HS130: Anatomy & Physiology II Unit 6 Seminar: The Urinary System
Tonight’s Agenda Welcome Course Questions, Problems & Issues Unit 5 Review Seminar discussion
Unit 5 Issues to Review Absorption-Where? Dietary fats are converted into? Carbs break down into? Where does Krebs cycle occur? Where is electron transport?
The Urinary System The Heart The Urinary System
Chapter 19 The Urinary System
Structures Kidneys Ureters Bladder Urethra
Function of Kidneys Excrete toxins and nitrogenous wastes Regulate levels of many chemicals in blood Maintain water balance Help regulate blood pressure
Kidneys Under back muscles Behind parietal peritoneum Just above waistline Right kidney usually a little lower than left
Inside the Kidneys Renal cortex Renal medulla Renal pyramids Renal pelvis Major calyces Minor calyces
Nephron Microscopic “Functional Unit” Renal corpuscle Renal tubule Bowman’s capsule Glomerulus Renal tubule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting tubule
Ureters Narrow long tubes with expanded upper end (renal pelvis) inside kidney Lined with mucous Muscular layer in wall Drains urine from renal pelvis to bladder
Urinary Bladder Elastic muscular organ Capable of great expansion Stores urine before voiding
Urethra Narrow tube from urinary bladder to exterior Opening of urethra to the exterior called urinary meatus
Steps in UrineFormation Filtration Reabsorption Secretion
Micturition Passage of urine from body (also called urination or voiding) Regulatory sphincters Internal urethral sphincter (involuntary) External urethral sphincter (voluntary) Bladder wall permits storage of urine with little increase in pressure
Micturition Initiated by stretch reflex in bladder wall Bladder wall contracts Internal sphincter relaxes External sphincter relaxes, and urination
Seminar question The kidneys function as important homeostatic mechanisms for many conditions in the body. Predict what changes in urine production would occur in a patient who suffered a surgical injury to the hypothalamus