Kidney 4 Flashcards
What is the concept of clearance?
Determines how much of a substance can be cleared from the body by the kidneys per given unit of time
How is clearance rate via glomerular filtration rate (GFR) estimated?
By comparine blood creatinine to urine creatinine
How to interpret clearance rate via GFR
- should eliminate 100% of creatinine, so amt in blood should equal amt in urine
- GFR can also be estimated by some formulas
BUN =
Blood urea nitrogen
What is BUN?
Reflects glomerular filtration and urineurine-concentrating capacity
Blood and urea
Urea is filtered in glomerulus, so it shouldn’t be present in blood
When will BUN levels rise?
- If glomerular filtration drops
- dehydration and renal failure
Urinalysis evaluates:
- color
- protein
- pH
- sediment
- etc
Ureters
- carry urine formed by nephron from collecting ducts to bladder via peristalsis
- closed off during bladder contraction during urination to prevent reflux
Bladder muscle
- smooth muscle fibers form the detrusor muscle
- lined with transitional epithelium
Urethra
From inferior bladder to outside body
Internal urinary or internal urethral sphincter
Bladder junction controlled by ANS
External urinary or external urethral sphincter
Voluntary control of urination
prostate gland
- surrounds proximal urethra just distal to bladder
Main function of prostate gland
secrete prostate fluid, which is a component of semen