lecture 2 - renal function and kidney disease Flashcards
(34 cards)
Kidneys
function + definition
Function: Production of urine.
Definition: Organs responsible for producing urine.
Ureter
function + definition
Function: Transporting urine towards the bladder.
Definition: Tube that transports urine from the kidneys to the bladder.
Bladder
Definition: A sac that temporarily stores urine.
Function: Temporary storage of urine.
Urethra
Definition: A tube that conducts urine to the exterior of the body.
Function: Conducting urine to the exterior.
Functions of the Urinary System
Function 1: Excretion and elimination of waste and fluids.
Function 2: Regulation of water-salt balance and acid-base balance.
Function 3: Production of hormones.
Basic Kidney Data
Definition: Key quantitative information about kidney function.
1.5L excreted per day in adults.
Renal blood flow is 20% of the cardiac output.
Ultrafiltration is 180L/day.
Reabsorption accounts for 99% of the amount filtered.
Homeostasis Function of the Kidneys
The role of the kidneys in maintaining stable body contents despite changes in dietary intake and endogenous production rate.
Endocrine Functions of the Kidneys
Definition: The hormonal functions of the kidneys.
Function 1: Production of erythropoietin.
Function 2: Production of renin.
Function 3: Paracrine and autocrine functions.
Other Kidney Functions
Function 1: Catabolism of small peptides.
Function 2: Production of glucose via gluconeogenesis.
Function 3: Elimination of many medications.
Function 4: Aiding in maintaining a healthy blood pressure range.
Renal Threshold
Definition: The concentration in blood beyond which a substance is excreted in urine.
Example 1: Renal threshold for glucose is 180mg/dL.
Example 2: Tubular maximum (Tm) for glucose is 350mg/min.
Concept of Balance in the Kidneys
Balance Types: Neutral, Positive, Negative.
Definition: The idea of neutral, positive, and negative balance in kidney function.
Nephrons
Definition: The functional units of the kidneys.
Features: Scaling the medulla and cortex, producing visible striations in the medulla.
Classes of Nephrons
Definition: Different types of nephrons in the kidney.
85%: Cortical nephrons.
Juxtamedullary nephrons.
Regulating Systemic Blood Pressure
Definition: How the kidneys regulate blood pressure.
Via: Juxtaglomerular complex.
Three Processes of Urine Formation
Glomerular filtration, reabsorption, secretion.
Glomerular Filtration
Definition: The first step of urine formation.
Hydrostatic Pressure: Provided by arterial pressure.
Result: Glomerular filtrate.
Reabsorption
Definition: The process where primary urine becomes concentrated, and low molecular weight constituents are reabsorbed in the proximal and distal tubules.
Reabsorption of water, glucose, amino acids, ions.
Secretion
Process: Active transport of various substances.
Definition: The release of substances into the urine via active transport, including H+, K+ ions, urea, creatinine, and drugs.
Hormones of the Kidney (Erythropoietin)
Definition: Erythropoietin is produced by the kidneys and stimulates the production of red blood cells in response to hypoxia (lack of oxygen).
Function: Regulation of red blood cell production.
Hormones of the Kidney (Renin)
Definition: Renin, produced by the kidneys, initiates a cascade leading to increased blood pressure and aldosterone production.
Function: Regulation of blood pressure and sodium-potassium balance.
Hormones of the Kidney (Calciferol)
Definition: Calciferol, a steroid hormone formed in the kidney, is involved in calcium and phosphorus homeostasis.
Function: Regulation of calcium and phosphorus levels.
Investigation Steps of Renal Disease
Definition: The sequence of steps used in diagnosing renal disease.
Personal history, physical examination, blood laboratory findings, urinalysis, assessment of renal function (GFR), imaging, renal biopsy.
Assessing Kidney Function (Urine)
Definition: Parameters used to assess kidney function based on urine characteristics.
Parameters: Anuria, oliguria, polyuria, urinalysis.
Urinalysis
Definition: The examination of urine for physical and chemical characteristics, as well as microscopy.
Tests: Color, turbidity, density, pH, presence of blood, albumin, nitrites, erythrocyte and leukocyte levels.
