renal 9 Flashcards
why is it important to assses renal function?
due to its central role in homeostasis
what two clinical situations is the ability to measure GFR important?
in patients with renal disease, progression of underlying disease results in nephorn distruction and decreased function
many drugs and anitbiotics removed from body by exretion/filtration when gfr falls excretion fallls so drug in plasma may rise causing toxicity may need to adjust dose in decreased renal function
what is total gfr?
sum of all filtration by functioning nephrons so progression of disease would be incadicated by reduction in gfr
how is gfr measured?
plasma clearance tests - measure ability of the kidney to clear the plasms of various substances
what does clearance relate to?
the volume of plasma cleared not a quantity of substance removed from plasma
what is the gold standard for measurement of gfr?
insulin clearnce, polyfructose, loading iv dose insulin allow time to equilibrate then sample simultaneously plasma and urine
how is insulin filtered?
why is inuslin no longer used in clinical practice what is used instead?
what is routinely used to estimate gfr?
what are factors affecting serum creatine?
muscle mass - athletes vs malnutrition
dietary intake - creatine suppliments vs vegetarians
drugs - some lead to spurios increases as does ketoacidosis
what is normal gfr usually?
100mls/min/1.73m2
what is the clearance of glucose?
what is the clearance of urea?
what is the clearance of PAH?
what is the clearance of penicillin?
what is the bladder?
big bag of smooth muscle arranged in spiral longitudinal and circular bundles - detrusor muscle
contractio of this muscle is mainly responsible for empything the bladder durig micturation
what is the internal urethral sphincter?
not a true sphincter but where the smooth muscle at the start of the urethra acts as a sphincter when the smooth muscle is relaxed
what is the external urethra; sphincter?
true sphincter made up of skeletal muscle under voluntary somatic control
how does urine flow from kidneys to the ureters?
via peristaltic contraction of the smooth muscle of the ureters they enter the bladder at an obliwue angle preventing reflux of urea
describe the anatomy of the bladder?
what do urethral obstructions lead to?
bilateral renal problems
what do ueter obstruction lead to?
unilateral renal problems
what does normal daily urine production vary between?
750-2500mls in temperate climates
describe the mechanism of control for motor innervation of micturation?
describe the mechanism of control for sensory innervation of micturation?
descirbe the operation of the local spinal reflex of micturation?
how is delay of micturation accomplished?
what is one of the initial events in voluntary urination?
what can be abnormalities of micturation?
how can paraplegic patients train them selves?
