1. THE URINARY (EXCRETORY) SYSTEM
NHS – Anatomy and Physiology
Dr. Smith

2. FUNCTION Produces and excretes urine from the body
Fluid, Electrolytes and wastes are filtered from blood - VITAL
Toxic levels in the blood - uremic poisoning
Normally adjust output to equal input

3. Characteristics of URINE

4. LOCATION
Lies above the waistline - between back muscles and peritoneum
right kidney is a little lower then left - surrounded by fat
20% of blood each minute gets pumped through the kidney’s - large renal arteries

5. Internal Structure Cortex - outer part of kidney
Medulla - inner part of kidney
Pyramid - triangular divisions of the kidney
Papilla - innermost end of pyramid- Minor calyx, Major calyx
Pelvis - end of ureter; Calyxes- part of renal pelvis
Minor calyx- from each papilla
Major calyx- into renal pelvis

6. Microscopic Structure
Nephron - functional unit of kidney ( 2 main parts
renal corpuscle
renal tubule

7. Renal Corpuscle Bowman’s capsule - top of nephron
Glomerulus - small network of capillaries - blood delivered by afferent arterioles and drained by efferent arterioles

8. Renal Tubule
Proximal convoluted tube - 1st branch tube - has several bends
Loop of Henle - hairpin loop
Distal convoluted tube - distal to Loop
Collecting tube – distal con. Tube drains into

9. MAKING URINE Millions of nephrons form urine by
1. Filtration - blood pressure causes substances to move out of glomeruli and into Bowman’s capsule
2. Reabsorption - movement of substances out of renal tubes into blood capillaries where they are reabsorbed (glucose, H2O, ions)
Secretion - moving undesired (not reabsorbed substances into urine

11. CONTROL OF MAKING URINE
ADH (antidiuretic hormone) - pituitary- little or no water is removed - (urine decreasing hormone)
aldosterone -adrenal- reabsorb sodium salts at a faster rate (water follows- is reasbsorbed)
PH - Urine
ABNORMAL AMOUNTS OF URINE
Anuria - absence of urine
Oliguria - low amounts of urine
Polyuria - excess amount of urine

12. URETERS
Long narrow tubes with an expanded upper end(renal pelvis)located inside the kidney and lined with mucous membrane (transitional epithelium).
Function: to drain the urine for the renal pelvis to the urinary bladder

13. URINARY BLADDER an elastic muscular organ capable of great expansion
it is lined with a mucous membrane (TE) arranged in rugae like stomach mucous, when it’s empty its wrinkled and when full it’s smooth, it stores urine before voiding and is responsible for voiding

14. URETHRA
narrow tube from the urinary bladder to exterior, lined with mucous membrane
the opening of the urethra to exterior is called the urinary meatus
passes urine to exterior of body
MALE: passage way of semen from the body

16. Micturition
Passing of urine to the exterior of the body (VOIDING, URINATION)
Reflex action up until about age 3 - then voluntary reaction
2 sphincter (muscle rings), internal and external seal off bladder.
Bladder can hold ml - need to urinate begins at 150mL
Emptying Reflex - opening of internal sphincter - and contraction of bladder muscles

17. Urinary retention - kidneys produce urine - bladder cannot empty
Urinary suppression - kidneys do not produce urine - bladder always empties
Incontinence - voids involuntary - usually do to spinal injury – age ( normal in infants)
Cystitis - bladder infection

18. Hemodialysis
Artificial Kidney machine - usually radial artery- takes blood through a solution where dialysis can occur - usually 2,3 treatments a week
CAPD - 1 to 3 liters of sterile fluid is introduced into peritoneum, allowed to perform dialysis then drained

19. Catheterization
Insertion of a tube or catheter into the bladder via the urethra to remove urine

20. KIDNEY STONES Renal caculli - very painful
Most are small enough to pass through system
Up until present most were surgically removed
NOW- possible- lithotripsy - produces ultrasonic waves that breaks up stones into smaller pieces