Urinary System Overview

The main function of the urinary system is to eliminate waste products from the body, including excess water, salts, and urea.

The renal capsule is a connective tissue layer that surrounds each kidney. It protects the kidney from injury and infection.

The hilum is an indentation on the medial side of the kidney. It contains the renal artery, renal vein, and ureter.

<p>The renal sinus is a space within the kidney that contains the renal pelvis, blood vessels, and nerves.</p> Signup and view all the answers

<p>Renal pyramids are cone-shaped structures located in the renal medulla. They are involved in concentrating urine.</p> Signup and view all the answers

<p>The renal pelvis is a funnel-shaped structure that collects urine from the calyces and directs it to the ureter.</p> Signup and view all the answers

<p>The nephron is the functional unit of the kidney; there are over one million nephrons per kidney. It filters blood and produces urine.</p> Signup and view all the answers

<p>Juxtamedullary nephrons have long loops of Henle that extend deep into the medulla, while cortical nephrons have shorter loops that remain mostly within the cortex.</p> Signup and view all the answers

<p>The glomerulus is a network of capillaries within the renal corpuscle. It is responsible for filtering blood and removing waste products.</p> Signup and view all the answers

<p>Bowman's capsule is an enlarged nephron end that surrounds the glomerulus. It collects the filtrate produced by the glomerulus.</p> Signup and view all the answers

<p>The filtration membrane is a specialized structure within the glomerulus that allows water and small solutes to pass through while blocking larger molecules and blood cells. It consists of three layers: the capillary endothelium, the basement membrane, and the podocytes.</p> Signup and view all the answers

<p>The juxtaglomerular apparatus is a regulatory structure located near the glomerulus. It helps control blood pressure.</p> Signup and view all the answers

<p>Filtration pressure is the pressure that drives fluid across the filtration membrane. It is the difference between the blood pressure in the glomerular capillaries and the pressure in Bowman's capsule.</p> Signup and view all the answers

<p>Urine formation involves three main processes: filtration, reabsorption, and secretion.</p> Signup and view all the answers

<p>Tubular reabsorption is the process of reclaiming substances from the filtrate. It occurs as the filtrate moves through the tubules of the nephron.</p> Signup and view all the answers

<p>Tubular secretion is the process of removing substances from the blood into the nephron. These substances are then excreted in urine.</p> Signup and view all the answers

<p>The countercurrent mechanism involves the opposite flow of fluids in the loop of Henle, which enhances the concentration of urine.</p> Signup and view all the answers

<p>The medullary concentration gradient is the difference in solute concentration between the renal medulla and the cortex. It plays a crucial role in concentrating the urine as it moves through the loop of Henle.</p> Signup and view all the answers

<p>The vasa recta are blood vessels that run alongside the loop of Henle. They remove excess water and solutes from the interstitial fluid, helping to maintain the medullary concentration gradient.</p> Signup and view all the answers

<p>The descending limb of the loop of Henle is permeable to water. It reabsorbs water from the filtrate, increasing the concentration of the remaining solutes.</p> Signup and view all the answers

<p>Aldosterone is a hormone produced by the adrenal glands that increases sodium (Na+) reabsorption in the kidneys, thereby increasing blood volume and pressure.</p> Signup and view all the answers

<p>Antidiuretic hormone (ADH) is a hormone produced by the pituitary gland that promotes water reabsorption in the kidneys, thereby decreasing urine volume and increasing blood volume and pressure.</p> Signup and view all the answers

<p>Atrial natriuretic hormone (ANH) is a hormone released by the heart that reduces sodium (Na+) reabsorption in the kidneys, thereby decreasing blood volume and lowering blood pressure.</p> Signup and view all the answers

<p>The micturition reflex is the involuntary reflex that triggers urination. It is initiated by the stretching of the bladder wall as it fills with urine.</p> Signup and view all the answers

<p>Intracellular fluid (ICF) is the fluid found inside cells, making up about two-thirds of the body's total water. Extracellular fluid (ECF) is the fluid outside cells, including plasma and interstitial fluid, making up the remaining one-third of the body's water content.</p> Signup and view all the answers

<p>Hydrostatic pressure is the pressure exerted by a fluid within a compartment. It is important for driving fluid movement across membranes, such as in the filtration of blood in the glomerulus.</p> Signup and view all the answers

<p>Osmotic pressure is the pressure that arises from the concentration of solutes within a compartment. It plays a role in determining the direction of water movement across membranes, driven by differences in solute concentration.</p> Signup and view all the answers

<p>The thirst center is a region in the hypothalamus that regulates water intake. It senses changes in blood volume and solute concentration, triggering thirst as needed.</p> Signup and view all the answers

<p>Maintaining ion concentration regulation is crucial for various bodily functions, including nerve impulse transmission, muscle contraction, and maintaining blood pressure.</p> Signup and view all the answers

<p>Sodium ions (Na+) are essential for various bodily functions, including maintaining osmotic pressure, nerve impulse transmission, and muscle contraction. They are the dominant extracellular cation, playing a major role in fluid balance, electrolyte balance, and blood pressure regulation.</p> Signup and view all the answers

<p>Potassium ions (K+) are vital for various critical bodily functions, including muscle contraction, nerve impulse transmission, and maintaining the electrical properties of cells.</p> Signup and view all the answers

<p>Calcium ions (Ca2+) play critical roles in various bodily functions, including muscle contraction, nerve impulse transmission, blood clotting, and bone formation.</p> Signup and view all the answers

<p>Phosphate ions (PO43) are essential for various bodily functions, including bone formation, energy metabolism, and genetic material (DNA and RNA). They contribute to providing structure and rigidity to bones, are involved in the production of ATP (adenosine triphosphate), and are critical for cellular processes.</p> Signup and view all the answers

<p>The renin-angiotensin-aldosterone mechanism is a hormonal pathway that regulates blood pressure and volume. It is activated when blood pressure drops, prompting the kidneys to release renin.</p> Signup and view all the answers

<p>Angiotensin II is a potent vasoconstrictor that raises blood pressure by causing contraction of smooth muscle in blood vessels.</p> Signup and view all the answers

<p>Parathyroid hormone (PTH) increases the concentration of calcium (Ca2+) in the blood by stimulating its release from bones and promoting calcium reabsorption in the kidneys.</p> Signup and view all the answers

<p>Calcitonin is a hormone that reduces blood calcium (Ca2+) levels by inhibiting the release of calcium from bones and promoting its deposition into bones.</p> Signup and view all the answers

<p>The kidneys perform several vital functions, including the excretion of waste products, regulation of blood volume and pressure, regulation of blood solute concentration, maintenance of blood pH balance, production of red blood cells, and synthesis of vitamin D.</p> Signup and view all the answers

<p>The urinary system consists of kidneys, ureters, the urinary bladder, and the urethra.</p> Signup and view all the answers