Lecture 37: What are the major functions of the ?

• Urinary System Organs • Primary Functions • Nitrogenous Wastes • Stones • & Bladder • • Transitional Epithelium • Ureter “valve” • Vesicoureteral reflux • Urination: Neural Controls Retroperitoneal: behind • External urethral abdominal cavity membranes http://antranik.org/the-urinary-system-kidneys/ • Internal Urethral sphincter https://www.youtube.com/watch?v=K3Z -Lt58H0s

11/27/2016 Dr. Karen Petersen, Biol. 118, Autumn 2015 1 What are the major parts of the urinary system?

11/27/2016 http://classes.midlandstech.edu/carterp/Courses/bio211/chap25/chap25.htm 2 What are the major functions of the kidneys? 1. Remove toxic nitrogenous (N) wastes 2. Regulate blood pressure & water balance 3. Regulate plasma pH 4. Regulate numerous minerals, Na+ , K+, Ca+2 5. Produce EPO & TPO - to regulate blood cell production Compare these nitrogenous wastes from amino acids & nucleic acids:

Water soluble Water soluble Largest, not water soluble Protein catabolism Made in liver Nucleic acid catabolism Most toxic Most common Least toxic What causes different types of kidney stones? Calcium Oxalates • Genetic: Metabolic Problem • Oxalates (common) • Uric acid • Cystine (rare) • Geography: • Southern states in U.S. • Warm, dry climates Uric acid • Dehydration • Diet: • High sodium, animal protein…. • May not matter, if not genetic • Medications: • Excess Vitamin A & D  Calcium phosphates Calcium in • Some antibiotics http://kidneystones.uchicago.edu/files/PIE-CHART-OF-STONES.jpg

11/27/2016 http://www.emedicinehealth.com/kidney_stones/page2_em.htm#kidney_stones_causes 4 Where do kidney stones form? How can kidney stones be removed?

Basket Ureter Stone

Ureteroscope

Urethra Ureteroscope

http://www.ucdenver.edu/academics/colleges/medicalschool/departments/surgery/divisions/urology/coloradourologists/KidneyStones/Pages/Kidney-Stones.aspx http://patients.uroweb.org/kidney-ureteral-stones/urs/ & http://www.kidneystoners.org/polls-and-surveys/what-should-i-expect-when-i-have- 11/27/2016 my-stent-removed-results-from-a-kidneystoners-survey/ 5 How is urine moved to the bladder? Why is storage possible in the bladder?

Cross section of a ureter

Why does a ureter have smooth muscle?

11/27/2016 6 What are the functions of this mucous-covered “transitional” epithelium in the ureter & bladder?

http://pre-nlnprep.blogspot.com/2014/03/types-of-tissues.html & 11/27/2016 7 https://www.med-ed.virginia.edu/courses/path/urinary/uroth1.cfm Does urination differ between males & females?

11/27/2016 8 Why are urinary tract infections are more common in women? What can be done to prevent them? Risk factors: You have a rectum and a

Increased risk: Being a woman, nerve damage around bladder, sexual intercourse, having a catheter

20% of young women with a first UTI will have recurrent infections.

Can cranberry products prevent UTIs?

Untreated UTIs can develop into kidney infections and septicemia.

How do we treat UTIs?

11/27/2016 9 Describe the neural pathways that control urination

http://www.rnceus.com/uro/ Bladder holds about 500ml

Urination is a simple reflex 1. Stretch receptors fire a. Excites parasympathetic neurons to smooth muscle of bladder b. Inhibits somatic motor neurons to external sphincter 2. Micturition!

NOT urinating is a learned reflex

Brain stem can override reflex inhibiting parasympathetic and reinforcing somatic motor 10 Topics to understand & review: 1. Where are your kidneys? What keeps the kidneys in place & helps protect them from mechanical injury? Why are the kidneys of starving individuals at risk of “moving” lower in the visceral cavity? List the parts of the urinary system in order. 2. List 5 major functions of the kidneys. Compare the 3 types of nitrogenous waste (ammonia, urea & uric acid) for: size, toxicity & water solubility. 3. What are 3 major contributors to the formation of kidney stones? Describe the potential consequences of kidney stones. 4. Compare the structure & function of the & . Why is it necessary for smooth muscle tissue to be so stretchable? Describe the design & function of their transitional epithelium. What causes urine to move in ureters? 5. How do urinary tract infections happen? 6. Where are the internal & external urethral ? Which sphincter is composed of ? Which sphincter is composed of smooth muscle? 7. Describe the pattern of autonomic control over the urinary bladder & internal urethral sphincter leading to urination. What part of the nervous system causes the external urethral sphincter to relax? How can failure of the sphincters lead to incontinence?

11 Additional Resources 1. Cooper CS. 2009. Diagnosis and management of vesicoureteral reflux in children. Nature Reviews Urology 6:481-489.

2. Diamond DA, Mattoo TK, (2012) Endoscopic treatment of primary vesicoureteral reflux. N Engl J Med 366:1218-1226.

3. Fakheri, RJ & Goldfarb, DS. 2011. Ambient temperature as a contributor to kidney stone formation: implications of global warming. Kidney International 79:1178–1185.

4. Fowler CJ, Griffiths D, & de Groat WC. (2008) The neural control of micturition. Nature Reviews Neurosci. 9:453-466. http://www.rnceus.com/uro/

5. Leung VY-F, Chu, WC-W. (2013) Chapter 6: Functional anatomy of the vesicoureteric junction: implication on the management of VUR/ UTI, in Recent Advances in the Field of Urinary Tract Infections. editor, Nelius T. http://www.intechopen.com/books/recent-advances-in-the-field-of-urinary-tract- infections/functional-anatomy-of-the-vesicoureteric-junction-implication-on-the-management-of-vur-uti

6. NIDDK (2013 updated) in women. NIH Publication No. 08– 4132http://www.niddk.nih.gov/health-information/health-topics/urologic-disease/urinary- incontinence-women/Pages/facts.aspx

http://www.brighamandwomensfaulkner.org/programs-and-services/urology/female- incontinence.aspx#.VlpfhnvhLqs

11/27/2016http://www.patienteducationcenter.org/articles/urinary -incontinence-description-anatomy/ 12