Neuroanatomy PDF Lecture Notes

l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuroanatomy dr. Ayodya Heristyorini, MSc, MSc Departemen Anatomi AKREDITASI “UNGGUL” ...

l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuroanatomy dr. Ayodya Heristyorini, MSc, MSc Departemen Anatomi AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Today’s topics 01 Neuro basics Intro to neuroanatomy 02 CNS Brain & spinal cord 03 04 Meninges Neurocranium Dura, arachnoid, pia Bones bones bones mater AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuro basics 01 Intro to neuroanatomy AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Functions Sensory function: to Motor function: to detect changes and initiate appropriate feel sensations responses to changes Integrative function: to organize information for immediate use and store it for future use AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuron AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuro basics Nerve cells are called neurons, or nerve fibers. Cell body (soma) contains the nucleus and is essential for the continued life of the neuron. Dendrites are extensions that transmit impulses toward the cell body. Axon transmits impulses away from the cell body. The cell membrane of the dendrites, cell body, and axon carries the electrical nerve impulse. A neuron carries impulses in only one direction. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neuro basics A nerve is a bundle of hundreds to thousands of axons that is outside the brain and spinal cord. Each nerve serves a specific region of the body. A nerve tract refers to groups of neurons within the central nervous system. These tracts are often referred to as white matter; the myelin sheaths of the neurons give them a white color. A ganglion (plural = ganglia) is a small mass of neuron cell bodies, that are located outside the brain and spinal cord. Ganglia are closely associated with cranial and spinal nerves. A nucleus (plural = nuclei) is a mass of gray matter; the neurons are not sheathed with myelin giving them a gray color. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Nervous system The nervous system has two divisions: The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) consists of cranial nerves and spinal nerves. The PNS is divided into three functional components: somatic nervous system, autonomic nervous system, and enteric nervous system The PNS relays information to and from the CNS, and the brain is the center of activity that integrates this information and initiates responses. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Types of neuron Sensory neurons (or afferent neurons) carry impulses from receptors to the CNS. Receptors detect external or internal changes and send the information to the CNS in the form of impulses. The CNS interprets the impulses as a sensation. Sensory neurons from receptors in skin, skeletal muscles, and joints are called somatic sensory neurons. Those from receptors in internal organs are called visceral sensory neurons. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Types of neuron Motor neurons (or efferent neurons) carry impulses from the CNS to effectors. The two types of effectors are muscles and glands. In response to impulses, muscles contract or relax and glands secrete. Motor neurons linked to skeletal muscle are called somatic motoric neurons. Those to smooth muscle, cardiac muscle, and glands are called visceral motoric neurons. Sensory and motor neurons make up the PNS. Visceral motor neurons form the autonomic nervous system, a specialized subdivision of the PNS. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Central Nervous System 02 Brain & spinal cord AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Central nervous system The central nervous system (CNS) is composed of the brain and spinal cord. The brain is enclosed and protected by the cranium and contains about 100 billion neurons. The spinal cord is enclosed and protected by the bones of the vertebral column in the vertebral canal and contains about 100 million neurons. The CNS processes incoming sensory information. It is also the source of thoughts, emotions, and memories. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  Brain l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Primary brain vesicles: prosencephalon, mesencephalon, and rhombencephalon The prosencephalon, or forebrain, becomes the telencephalon and diencephalon The telencephalon develops into the cerebrum and lateral ventricles. The diencephalon forms the thalamus, hypothalamus, epithalamus, and the third ventricle. The mesencephalon, or midbrain, becomes the midbrain and cerebral aqueduct The rhombencephalon, or hindbrain, develops into the metencephalon and myelencephalon The metencephalon becomes the pons, cerebellum, and upper part of the fourth ventricle. The myelencephalon forms the medulla oblongata and lower part of the fourth ventricle. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Forebrain 02 Cerebrum hemispheres & basal ganglia AKREDITASI “UNGGUL”  Cerebrum l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The largest portion of the human brain. Consists of the cerebral hemispheres and the basal nuclei (or known as basal ganglia). Cerebral hemispheres are the right and left halves of the cerebrum. The hemispheres consist of an outer rim of gray matter (cerebral cortex), an internal region of white matter, and gray matter nuclei deep within the white matter. AKREDITASI “UNGGUL”  Cerebrum l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The folds are called gyrus (plural = gyri); the deepest grooves between gyri are known as fissures; the shallower grooves between gyri are termed sulcus (plural = sulci). The hemispheres are separated by a deep groove called the longitudinal fissure that is occupied by the falx cerebri. The hemispheres are connected internally by the corpus callosum, a broad band of white matter containing axons. AKREDITASI “UNGGUL”  Cerebrum l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Each cerebral hemisphere can be subdivided into 4 lobes named after the cranial bones that cover them. The central sulcus separates the frontal lobe from the parietal lobe. The precentral gyrus—anterior to the central sulcus—contains the primary motor area of the cerebral cortex. The postcentral gyrus, posterior to the central sulcus, contains the primary somatosensory area. The lateral cerebral sulcus separates the frontal lobe from the temporal lobe. The parieto-occipital sulcus separates the parietal lobe from the occipital lobe. AKREDITASI “UNGGUL”  Basal ganglia l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Deep within each cerebral hemisphere are three nuclei collectively termed the basal nuclei/ganglia Two of them lateral to the thalamus are the globus pallidus and the putamen. Together, they are referred to as the lentiform nucleus The third of the basal nuclei is the caudate nucleus AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Diencephalon 02 Thalamus, hypothalamus, & epithalamus AKREDITASI “UNGGUL”  Thalamus l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The diencephalon includes the thalamus, hypothalamus, and epithalamus. Projecting from the hypothalamus is the hypophysis, or pituitary gland. The thalamus is the major relay station for sensory impulses (except smell) that reach the primary sensory areas of the cerebral cortex. Parts of the thalamus are also involved in alertness and awareness (consciousness), and others contribute to memory. AKREDITASI “UNGGUL”  Hypothalamus l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Located inferior to the thalamus, the hypothalamus is a small area of the brain with many diverse functions: Production of antidiuretic hormone (ADH) and oxytocin Production of releasing hormones that stimulate the secretion of hormones by the anterior pituitary gland. Regulation of body temperature. Regulation of food intake. Integration of the functioning of the autonomic nervous system, which in turn regulates the activity of organs such as the heart, blood vessels, and intestines. Stimulation of visceral responses during emotional situations. Regulation of body rhythms/circadian rhythms. AKREDITASI “UNGGUL”  Epithalamus l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The epithalamus, a small region superior and posterior to the thalamus, consists of the pineal gland and habenular nuclei. The pineal gland is part of the endocrine system because it secretes the hormone melatonin. Melatonin is thought to promote sleepiness. When taken orally, melatonin also appears to contribute to the setting of the body’s biological clock by inducing sleep and helping the body to adjust to jet lag. The habenular nuclei, are involved in olfaction, especially emotional responses to odors. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Ventricles 02 AKREDITASI “UNGGUL”  Ventricles l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Ventricles are cavities within the brain that are filled with cerebrospinal fluid (CSF). There is one lateral ventricle located in each hemisphere of the cerebrum Anteriorly, the lateral ventricles are separated by a thin membrane, the septum pellucidum The third ventricle is along the midline superior to the hypothalamus and between the right and left halves of the thalamus. The fourth ventricle lies between the brain stem and the cerebellum. AKREDITASI “UNGGUL”  Ventricles l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The majority of CSF production is from the choroid plexuses, networks of modified blood capillaries in the walls of the ventricles The CSF functions in three main ways: 1. Mechanical protection (shock-absorbing medium). 2. An optimal chemical environment for efficient neuronal signaling. 3. Circulation. A small amount of CSF passes downward into the central canal of the spinal cord, while the majority of the CSF circulates in the sub-arachnoid space around the surface of the brain and spinal cord. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Cerebellum 02 AKREDITASI “UNGGUL”  Cerebellum l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The cerebellum is separated from the medulla and pons by the fourth ventricle and is inferior to the occipital lobes of the cerebrum. Three paired cerebellar peduncles attach the cerebellum to the brain stem. Many of the functions of the cerebellum are concerned with movement, including coordination, regulation of muscle tone, the appropriate trajectory and endpoint of movements, and the maintenance of posture and equilibrium. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Truncus cerebri 02 Midbrain, pons, & medulla oblongata AKREDITASI “UNGGUL”  Midbrain l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The midbrain (mesencephalon) extends from the pons to the diencephalon and is about 2.5 cm long where the cerebral aqueduct passes through. The anterior part of the midbrain contains a pair of tracts called cerebral peduncles, they conduct nerve impulses from the cerebrum to the spinal cord, medulla, and pons. The posterior part of the midbrain, called the tectum, are reflex centers for certain visual activities, part of the auditory pathway, and the startle reflex. The midbrain contains the substantia nigra. Neurons that release dopamine from the substantia nigra to the basal nuclei helps control subconscious muscle activities, such as righting reflexes, that keep the head upright and maintain balance. AKREDITASI “UNGGUL”  Pons l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Within the pons are two respiratory centers that work with those in the medulla to produce a normal breathing rhythm. The pons also contains nuclei associated with the following four pairs of cranial nerves: Trigeminal (V) nerves. Abducens (VI) nerves. Facial (VII) nerves. Vestibulocochlear (VIII) nerves. AKREDITASI “UNGGUL” Medulla oblongata l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The medulla extends from the spinal cord to the pons and is anterior to the cerebellum. Its functions are those of “vital signs”. The medulla contains cardiac centers that regulate heart rate, vasomotor centers that regulate the diameter of blood vessels and blood pressure, and respiratory centers that regulate breathing. AKREDITASI “UNGGUL” Reticular formation l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN A broad region where white matter and gray matter exhibit a netlike arrangement is known as the reticular formation It extends from the superior part of the spinal cord, throughout the brain stem, and into the inferior part of the diencephalon. The ascending portion of the reticular formation is called the reticular activating system (RAS) The most important function of the RAS is consciousness. Another function of the RAS is to help maintain attention and alertness. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Spinal cord 02 AKREDITASI “UNGGUL”  Spinal cord l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The spinal cord extends from the foramen magnum of the occipital bone to the disc between the first and second lumbar vertebrae. There are 31 pairs of spinal nerves. The nerves are named according to their respective vertebrae: 8 cervical pairs, 12 thoracic pairs, 5 lumbar pairs, 5 sacral pairs, and 1 very small coccygeal pair. The length of the adult spinal cord ranges from 42 to 45 cm. Its diameter is about 2 cm. AKREDITASI “UNGGUL”  Spinal cord l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The superior enlargement, the cervical enlargement, extends from the C4 to T1 vertebra. Nerves to and from the upper limbs arise from the cervical enlargement. The inferior enlargement, called the lumbar enlargement, extends from T9–T12. Nerves to and from the lower limbs arise from the lumbar enlargement. Inferior to the lumbar enlargement, the spinal cord terminates as a tapering, conical structure called the conus medullaris ends at the level of the intervertebral disc between the L1–L2 in adults. AKREDITASI “UNGGUL”  Spinal cord l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Arising from the conus medullaris is the filum terminale, an extension of the pia mater that extends inferiorly and fuses with the arachnoid mater and dura mater to anchor the spinal cord to the coccyx. The roots of these lower spinal nerves angle inferiorly alongside the filum terminale in the vertebral canal, named the cauda equina. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Meninges 03 AKREDITASI “UNGGUL”  Meninges l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The connective tissue membranes that cover the brain and spinal cord are called meninges: the outer dura mater, the middle arachnoid mater, and the inner pia mater Three extensions of the dura mater separate parts of the brain: (1) The falx cerebri separates the two cerebrum hemispheres. (2) The falx cerebelli separates the two cerebellum hemispheres. (3) The tentorium cerebelli separates the cerebrum from the cerebellum. AKREDITASI “UNGGUL”  Meninges l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The epidural space is a potential space between the periosteal layer of the dura mater and skull bones Between the arachnoid and the pia mater is the subarachnoid space, which contains CSF From the cranial subarachnoid space, cerebrospinal fluid is reabsorbed through arachnoid villi into the blood in cranial venous sinuses (large veins within the double-layered cranial dura mater). The cerebrospinal fluid becomes blood plasma again. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN Neurocranium 03 AKREDITASI “UNGGUL”  Neurocranium l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN The cranial bones form the brain- case (lined with the meninges) that encloses and protects the brain, eyes, and ears. These are the frontal bone, parietal bones (2), temporal bones (2), and occipital bone. The sphenoid bone and ethmoid bone are part of the floor of the braincase and the orbits (sockets) for the eyes. AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”  l KEMENTERIAN PENDIDIKAN DAN KEBUDAYAAN UNIVERSITAS PEMBANGUNNAN NASIONAL VETERAN JAKARTA FAKULTAS KEDOKTERAN AKREDITASI “UNGGUL”