Urine Formation and Micturition Flashcards
(24 cards)
What are the three main processes of urine formation?
Filtration, reabsorption, and secretion.
Where does filtration occur in the nephron?
Glomerulus within Bowman’s capsule.
Where does most reabsorption occur?
Proximal convoluted tubule.
What is tubular secretion?
Transfer of substances from blood into the nephron tubule.
What is the final composition of urine mostly influenced by?
Hormonal regulation (e.g., ADH, aldosterone).
What does the presence of glucose in urine indicate?
Possible diabetes mellitus (glycosuria).
What hormone influences urine concentration in the collecting duct?
Antidiuretic hormone (ADH).
Where does urine flow after the collecting ducts?
Renal pelvis → ureter → bladder.
What structure stores urine before excretion?
The urinary bladder.
What is the function of the ureters?
Transport urine from kidneys to bladder via peristalsis.
What type of muscle lines the bladder wall?
Detrusor muscle (smooth muscle).
What is the micturition reflex?
Spinal reflex controlling bladder emptying.
Which nervous system controls bladder contraction?
Parasympathetic nervous system.
What relaxes to allow urination?
Internal and external urethral sphincters.
What type of control is the external urethral sphincter under?
Voluntary (somatic nervous system).
What is polyuria?
Excessive urination (e.g., in diabetes or diuretics).
What is oliguria?
Low urine output (<400 mL/day).
What is anuria?
Severely reduced or absent urine output (<100 mL/day).
What is nocturia?
Frequent urination at night.
What is urinary incontinence?
Loss of bladder control or leakage of urine.
What can cause urinary retention?
Obstruction, nerve damage, or medications.
How does aging affect bladder function?
Reduced bladder capacity, detrusor instability.
What triggers the sensation to urinate?
Bladder stretch receptors send signals to the spinal cord.
What is residual volume in the bladder?
Urine left in the bladder after urination.
