Chapter 10 provides knowledge of urinary system. The following will be discussed in this chapter: Urinary system, kidneys, urine formation, maintaining water-salt balance, maintaining acid-base balance, homeostasis, problems with kidney function. | Chapter 10 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition Excretory (Urinary) System Components: Kidneys, bladder, urethra, and associated ducts. Functions: Kidneys remove nitrogen containing waste from blood. Urine with waste is temporarily stored in bladder. Excretion of urine. Homeostatic Role: Regulates water levels in body. Removes excess water Helps conserve water Kidney Function Regulation of ECF through formation of urine. (primary function). Regulate volume of blood plasma. BP. Regulate concentration of waste products in the blood. Regulate concentration of electrolytes. Na+, K+, and HC03-. Regulate pH. Secrete erythropoietin. Micturition Reflex Actions of the internal urethral sphincter and the external urethral sphincter are regulated by reflex control center located in the spinal cord. Filling of the urinary bladder activates the parasympathetic neurons causing rhythmic contraction of the detrusor muscle and relaxation of the internal urethral sphincter. Voluntary control over the external urethral sphincter. Structure of the Urinary System 2 distinct regions: Outer cortex: Many capillaries. Medulla: Renal pyramids separated by renal columns. Pyramid contains minor calyx which unite to form a major calyx. Nephron Functional unit of the kidney. Consists of: Blood vessels vasa recta peritubular capillaries Urinary tubules PCT LH DCT CD Renal Blood Vessels Afferent arteriole: Delivers blood into the glomeruli. Glomeruli: Capillary network produces filtrate that enters the urinary tubules. Efferent arteriole: Delivers blood from glomeruli to peritubular capillaries. Renal Blood Vessels Peritubular capillaries: Deliver blood to vasa recta. Juxtamedullary nephrons. Deliver blood to veins. Cortical nephrons. Nephron Tubules Glomerular capsule Proximal convoluted tubule (PCT) Loop of Henle (LH) Distal convoluted tubule (DCT) Collecting duct (CD) Glomerular Capsule Bowman’s capsule: Surrounds | Chapter 10 Biology 25: Human Biology Prof. Gonsalves Los Angeles City College Loosely Based on Mader’s Human Biology,7th edition Excretory (Urinary) System Components: Kidneys, bladder, urethra, and associated ducts. Functions: Kidneys remove nitrogen containing waste from blood. Urine with waste is temporarily stored in bladder. Excretion of urine. Homeostatic Role: Regulates water levels in body. Removes excess water Helps conserve water Kidney Function Regulation of ECF through formation of urine. (primary function). Regulate volume of blood plasma. BP. Regulate concentration of waste products in the blood. Regulate concentration of electrolytes. Na+, K+, and HC03-. Regulate pH. Secrete erythropoietin. Micturition Reflex Actions of the internal urethral sphincter and the external urethral sphincter are regulated by reflex control center located in the spinal cord. Filling of the urinary bladder activates the parasympathetic neurons causing rhythmic contraction of the detrusor .
