1. Urinary system
Lab 8

2. Urinary System Two Kidneys Two Ureters Urinary Bladder Urethra
Perform all functions except actual excretion.
Two Ureters
Convey urine from Kidneys to Urinary Bladder
Urinary Bladder
Holds Urine until excretion
Urethra
Conveys urine from bladder to outside of body

3. Complete System

4. Kidney general info
Lie against posterior abdominal wall at level of T12-L3.
Right kidney is lower than left kidney due to the shape of the liver.
Lateral surface of kidney is convex while medial is concave.
Concave side has a cleft – Renal Hilus
Inside hilus is Renal sinus
Where kidneys receive renal vessels and nerves.

5. Kidney External Anatomy
Average size – 12cm x 6cm x 3 cm
Weights 150 grams or 5 oz
Surrounded by three membranes (deep to superficial)
Renal capsule – fibrous barrier for kidneys.
Adipose capsule – fatty tissue designed for protection / stability.
Renal fascia – dense fibrous CT anchors kidneys/ adrenals/ membrane 1 and 2 to surroundings.

6. Kidney Anatomy Renal arteries and veins Renal cortex Renal medulla
Nephron
Renal pyramids (6-10)
Renal papilla
Calyx (ces)
Renal pelvis
Ureter

7. Kidney- External Anatomy
Lateral surface- convex
Medial is concave-
Renal Hilum
Opening to Kidney
Renal Sinus
Space within hilus
Kidneys receive blood vessels and nerves.

8. Kidney Internal Anatomy I
Renal arteries and veins
Bring blood in and out of kidney
Renal cortex
Outer layer of Kidney
Renal medulla
Inner layer of Kidney
Nephron

9. Kidney Internal Anatomy II
Renal Pyramids
Renal Columns
Space between pyramids within the medula
Renal Papilla
Narrow end of pyramid
Calyx (ces)
Collecting tubes
Renal Pelvis
Collecting vessel prior to ureter

10. Human Kidney

11. Nephron Blood processing unit which serves to produce urine
1 million per kidney
Consists of a glomerulus and tubules

12. Nephron: Vascular System
Afferent arteriole
Glomerulus
Efferent arteriole
Peritubular capillaries
Capillary beds reabsorb in cortex
Vasa recta
Capillary beds reabsorb in medulla

13. Nephron Tubular system Glomerular Capsule Proximal convoluted tubule
Loop of Henle (nephron loop)
Descending limb
Ascending limb
Distal convoluted tubule
Collecting duct

14. Nephron

15. Gross Anatomy Urinary system Kidney Nephron
Dynamic Human
Gross Anatomy
Urinary system
Kidney
Nephron

16. Urine Formation I Glomerular filtration
Water, ions, amino acids, and glucose get into capsular space from blood
Proteins stay in blood – too big to leave capillaries.

17. Urine Formation II
Proximal convoluted tubule and Peritubular capillary
Na+ goes down gradient and brings glucose, amino acids, etc. back into blood stream (cotransport).
Reabsorbs about 65% of filtrate.

18. Countercurrent Multiplication
Urine Formation III
Countercurrent Multiplication
in the Nephron Loop
Descending limb
Goes into medulla increasing salt gradient
Water leaves
Fluid concentrates
Ascending limb
Goes up toward cortex - decreasing salt gradient
Na+ pumped out
Fluid relatively diluted

19. Nephron Loop

20. Urine Formation IV Collecting duct Travels down into medulla
Water leaves tubule and enters blood
Urine becomes concentrated and enters renal papilla
ADH controls water channel
ADH – Antidiuretic hormone

21. Collecting duct

22. Dynamic Human
Urine Formation

23. Micturition Ureters Urinary Bladder 25 cm long
Enters on the floor of bladder
Urinary Bladder
Muscular sac on floor of pelvic cavity
Muscle layer formed by detrusor muscle
Average bladder volume is 500 ml
Max capacity is ml

24. Micturition Urethra Conveys urine out of body
Female urethra – cm
Opens into external urethral oriface
Lies between vaginal oriface and clitoris
Male urethra – 18 cm
3 regions
Prostatic urethra – 2.5 cm
Membranous urethra – 0.5 cm
Penile urethra – 15 cm

25. Micturition Reflex Bladder with >= 200 ml of urine
Sensory input to parasympathetic system
Contraction of detrusor muscle and relaxation of internal urethral sphincter
Relaxation of external urethral sphincter

26. Micturition

27. Kidney stones
A hard granule of calcium, phosphate, uric acid and protein.
Form in renal pelvis and get lodged in pelvis or ureter.
Caused by urinary tract infections, dehydration, pH imbalances, or an enlarged prostate gland.
Treated with stone dissolving drugs, surgical removal, or lithotripsy (ultrasonic vibrations)