1. EXCRETORY SYSTEM

2. Function Disposes of wastes & excess ions
Regulates volume & chemical makeup of blood by maintaining proper balance between water &
salts, acids & bases
UREA

3. Produces renin to regulate blood pressure & kidney function
Produces erythropoietin to stimulate RBC production in bone marrow
Metabolizes vitamin D
to its active form

4. Organs
Kidneys
Ureters
Urinary Bladder
Urethra

6. Anatomy of Kidney Bean-shaped
Located between 12th thoracic vertebra and 3rd lumbar vertebra (partial protection)
Rt. kidney lies lower than left
Concave cleft on medial surface called- hilus which leads to the renal sinus

7. Adrenal Glands lie on top of each kidney 

8. External anatomy
surrounded by renal capsule (protects from surrounding infection and trauma),  
adipose capsule (holds kidneys in place and protects from trauma),
renal fascia (anchors).

9. Internal anatomy
renal cortex - outer region
renal medulla - inner region with cone shaped renal pyramids
renal columns separate pyramids
renal pelvis - continuous with the ureter leaving the hilus
major and minor calyces

10. Renal column
Renal pyramid
Renal calyx

11. Blood and Nerve Supply
renal arteries - deliver 1/4 total cardiac output to kidneys per minute 
lobar arteries
interlobar arteries 
arcuate arteries 
Interlobular arteries

12. Nephron (this is where the action is!)
Interlobar, Interlobular, Arcuate, Lobar, Renal veins 
Renal Plexus – sympathetic nerve fibers

13. Nephron
over 1 million/ kidney; filtering unit of kidney; results in production of urine 

14. renal corpuscle - consisting of glomerulus,
Bowman's
capsule
proximal
convoluted
tubule (PCT) 
loop of Henle

15. distal convoluted tubule (DCT) 
collecting tubule (urine collecting duct)
papillary ducts (collection of all collecting tubules)

16. Nephron

17. Bowman’s Capsule
PCT
DCT
Loop of Henle
Collecting Tubule
Renal artery

18. 7. Renal vein
8. Interlobular artery
9. Afferent artery
10. Glomerulus
11. Efferent artery
12. Peritubule capillaries

21. Kidney Physiology 3 Steps involved in kidney filtration
Glomerular Filtration 
Passive
Mechanical

22. based on hydrostatic pressure
enhanced by permeability of filtration membrane
filtration membrane consists of 3 layers

24. porous endothelium - prevents passage of cells & large proteins
thin basement membrane – charged to repel charged proteins

25. visceral membrane with slit-like openings; prevents passage of large plasma proteins
Net Filtration Pressure –
Glomerular hydrostatic pressure + Bowman's hydrostatic pressure (opposing forces)

26. Filtration Rate: rate at which fluid
is forced from blood into Bowman's capsule; dependent upon:
- surface area
- filtration membrane permeability 
- Net filtration pressure

27. Glomerular filtration rate
is proportional to Net filtration pressure
anything changing pressure at the membrane also changes the GFR, therefore higher blood pressure = higher GFR; dehydration = lower GFR

28. Tubular Reabsorption - reclamation of tubule contents
difference b/t filtrate & urine
filtrate - everything in blood plasma except proteins & cells
urine - wastes & unneeded substances

29. reclamation begins in PCT (both active/passive transport)
active - glucose; a.a., vit, Na, Ca, Cl, K, P,; most require a carrier molecule. When all carrier molecules are bound, excess are excreted into urine

30. passive - (diffusion, osmosis)
usually tied to active transport of Na
other anions move with Na to balance charges in the blood.
The anions that move depend on the blood pH
H2O moves passively (osmosis) due to its linkage to Na+

31. solvent drag occurs when filtrate becomes concentrated & solvent follows the concentration gradient back into the body
Explains why some drugs & toxins are not excreted easily

32. Nonreabsorbed substances Urea (40% reabsorbed) Creatine uric acid
Tubule absorption capabilities
PCT most reabsorption occurs here
Uric Acid

33. DCT permeable to Na but not H2O urine concentration determined here
dependent on blood pressure or volume
dependent on hormone release:

34. aldosterone - increases Na reabsorption & therefore H2O
ANF - opposes this
sex hormones
glucocorticoids

35. Tubular Secretion – Reabsorption in reverse
ammonia (secreted into the collecting tubule from the blood)
Active process
Some drugs (penicillin)

38. Pathology Suppression - holding back Pyuria - tract infection
Ptosis (hydronephrosis) - kinked ureter
Pyelonephritis –
kidney inflammation

39. Pyelitis - inflammation of pelvis
Anuria - no output due to low pressure
Urethritis - inflammation of urethra
Cystitis- inflammation of bladder

40. Dysuria- painful urination
Incontinence - sphincter control
Retention - involuntary suppression
Diabetes insipidus – lack of ADH
Addison's Disease – not enough aldosterone
Excess Cl – indicate stone formation

41. Excess phosphates - alkaline urine
Cushing's Disease - hyperaldosteronism
 Dehydration – low GFR
Hypotonic hydration – “water intoxication”; Hyponatremia, too much ADH
Renal calculi – kidney stones