Renal (Kidney) Function and Hormonal Regulation

This set of 30 vocabulary flashcards covers renal physiology, the hormonal regulation of blood pressure (RAAS), and clinical methods for testing kidney function including GFR and clearance markers.

Renal Function

The kidneys' role in filtering blood, regulating blood pressure, and maintaining the physiological balance of chemicals through hormones.

Hormones

Chemical signals that act on cellular receptors of effector cells to cause physical, chemical, or biological changes.

Effector Cells

Specialized cells that initiate a change after receiving a chemical signal from a hormone.

RAAS

The Renin-Angiotensin-Aldosterone System, which is used to regulate blood pressure and water/sodium levels.

Renin

An enzyme released from the kidneys that reacts with angiotensinogen to begin the hormonal cascade.

Angiotensinogen

A precursor chemical produced by the liver that reacts with renin to form Angiotensin I.

Angiotensin Converting Enzyme (ACE)

An enzyme produced in the lungs that converts Angiotensin I into Angiotensin II.

Angiotensin I

The intermediate chemical produced by the combination of renin and angiotensinogen.

Angiotensin II

A chemical that causes direct physiological effects such as vasoconstriction and signals the adrenal glands to release aldosterone.

Aldosterone

A hormone triggered by Angiotensin II that promotes the retention of water and the reabsorption of sodium ($Na$).

Shock

A condition resulting from a massive drop in blood pressure, which can be caused by trauma, blood loss, or lack of oxygen.

Antidiuretic hormone (ADH)

A hormone produced by the hypothalamus and released by the pituitary gland that promotes water reabsorption in the DCT and causes vasoconstriction.

Hypothalamus

The brain structure that produces ADH and controls all critical life functions.

Pituitary gland

The gland responsible for the storage and release of the antidiuretic hormone (ADH).

Microalbumin

A sensitive early indicator of glomerular damage that measures small amounts of albumin in the urine.

Albumin

A protein whose presence in urine indicates later-stage glomerular damage, often seen in Type $2$ Diabetes.

Creatine

A chemical precursor to muscle found in the body.

Creatinine

A waste product of muscle breakdown with no recycle value that is filtered by the glomerulus.

Blood Urea Nitrogen (BUN)

A measure of the concentration of urea in the blood used to evaluate kidney function.

BUN/Creatinine Ratio

A diagnostic indicator where the normal ratio of urea to creatinine is typically between $10$ to $20\,\%$.

Glomerular Filtration Rate (GFR)

A more accurate indicator of kidney function than the BUN/Creatinine ratio, often quantified as creatinine clearance.

P

The variable in the creatinine clearance formula representing the plasma creatinine concentration.

V

The variable in the creatinine clearance formula representing the volume of urine collected over a $24$-hour sample in $mL$.

U

The variable in the creatinine clearance formula representing the urine creatinine concentration.

$$1.73$$

The value in $m^2$ used in the GFR formula to represent the assumed average body surface area for a person.

Inulin Clearance

A special function test involving an IV-infused fructose derivative that is not processed by the body to measure clearance speed into the urine.

Beta-2 microglobulin

A marker where elevated levels in the urine indicate damaged tubules and elevated levels in the blood indicate damaged glomeruli.

Cystatin C

A protein filtered by the glomerulus; elevated amounts in the blood serve as an indicator of damaged glomeruli.

Osmolality

A measure of urine concentration that serves as an indicator of the kidneys' concentrating ability.

VACR test

Identified as the most descriptive indicator test for evaluating renal function.