Topic 17: Excretory System (Osmoregulation and Excretion) Flashcards
Greater osmotic pressure occurs in areas of
higher solute concentration
Osmoregulators hypotonic to environment constantly
lose water
Examples of osmoregulators hypotonic to environment
sea animals and terrestrials
Osmoregulators hypertonic to environment constantly
gain water
Examples of osmoregulators hypertonic to environment
Freshwater fish, amphibians, etc.
Number of nephrons in humans
1 M nephrons in humans
expanded part of ureter that receives urine from kidney
Renal pelvis
tuft of capillaries in kidney
Glomerulus
expanded end of nephron tubule surrounding glomerulus
Bowman’s capsule
returns 2/3 of water and NaCl from filtrate
tubule after bowman’s capsule; located in renal cortex
Proximal tubule
creates hypertonic interstitial fluid in medulla
water leaves in descending loop
Na+ and Cl- actively pumped out in ascending loop
tubule loop into medulla, unique to mammals and birds
Loop of Henle
H+, K+, other solutes actively pumped into filtrate from the blood
Water leaves filtrate because it’s hypertonicity compared to blood
tubule after loop of Henle; located in renal cortex
Distal tubule
water leaves filtrate due to its hypertonicity compared to blood
water permeable
drains from tubule at cortex, merges with other ducts in medulla, empties urine to renal pelvis
collecting duct
How much blood passes through kidneys each day
2000 L of blood
How much fluid is taken from blood at glomerulus
180 L fluid
Urine expelled each day
1-2 L
Flow of glomerular filtrate
nephron tubule at Bowman’s capsule
passes through proximal tubule
loop of Henle
distal tubule
exits as urine into collecting duct
Parts of nephron that are water permeable
distal tube and collecting duct
How is ammonia obtained
when amino acids are catabolized
method of excretion by secreting from gills
flushing
method of excretion by cartilaginous fishes, adult amphibians, and mammals
Detoxification
Method of excretion where ammonia is converted to urea
Detoxification
method of excretion by reptiles and birds
Insolubilization
Method of excretion where ammonia converted to uric acid (not water soluble, precipitates, little loss of water)
Insolubilization
How is uric acid obtained
nucleic acid degradation
enzyme that turns uric acid into allantoin
uricase
These animals secrete uric acid because they have no uricase
Humans, apes, and dalmations
what uric acid turns into after uricase enzyme
Allantoin
hormone released by posterior pituitary
Antidiuretic hormone (ADH)
Hormone that causes more water reabsorbed
Antidiuretic hormone (ADH)
Hormone that increases number of opened water channels in membranes of collecting ducts
Antidiuretic hormone (ADH)
hormone released in response to water conservation
Antidiuretic hormone (ADH)
hormone released by adrenal cortex
Aldosterone
hormone released in response to low [Na+] in blood
Aldosterone
hormone that increases blood volume (greater retention of salt and water)
Aldosterone
hormone that increases Na+ reabsorption in distal tubules
Aldosterone
released by right atrium when stretched by increased blood volume
Atrial natriuretic hormone
Decreases blood volume (greater excretion of salt and water)
Atrial natriuretic hormone
