Renal System
The functional unit of the kidney.
Contains multiple different parts.
1-2 million in each kidney.
What is the Nephron?
Fine-tunes the reabsorption of sodium, potassium, and calcium.
What is the Distal Convoluted Tubule?
Regulates Bp and fluid balance.
What is RAAS?
Due to a reduction of blood flow to the kidneys.
Caused by low Bp, severe dehydration, blood loss, and decreased CO.
Results in Oliguria.
What is Pre-Renal AKI?
Gradual increase in urine production (polyuria).
Decreased electrolytes lead to dehydration and low Bp.
What is Diuretic Phase of AKI?
Final site of urine concentration.
Regulated by ADH & Aldosterone.
What is the Collecting Duct?
Enzyme secreted by the kidneys in response to low Bp, Na+, or SNS activation.
Due to direct damage to kidney tissue.
Caused by NSAIDs/ATBs, autoimmune, sepsis, ATN/AIN, and glomerulonephritis.
What is Intrinsic/Intrarenal AKI?
Kidney function returns to normal.
Increased energy, appetite, & urine concentration.
What is the Recovery Phase of AKI?
Crucial for urine concentration and fluid balance.
It has 2 limbs: descending and ascending.
What is the Loop of Henle?
Increases water reabsorption in the kidneys.
Decreases UO and prevents dehydration.
Trigger by low Bp and high blood osmolarity.
What is ADH?
Protein that constricts BVs.
Increases Bp.
What is Angiotensin?
Due to blocked urine flow.
Caused by stones, enlarged prostate, tumors, and obstructions.
What is Post-renal AKI?
Hormone synthesized and released by the kidneys.
Stimulates the bone marrow to produce RBCs.
Released in response to low blood O2.
What is Erythropoietin?
Permeable to water but not sodium.
Concentrates the filtrate.
Increases sodium & water reabsorption in the kidneys.
Increases Bp/blood volume, excretes K+.
Triggered by low Bp/Na+ or high K+.
What is Aldosterone?
*ADRENAL CORTEX*
When Bp normalizes, signals are sent to stop renin.
What is the Negative Feedback Loop?
Onset lasts hours-days; often asymptomatic.
Caused by reduced BF, direct kidney damage, and urine flow obstruction.
What is the Initiation Stage of AKI?
Males: 0.7-1.3 mg/dL.
Females: 0.6-1.1 mg/dL.
~0.6-1.3 mg/dL.
What is Creatinine?
Permeable to sodium but not water.
Actively transports Na+, K+ and Cl- into the interstitial fluid.
Loop diuretics work here.
What is the Ascending Limb?
Opposite of Aldosterone; increases secretion of water and sodium.
Increases UO, decreases blood volume and BP.
What is ANP?
*ATRIA OF THE HEART*
Stimulates the adrenal cortex to release Aldosterone.
What is Angiotensin II?
Decreased function: oliguria (<400-500 mL/day).
High creatinine, K+, phosphate. Low calcium.
Leads to fluid overload, HTN, nausea, and confusion.
Metabolic Acidosis.
What is Oliguric (Maintenance) Phase of AKI?
6-20.
Indicates liver & renal function.
Low=overhydration.
High=dehydration.
What is BUN?