chapter18 - urinary system

Copyright © 2012 F.A. Davis Company

Understanding Anatomy & PhysiologyUnderstanding Anatomy & PhysiologyA Visual, Interactive ApproachA Visual, Interactive Approach

Chapter 18

The Urinary SystemThe Urinary System



KidneysKidneys



Renal cortex

Renal medulla

Renal columns

Renal pyramid

Minor calyx

Major calyx

Renal pelvis



Blood vessels, nerves, and the ureter enter and leave the kidney from the:

A.renal pelvis.B.hilum.C.calyx.D.renal pyramid.



Correct answer: B

Rationale:The renal pelvis, formed by the convergence of the major calyces, channels urine out of the kidney.The calyx collects urine leaving the papilla.Renal pyramids are the cone-shaped sections in the kidney.



Renal circulationRenal circulation

Renal artery

Renal vein

Nephron



Afferent arteriole

Glomerulus

Efferent arteriole

Peritubular capillaries

Vein



Renal corpuscleRenal corpuscle

Bowman’scapsule



Proximal convoluted tubule

Loop of Henle

Distal convoluted tubule

Collecting duct



What are the filtration units of the kidney?

A.Renal corpuscleB.GlomerulusC.NephronD.Renal pelvis



Correct answer: C

Rationale: The renal corpuscle is part of the nephron.The renal corpuscle contains the glomerulus.The renal pelvis funnels urine out of the kidney.



Urine formationUrine formationUrine formation involves three processes:1.Glomerular filtration2.Tubular reabsorption3.Tubular secretion



Glomerular filtrationGlomerular filtration



Regulation of GFRRegulation of GFR Glomerular filtration rate [GFR]

should be constant, despite changes in blood pressure.

If flow is too high, the body will lose excessive water and nutrients.

If flow is too low, tubules may reabsorb toxins.



<View animation on "Renin-angiotensin-aldosterone system">

http://resources.fadavis.com/thompson/Renin-AA-System.mp4

http://resources.fadavis.com/thompson/Renin-AA-System.mp4



Tubular Tubular reabsorption and reabsorption and

secretionsecretion

<View animation on "Urine formation">

http://resources.fadavis.com/thompson/Urine-Formation.mp4



Most sodium is reabsorbed from the glomerular filtrate in the:

A.proximal convoluted tubule.B.distal convoluted tubule.C.collection duct.D.glomerulus.



Correct answer: A

Rationale:The distal convoluted tubule and collection ducts reabsorb variable amounts of water and salt.In the glomerulus, water and small solutes filter out of the blood and into Bowman’s capsule.



Hormones that affect the Hormones that affect the urinary systemurinary system

HORMONE EFFECT ON RENAL TUBULE

Aldosterone Reabsorbs: NaCl; H2OExcretes: K+

Atrial natriuretic peptide (ANP) Excretes: NaCl; H2O

Antidiuretic hormone (ADH) Excretes: H2O

Parathyroid hormone (PTH) Reabsorbs: CalciumExcretes: Phosphate



Composition of urineComposition of urine Consists of 95% water; 5% dissolved

substances Reveals information about health of

kidneys and other organs



Storage and elimination of Storage and elimination of urineurine

Ureter



Urinary bladderUrinary bladder

External urinary meatusExternal urinary sphincter

Internal urethral sphincter

Trigone

Rugae

Detrusor muscle



UrethraFemale Male



UrinationUrination1. Stretch receptors send impulses to

spinal cord.2. Spinal cord sends motor impulses to

bladder.3. Pons can override impulses.4. The brain sends signals to contract

or relax sphincters.<View animation on "Micturition reflex">

http://resources.fadavis.com/thompson/Micturition-Reflex.mp4



The triangular-shaped smooth area on the floor of the bladder is called the:

A.rugae.B.papilla.C.cortex.D.trigone.



Correct answer: D

Rationale:Rugae are folds of tissue on the inside of the bladder.Papillae are the blunt points of the renal pyramids.The cortex is the outer zone of the kidney.

chapter18 - urinary system

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