7.1 Anatomy of the Urinary System Part 6 Flashcards
What is the function of the DCT?
hormonally controlled reabsorption of water and solutes
secretion of unwanted substances
When is the filtrate considered urine?
when it reaches the renal pelvis
What do the collecting ducts converge to form?
papillar ducts
Where do the papillary ducts drain?
calcyces and then the renal pelvis
What are the three capillary beds that nephrons are closely associated with?
glomerular capillaries
peritubular capillaries
vasa recta
What are the glomerular capillaries?
highly coiled capillary beds formed from the afferent arterioles leaving as the efferent arteriole
What allows the glomerular capillaries to specialize in filtration?
porosity and high pressure
How much of the glomerular filtrate is reabsorbed by the renal tubule?
99%
Where do the peritubular capillaries run?
closely follow the renal tubules and drain into the interlobular vein
Why are the peritbuluar capillaries specialized for absorption?
porosity and low pressure
Where do the vasa recta run?
follows the loops of henle in the juxtamedullary nephrons of the medulla
When does the urge to urinate start?
200 ml
What causes the urge to urinate?
stretching of the bladder walls initiating a visceral reflex arc
What is a result of the visceral reflex arc in the bladder?
detrusor muscles contracts and the internal sphincter relaxes forcing stored urine through the internal sphincter
When will micturition occur involuntarily?
when urine reaches 100%
