Filtration and Reabsorption
What is the process of moving fluid from blood into Bowman's capsule called?
filtration
Which part of the nephron is associated with establishing a high salt concentration in the medulla of the kidney?
Loop of Henle
When ADH from the posterior pituitary is released in greater amounts, what will happen to the fluid in the collecting ducts in the kidney?
it will become more concentrated
The voluntary control of urination involves what muscle type?
Skeletal muscle (external urethral sphincter)
What is the presence of blood in urine called?
hematuria
What is the process of moving substances from the filtrate back into the blood called?
reabsorption
Loss of solute (Na+ and Cl-) and retention of H20 that occurs in the ascending limb of the LOH caues the tubular fluid to be ____________ as compared with plasma.
hypotonic
How would detection of increased osmoconcentration of the extracellular fluid (ECF) by osmoreceptors in the hypothalamus affect the concentration of urine?
increase urine concentration
What is the dominant afferent nerve supply to the kidneys?
the sympathetic division of the autonomic nervous system
What is the hormone produced in response to hypoxia that causes increased RBC production in the bone marrow?
erythropoietin (EPO)
What is the term describing filtrate that has the same osmolarity as blood?
isosmotic
The descending limb of the LOH is primarily permeable to what substance?
water
What is the measure of urine concentration called?
specific gravity
What is the primary electrolyte responsible for controlling blood pressure, blood volume, and fluid balance by the kidneys?
sodium
Kidney failure often leads to imbalance of what mineral afecting bones?
Ca2+
What is the maximum concentration at which a substance can be reabsorbed called?
renal threshold
What is the name of the system that creates a hyperosmotic (high salt/urea concentration) gradient in the renal medullary interstitium, which enables the kidneys to reabsorb water and produce concentrated urine
countercurrent multiplier
What are 3 of the main components of urine?
water, urea, creatinine, electrolytes (sodium, potassium, chloride, phosphates), uric acid, amino acids, hormones, vitamins, drug metabolites
In what 2 nephron locations does aldosterone act to increase Na+ (and therefore water) reabsorption and K+ secretion?
distal tubule and collecting duct
Excess glucose in urine indicates what condition?
What is diabetes mellitus?
What limits the rate of active reabsorption in the nephron?
the number of transporters
Primarily functioning through the vasa recta in the renal medulla, what part of the counter current mechanism maintains the osmotic gradient established by the loop of Henle (countercurrent multiplier) by passively reabsorbing water. As blood descends into the medulla, it loses water and gains solutes, becoming more concentrated. As it ascends back to the cortex, it gains water and loses solutes, becoming less concentrated.
countercurrent exchanger
What is the principal nitrogenous constituent of mammalian urine?
urea
In what 2 nephron locations does ADH act to increase water reabsorption, thus concentrating urine?
distal tubule and collecting ducts
A deficiency or resistance to what hormone leads to diabetes insipidus?
Anti-diuretic hormone (ADH)