Biology 1201A Lecture Notes - Lecture 25: Blood Plasma, Blood Vessel, Juxtaglomerular Apparatus
2 Oct 2016
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Document Summary
Overview of the raas system and renin production: raas = renin angiotensin aldosterone system. It begins with a set of cells that releases messengers: the key cell is the juxtaglomerular cells, which are in the blood vessels of the kidney. They"re made of smooth muscle, and release renin: an endocrine peptide hormone that helps raise blood pressure: recall that in the kidney, the afferent arteriole leads in to the glomerulus, and the efferent arteriole leaves. When released, renin enters afferent arteriole, goes through the glomerulus, and exits through the efferent arteriole. Macula densa cells sense concentration of sodium ion in glomerular filtrate. Macula densa cells taste the fluid going by and sense that there"s not much salt in it (bc blood pressure is low), so they signal jg cells to release renin through paracrine (short-ish distance) prostaglandins. Pressure: in addition to the kidney, with its juxtaglomerular apparatus (and sympathetic nerves), the liver.
