Final answer:
The juxtaglomerular complex (JGC) in the kidney produces renin and erythropoietin, which help regulate blood pressure and oxygen levels in the blood, respectively.
Step-by-step explanation:
The endocrine structure in the kidney that secretes renin and erythropoietin is the juxtaglomerular complex (JGC). This structure consists of juxtaglomerular cells that react to changes in blood pressure or volume by releasing renin, an enzyme that is involved in the renin-angiotensin-aldosterone system to regulate sodium and water balance, ultimately affecting blood pressure. It also contains macula densa cells that signal the need for the secretion of erythropoietin (EPO), a hormone that stimulates the production of red blood cells in response to low oxygen levels in the blood. Both hormones play significant roles in maintaining essential bodily functions, such as blood pressure regulation and oxygen transport.