Download Lecture 37: What are the major functions of the urinary system?

Lecture 37: What are the major
functions of the urinary system?
•
•
•
•
•
Urinary System Organs
Primary Functions
Nitrogenous Wastes
Kidney Stones
Ureter & Bladder
• Smooth Muscle
• Transitional Epithelium
• Ureter “valve”
• Vesicoureteral reflux
• Urination: Neural Controls
• External urethral sphincter
• Internal Urethral sphincter
11/27/2016
Retroperitoneal: behind
abdominal cavity membranes
http://antranik.org/the-urinary-system-kidneys/
https://www.youtube.com/watch?v=K3Z-Lt58H0s
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.
2.
3.
4.
5.
Remove toxic nitrogenous (N) wastes
Regulate blood pressure & water balance
Regulate plasma pH
Regulate numerous minerals, Na+ , K+, Ca+2
Produce EPO & TPO - to regulate blood cell production
Compare these nitrogenous wastes from amino acids & nucleic acids:
Water soluble
Protein catabolism
Most toxic
Water soluble
Made in liver
Most common
Largest, not water soluble
Nucleic acid catabolism
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 urine
http://kidneystones.uchicago.edu/files/PIE-CHART-OF-STONES.jpg
• Some antibiotics
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
11/27/2016
http://patients.uroweb.org/kidney-ureteral-stones/urs/ &
http://www.kidneystoners.org/polls-and-surveys/what-should-i-expect-when-i-havemy-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?
11/27/2016
http://pre-nlnprep.blogspot.com/2014/03/types-of-tissues.html &
https://www.med-ed.virginia.edu/courses/path/urinary/uroth1.cfm
7
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 urethra
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 ureters & urinary bladder. 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 sphincters? Which sphincter is
composed of skeletal muscle? 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-tractinfections/functional-anatomy-of-the-vesicoureteric-junction-implication-on-the-management-of-vur-uti
6. NIDDK (2013 updated) Urinary incontinence in women. NIH Publication No. 08–
4132http://www.niddk.nih.gov/health-information/health-topics/urologic-disease/urinaryincontinence-women/Pages/facts.aspx
http://www.brighamandwomensfaulkner.org/programs-and-services/urology/femaleincontinence.aspx#.VlpfhnvhLqs
11/27/2016http://www.patienteducationcenter.org/articles/urinary-incontinence-description-anatomy/
12