Gross kidney anatomy
This tube carries urine to the bladder.
What is the ureter?
The functional unit of the kidney.
What is the nephron?
Filtration at the glomerulus is determined by these forces.
What are Starling forces?
The major extracellular cation.
Water reabsorption in the proximal tubule is linked to reabsorption of this solute.
What is sodium (Na⁺)?
Ling’s sodium level on admission was 127 mmol/L. This condition is defined as serum sodium <135 mmol/L.
What is hyponatremia?
These vessels supply blood to the kidney.
What are the renal arteries?
This capillary network filters plasma into Bowman’s capsule.
What is the glomerulus?
Put the following steps of urine formation in the correct order:
Tubular reabsorption, Excreted, Glomerular filtration, Tubular secretion
Glomerular filtration: Initial filtering of blood
Tubular reabsorption: Recovery of essential substances
Tubular secretion: Active removal of additional waste
Excreted: Filtered/secreted but not reabsorbed
The main intracellular cation.
What is potassium (K⁺)?
Ling's potassium level was 5.1 mmol/L. This is the upper limit of normal, and elevations may be exacerbated by this class of antihypertensive drug she was taking.
What are ACE inhibitors (e.g., candesartan)?
The outer region of the kidney.
What is the renal cortex?
This type of nephron has long loops of Henle that extend deep into the medulla.
What is a juxtamedullary nephron?
This autoregulatory mechanism helps maintain stable renal blood flow despite changes in systemic blood pressure.
What is myogenic regulation?
Urea is important for generating this.
What is the osmotic gradient?
Ling’s elevated creatinine and low eGFR on admission are hallmark lab findings of this renal condition.
What is acute kidney injury (AKI)?
These triangular structures form the medulla.
What are renal pyramids?
This type of nephron has short loops extending to the boundary between outer and inner medulla.
What are superficial (cortical) nephrons?
In pre-renal AKI, decreased blood volume lowers this Starling force in the glomerulus, reducing net filtration.
What is glomerular capillary hydrostatic pressure?
The descending limb of the loop of Henle is permeable to ___ but not ___ .
water, sodium
A serum BUN:creatinine ratio > 20:1 typically points toward this category of AKI.
What is pre-renal AKI?
Urine drains from the renal papilla into this structure.
What is the renal pelvis?
Filtrate passes through these structures in a specific sequence before leaving the nephron.
Arrange these in order: Bowman’s capsule, Ascending limb of loop of Henle, Distal convoluted tubule, Proximal convoluted tubule, Descending limb of loop of Henle, Collecting duct.
Bowman’s capsule → proximal convoluted tubule → descending limb of loop of Henle → ascending limb of loop of Henle → distal convoluted tubule → collecting duct
List (5) functions of urinary system beyond filtration and waste removal.
Any of the following:
- Maintains correct osmolarity of body fluids
- Regulates the quantity and concentration of most ECF ions
- Regulates plasma volume
- Maintains acid-base balance
- Excretes metabolic end products
- Excretes foreign compounds
- Produces erythropoietin
- Produces renin
- Converts vitamin D to its active form
This hormone increases water reabsorption by inserting aquaporins in the collecting duct.
What is vasopressin/ADH?
Ling’s admission Na⁺ of 127 mmol/L plus her volume-depleted state classify her hyponatremia as this subtype.
What is hypovolemic hypotonic hyponatremia?