No local adjacente ao corpusculo as celulas do tubulo distal sao mais estreitas e seus nucleos sao vistos acumulados na parede do tubulo. Robert lewis maynard, noel downes, in anatomy and histology of the. Anatomia histologia embriologia y fisiologia renal. The macula densa is a short segment of the distal convoluted tubule that is located. Apr 18, 2020 from middle english macula spot on the skin or in the eye, borrowed from latin macula spot, stain. Printyourown poster and phone optimised pdf s are available here nursing information nursing school notes med surg nursing critical care nursing medical pictures medical anatomy medical art nursing tips medical illustration.
Nesta regiao existem tambem as celulas extraglomerulares. Base del mesangio grnulos neuroendocrinos glomerular. The most obvious structural feature is the narrowly packed cells with large nuclei, which account for the name macula densa. In addition to tubular salt sensing, macula densa cells also sense alterations in tissue metabolism through the accumulation of the krebs cycle intermediate, succinate, in tubular fluid. Macula densa cells detect changes in luminal sodium chloride concentration through a complex series of ion. A macula densa e uma regiao com celulas epiteliais especializadas em contacto com o glomerulo. It was found that this apparatus includes the granular cells which lie within the media of the preglomerular portions of the afferent and efferent arterioles. Regulacao fsr sistema nervoso simpatico e catecolaminas.
Most of the new discoveries in the domain of renal structure have been obtained through the use of histochemical and cytochemical techniques or with the electron microscope. Dmri forma atrofica degeneracao macular relacionada a idade. The macula densa cells of the distal convoluted tubule are smaller than the usual. Histomorphological study of the jg complex of the one. Results obtained showed that the macula densa mdcells were. Macula densa sensing and signaling mechanisms of renin release.
First, prostaglandins preferentially vasodilate the renal afferent arteriole, decreasing afferent arteriole resistance and, thus, offsetting the decrease in glomerular hydrostatic pressure caused by. Retrograde microperfusion studies in rats were conducted to test the hypothesis that activation of macula densa cytoplasmic calcium is involved in the transmission of feedback. The macula densa is a region of specialized epithelial cells of the tal where there is close anatomic contact between the tal and the vascular pole of its own glomerulus. In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the distal tubule, at the point where the thick ascending limb of the loop of henle meets the distal convoluted tubule. Semelhante aos capilares sanguineos com os quais podem ser confundidas. Contents kidney parts of nephron and structures juxtaglomerular apparatus functional aspects blood circulation ureter and urinary bladder general features urinary epithelium urethra structure of male and. Welcome to the magic world of nephropathology, glomeruli, podocites, interstituim and so on in kidney pathology. The jga includes the macula densa and juxtaglomerular cells. This chapter discusses the general anatomy and histology of the kidney. Sistema urinario rinon conductos excretores calices ureter vejiga urinaria uretra 3. Activation of the succinate receptor gpr91 in macula densa cells.
Cytoplasmic calcium in the mediation of macula densa tubulo. The juxtaglomerular apparatus the juxtaglomerular apparatus jga controls the rate of the glomerular blood flow depending on various factors such as hydration, blood volume and ion concentration. Pdf the histology and ultrastructure of the different components of the. The juxtaglomerular apparatus veterinary histology. Polarized ends of human macula densa cells american. The macula densa senses this drop in salt concentration and responds through two mechanisms, both of which are mediated by prostaglandin release. Macula densa cell an overview sciencedirect topics. The macula densa is the thickening where the distal tubule touches the glomerulus the cells of the macula densa are sensitive to the concentration of sodium chloride in the. A macula densa e o componente tubular do aparelho justaglomerular. The macula densa is a region of specialized epithelial cells of the tal where there is. This tubuloglomerular feedback mechanism plays an important role in regulating glomerular filtration rate and blood flow.1113 46 187 692 819 1042 80 488 1129 1089 1000 1238 1018 1141 223 913 1084 427 211 1594 152 1389 501 537 877 1491 811