Embryology /organogenesis/ Development and teratology of nervous system. Embsmall •2 http://classconnection.s3.amazonaws.com/391/flashcards/578391/png/untitled1308508383511.png •NOTOCHORD •DEVELOPMENT •NOTOCHORD - induces neural plate development http://bio.sunyorange.edu/updated2/embry.html/1.%20%20The%20Notochord_files/27%20EMBRYO.jpg •Neuroectoderm • •Neural plate •3 1 •Neural plate – thickened area of embryonic ectoderm ð neuroectoderm • • • •Pharyngeal •membrane •Primitive •streak •and node •Cloacal membrane •Notochord • •pseudostratif. •columnar ep. •4 https://people.creighton.edu/~idc24708/Genes/Behavioral%20Genetics/3-step%20neurulation.png •NEURULATION – invagination of neural plate (day 16 - 24) -neural folds -neural groove - - - - - - - -neural tube -neural crest •notochord •5 Nervový systém - 42 •Day 20 •Neural folds •6 Nervový systém - 44 •Neuroporus anterior •Neuroporus •posterior •Day 22, 23 •closes •on D 25 •closes •on D 27 •7 Nervový systém - 43 •NEURAL CREST •8 neuralcrest.jpg image by musuq • •Odontoblasts •Leptomeningeal cells •9 http://www.biog1105-1106.org/demos/106/unit03/media/neuralcrest.jpg •EKTOMESENCHYME •10 SC-XSect •Histogenesis of neural tube •The wall of neural tube: (simple → pseudostratified neural epithelium) •Cell proliferation ð 3 zones: • Ependymal Intermediate Marginal • • zone • • • Ependyma Gray matter White matter •(in medulla spinalis) •11 •HISTOGENESIS of NEURAL TUBE Nervový systém - 48 •Marginal zone (white matter) • • • • •Intermediate zone (gray matter) •(mantle zone) • • • •Ependymal zone (germinal) • •12 Histogenesis of neural tissue Early development of the neural tube •Three zones line neural tube (the spinal cord and brain stem). Marginal zone (white matter) – without neurons, but with axons of neurons and glial cells Mantle zone (gray matter) – neuroblasts + spongioblasts give rise to bodies of neurons and glial cells Ependymal zone (germinal) – lining of central canal • •ependyme •gray matter •white matter •In spinal cord •13 Early development of the neural tube •ependyme •white matter •gray matter •In brain and cerebellum •In brain and cerbellum: •mantle zone cells migrate through marginal layer and the gray matter coveres white matter. Some neurons stay in white matter ð nuclei. • • • • • • • • • •14 DrwNeurtube •Spinal cord development • •Dorsal •horns •Ventral •horns • • motor zone •sensory zone •future white matter •future gray •matter •15 Nervový systém - 49 SPINAL CORD: 1.Ependymal layer (germinal) 2.Mantle layer (gray matter) 3.Marginal layer (white matter) • • • • •16 Nervový systém - 52 •Positional changes of spinal cord •Vertebrate canal grows more rapidly than spinal cord and caudal end of spinal cord doesn‘t extend the entire length of canal in adult; it terminates at L2 in adults # . •the end fo the 2nd month the 5th month new-born child # •Cauda equina Brain development •Brain develops from cranial part of neural tube •Week 4 – three primary brain vesicles: • - prosencephalon (forebrain) • - mesencephalon (midbrain) • - rhombencephalon (hindbrain) •17 • •18 3-1-2-5 •week 5 •3 primary → 5 secondary vesicles: • • • • • •Lamina terminalis •Prosencephalon • • • •Mesencephalon • • • •Rhombencephalon • Telencephalon •Diencephalon •Metencephalon •Myelencephalon •1 •2 •4 •1 – ventriculi lat., 2 – ventriculus tertius, 3 – aqueductus cerebri, 4 – ventriculus quartus •3 •Optic vesicle •Neurohypophysis •Epiphysis •Cerebellum •Pons •week 4 •19 Nervový systém - 46 • • • • Midbrain flexure Cervical flexure •20 http://www.startsateight.com/wp-content/uploads/2011/05/48_23BrainDevelopment.jpg •21 Myelination of nerve fibers Nervová tkáň - 16 Obaly nervových výběžků Myelinani •from the 4th prenatal month •to the end of 2nd postnatal year •22 CNS malformations •failure neurulation (absence of notochord inductive influence or teratogen influence on neuroectodermal cells) •defects of spinal cord •defects of brain •difficult malformations of CNS are usually connected with skull or spinal column (vertebral) defects. • •Etiology: usually multifactorial (fever, drugs during gravidity, hypervit. A etc.) or hereditary disposition. •Folic acid use influence normal development of CNS. •Sonography detects anomalies. •23 Spinal cord malformations •Defects (clefts) of vertebral •arches •Menigocele •Menigomyelocele •Menigohydromyelocele • •Myeloschisis – complete cleft of spinal column in the whole length http://www.primehealthchannel.com/wp-content/uploads/2012/06/Neural-tube-defect-Image.jpg • •spina •bifida •cystica • http://skeletalsystemdev.weebly.com/uploads/7/0/4/3/7043675/7236642_orig.jpg •24 http://media.tumblr.com/tumblr_m4ynmmYZdJ1r261r3.jpg 19087 • •25 Nervový systém - 53 •26 • Urodynamics FIG01 •Examples of external signs of spina bifida: • • 1) hairy patch 2) hemangioma • 3) skin appendage 4) lipomatous mass •27 Brain malformations •Anencephalia (†) (with myeloschisis) zarte%20seele%201 •28 http://escuela.med.puc.cl/paginas/cursos/tercero/patologia/fotos242-248/244.jpg •29 Brain malformations • • • • • tcge010 •MICROCEPHALIA ANENCEPHALIA Final_Microcephaly2 •30 Image •31 Hydrocephalus -accumulation of abundant cerebrospinal fluid in brain ventricular system, -etiology: stenosis or obliteration of aqueductus cerebri between 3rd and 4th ventricles fluid is accumulated in lateral ventricles pushes on the brain tissue (is thinned); internal pressure complicates drenage of fluid insubarachnoid space; -until skull suture don‘t ossify – skull can grows extremely . Roční dívenka z Indie umírá, trpí strašnou chorobou •32 VPS_Shunt •HYDROCEPHALUS fig84_1 •ventriculoperitoneal shunt •33 microcephalus-and-hydrocephalus •34 Nervový systém - 58 •Brain and meninges hernia(tion) •35 http://neuropathology-web.org/chapter11/images11/11-4l.jpg http://neuropathology-web.org/chapter11/images11/11-2al.jpg •36 end Výsledek obrázku pro hypophysis development Výsledek obrázku pro hypophysis development •Neurohypophyseal diverticle •of diencephalon floor •+ •Rathke‘s pouch •of stomodeum roof Výsledek obrázku pro congenital anomalies of hypophysis •Pineal gland (epiphysis) – diverticulum of the roof of diencephalon •the floor of diencephalon •Thyroid gland Výsledek obrázku pro development of thyroid gland •Descensus of thyroid gland •Ductus thyroglossus •Ultimobranchial body – the 4th endodermal pouch – parafollicular cells Výsledek obrázku pro development of thyroid gland Související obrázek CORTEX -mesoderm (coelomic epithelium) MEDULLA -neuroectoderm (neural crest) Související obrázek •46 end •47 Terms •Neuron – perikaryon – axon (= neurite) – dendrite(s) •Nissl bodies = rough ER •Axon hillock •Myeline sheath •Schwann sheath •Mesaxon •Internodium •Node of Ranvier •Neuron – classification •Synapse (presynaptic knobe, synaptic cleft, postsynaptic memrane) •Neurotransmitters • •48 Terms •Neuroglia - classification •Oligodendroglia •Astrocytes •Microglia (of Horteg) •Ependyma - tanycytes •Schwann cells •Satelite cells • • • • •in CNS • • • • •in PNS • • •49 •Structure of the brain cortex. Cyto- and myeloarchitecture. •Structure of the cerebellum. Synapses of the cerebellum. •Microscopic structure of the spinal cord. •Microscopic structure of ganglia and peripheral nerves. •Ependyma, plexus chorioideus and meninges. Special histology - questions •50 Terms •Brain cortex – 6 layers (lamina) •Cajal cells, Martinotti cells, granular and pyramidal cells •Membrana limitans gliae superficialis et profunda (seu perivascularis) •Brain barrier •Cerebellum – 3 layers of cortex (stratum) •Purkinje cells, basket cells, granular cells •Glomeruli cerebellares •Mossy and climbing fibers •51 Terms •Dura mater – arachnoidea – pia mater •Endoneurium – perineurium – epineurium •Plexus chorioideus •52 end •53 Braincase3 •54 Fig. 1 (a) A myelinated axon in the peripheral nervous system and (b) its development. Each Schwann cell myelinates a single axon, to which it is directly apposed. During development (anticlockwise) Schwann cells loosely ensheath axons and the myelin sheath grows around the axon to form concentric layers, which become tightly apposed •Fig. 1 (a) A myelinated axon in the peripheral nervous system and (b) its development. Each Schwann cell myelinates a single axon, to which it is directly apposed. During development (anticlockwise) Schwann cells loosely ensheath axons and the myelin sheath grows around the axon to form concentric layers, which become tightly apposed •55 Fig. 3 Myelination in the central nervous system. A single oligodendrocyte myelinates numerous axons (a) and, in section, concentric layers of myelin are seen to spiral around the axon (b). Myelin sheaths are arranged along axons in segments 1 mm long separated by short nodes, and would appear as large sheets if they were unwrapped from around the axon •Fig. 3 Myelination in the central nervous system. A single oligodendrocyte myelinates numerous axons (a) and, in section, concentric layers of myelin are seen to spiral around the axon (b). Myelin sheaths are arranged along axons in segments 1 mm long separated by short nodes, and would appear as large sheets if they were unwrapped from around the axon •56 Nervový systém - 48 Nervový systém - 47 •57 Nervový systém - 51 •58 Nervový systém - 39 Vztah míchy k rostoucí páteři •59 http://www.histology-world.com/photoalbum/albums/userpics/normal_Gray640.png http://www.histology-world.com/photoalbum/albums/userpics/normal_Gray641.png •roof plate • • •central canal • •ependymal •layer • •mantle •layer • •marginal •layer •floor plate •60 http://oxfordmedicine.com/doc/10.1093/med/9780195378580.001.0001/graphic005015-inline.gif •61 http://biology.kenyon.edu/courses/biol114/Chap14/PEPhelps-neurulation.jpg •62 1 •Invagination of neural plate ð neural folds + neural groove •63 1 •Neural tube and neural crest •Neuroporus ant., post. • • •Neural tube •Neural crest •64 1 • •future brain •future spinal cord • •future spinal and autonomic ganglia •65 HumHPD6L •66 Nervový systém - 54 •67 http://www.phasmatodea.org/anatphys/jpegs/12-27_EmbrSpinlCrd_1.jpg http://www.brainviews.com/abFiles/DrwNeurtube.jpg