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8Google Meet allows you to conduct quality and most effective online classes. During the pair, teachers show students macrophotographs of the organs being studied, focusing on the features of their structural organization. To better master the topic of the lesson, sit-uational tasks, clinical correlations, and videos are considered and discussed. Participants in the educational process also communicate with each other in the Google Meet chat. Lectures are held in video mode.
Knowledge control is carried out with the help of SDO Moodle, where students take tests, as well as teachers evaluate the results of individual assignments and oral answers in Google Meet online classes. The grade for the practical lesson, as the average for the performance of all tasks, is placed in the electronic journal of BSMU success.
Using individual e-mail addresses, the participants of the educational process maintain a constant communication. Teachers provide consultations to students both for practical classes and for modular classes, answer questions, help to solve problems.
It is important to note the shortcomings of distance learning during quarantine at the Department of Human Anatomy. Being outside the university, students do not have the opportunity to use models and anatomical preparations of organs, can not visit libraries and reading rooms, do not have wide access to the base of modern science. There is also no direct communication between students and the teacher.
Due to the increasing load on the Internet, it is necessary to improve the quality of communication in both departments and dormitories. Each student should have a personal computer, not just a smartphone on the screen of which it is difficult to see the photos and videos shown by teachers of the department.
Conclusions and offers. Thus, the introduction of distance learning at the Bukovynian State Medical University of the Ministry of Health of Ukraine, in connection with the global spread of the SARS-CoV-2 virus, took place quickly and in an organized manner. Qualitative developments of teachers and programmers
of the university for the last decade allowed to adapt quickly to the new conditions of educational services and gave students the opportunity to qualitatively acquire knowledge in quarantine. In order to improve distance learning methods, a gradual reorganization of SDO Moodle on a new newer platform is planned, a new version of the electronic journal of success is introduced, a video resource of both practical and lecture classes is created, which will be displayed on the university distance learning server and https: / /www.youtube.com.
References
1. Features of distance learning in the framework of postgraduate training of doctors in emergency medicine / A.O. Volosovets, B.I. Slonetsky, I.S. Zozula [etc.] // Medical education. - 2020. - № 3. - P. 5-8.
2. On approval of the Regulations on distance learning: Order of the Ministry of Education and Science of Ukraine dated 25.04.13 No 466. - Access mode: https://osvita.ua/legislation/Distosv/2999/.
3. Fedchyshyn NO Distance learning of foreign language of future doctors: challenges of time / NO Fedchyshyn. Fedchyshyn, NI Yelagina, OG Permyakova // Medical education. - 2020. -№2. -P.32-39.
4. Divnych T. Ya. Distance form of education in higher educational institutions as one of the technologies of organization of educational process / T.Ya. Divnich // Medical education. - 2015. - № 3. - P. 66-69.
5. Pilaeva T. History of the development of distance education in the world / T. Pilaeva // Scientific notes of Kirovohrad State Pedagogical University named after Volodymyr Vynnychenko. - 2016. - № 147. - P. 114-117.
6. Yastremska SO Application of MOODLE system in distance learning of masters of nursing / S. Yastremska. Yastremska // Bulletin of the Lviv State University of Life Safety. - 2017. - № 16. - P. 186190.
PECULIARITIES OF MORPHOGENESIS AND TOPOGRAPHY OF THE CERVICAL SPINE IN THE
PRENATAL PERIOD OF HUMAN ONTOGENESIS
Narcia V.
getter, Head of the Department of Human Anatomy named after M.G. Turkevich, Bukovynian State Medical
University, Chernivtsi, Ukraine Kryvetskyi V.
Doctor of Medical Sciences, Professor, Head of the Department of Human Anatomy named after M.G. Tur-
kevich, Bukovynian State Medical University, Chernivtsi, Ukraine
ABSTRACT
The peculiarities of morphogenesis of the cervical spine of 40 fetuses and 30 newborns were studied by a set of morphological research methods. Peculiarities of morphogenesis and chronological sequence of formation of topography of cervical spine during prenatal period of human ontogenesis are established. Keywords: spinal column, cervical vertebra, ontogenesis, human.
Introduction. The study of the morphology of the organ complex is of great practical importance [1-4]. In cervical spine and other related structures as a single Chernivtsi region, as well as in Ukraine as a whole,
congenital malformations is an urgent medical and social problem, as their levels remain consistently high. They affect perinatal and infant mortality, disability of children, need high-value medical care. Analysis of the structure and nosology of congenital malformations is necessary to plan the scope of diagnostic, therapeutic, rehabilitation and, of course, preventive measures [56]. Among the preventive programs aimed at reducing the frequency of congenital malformations in children, the monitoring of congenital malformations occupies a prominent place. The main purpose of the monitoring system is to detect changes in the frequencies of malformations, which may be a signal to search for new terato- and mutagens [7-8].
Pathological processes of the craniovertebral junction are extremely difficult for both diagnosis and surgical treatment. First of all, this is due to the topographic and anatomical features of this area, the close location of vital stem structures of the brain and spinal cord, as well as the main vessels of the brain. Destruction of bone structures of the craniovertebral junction and compression of the cervical segments of the spinal cord, stem structures are most often caused by the following pathological processes: tumor lesions (chordoma, giant cell tumor, osteoblastoma, metastases), inflammatory processes (rheumatism) and developmental abnormalities.
Craniovertebral anomalies are defects in the development of craniovertebral structures, which are often accompanied by compression of the medulla oblongata, cerebellum and cervical spinal cord. Craniovertebral abnormalities can be congenital or occur during the development of the organism. The most commonly diagnosed major craniovertebral abnormalities: occipital-ization, abnormal development of the tooth of the second cervical vertebra (epistrophy), platybasia, Arnold-Chiari anomaly, Klippel-Feil syndrome. Occipitaliza-tion (assimilation of the atlas) - fusion of the first cervical vertebra (atlanta) with the occipital bone; often combined with underdevelopment and displacement of the atlas relative to the second cervical vertebra.
The aim of the study. To study the morphogenesis and features of the chronological sequence of formation of the topography of the cervical spine during the prenatal period of human ontogenesis.
Material and methods. The study was conducted on 40 fetuses and 30 newborns. Macroscopy, microscopy of series of consecutive histological and topographic-anatomical sections, usual and thin preparation, graphic and plastic reconstruction, injections of vessels with the subsequent roentgenography, mor-phometry (digital computer histometry), statistical processing of digital data were applied. The use of these methods made it possible to trace and objectively assess the topographic and anatomical features of the spine during the prenatal period of human ontogenesis.
Research results and their discussion. The cervical spine develops from mesenchymal cells that migrate from the sclerotomes and gather in dense clusters around the chord, separating it from the neural tube and dorsal aorta.
The source of cartilage and bone formation is the mesenchyme. In the early stages of development, the
entire skeleton of the embryo consists of mesenchymal rudiments, which only in shape remotely resemble the outlines of future cervical vertebrae. In the future, this mesenchyme is either directly transformed into bone tissue, or pre-replaced by hyaline cartilage, in place of which bone develops.
The great mobility of the cervical spine, the need to keep the head, mainly in an upright position, the nature of the connection of the spine with the head - all this determines the structure of both the first two cervical vertebrae and the entire cervical spine.
Atlantis - the 1st cervical vertebra develops from the four primary lateral ossification nuclei, which give rise to the lateral masses and the posterior arch. The connection of the two halves of the posterior arch occurs in the postnatal period of development. A 4-5 month old child develops four secondary ossification nuclei, two for the anterior arch and one for each transverse process.
Axis - the 2nd cervical vertebra undergoes the process of ossification of the seven primary nuclei. The four lateral nuclei are designed for the vertebral arch. The arc behind the baby closes at 8 months. and grows with the body of the 2nd cervical vertebra in the postnatal period of ontogenesis. The nucleus of ossification of the apex of the tooth connects with the main part of the tooth in humans in the postnatal period of human ontogenesis. This is important to keep in mind when diagnosing a fracture of the 2nd cervical vertebra and the presence of so-called dentary bone.
The atlas is a bone ring consisting of lateral masses that connect the anterior and posterior arches. Located in the form of a kind of washer between the skull, the atlas takes on all the weight of the head. The lateral masses have articular surfaces - the upper, which connects with the condyles of the occipital bone (upper joint of the head), and the lower, which connects with the articular processes of the axial vertebra (lower joint of the head). The upper articular surfaces of the atlas are concave and directed upwards and outwards. Together with the condyles of the occipital bone, they form a block-like joint, the main types of movements in which are flexion and extension. The lower articular surfaces are slightly concave and directed outwards and downwards. The lower joint of the head refers to the flat joints, the main type of movement in it is rotation. On the inner surface of the side masses there are bumps - places of attachment of the transverse ligament. The main load, which is transmitted from the head to the spine, passes through the lateral masses. From the lateral masses outward depart rib-transverse processes with holes in which the vertebral arteries pass. The inner surface of the anterior arch has an articular surface that connects to the tooth of the axial vertebra (Kruvelier joint). As a rule, the anterior arch is more developed than the posterior. At the junction of the posterior arch and lateral masses, there are grooves through which the vertebral arteries pass.
The axial vertebra has a body, an arch and a spi-nous process. The body of the axial vertebra, in turn, has a dentate process, upper articular and rib transverse processes. The dentate gyrus, or tooth of the axial vertebra, is the body of the atlas fused in ontogenesis with
the body of the 2nd cervical vertebra. The tooth on the anterior and posterior surfaces has articular surfaces for connection to the anterior arch of the atlas and the transverse ligament. The dentate process at the level of the connection with the body of the axial vertebra, narrowing slightly, forms a neck. On the side of the tooth are the upper articular surfaces, elliptical, flat, directed outward and downward. Below and lateral to the upper articular surfaces are the transverse processes, directed outward and downward. The latter have holes through which the vertebral arteries pass. The holes are located almost horizontally, which allows the vessels to deviate outward, bypassing the lateral masses of the atlas. In embryos of 7.0 mm PCL (parietal coccygeal length), it is possible to clearly distinguish 21 primary somite segments, each of which is divided into myotoma and scle-rotia. Due to the varying degrees of density of the nuclei, the tabs of the arches and bodies of the vertebrae, as well as the processes, are clearly distinguished. The arches of vertebrae are most clearly expressed, bodies are rather weakly differentiated. In embryos 10.0 mm PCL vertebral bodies at this stage are well differentiated. They all have the same, primitive, quadrangular body shape and are separated from each other by a layer of mesenchyme with a dense arrangement of nuclei. The layers correspond to the future intervertebral discs (Fig. 1). Cartilage formation first begins in the body of the cervical vertebrae, and then spreads to the articular and transverse processes. As a result, a cartilaginous vertebra is formed, which is initially a single whole, without division into separate parts, which occur later when the cartilage is replaced by bone tissue. By this time, the cartilaginous bookmarks of the transverse processes are separated from the vertebrae.
In embryos 13.5 mm PCL vertebral arches depart from the bodies perpendicular to the dorsal direction. The differentiation of arc processes begins: articular and transverse (Fig. 2). At this early stage of development, embryos in the spine do not yet have any joint connections. The spinal canal reaches great depth. Vertebral bodies at this stage are well differentiated. They all have the same, primitive, quadrangular body shape and are separated from each other by a layer of mesen-chyme with a dense arrangement of nuclei. The layers correspond to the future intervertebral discs (Fig. 3).
In these early embryonic stages, the basis of the skeleton is still the dorsal string, which reaches a significant development. Of the two layers that distinguish the chord in those vertebrates in which it functions in adulthood - in humans it can be differentiated only one layer, the so-called "epithelium" of the chord. It is represented in early-stage embryos by regular rows of narrow, elongated, small, epithelial-like cells located on the periphery of the organ on both sides and turned by the basal ends to the middle, to each other.
The human spinal column is a part of the skeleton with a complex phylogeny and ontogenesis, and it is unlikely that among the vertebrates there is another organ that has undergone such an evolution from the lower stages of development to the higher ones performed by the spinal column. The spine in terms of phy-logeny is an ancient skeletal formation. In the process
of phylogeny, it goes through 3 stages: connective tissue, cartilage and bone. In ontogenesis, similar three stages are inherent in the axial skeleton of man. The formation of the spine in humans is preceded by the appearance of the chord.
In higher vertebrates and humans, the rudiment of the chord arises from the so-called main, or chordal process, which is a dense strand of cells that grow from the Gensen node toward the anterior embryonic shield. In the process of further development, the rudiment of the chord separates from the surrounding ectoderm and turns into a cellular cord, which consists of densely spaced and sharply contoured cells, covered from the surface with a thin shell.
In the 4-week embryo, the chord reaches its highest development and occupies its final position. It lies exactly along the midline, between the rudiment of the spinal cord and the aorta. The chord begins from the processus infundibularis of the diencephalon and extends to the caudal division. In embryos 10.0 mm long PCL, in which the axial mesenchyme begins to differentiate in the vertebrae, the chord forms wavy curves in the dorso-ventral direction. It is interesting to note that the length of each bend of the chord is quite identical to the length of the body segment.
The chord is the basis for the formation of the spine and the body of the developing vertebrae in its environment. It passes in the middle of the cartilaginous spine, passing without a break through the vertebral bodies and the rudiments of the intervertebral discs. As the spine develops, regressive changes occur in the chord. It breaks up into individual, irregularly shaped fragments, which are located mainly in the rudiments of the intervertebral discs.
First of all, these clusters of axial mesenchyme reveal traces of segmental placement, separated from each other by lighter gaps in which the intersegmental arteries pass. However, in the future, this primary segmentation is disrupted due to the fact that in the formation of the rudiment of the body of each vertebra involved mesenchymal cells of two adjacent seals of the mesenchyme, arising from different sclerotomes.
Each of these seals is divided into two sections -cranial and caudal, which differ from each other, respectively, lower and higher cell density. At formation of a body of a vertebra the caudal part of one mesen-chymal consolidation approaches cranial department of another, giving the beginning of a bookmark of a body of a vertebra. This bookmark is placed, no longer at the level of previous segments, but in between. Thus mesenchymal rudiments of vertebral and rib brackets are formed. The mesenchymal stage in the development of the cervical spine is rapidly replaced by cartilaginous. The formation of cartilage first begins in the body of the cervical vertebra, and then spreads to the arches and processes.
Cartilage formation first begins in the vertebral body and then spreads to the articular and transverse processes. As a result, a cartilaginous vertebra is formed, which is initially a single whole, without division into separate parts, which occur later when the cartilage is replaced by bone tissue. By this time, the cartilaginous bookmarks of the ribs are separated from the
vertebrae.
Rudimentary ribs in the cervical spine are found in embryos of 13.0-15.0 mm PCL, they differ from the thoracic in histological structure. The longest of them is the seventh cervical, which determines, in the case of stopping the development process, the possibility of deviations from the norm in the form of its preservation in the definitive state. The development of cervical ribs or thoracolization of the cervical vertebrae is more common in the VII vertebra. Quite seldom ribs in VI and above located vertebrae are formed. Our material describes two cases of anomaly of the anterior spinal column in newborns: in one - the rib did not go beyond the transverse process, and in the second - went beyond the process, but did not reach the first thoracic rib.
The cervical ribs extend from the anterior costal tubercle of the transverse process of the vertebra. In 7080% of all cases, additional cervical ribs develop on both sides, but are almost never symmetrical.
A characteristic feature of the spinal column in the early stages, we consider almost the same shape of the vertebral bodies - quadrangular, but in cross section with rounded corners. At the stage of mature prochon-dria, the vertebrae of different parts of the spine are difficult to distinguish from each other and due to their similarity can be differentiated only by their different sizes, especially cervical, whose bodies in the early stages are smaller than others. Then they begin to increase rapidly in the prenatal end of the 2nd month of fetal development, dominated by the size of the body of other parts of the spine (correlative connections with the spinal cord - the massiveness of the cervical thickening).
The source of the formation of the nervous system in the process of embryogenesis is the neural tube, which arises from the neural plate. Its cranial, expanded end gives rise to a bookmark of a brain, and all other part located in a neck site, turns to a spinal cord.
Between the atlas and the occipital bone, between the first and second cervical vertebrae in the early stages there is a cartilaginous layer. At the end of the embryonic period, cholesterol begins not with the first cervical vertebra, but with the first intervertebral cartilage. The cartilaginous fragments of the future atlanto-occipital joint in the early stages are connected by mes-enchymal strips, similar in structure to the intervertebral discs of other parts of the spine. The strips then form a ligament that is defined in this joint earlier than in others.
The formation of arcuate joints precedes the development of rib-vertebral (Fig. 4). They also go through three stages of development: from synarthrosis (6 weeks) to hemiarthrosis (7 weeks) to diarthrosis (9
weeks).
The formation of joints is closely related to the development of neuromuscular
apparatus. Intervertebral foramina are formed in the placenta 13.0-15.0 mm PCL.
The degree of development of the spinal nerves in the prenatal and fetal periods, which provide innervation of the joints of the spine and muscles in the cervical spine, suggests that these connections are possible single movements, which is important for the formation of joints.
Conclusions
1. Cervical vertebrae develop from the primary segments - somites, namely the anterior medial part of the somite sclerotomy. In embryos of 5.0-7.0 mm PCL mesenchyme of each sclerotomy, growing, surrounds the chord and neural tube, forming the primary (membranous) spinal vertebrae. At 5 weeks, the embryos of 7.0-8.0 mm PCL in the bodies and arches of the primary cervical vertebrae form islands of cartilaginous tissue, which then merge with each other. Surrounded by cartilaginous tissue, the chord loses its purpose and is preserved only in the form of a gelatinous nucleus of the intervertebral discs between the vertebral bodies. Dorsal arches of the primary vertebrae, growing, form at the fusion of odd spinous processes, even articular and transverse processes.
2. Ossification of the vertebrae begins at the end of the 8th week of embryogenesis (prenatal 28.0-30.0 mm PCL). There are 5 ossification centers (sometimes more) in each vertebra, which then merge (merge). However, the three main centers of ossification of the vertebrae are preserved for a long time: one - in the body and two - in the arch. The centers of ossification in the arc merge in the postnatal period. The legs of the arch of the cervical vertebrae up to 36 weeks retain cartilaginous character. Primary ossification nuclei appear in the arches of the cervical vertebrae in the prenatal 25.0-27.0 mm PCL.
3. The development of rib-vertebral joints occurs in three stages: from synarthrosis (7th week) - through hemiarthrosis (9th week) - to diarthrosis (11th week). The arcuate joints precede the development of the rib-vertebral joints, which is associated with the early formation of articular processes.
4. In prenatal 24.0-28.0 mm PCL formed the main components of the joints of the spine: the articular surface, the articular capsule and the articular cleft.
Prospects for further research. In the future it is planned to conduct research on the development and formation of the vascular bed of the cervical part of the spine in other age periods of human ontogenesis.
Fig. 1. Frontal section of the embryo 12.0 mm PCL. Hematoxylin-eosin. Microphoto. Micropreparation.
Vol.x 3,5. Ok.x7:
1 - chord; 2 - vertebral artery; 3 - transverse process; 4 - the body of the cervical vertebra; 5 - the body of the thoracic vertebra; 6 - rib; 7 - spinal cord.
Fig.2. Horizontal section of the foreskin 19.0 mm PCL. Hematoxylin-eosin. Micropreparation. Vol.x8, Ok.x7: 1 - the central channel of the spinal cord; 2 - anterior horn; 3 - side horn; 4 - rear horn; 5 - spinal node; 6 - the body of the vertebra; 7 - vertebral arch; 8 - chord; 9 - transverse process.
Fig. 3. Sagittal section of the spinal cord 21.0 mm PCL in the cervical and thoracic departments. Hematoxylin-eosin. Micropreparation. Vol.x 3,5. Ok.x7: 1 - the main part of the occipital bone; 2 -1 cervical vertebra; 3 - hypochordal process of the I vertebra; 4 - III cervical vertebra; 5 - trachea; 6 - esophagus; 7 - heart; 8 - spinal cord; 9 - epiglottis;
10 - language; 11 - hyoid bone.
Fig. 4. Sagittal section of the pre fetus 56.0 mm PCL. Hematoxylin-eosin. Micropreparation. Vol.x 3,5. Ok.x7: 1 - cervical vertebra; 2 - vertebral arch; 3 - arcuate joint; 4 - spinal node; 5 - spinous process; 6 - interosseous muscle; 7 - supraspinatus muscle; 8 - anterior longitudinal ligament; 9 - esophagus; 10 - trachea.
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SOME MORPHOLOGICAL PECULIARITIES OF VERTEBRAL COLUMN IN EMBRYOLOGICAL AND EARLY PREFETAL PERIOD OF HUMAN ONTOGENESIS
Marchuk O.
Department of Traumatology and Orthopedics of Bukovinian State Medical University, Chernivtsi, Ukraine, PhD, assistant
Marchuk Yu.
Department of Clinical Immunology, Allergology and Endocrinology of Bukovinian State Medical University, Chernivtsi, Ukraine, PhD, Associate Professor
Andriychuk D.
Department of Pediatrics and Medical Genetics of Bukovinian State Medical University, Chernivtsi, Ukraine, PhD, Associate Professor
ABSTRACT
Background: Knowledge of the development of the vertebral column is a morphological basis to determine abnormalities in the formation and development of the axial skeleton and represents a timely opportunity to correct them. In recent years, considerable attention is paid to the study of combine pathology of vertebral column with some somatic conditions.
Material and methods: The study was carried out on 16 series of histological sections of the specimens of human embryos and prefetuses measuring from 5.0 - 40.0 mm of parietococcygeal length (PCL), by means of the methods of microscopy and morphometry.
Results: Anlage of the vertebral bodies and the intervertebral discs are determined in embryos of length 5.0 mm. In the embryos of 7-8 mm, traced out to be more clear boundaries between the anlages of the vertebral bodies and intervertebral discs. In the subsequent development, there is some differentiation in the development of the cervical, thoracic, lumbar and sacral vertebrae. In early prefetal period, the number of vertebrae and intervertebral discs corresponds to the definitive age.
Conclusions: 1. In the embryonic period in the places of anlage of the vertebral bodies and intervertebral discs occurs pronounced condensation of mesenchymal cells, which is represented by a homogeneous mass, and anlage of intervertebral discs become more intensive condensation. 2. At the beginning of prefetal period marked of contrast morphometric thickness, width and shape of the vertebral bodies and intervertebral disks in different parts of the vertebral column, and begins the formation of vertebral arch.
Keywords: embryo, prefetus, vertebra, human.
Topicality. Knowledge of the peculiarities the spinal column development is a morphological basis for identifying the deviations in the formation of the axial skeleton. It also provides the possibility of their timely correction [1, p. 17; 2. p. 127]. In recent years, considerable attention has been paid to the study of the combined pathology of the spinal column with some somatic diseases [3, p. 515]. The paper presents some interesting data on the relationship between morphogenesis of the cervical spine and morphogenesis of the bones of the facial skull [4, p. 448; 5, p. 428; 6, p. 399].
Material and methods. The research has been carried out on 16 embryos and pre-fetuses of 5.0 - 40.0
mm parietococcygeal length (PCL), by microscopy and morphometry. Material for histological examination was prepared in the following way: fresh preparations of human embryos and pre-fetuses have been fixed in a 6-8% solution of neutral formalin for 2 weeks. After fixation, the object was washed in running water for 12 days, and then immersed into 35% ethyl alcohol for a day, after which it was totally stained with hematoxylin and eosin for 1-3 days (depending on the size of the object). Dehydration of the preparations was carried out by processing them in ethyl alcohol of increasing concentration (from 30% to absolute), and then the prepa-
