6 - Renal II Flashcards
True/False: Sodium and water undergo tubular secretion.
False; DO NOT therefore Amount excreted = Amount filtered - Amount reabsorbed
Part of nephron, where most sodium and water reabsorption occurs.
Proximal tubule
Part of nephron, main hormonal control of sodium and water reabsorption.
Distal tubule and collecting duct
[Sodium/Water] reabsorption: Active transport/Requires renal energy/Carrier-mediated/Occurs against a concentration gradient
Sodium
[Sodium/Water] reabsorption: Diffusion/Depends on (i.e. is coupled to) reabsorption of sodium.
Water
Methods by which sodium move from the lumen of the tubule and into the cells forming the tubule walls.
Cotransport with glucose or AA, countertransport with hydrogen ions, or via diffusion through sodium channels (ADD PICTURE FROM PP)
As sodium is removed from the lumen of the tubule, water concentration […] in the tubular fluid thus […] osmolarity in the tubular fluid.
Increases; Decreasing (i.e. the opposite is the case in the nearby interstitial fluid)
Establishes a concentration gradient for water.
Active transport of sodium
As water and sodium moves into the interstitial fluid it moves via […] into the peritubular capillaries as the final step of reabsorption.
Bulk flow
Part of nephron where water permeability IS regulated.
Collecting duct/Late distal tubule
Posterior pituitary hormone, stimulates the insertion of AQUAPORINS into the tubular cell luminal membranes.
Antidiuretic hormone/Vasopressin
Increase in ADH = […] in urine.
Decrease (i.e. urine will become more concentrated)
Occurs when pituitary fails to release ADH or kidneys do not respond to ADH; patient can produce 25 L urine/day.
Diabetes inspidus
Increase in urine production but no increase in solute excretion.
Water diuresis
Increase urine flow due to increase in solute excretion.
Osmotic diuresis
Having an osmolarity equal to that of normal ECF
Isoosmotic (i.e. 300 milliosmoles per liter)
Having an osmolarity GREATER than normal ECF.
Hyperosmotic (i.e. more concentrated)
Having an osmolarity less than normal ECF.
Hypoosmotic (i.e. less concentrated)
Normal daily excretion of urea, sulfate, phosphate, and other wastes and ions.
600 mOsmol
Volume or urine that MUST be excreted per day.
Obligatory water loss (i.e. 0.46 L/day)
Receptors for the reflexes that control body sodium.
Baroreceptors (i.e. of the cardiovascular system) and sensors in the kidney (i.e. monitor filtered load of sodium)
Major determinant of ECF volume.
Sodium
Low total body sodium = […] arterial and venous blood pressure.
Low
Enzyme, catalyzes the conversion of angiotensinogen to angiotensin I.
Renin (i.e. secreted from the kidney, functions in blood)
Cells of the kidney, secrete renin.
Juxtaglomerular cells (INSERT PICTURE)
Peptide hormone, produced by the liver, converted via renin.
Angiotensinogen
Enzyme, found in epithelial cells of blood capillaries especially in the lungs, converts angiotensin I to angiotensin II
ACE/Converting enzyme (i.e. does so as blood flows through the lungs)
Stimulates the adrenal cortex to secrete hormone aldosterone into the blood.
Angiotensin II (i..e also causes vasocontriction)
Hormone, acts on late distal tubule and CD of the kidney to increase sodium reabsorption.
Aldosterone
Inputs to juxtaglomerular cells that increase renin secretion.
Sympathetic nerves to JG cells, baroreceptors within the kidney, paracrine factors released from the macula densa
[…] causes vasoconstriction in many body regions, helps regulate peripheral resistance (i.e. contributes to controlling arterial blood pressure)
Angiotensin II
Cardiac hormone, decrease sodium reabsorption by directly inhibiting aldosterone secretion.
Atrial natriuretic peptide (ANP)
Sensory receptor, found in hypothalamus, detects ECT osmolarity, involved in initiating reflexes that alter water excretion without altering sodium excretion.
Osmoreceptors
Hormone, posterior pituitary hormone, mediates water excretion without altering sodium excretion.
ADH/Vasopressin
Hypothalamic osmoreceptors are neurons that […] their frequency of action potentials when they shrink.
Increase (i.e. Do this when ECF osmolarity is above normal) (INSERT PICTURE)
Arterial baroreceptors can influence ADH secretion rates which is important during scenarios such as […].
Hemorrhage
ADH also cause widespread constriction of arterioles, which influences […] in the cardiovascular system.
Total peripheral resistance
The response to severe sweating is [hyperosmotic/hyoosmotic] relative to ECF.
Hypoosomtic (i.e. sweat causes sodium loss but an even greater water loss)
Filtered potassium [is/is not] reabsorbed.
Is not
Aldosterone acts on CD cells to [increase/decrease] their rate of potassium secretion.
Increase
Higher than normal potassium in the ECF.
Hyperkalemia
Lower than normal potassium in the ECF.
Hypokalemia
[Hypercalcemia/Hypocalcemia] depresses nervous system and muscle activity.
Hypercalcemia
[Hypercalcemia/Hypocalcemia] causes nervous system excitement and tetany.
Hypocalcemia
[…] are reservoirs of calcium, releasing it when ECF concentration is low.
Calcium
Vitamin […] promotes the absorption of calcium across the intestinal wall (i.e. about 35)
B (i.e. the rest is excreted in the feces)
Homogeneous gelatinous substance that makes up the organic matrix of bone (i.e. along with collagen fiber)
Ground substance
Main crystalline salt (i.e. calcium and phosphate) deposited in organic matrix of bone.
Hydroxyapatite
Bone-resorbing cells, removes calcium from bone matrix and adds to ECF.
Osteoclast
Hormone, stimulates osteoclast
Parathyroid hormone (PTH)
In the absence of vitamin […] the effect of PTH in causing bone resorption is reduced.
D
Bone depositing cell, can incorporate calcium back into the bone matrix
Osteoblasts
PTH [increase/decreases] calcium ion reabsorption in the DT/CD.
Increases
Considered to be a hormone, carried via the blood to the intestine where it increase the absorption of dietary calcium and phosphate.
1,25 Dihydroxyvitamin D
Thyroid hormone, acts mainly on bone to decrease ECF calcium concentration.
Calcitonin
