JG apparatus
- where the distal convoluted tubule meets with the afferent arterioles
- made up of JG cells in the afferent arterioles - secrete renin
- macula densa cells in the distal tubule - senses sodium in the distal tubule
JG cells are stimulated to secrete renin by
- beta adrenergic stimulation B1
- low Na+ in the DCT
- low pressure in the afferent arterioles
Cortex vs. Medulla
Glomeruli are found in the cortex
Nephrons are found in the medulla
Ureters
Pass under the uterine artery (females) under the vas deferens (males)
Kidney Embryology
526
Causes of Potter Sequence
- ARKPD
- obstructive uropathy - posterior urethral valves
- bilateral renal agenesis
REMEMBER TURNER SYNDROME = Horseshoe Kidney
Multi cystic Dysplastic Kidney
527
Renal Transplantation
Left kidney is usually taken during donor transplantation because it has a longer renal vein
Renal Blood Supply
Renal artery –> segmental artery –> inter lobar artery –> inter lobular artery –> arcuate artery
Fluid Compartments
Pg 529
Renal Plasma Flow
- blood that goes into the glomeruli and the tubules
- use PAH to estimate because it is filtered by glomerulus and secreted into the proximal tubule
Pg 530
Filtration Fraction
Fraction of blood going to the kidney that is filtered through the glomerulus
Normal = 20%
NSAIDs = constrict the afferent arterioles
- decreases RBF, GFR
- no net change for FF
Angiotensin 2 = constricts the efferent arterioles
- RBF decreases
- GFR increases
- FF increases
ACE inhibitors = dilate the efferent arterioles
- FF decreases
Ureter stone obstruction
- decrease GFR
- no change of RBF
- decrease FF
SEE PICTURE
Glucose and Amino acids
- free filter able and all reabsorbed
Glucose
- normally completely reabsorbed in PCT by Na/glucose transporter
- at plasma glucose of 200 glucosuria begins (threshold)
- at 375 all transporters are fully saturated (Tm)
- Normal pregnancy can decrease the ability of PCT to reabsorbed glucose and amino acids
Amino Acid Clearance
- Na+ dependent transporters in PCT
- 3 carrier systems = positive, negative, and neutral
- deficiency of neutral transporter = Hartnup disease
Psammoma bodies
- Papillary adenocarcinoma of the thyroid
- serous cyst adenocarcinoma of the ovary
- meningioma
- mesothelioma
Proximal Convuluted Tubule
- reabsorbs all glucose and amino acids
- reabsorbs most HCO3-
- isotonic reabsorption = water follows
Pg 533!!!!
In Late PCT
= Sodium is being reabsorbed with Chloride
To secrete an anion you use alpha ketoglutarate
To secrete cation you use Na/K+ pump and you bring in H+ into the cell
Loop of Henle
Thin descending limb
- responsible for water reabsorption
- impermeable to water
Thick Ascending Limb
- NKCC - inhibited by loop diuretics (Causing an isotonic water excretion)
- Calcium and magnesium are reabsorbed par acellular
- impermeable to water
- makes urine less concentrated as it ascends
Early DCT
- activate reabsorption of Na and Cl = inhibited by thiazides
- Calcium reabsorption occurs here due to PTH
Collecting Tubule
Principal cells
- reabsorb Na and water
- secrete K+
- ADH acts on the principal cells (lithium inhibits this effect)
- aldosterone acts on this = reabsorption of Na+ and secretion K+
- K+ sparing diuretics act here = triamterene and amiloride inhibit epithelial Na+ channels; aldosterone antagonists
Intercalated cells
- secrete hydrogen or bicarbonate
- reabsorbs K+
- alpha cells = secrete H+ ions
- beta cells = secrete bicarbonate
- aldosterone acts on this = stimulates secretion of H+ ions
Diuretics
Pg 554
See Picture
Acute pulmonary edema = loop diuretic
Idiopathic hypercalciuria = thiazide diuretic
Glaucoma = Acetozolamide or mannitol
Edema associated with nephrotic syndrome = loop diuretic
Mannitol = ICP increased
- mild to moderate hypertension = thiazide
Altitude sickness = Acetozolamide
ADH
- binds on the principal cells SIADH causes - ectopic ADH production by small cell lung cancer - pulmonary pathology - head trauma - stroke - CNS infection - drugs = cyclophosphamide - idiopathic - treatment of SIADH = demeclocycline
Diabetes insipidus
- increased urine volume that is very dilute
- increased serum osmalality
- CENTRAL = pituitary
- Nephrogenic = kidneys unresponsive to ADH ==> can be due to lithium, demeclocycline, hypercalcemia, hereditary mutation of ADH receptor
- must do water deprivation test to confirm = healthy patient rise in urine osmolarity but in DI there is still a decrease in urine osmolarity
- Desmopressin challenge = helps you tell if patient has central or Nephrogenic DI
Treatment for Central DI = intra nasal Desmopressin
Treatment for Nephrogenic DI = HCTZ, indomethacin, if lithium induced = amiloride
Lithium uses ENaC to get into collecting tubule = Amiloride blocks this channel
Central Pontine myelinolysis
Correcting hyponatremia by giving person sodium too quickly
Electrolyte Disturbances
537
Hyperkalemia - low insulin - beta blockers - acidosis - digoxin - cellular lysis - K+ sparing diuretics Treatment = beta agonist, IV insulin + dextrose, and bicarbonate
Hypokalemia
- insulin
- beta agonists
- alkalosis
- loop diuretics and thiazides
- cell creation/proliferation = cancer
Mesonephros
forms bowmans capsule, glomerulus, and wolffian duct
the mesonephric ducts ==> ureteric buds –> form the ureters in both sexes and the ejaculatory ducts in males
Direction of urine
apex of each pyramid –> minor calyx –> major calyx –> renal pelvis –> ureter
