renal anatomy and disease

Question 1

what does TBW stand for

Answer 1

-total body water

Question 2

facts about TBW

Answer 2

-50-70% of body weight in water
-plasma holds 3-4 L
-interstitial fluid holds 11-12 L
-intracellular holds 25-30L
-transcellular (cerebrospinal) holds 1.5-2L

Question 3

what are the intracellular and extracellular ion concentrations like

Answer 3

-ICF and ECF have very different compositions of fluid
-plasma membrane is very selective
-capillary endothelium is non-selective
-the same concentrations in both the interstitial fluid and the plasma membrane
-ECF cations in interstitial fluid is K+=5, Na+= 140
-ECF anions in interstitial fluid is Cl-=103, protein= 15
-ICF cations in interstitial fluid is K+= 148, Na+= 10
-ICF anions in interstitial fluid is Cl-=4, protein= 55
-amount of Na+ in plasma sets effective circulating volume

Question 4

daily balances of H2O and Na+- inputs and outputs

Answer 4

-inputs:
=Na+ 150 mmoles a day (dietary)
=H2O 2.6 litres per day
drink 1.2l/day
food1l/day
metabolism 0.35l/day
-outputs:
=urine 1.5l/day, 140mmoles
=respiration, stool, sweat 1.1l/day , stool and sweat 10 mmoles/day
urine and respiration = 2.6 l/day, 150 mmoles
-therefore kidneys are major route of excretion

Question 5

what are some congenital abnormalities

Answer 5

-renal genesis (where babies are born with one or no kidneys) is 1/2500 in fetuses- incompatible with life
-ectopic kidney- number of different locations, happens to 1/800
-thoracic kidney
-horseshoe kidney, 1/400-500, kidneys fused across midline- risk of renal stones

Question 6

what does the nephron consist of

Answer 6

-glomerulus (in capillary bed), filtrate moves from here to the Bowmans capsule
-move down the nephron to the proximal tubule then down to the loop of hence which includes the thin descending, thin ascending and thick ascending regions
-then moves to the distal tubule (early and late)
then to the collecting duct (cortical and medullary)

Question 7

what are the different types of nephron

Answer 7

-superficial nephron (85%)
-juxtamedullary nephron (15%)

Question 8

how does glomerulus filtration occur

Answer 8

-plasma is filtered into the glomerulus and passed to the Bowmans capsule
-20% of plasma is removed
-180 l/day filtrate produced
-human glomerular filtration rate (GFR) is 125 ml/min
-plasma volume is 3 litres
-filtered volume equivalent to 60 x plasma volume

Question 9

what’s renal failure described as

Answer 9

-fall in GFR, leads to an increase in serum urea and creatine

Question 10

what are the different type of renal failure

Answer 10

-acute- reversible
-chronic- irreversible, dialysis or transplant needed, happens over and extended period of time

Question 11

what is acute renal failure like

Answer 11

-short lived
-Hb levels stay the same
-renal size stays the same
-peripheral neuropathy is absent

Question 12

what is chronic renal failure like

Answer 12

-long lived
-decrease in Hb levels
-decrease in renal size
-peripheral neuropathy is present

Question 13

what’s peripheral neuropathy

Answer 13

• peripheral nerve damage leading to problems with sensation and movement

Question 14

how does renal failure progress

Answer 14

-thickening of glomerular membranes
-this leads to damage to the glomeruli
-this leads to progressive scaring of glomeruli (unable to filter) (glomerulosclerosis)
-tubular atrophy, interstitial inflammation and fibrous occur
reception of renal size

Question 15

what describes the group of symptoms for renal failure

Answer 15

-uraemia

Question 16

what does uraemia consist of

Answer 16

-failure to excrete salt and water- leads to hypertension, hyperkalaemia and mild acidosis
-poor excretion of urea/creatine- leads to anorexia, nausea and vomiting which can lead to neuropathy and pericarditis (inflamed pericardium(layer surrounding heart))
-leak of protein into urine- associated with a number of the symptoms
-failure production of erythropoietin leading to anaemia and lethargy
-failure to excrete PO4^2- which lowers serum Ca2+ - this leads to metastatic calcification (prutitus) and bone disease called osteomalacia, osteoporosis (soft bone)

Question 17

what does the end stage of renal failure show

Answer 17

-GFR ml/min is < 5-10
-ureamic syndrome is severe
-serum biochemistry is severe

Question 18

causes of renal failure

Answer 18

-glomerulonephritis (inflammation of glomerulus caused by infection) 30%
-diabetes mellitus (insulin and regulation of blood sugar) 25%
-hypertension (both cause each other) 10%
-polycystic kidney disease (inherited condition where you find cysts on the kidney) 20%
-unknown 10%
-other 5%

Question 19

how to treat renal failure

Answer 19

-assess whether its acute or chronic
-aetiology and severity (treat cause if obvious)
-treat reversible factors and complications
-reduce symptoms (slow progression
-plan dialysis and transplant
-diet- restrict proteins, slat and water
-phosphate binders for hyperphos
-Na bicar for acidosis
-diuretics for Na retention (good for early stages of renal failure)