Hello everyone, today I’ll be presenting my poster on the renal, or urinary, system. The kidneys are often called the body’s natural filters, but they do much more than waste removal. They regulate blood pressure, balance fluids and electrolytes, control acid–base equilibrium, and even produce hormones that support oxygen delivery and calcium absorption. My presentation will highlight the main structures of the renal system, the processes that occur in the nephron, and the role of hormones in maintaining homeostasis.” “Let’s begin with Figure 1, which shows the main structures of the renal system: the kidneys, ureters, bladder, and urethra. The kidneys house millions of nephrons, which are the functional units responsible for filtering blood and fine-tuning its composition. Urine formed in the kidneys flows through the ureters, is stored in the bladder, and leaves the body via the urethra. These structures work together to eliminate waste and maintain the body’s fluid balance, which is essential for a stable internal environment.” “Figure 2 focuses on the nephron itself. Blood enters the glomerulus, where plasma is filtered into Bowman’s capsule under pressure. In the proximal tubule, most water, glucose, and electrolytes are reabsorbed. The loop of Henle creates concentration gradients — the descending limb allows water to leave, while the ascending limb pumps out sodium and chloride. The distal tubule and collecting duct adjust electrolytes and pH while actively secreting hydrogen ions, potassium, and toxins. These processes together maintain homeostasis by conserving what the body needs and excreting what it doesn’t.” “Figure 3 summarises the four steps of urine formation: filtration, reabsorption, secretion, and excretion. Filtration removes plasma and wastes, reabsorption recovers useful substances, secretion adds unwanted ions and toxins, and excretion eliminates urine. Each step is interdependent, and this cycle ensures that fluid and electrolyte levels remain within narrow limits, which is critical for normal cell function.” “Figure 4 shows the renin–angiotensin–aldosterone system, or RAAS. When blood pressure drops, the kidneys release renin, which eventually produces angiotensin II. This hormone constricts blood vessels and triggers aldosterone release, increasing sodium and water reabsorption. The result is restored blood volume and pressure. This highlights how the kidneys actively regulate cardiovascular stability, not just waste removal.” “Finally, Figure 5 demonstrates the role of erythropoietin, or EPO. When oxygen levels fall, the kidneys release EPO, which stimulates the bone marrow to produce more red blood cells. This improves oxygen delivery to tissues and maintains balance between oxygen demand and supply. Alongside calcitriol, which supports calcium absorption, these hormones show how the kidneys contribute to multiple body systems.” “To conclude, the renal system is essential for homeostasis. Its structures — from the kidneys to the urethra — remove wastes and balance fluids. The nephron fine-tunes blood composition through filtration, reabsorption, and secretion. And through hormones like renin and erythropoietin, the kidneys regulate blood pressure and oxygen delivery. Together, these functions highlight the kidneys as both excretory and endocrine organs, critical to the stability and health of the entire body. Thank you.”