Draw the Lewis structure for each molecule. CC l 4

Urinary System  Function of urinary system: o Maintains homeostasis  Regulates water volume, concentrations, and pH levels  Regulates he balance of salt and water in the blood  Influences red blood cell production and blood pressure o Filters out (excretes) wastes from the body  Filters out nutrients and wastes allowing for the nutrients to be absorbed into the body and removes the waste from the body  Kidneys o Retroperitoneal – lie between the dorsal wall and the peritoneum o 3 distinct layers:  Renal cortex – outermost layer  Renal medulla – a set of cone-shaped masses of tissue that secrete urine into tiny sac-like tubules  Renal pelvis – innermost layer; funnel-shaped tube surrounded by smooth muscle that uses peristalsis to move urine out of the kidney, into the ureter, and to the bladder o Main function: filter blood continuously (20% of total blood volume) o Each kidney is composed of many tubular nephrons that produce urine o Each nephron is composed of several parts  Glomerular capsule (Bowman’s capsule)  Glomerulus  Renal tubule  Proximal convoluted tubule (PCT) o Cuboidal epithelial cells o Mitochondria makes ATP to pull sodium ions from the filtrate, using active transport o Cells are covered in microvilli that increase their surface area and help with reabsorption  Loop of the nephron (loop of Henle) o Drives the reabsorption of water by creating a salt concentration gradient in the tissue of the medulla  Distal convoluted tubule (DCT) o Steps of nephrons:  Glomerular filtration  Tubular reabsorption  Tubular secretion