terlibat dalam memori, fikiran abstrak dan keputusan

e. Cerebelum fungsinya equilibrium

3. Jaras saraf yang menghubungkan corteks dalam hemisfer yang sama disebut serabut asosiasi, antara hemisfer berbeda disebut serabut commisural dan dengan bagian otak lain dan medula spinalis disebut serabut projeksi

AREA FUNGSIONAL DARI KORTEKS SEREBRI

AREA MOTORIK DAN SENSORIK

Area fungsional korteks yang utama :

1. Area sensoris menerima dan menginterpretasikan impuls

2. Area motorik mengontrol pergerakan otot

3. Area asosiasi mengurusi fungsi integratif yang lebih kompleks seperti memori, emosi, keinginan, penilaian, personaliti dan kecerdasan

Area sensosik

1. Input sensorik ke korteks serebri masuk terutama ke setengah hemisfer bagian bawah menuju ke sulci

2. Di dalam korteks, reseptor sensori primer langsung berhubungan dengan reseptor sensori perifer

3. Ares sensoris sekunder dan area asosiasi bersebelahan dengan area primer. Menerima input dari area primer dan disebarkan ke bagian lain otak. Berperan dalam pola pengenalan dan kewaspadaan

AREA MOTORIK

INPUT MOTORIK DARI KORTEKS SEREBRI MENJALAR TERUTAMA DARI BAGIAN ANTERIOR DARI SETIAP

HEMISFER

REFLEKS REFLEKS DI BATANG OTAK MELIBATKAN SARAF KRANIA

1. Banyak refleks yang melibatkan homeostatis berkaitan dengan syaraf kranial dan muncul di batang otak

2. Banyak dari refleks di batang otak berhubungan dengan fungsi nervus kranialis

INTEGRASI DAN SARAF PUSAT

SENSASI

1. SENSASI MELIPUTI SENSASI UMUM DAN SPESIAL

2. Sensasi somatik meliputi sentuhan, tekanan, suhu, proprioseptif dan nyeri

3. Sensasi visceral terutama sakit dan tekanan

4. Sensasi spesial meliputi penciuman, perasaan, penglihatan, pendengaran dan keseimbangan

5. Sensasi atau persepsi adalah kewaspadaan yang disadari terhadap stimulus yang diterima oleh reseptor sensori

6. Sensasi memerlukan stimulus, sebuah reseptor , konduksi dari potensial aksi ke ssp, translasi dari potensial aksi, dan pemrosesan potensial aksi dalam SSP sehingga seseorang sadar akan adanya sensasi

RESEPTOR

1. Reseptor meliputi mekano reseptor, kemoreseptor , fotoreseptor dan nociceptor

2. Ujung saraf bebas mendeteksi sentuhan ringan, nyeri, gatal, geli, dan temperatur

Reseptor di dalam kulit

1. Lempengan Merkel’s berespon terhadap sentuhan ringan dan tekanan superfisial

2. Reseptor Folikel Rambut terlibat juga dalam sensasi sentuhan ringan apabila rambut tertekuk

Reseptor di kulit

3. Badan pacini ada di lapisan dermis mendeteksi tekanan dan juga terlibat dalam fungsi proprioseptif

4. Badan Meissner’s ada di lap dermis bertanggung jawab mendiskriminasi dua titik sentuhan yang berbeda

Reseptor di kulitOrgan Ruffini’s terlibat dalam sentuhan yang kontinyu atau tekanan

organ

Reseptor sensori dalam otot

Serabut otot yang ada di dalam otot skelet merupakan proprioseptor

Reseptor Sensori di tendon

Organ golgi tendon yang ada di dalam tendon berespon pada perubahan tekanan

TWO-POINT DISCRIMINATION

Apabila dua titik sentuhan atau tekanan berdekatan makaorang akan merasakan satu titik, tapi apabila berjauhan maka akan bs membedakan dua titik

Respon dari reseptor sensori

1. Menciptakan potensial reseptor di dalam reseptor sensoris. Umumnya reseptor memiliki akson yang kemudian akan mentransmisikan potensial

2. Proses adaptasi dapat menurunkan sensitifitas terhadap stimulus yang kontinyu

Jalur Saraf Sensori

Spinothalamic System

Traktus spinothalamic bagian sisi menyalurkan potensial aksi dr nyeri dan suhu

Traktus Saraf Sensori

Spinothalamic System

Bagian depan traktus spinothalamic menyalurkan potensial aksi untuk sntuhan ringan

Posterior Spinocerebellar Tract

Traktus ini menjalarkan informasi proprioseptif dr toraks, tungkai atas dan begian lumbar atas ke cerebelum

AREA SENSORI KORTEKS SEREBRI

FUNGSI SISI KIRI DR KORTEKS SEREBRI

Areas of Referred pain on the Body Surface

Topography of the Somatic

Sensory Cortex

Topography of the Primary Motor

Cortex

MOTOR CORTEX

Direct Pathways

Lateral and anterior corticospinal tract, which are responsible for movement below the head. Lines in the inset indicate levels of section

Indirect Pathways

Examples of indirect pathways: rubrospinal and reticulospinal tracts. Lines in the inset indicate levels of section

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

1. The motor cortex sends action potentials to lower motor neurons in the spinal cord

2. Action potentials from the motor neuron inform the cerebellum of the intended movement

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

3. Lower motor neurons in the spinal cord send action potentials to the skeletal muscle, causing them to contract

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

4. Proprioceptive signals from the skeletal muscles and joints to the cerebellum conveys information concerning the status of the muscle and the structure being moved during contraction

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

5. The cerebellum compares the information from the motor cortex to the proprioceptive information from the skeletal muscles and joints

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

6. Action potentials from the cerebellum to the spinal cord modify the stimulation from the motor cortex to the lower motor neuron

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

7. Action potentials from the cerebellum are sent to the motor cortex, which modify its motor activity

Cerebellar Comparator Function

Motor Cortex

Skeletal muscle

1

2

3

4

56

7

Red nucleus

Proprioception

Thalamus

Cerebellum

Spinal cord

Lower motor neuron

BRAIN WAVES AND SLEEP

EEG showing brain waves

(a) EEG tracing when a person is awake and during four stage of sleep.

(b) Atypical night’s sleep pattern in a young adult. The time spent in REM sleep is labeled and shown by dark bars

MEMORY

1. Sensory memory

Very short-term retention of sensory input received by the brain while something is scanned, evaluated, and acted on.

Lasts less than a second

2. Short term memory

If a given piece of data held in sensory memory is considered valuable enough, information is retained for a few second to a few minute

This memory is limited by the number of bits of information (usually about seven, telephone number) that can be stored at one time, although the amount varies from person to person. More bit can be stored when the number are grouped into specific segments separated by the spaces, such as when adding an area code. This memory will be eliminated when a new information is given

3. Long-term memory………..

Limbic System

12

3

4

56

7

8

9

10

11

12

13

1. Fornix

2. Anterior thalamic nucleus

3. Anterior commissure

4. Septal nucleus

5. Olfactory bulb

6. Olfactory Cortex

7. Mammillary body

8. Cingulate gyrus

9. Corpus callosum

10. Habenular nucleus

11. Dentate nucleus + 12 Fimbria = Hippocampus

13. Amygdaloid nucleus

Limbic System

1. The limbic system includes parts of the cerebral cortex, basal nuclei, thalamus, hypothalamus, and the olfactory cortex

2. The limbic system controls visceral function through the autonomic neurons system and the endocrine system and is also involved in emotion and memory

Cranial Nerves

1. Cranial nerves perform sensory, somatic motor, prorprioceptive, and parasympathetic function

2. N. I (olfactory) and II (optic) are involved in sense of smell and vision

3. N. III (oculomotor) innervates four of six extrinsic eye muscles and the upper eyelid. The N. III also provides parasympathetic supply to the iris and lens of the eye

4. N. IV (trochlear) controls an extrinsic eye muscle

5. …..

Cranial Nerves

5. N. V (trigeminal) supplies the mastication muscles, as well as middle ear muscle, a palatine muscle, and two throat muscle. Has the greatest sensory distribution of the cranial nerve. Has three branches, two of them innervate teeth

6. N. VI (abducens) control an extrinsic eye muscle

7. N. VII (facial) supplies the muscles of the facial expression, an inner ear muscle, and two throat muscles. It is involved in the sense of taste. It’s parasympathetic to two set of salivary glands and to the lacrimal glands

8. N. VIII (vestibulocochlear) is involved in the sense of hearing and balance

9. ………..

9. N. IX (glossopharyngeal) in involved in taste and supplies tactile sensory innervation from the posterior tongue, middle ear, and pharynx. It’s also sensory for receptors that monitor blood pressures and gas level in the blood. N. IX is parasympathetic to the parotid salivary glands

10. N. X (vagus) innervates the muscles of the pharynx, palate, and larynx. It’s also involved in the sense of taste. N. X is sensory for pharynx and larynx and for receptors that monitor blood pressure and gas level in the blood. N. X. is sensory for thoracic and abdominal organs. N. X provides parasympathetic innervation to the thoracic and abdominal organs

11. …….

11. N. XI (accessory) has a cranial and a spinal component. The cranial component joins the vagus nerve. The spinal component supplies the sternocleidomastoid and trapezius muscles.

12. N. XII (hypoglossal) supplies the intrinsic tongue muscles, three of four extrinsic tongue muscles, and two throat muscles.