1. The Urinary System

2. Urinary System Structures pair of kidneys pair of kidneys remove substances from blood, form urine, help regulate certain metabolic processes remove substances from blood, form urine, help regulate certain metabolic processes pair of ureters pair of ureters transports urine from kidneys to bladder transports urine from kidneys to bladder urinary bladder urinary bladder stores urine stores urine urethra urethra transports urine from bladder to external environment transports urine from bladder to external environment

4. Urinary System Functions remove certain salts and nitrogenous wastes from body remove certain salts and nitrogenous wastes from body help maintain normal water and electrolyte concentrations help maintain normal water and electrolyte concentrations regulates pH and volume of body fluids regulates pH and volume of body fluids helps control RBC formation and blood pressure helps control RBC formation and blood pressure

5. Kidneys reddish-brown, bean- shaped organ with a smooth surface reddish-brown, bean- shaped organ with a smooth surface lie on either side of vertebral column in a depression on the posterior wall of the abdominal cavity lie on either side of vertebral column in a depression on the posterior wall of the abdominal cavity enclosed in a tough fibrous capsule enclosed in a tough fibrous capsule

6. Kidney Structure renal sinus – hollow chamber through which blood vessels, nerves, lymphatic vessels, and the ureter pass renal sinus – hollow chamber through which blood vessels, nerves, lymphatic vessels, and the ureter pass renal pelvis – funnel-shaped sac in the renal sinus renal pelvis – funnel-shaped sac in the renal sinus subdivides into 2 or 3 tubes (major calyces) which subdivide into several smaller tubes (minor calyces) subdivides into 2 or 3 tubes (major calyces) which subdivide into several smaller tubes (minor calyces) renal medulla – contains renal pyramids which appear striated. renal medulla – contains renal pyramids which appear striated. Renal pyramids are numerous triangular wedges of tissue in the renal medulla. Renal pyramids are numerous triangular wedges of tissue in the renal medulla. renal cortex – forms a shell around medulla and dips in between renal pyramids forming renal columns renal cortex – forms a shell around medulla and dips in between renal pyramids forming renal columns

7. Kidney Function 1. help maintain homeostasis by regulating the composition, volume, and pH of extracellular fluid 2. secrete erythropoietin (EPO) to help control the rate of RBC production. 1. EPO is a hormone from the kidneys that causes the red bone marrow to produce more RBC 3. play a role in activating vitamin D 4. help maintain blood volume and blood pressure by secreting the enzyme renin