50 terms

DAT Bootcamp - Excretory System

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what is the primary role of the excretory system?
filter out metabolic wastes from the body
humans have _____, which are the most significant part of the excretory system
2 kidneys
the _____ is the outer part of the kidney, where blood enters
cortex
the _____ is the middle portion of the kidney
medulla
the _____ is the inner portion of the kidney where filtrate exits
pelvis
what is a nephron?
a single, functional unit of the kidney
kidneys are made of thousands of individual _____
nephrons
what are the 4 main processes that occur in the nephron of the kidneys?
filtration; reabsorption; secretion; excretion
how does blood flow to the glomerulus?
renal artery --> afferent arteriole --> glomerulus
the _____ is a ball/collection of blood vessels in the renal cortex portion of a kidney nephron
glomerulus
the glomerulus is located adjacent to the _____
Bowman's capsule
what is a renal corpuscle?
glomerulus + bowman's capsule
filtration occurs from the _____ to the _____ of a renal corpuscle
glomerulus; Bowman's capsule
the glomerulus acts like a sieve because it does not allow _____ or _____ to enter the Bowman's capsule
proteins; RBCs
the Bowman's capsule has _____ that wrap around the glomerulus to form _____
podocytes, fenestrations

red arrow = podocytes
Bowman's capsule _____ are large enough for some molecules but too small for others
fenestrations
blood leaves a renal corpuscle via the _____
efferent arteriole
the efferent arteriole goes on to form the _____
peritubular capillaries
_____ surround the different tubes of the nephron and exchange water, salts, and other important molecules
peritubular capillaries
_____ is the removal of water and solutes from the filtrate back into the blood vasculature
reabsorption
where does reabsorption occur?
proximal convoluted tubule (predominantly) up to the collecting duct
the _____ is the part of the nephron that descends from the cortex of the kidney to the medulla
loop of Henle
the descending limb of the loop of Henle has a _____ permeability to water and _____ permeability to solutes
high; low
filtrate becomes _____ concentrated at the descending limb of the loop of Henle
more

(water leaves)
water that leaves the descending limb is taken up by the _____
vasa recta
_____ are blood capillaries that run adjacent and parallel to the loop of Henle
vasa recta
the ascending limb of the loop of Henle has a _____ permeability to water and _____ solutes out
low; actively transports
filtrate becomes _____ concentrated at the ascending limb of the loop of Henle
less (solutes leave)
solutes that leave the ascending limb are taken up by the _____
vasa recta
secretion
transfer of solutes/harmful substances from the blood and directly into the nephron tubule filtrate
secretion occurs in the _____ & _____
proximal; distal convoluted tubules

(predominantly distal)
the proximal convoluted tubule lies between the _____ and the _____ of the loop of Henle
renal corpuscle; descending limb
the distal convoluted tubule lies between the _____ of the loop of Henle and the _____
ascending limb; collecting duct
what is excretion?
filtrate removal from the body as urine
_____ occurs after filtration, reabsorption, and secretion
excretion
the _____ collects filtrate from several different nephrons, and it leads into the renal pelvis
collecting duct
what is a ureter?
connecting passageway between the kidneys and the urinary bladder
the _____ is where the urine is temporarily stored until the body signals for it to be excreted
urinary bladder
the _____ is where the urine is excreted
urethra
parathyroid hormone (PTH) _____ reabsorption of Ca2+ in the nephron tubules
stimulates
PTH _____ Ca2+ in the blood
increases
calcitonin _____ the reabsorption of Ca2+ from the tubules
inhibits

(calcitonin is released by the thyroid gland)
calcitonin _____ Ca2+ in the blood
decreases
aldosterone is considered a _____ hormone, so it is secreted from the adrenal _____
mineralocorticoid; cortex
what is the function of aldosterone?
increase Na+ and H2O reabsorption; increase K+ secretion
aldosterone functions in the _____ and _____ of the kidney nephrons
distal tubules; collecting duct
antidiuretic hormone (ADH/vasopressin) prevents _____, by reabsorbing water from the kidneys when we are dehydrated
diuresis (production of urine)

(leads to very concentrated urine)
ADH is produced by the _____; however, it is stored in the _____
hypothalamus; posterior pituitary
the hypothalamus stimulates ADH to release when the extracellular fluid volume is _____
low
ADH causes _____ to insert into the _____, which allows more H2O reabsorption
aquaporins; collecting duct