Final answer:
Macula densa cells are responsible for detecting filtrate osmolality and stimulating renin release, playing a central role in blood pressure regulation as part of the Juxtaglomerular complex.
Step-by-step explanation:
The cells responsible for detecting the chemical levels and osmolality of filtrate and stimulating the release of renin as part of the blood pressure regulation in the distal tubule are known as macula densa cells. These cells, located in the ascending limb of the loop of Henle Juxtaglomerular complex (JGC), work closely with the juxtaglomerular cells. When changes in blood volume, blood pressure, or electrolyte balance are detected, the macula densa cells communicate with the afferent and efferent arterioles to adjust the glomerular filtration rate (GFR). This regulation involves the secretion of renin, which contributes to the Renin-Angiotensin-Aldosterone System (RAAS), playing a crucial role in maintaining blood pressure homeostasis by affecting blood vessel constriction and sodium reabsorption.