Lesson 4 - Renal Physiology Flashcards
What are the important functions of the kidney?
Ability to maintain the stability of the ECF volume, electrolyte composition, and osmolarity
What is the percentage of water concentration in the body?
60%
Give the breakdown of water concentration in the body.
40% intracellular fluid
20% extracellular fluid = 15% interstitial fluid + 5% plasma
Where is the kidney located and situated in?
Located along T12-L3 and situated in the retroperitoneum
What are the outer and inner divisions of the kidney called?
Renal Cortex and Renal Medulla, respectively
Formed urine exits the kidney through the _________, into the _________, and is stored in the _________.
Renal pelvis, ureter, and urinary bladder
What are the functions of the kidney? (Maintenance, Production, Elimination, and Conversion)
Maintenance of:
- H2O
- Osmolarity
- Electrolytes
- Plasma volume
- Acid-base balance
Production of:
- Erythropoietin
- Renin
Elimination of:
- Waste products
- Drugs
Conversion of:
- Vitamin D into its active form
What is the unit of the kidney?
Nephron
What are the two major types of nephrons?
- Cortical nephrons
- Juxtamedullary nephrons
Nephrons are made up of what 3 components?
- Vascular component
- Tubular component
- Combined component
This nephron is located in the renal cortex; has shorter Loops of Henle; has peritubular capillaries
Cortical Nephron
This nephron makes up 25% of nephrons; is located in the corticomedullary junction; has longer Loops of Henle; has vasa recta
Juxtamedullary Nephron
This carries blood to the glomerulus
Afferent arteriole
It is a tuft of capillaries that filters plasma into the tubular component
Glomerulus
It carries blood away from the glomerulus
Efferent arteriole
Involved in the exchange of substances with the fluid in the tubular component
Peritubular capillaries
Serves as an osmotic exchange for the concentration of urine
Vasa recta
Collects the glomerular filtrate
Boman’s capsule
How much glucose must be reabsorbed?
100% Glucose
Loop of Henle: The descending limb is permeable to _________; the ascending limb is permeable to _________
Water and solutes, respectively
What happens in the distal tubule?
- Reabsorption of Na
- Secretion of H+
- Reabsorption and secretion of K
What are the basic steps in urine formation?
- Glomerular Filtration
- Tubular Reabsorption
- Tubular Secretion
- Excretion
It is the process of expelling urine
Micturition
Micturition is initiated by a nervous reflex that causes the contraction of the _________
Detrusor muscle
What is the average volume of urine?
0.5 - 1.5 mL/kg/hour
After examination, a patient is revealed to have nitrite but no leukocyte esterase. What can you conclude?
The condition must be treated as UTI.
After examination, a patient is revealed to have no nitrite but has leukocyte esterase. What can you conclude?
Patient has urine culture; treat if with symptoms
End product of bilirubin metabolism
Urobilinogen
What are the normal levels of proteinuria and albuminuria?
Proteinuria: <150 mg/day
Albuminuria: <30 mg/day
This disease is caused by low reabsorption at proximal tube.
Fanconi syndrome
What is the normal range of pH in urine?
pH 5.5 - pH 6.5
Presence of blood cells in urine
Hematuria
Most common type of stone linked to high consumption of food high in oxalate
Calcium oxalate
Caused by hyperparathyroidism, renal tubular acidosis, or UTI
Calcium Phosphate
Result of certain types of UTI
Struvite
Occur in people who don’t drink enough water or have a diet high in animal protein
Uric Acid
Caused by a genetic disorder called cystinuria —> excessive cystine in urine
Cystine
Urinary casts are formed from an aggregation of proteins called ___________.
Tamm-Horsfall proteins
