Formation of Cast Flashcards
(14 cards)
What are casts in the context of kidney function?
Casts are cylindrical bodies formed in the distal convoluted tubules or the collecting ducts of the kidney.
Where are narrow casts formed?
Narrow casts are formed in the distal tubules.
Where are broad casts formed?
Broad casts are formed in the collecting ducts.
What is the matrix of all casts?
The matrix of all casts is uromodulin (formerly known as Tamm-Horsfall protein).
What is uromodulin?
Uromodulin is a glycoprotein secreted by the distal loop of Henle and the distal tubule.
Under what conditions is uromodulin soluble?
Uromodulin is soluble under normal conditions.
What can happen when conditions change in the kidney?
Cells and granular material of tubular origin can be entrapped.
What might a significant number of urinary casts indicate?
A significant number of urinary casts may indicate the presence of renal disease.
What promotes the formation of casts in the kidney?
Factors include:
* Larger than average amounts of plasma proteins entering the tubules
* Decreased pH
* Decreased urinary flow rate (urinary stasis)
* Increased urine concentration (increased specific gravity)
These factors create an environment conducive to cast formation.
What happens to casts after formation in the kidney?
Casts are loosened from the tubules and discharged into the urine.
This process indicates the movement of casts from the nephron into the urinary system.
True or False: Increased urine concentration can promote the formation of casts in the kidney.
True
Increased specific gravity is one of the key factors that contribute to cast formation.
Fill in the blank: Decreased _______ can lead to urinary stasis and promote cast formation.
urinary flow rate
Urinary stasis allows for the conditions necessary for casts to form.
What role do larger than average amounts of plasma proteins play in the kidney?
They promote the formation of casts in the kidney.
The presence of excess proteins in the tubular fluid is a critical factor in cast development.
How does decreased pH affect cast formation in the kidney?
It promotes the formation of casts.
A lower pH can alter the solubility of certain components, aiding in cast formation.
