Macula densa definition of macula densa by medical dictionary. Macula densa cells stimulate flashcards and study sets quizlet. These cells are in close approximation to the juxtaglomerular vascular smooth muscle cells of the afferent arterioles of their glomeruli, and together they form what is known as the juxtaglomerular apparatus. However, the distal tubule is actually composed of several structurally and functionally distinct segments. Macula densa medical definition merriamwebster medical. Oct 03, 2017 the tubuloglomerular feedback mechanism of renal autoregulation is the key function of the macula densa. In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the thick ascending limb of henle talh at the point of return of the nephron to the vascular pole of its parent glomerulus glomerular vascular pole the cells of the macula densa are sensitive to the ionic content and water volume of the fluid in the talh, producing molecular signals that. Learn vocabulary, terms, and more with flashcards, games, and other study tools. It is ideally situated close to the afferent arteriole which governs glomerular filtration and the granular cells which surround the afferent arteriole and secrete renin when appropriately stimulated. Macula densa cells sense changes in sodium chloride level, and will trigger an autoregulatory response to increase or decrease reabsorption of ions and water to the blood as needed in order to alter blood volume and return blood pressure to normal a decrease in afferent arteriole diameter causes a decrease in the gfr glomerular filtration rate, resulting in a decreased concentration of. Get answers you seek today in your free tarot reading. Dal punto di vista morfologico essa rappresenta il punto di passaggio fra il segmento rettilineo e quello convoluto del tubulo distale. Macula densa definition of macula densa by medical. The cells of the macula densa are sensitive to the concentration of sodium chloride in the distal convoluted tubule.
What is the function of the macula densa cells of the. It monitors tubular nacl concentrations and adjusts glomerular filtration accordingly. A decrease in sodium chloride concentration initiates a signal from the macula densa that has two effects. Degeneracion macular causas, sintomas y tratamiento. The macula densa is worth its salt pubmed central pmc.
Macula densa definition of macula densa by the free. When prolonged deviations in nacl concentration signal a state of salt deficit or excess, the macula densa resets the operating point of the tgf loop by altering the local. The macula of utricle allows a person to perceive changes in longitudinal acceleration in horizontal directions only. 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. Learn macula densa cells stimulate with free interactive flashcards. The macula of utricle allows a person to perceive changes in. The nephron segment between the macula densa and the first junction of two tubules is often referred to as the distal tubule. In the kidney, the macula densa is an area of packed specialized cells lining the wall of the distal tubule, at the point where the thick ascending limb meets the distal convoluted tubule. 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.
The macula densa cells are a small subset of approximately 20 cells per nephron at the distal end of the ctal of the loop of henle. Choose from 48 different sets of macula densa cells stimulate flashcards on quizlet. The juxtaglomerular apparatus is a structure in the kidney that regulates the function of each. Macula densa sensing and signaling mechanisms of renin release.
Macula densa definition of macula densa by the free dictionary. The cells on the side of the tubule facing the glomerulus have a distinct appearance and constitute the macular densa figure 1. Sistema renina angiotensina aldosterona linkedin slideshare. As the distal proximal tubule rises from the renal medulla, it makes close contact with the glomerulus. These cells sense the nacl content of the tubule and make changes to gfr appropriately. Tratamiento del agujero macular american academy of. The cells of the macula densa are taller and have more prominent nuclei than surrounding cells of the distal straight tubule. A decrease in sodium chloride concentration initiates a. The first portion of the distal tubule usually 100150. The macula of the utricle, or utricular macula is the region of the utricle that receives the utricular filaments of the vestibulocochlear nerve. Macula densa cells sense changes in sodium chloride. Oct 15, 1999 the macula densa acts as a sensor of nacl concentration in tgf, the mechanism critical for the rapid adaptation of filtration rate to the absorptive capacity of the tubule.
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