The Urinary System

1
The Urinary System

• Chapter 17

2
Terminology

• Nephrology study of the S/F of the kidney
• Urology
• Males specialty of male urinary system
  reproductive system
• Females speciality of urinary system
• Dialysis (hemodialysis) removal of solutes from
  urine artificially if kidneys are impaired
• Incontinence lack of voluntary control of
  bladder emptying

3
Dialysis
4
4 Functions of Urinary System

• Regulate blood volume composition (kidneys)
• Transportation of filtrate (ureters)
• Storage of urine (urinary bladder)
• Discharge of waste/excretion (urethra)

5
Kidneys - 2

• Sit above waist
• Back of abdominal cavity (retroperitoneal)
• Right kidney sits lower than left
• 4-5 inches long, 2-3 inches wide, 1 inch thick
  bar of soap
• Surrounded by adipose tissue
• Hilus where vessels enter/exit

6
Layers of the kidney

• Renal cortex (bark)
• Renal medulla (middle)
• Renal pyramids here
• Renal pelvis (inner)
• Funnel-shaped basin for draining urine

7
Basic Functioning Unit of Kidney

• The Nephron p. 474-475
• 2 parts
• Renal corpuscle (cortex) filtration
• Glomerulus
• Glomerular (Bowmans) capsule
• Renal tubules (cortex medulla) reabsorption
• Proximal convoluted tubule
• Loop of Henle
• Distal convoluted tubule
• Collecting duct

8
The Nephron
9
Did you know

• Only 1 of what your kidneys filter is excreted
  as urine
• The other 99 is water and is reabsorbed to
  prevent dehydration
• Which hormones control this action??

10
Ureters - 2

• Transport urine from kidneys to urinary bladder
• Empty posteriorly and inferiorly into urinary
  bladder

11
Urinary Bladder - 1

• For storage
• Capacity ¾ quart (600mL)
• Usually signals start at 150mL full
• Trigone area made by ureters and urethra
  triangular area with no folds
• Lots of folds to allow for stretching
• Do you remember what tissue makes up the urinary
  bladder?

12
Urinary Bladder
13
Urination reflex

• To empty the bladder urination, voiding,
  micturition
• Spinal cord reflex
• Controlled by 2 sphincters (similar to defecation
  reflex)
• Internal sphincter released involuntarily when
  bladder reaches a certain capacity controlled by
  detruser muscle
• External sphincter voluntarily controlled to
  release urine when appropriate

14
Urethra - 1

• Tube that discharges urine from body
• Terminal end urinary meatus
• In males, it also dicharges semen

15
Urinalysis

• Analysis of volume, physical, chemical
  microscopic urine properties
• Normal characteristics
• 95 water
• Volume 1-2L (varies with fluid intake)
• Color yellow/amber ? clear
• Turbidity clear/transparent
• Odor after time, mild ammonia
• pH 4.6 8.0 (varies with fluid intake)
• Specific gravity/density 1.001 1.0035
  (slightly more dense than water 1)
• Normal solutes urea, uric acid, amino acids

16
Urinalysis continued

• Abnormal solutes
• Albumin (protein) (proteinuria)
• Glucose
• Ketones (ketonuria)
• Blood (hematuria)
• Stones

17
Disorders

• Urinary Tract Infection (UTI) bacterial
  infection in any part of the urinary system
• Cystitis infection of urinary bladder
• Nephritis infection of kidney (nephron)
• Polyuria increased urine production
• Nocturia increased urine output at night
• Dysuria painful urination often associated with
  UTIs and STDs
• Uremia/uremic poisoning toxic levels of urea in
  the blood due to kidney failure