Biomaterial Database

[Ultrastructure of the median eminence and posterior lobe of the hypophysis in newborn Diocrostonyx torquatus lemmings during a decline in the population count]. 1987

T V Arshavskaia, and O A Danilova

Electron microscopically using morphometric analysis, the median eminence and hypophysis posterior lobe have been studied in newborn lemmings (Dicrostonyx torquatus Pallas) at the stage of decreasing population. A comparative characteristics of capillaries in the primary plexus of the portal system and capillaries of the hypophysis posterior lobe is presented. Overtaking developmental rate is demonstrated in the posterior hypophyseal lobe in comparison to that of the median eminence. In the lemmings investigated level of differentiation of the neurohemal areas of the hypothalamus is lower than development of these areas in laboratory mice and rats, according to the literature data. Possible results of weak development of the hypothalamo-hypophyseal connections in newborn lemmings at the stage of decreasing population are discussed.

UI	MeSH Term	Description	Entries
D008473	Median Eminence	Raised area at the infundibular region of the HYPOTHALAMUS at the floor of the BRAIN, ventral to the THIRD VENTRICLE and adjacent to the ARCUATE NUCLEUS OF HYPOTHALAMUS. It contains the terminals of hypothalamic neurons and the capillary network of hypophyseal portal system, thus serving as a neuroendocrine link between the brain and the PITUITARY GLAND.	Eminentia Mediana,Medial Eminence,Eminence, Medial,Eminence, Median,Eminences, Medial,Eminentia Medianas,Medial Eminences,Mediana, Eminentia,Medianas, Eminentia
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009490	Neurosecretory Systems	A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.	Neuroendocrine System,Neuroendocrine Systems,Neurosecretory System,System, Neuroendocrine,System, Neurosecretory,Systems, Neuroendocrine,Systems, Neurosecretory
D010904	Pituitary Gland, Posterior	Neural tissue of the pituitary gland, also known as the neurohypophysis. It consists of the distal AXONS of neurons that produce VASOPRESSIN and OXYTOCIN in the SUPRAOPTIC NUCLEUS and the PARAVENTRICULAR NUCLEUS. These axons travel down through the MEDIAN EMINENCE, the hypothalamic infundibulum of the PITUITARY STALK, to the posterior lobe of the pituitary gland.	Neurohypophysis,Infundibular Process,Lobus Nervosus,Neural Lobe,Pars Nervosa of Pituitary,Posterior Lobe of Pituitary,Gland, Posterior Pituitary,Infundibular Processes,Lobe, Neural,Lobes, Neural,Nervosus, Lobus,Neural Lobes,Pituitary Pars Nervosa,Pituitary Posterior Lobe,Posterior Pituitary Gland,Posterior Pituitary Glands,Process, Infundibular,Processes, Infundibular
D011156	Population Density	Number of individuals in a population relative to space.	Overpopulation,Population Size,Underpopulation,Densities, Population,Density, Population,Population Densities,Population Sizes
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D003411	Arvicolinae	A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.	Clethrionomys,Cricetidae,Dicrostonyx,Lemmings,Lemmus,Mice, Red-Backed,Microtinae,Microtus,Muskrats,Ondatra,Voles,Arvicolines,Microtines,Mouse, Red-Backed,Myodes,Ondatra zibethicus,Arvicoline,Lemming,Mice, Red Backed,Microtine,Mouse, Red Backed,Muskrat,Red-Backed Mice,Red-Backed Mouse,Vole
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000831	Animals, Newborn	Refers to animals in the period of time just after birth.	Animals, Neonatal,Animal, Neonatal,Animal, Newborn,Neonatal Animal,Neonatal Animals,Newborn Animal,Newborn Animals