And then Pantagruel had a sudden, urgent need to piss. and he pissed
all over their camp, so thoroughly and in such quantities, that his private
and personal flood drowned everyone for ten miles around.
Francois Rabelais - Gargantua and Pantagruel
Audesirk, Audesirk & Byers Chapter 35
Today's musical selection
Frank Zappa and the Mothers of invention, Don't
eat the yellow snow
Kidneys, transplantation, dialysis
Consider the work of the kidneys
Dialysis10 hr 2 times per week
Figure (chapter opener)
This is why transplant important, and there is difficulty getting a compatable
In the 1978 thriller movie Coma,
unscrupulous doctors harvest organs from the amazing number of patients
they have who slip into a coma for seemingly unexplained reasons.
Cell makes wastes go to plasma
heart pumps 7000 l/day (32 55 gal drums)
1/4 (8 55 gal drums) through kidneys
Glomerulus - Bowman's capsule 180 l/day filter
1 l urine/day
Hypertonic (concentrated), isotonic, hypotonic (dilute)
Nitrogenous waste is from catabolism of amino acids and nucleotides
Water animals - nitrogenous waste can be ammonia (toxic)
There is a tradition in undergraduate biology to emphasize comparative aspects:
("nephron" is the term for "higher" organisms)
Protonephridia in planaria
earthworm has nephrostome with nephridiopore in each segment in close juxtaposition
with vascular system.
Insect Malpighian tubule puts out uric acid and rectum recovers water and
Freshwater fish - gills leak water in, pump salt in, TRANSPARENCY Fig. 44.14
Salt water fish, gills lose water- pump salt out through gills, not much
(When we get to neurons, we will see how universal ion pumping is.)
Salmon (which move from fresh to salt to fresh water) must adapt
Cartilagenous fish keep urea in blood for equal tonicity- need to dialyse
meat for preparation
Marine birds - nasal salt gland
Kangaroo rat - metabolic water, hypertonic urine
Uric acid (birds, reptiles, insects)
Nitrogen - An integrative story
Although 78% of the atmosphere is nitrogen in the form of N2, this is
Thus there are these important processes: N2 to NH3 nitrogen fixation, NH3
to NO3- (nitrate) nitrification, NO3 to NH3 (nitrate reduction) in plant
Also nitrogen is recycled.
In Pacific, off the coast of Peru, the Humbolt current causes an upwelling
of nutrients, anchovies thrive, bird droppings (guano) were used as fertilizer.
El Nino (the Child, named not for misbehavior but because it comes near
Christmas) is a periodic climate misbehavior that disrupts this.
kidney, ureter, bladder, urethra
Pelvis=basin; Medulla=marrow; Cortex=bark ("medulla" and "cortex"
are terms used a lot, like in brain and in adrenal gland)
many blood vessels - kidney is supplied by major blood vessels
Renal artery and vein branches near eachother
each kidney has 1 million nephrons
Blood flow in glomeruli
Glomerulus - Bowman's capsule filter 180 l/day (throwing out the baby with
the bath water)
blood and osmotic pressures drive
Glomerulus - capillaries a sieve
a picture from the histology
highlights glomerulus by dye injected into artery
large molecules dye do not pass
- small molecules dye passes through
blood proteins and cells do not pass
test if blood, cells or protein is present
Need for resorption
Proximal Convvoluted tubule - bring back amino acids, glucose note active
(NaCl) vs passive (water) transport
6% of body's energy at rest
Ascending loop - salt resorbed but not water
Ascending loop of Henle - salt outward resorption is stimulated by aldosterone
ADH (vasopressin) makes water follow back into interstitial fluid which
is hypertonic from salt
alcohol and caffeine inhibit ADH, hence diuresis (excessive urination)
regulation of ADH (from hypothalamus to pituitary) and relation to thirst
(related to kidney coverage)
neurosecretion from hypothalamus (peptides)
oxytocin (milk, delivery)
(synthetic to induce labor)
Chapter 38 case study ("How do I love thee?")
hormones involved in love, oxytocin called the trust hormone
Covered in Excretion lecture: ADH action on kidney
vasopressin (ADH), H2O and blood pressure
alcohol, caffein inhibit anti [diuresis] hormone
Filter, resorb (salt and water)
Sweat pores not as good -which is why gatorade tastes good to athletes
especially bad in cystic fibrosis (salty sweat) molecular genetics shows
a chloride channel defect
Kidney also secretes - pump out (penicillin)
Questions used in 2007 and 2008 related to this outline
Where does the ADH-dependent water resorption occur in the kidney?
(a) in the urethra
(b) in Bowman's capsule
(c) in the afferent arteriole
(d) in the bladder
*(e) in the collecting duct
To regulate osmolarity, salt water fish
(a) pump uric acid out through the fins.
(b) move water in through the gills by osmosis.
(c) have kidneys that excrete large amounts of dilute (hypotonic) urine.
*(d) pump salt out through the gills.
(e) move salt in through the gills by osmosis.
What is urea?
*(a) nitrogenous waste
(b) the tube connecting the kidney to the bladder
(c) the organ for excretion in the insect
(d) the hormone that helps the kidney maintain isotonic body fluids
(e) the unit of the kidney, 1 million per kidney
What happens in the proximal tubule of the nephron?
(a) Aldosterone is secreted.
(b) Filtration takes place.
*(c) Water and nutrients are resorbed.
(d) Memory cells of the immune system are stored.
(e) Urine exits from the bladder.
The Kangaroo rat, a desert animal
(a) is considered to be a producer by ecologists.
(b) uses dialysis.
(c) has diuresis.
*(d) excretes hypertonic urine.
(e) loses glucose through its urine.
What is the fundamental unit of the kidney in humans?
(b) the polymorphonuclear granulocyte
*(c) the nephron
(d) the Malpighian tubule
(e) the urethra
"Secretion" (as opposed to excretion)
A) refers to active transport of water in the proximal tubule.
*B) refers to output of wastes in the distal tubule.
C) refers to the passive salt transport in the proximal tubule.
D) refers to the salt transport in the collecting duct.
E) refers to the filtration in the glomerulus.
What does the Humboldt current have to do with nitrogenous wastes?
A) The flame cell of the flatworm creates the Humboldt current.
B) This is the part of the nephron between proximal and distal tubules where
there is a flow (current) of urine.
*C) Because it creates a rich marine environment, nitrogen-rich bird droppings
are on the islands.
D) El nino is high in nitrogen.
E) The Humboldt current dilutes nitrogenous wastes in the kangaroo rat.
Where does ADH exert its influence in the kidney?
*A) collecting duct
B) loop of Henle
C) proximal tubule
D) distal tubule
After a salmon has returned to its mating area
A) it should need to pump salt out by active transport through its gills.
B) it should need to put out small amounts of salty urine.
C) its malpighian tubules would need to get rid of more urea.
*D) it should need to excrete copious amounts of dilute urine.
E) its osmoregulation would be no different than when it grew for 5 years
in the ocean.
Why did they refer to the blood vessel returning blood from the glomerulus
as an "arteriole?"
*A) because of the portal system
B) because the extracellular fluid in the kidney medulla is isotonic
C) because blood flows straight into the ureter
D) because it returns blood straight to the vena cava
E) because this is where water, salt and nutrients are secreted
What is the correct order of flow?
A) Bowman's capsule, urethra, loop of Henle
*B) proximal tubule, collecting duct, ureter
C) bladder, distal tubule, glomerulus
D) loop of Henle, collecting duct, proximal tubule
E) ureter, urethra, collecting duct
Where is dilute urine first formed by filtration of the blood?
A) the proximal tubule
B) the loop of Henle
C) the Purkinje cell
*D) the glomerulus
E) the kidney's medulla
ADH (antidiuretic hormone)
A) is no longer needed now that they add vitamins A and D to milk.
*B) is regulated by the hypothalamus that monitors your state of hydration.
C) is why you should soak shark meat in water before cooking and eating
D) is a hormone that tells your brain how hungry you should be.
E) has its effects on osteoclasts.
Which is NOT true about aldosterone?
A) It comes from the adrenal cortex.
B) The gland it comes from is near the kidney anatomically.
C) It has its effects in the kidney.
D) It mediates salt reuptake.
*E) It is a peptide.
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