Shared Flashcard Set

Details

DAT
Barrons Review (Excretion)
10
Biology
Graduate
10/05/2011

Additional Biology Flashcards

 


 

Cards

Term
Kidney
Definition
composed of one million nephrons; outer cortex, inner medulla, and renal pelvis
• ureter – where urine leaves kidneys
Term
Nephrons
Definition
composed of renal corpuscle and renal tubule; reabsorbs nutrients, salts, and water
• Renal corpuscle – glomerulus (sieve) surrounded by Bowman’s capsule
• Renal tubule – proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct
Term
Urine Formation
Definition
filtration, secretion, and reabsorption
Term
Filtration
Definition
fluid that goes through glomerulus (afferent arteriole => glomerulus => efferent) to the rest of the nephron is called filtrate; particles that are too large to filter through (blood and albumin) remain in circulatory system; passive process; driven by hydrostatic pressure of blood
Term
Secretion
Definition
– substances such as acids, bases, and ions (K+) are secreted by both passive / active transport; secreted from peritubular capillaries
Term
Reabsorption
Definition
– glucose, salts, AA, and water are reabsorbed from filtrate & return to blood; takes place namely in PROXIMAL convoluted tubule (active)
Term
Concentration
Definition
when dehydrated volume of fluid in bloodstream is low so you need to make small amounts of concentrated urine => ADH prevents water loss by making distal tubule permeable to water /// when Blood Pressure is low => aldosterone increases reabsorption of Na+ by distal nephron which increases water retention (serum [Na+] increases BP)
Term
Selective Permeability
Definition
Selective permeability of the tubules establishes an osmolarity gradient in the surrounding interstitial fluid
Urine is hypertonic to the blood and contains a high urea and solute concentration.
Term
Osmolarity Gradient
Definition
created by exiting / entering of solutes; increases from cortex to medulla
Term
Counter Current Multiplier
Definition
descending loop permeable to water & ascending is permeable to salts / ions; this makes the medulla very salty and facilitates water reabsorption
Supporting users have an ad free experience!