1. Osmoregulation & Excretion

2. Osmoregulation Osmosis between organisms and environment
Stenohaline: can't tolerate extreme changes in external osmolarity
Euryhaline: can survive changes
-Osmolarity= mol solute/ L soln (mOsm/L)
1000 mOsm/L = 1 M
thus for human blood (300 mOsm/L) is equal to .3 M (ask class to solve?)

3. Osmoconformers Are iso-osmotic with their environment
-all osmoconformers are marine animals

4. Osmoregulators
Can control their internal osmolarity independent of their environment
-To survive in a hypo-osmotic environment, the osmoregulator must discharge the excess water. In a hyperosmotic environment, it must take in water to offset the osmotic loss. -

5. Nitrogenous Waste
-ammonia excretion is more common to aquatic species b/c NH3 is very toxic to organisms unless at low concentrations. those that can tolerate such levels must have access to large amounts of water. On the molecular level, NH3 molecules pass thru the membranes and diffuse to the surrounding water.
-urea is the product of a metabolic cycle that combines NH3 and CO2. It is produced in the vertebrate liver. less toxic, thus it can be stored at high concentrations and can be transported thru the circulatory system. Also less water is lost. Disadvantage: needs more energy. humans use this
-uric acid: needs even more energy. conserves more water. even less toxic. birds use this.

6. Excretory Processes
-body fluid undergoes filtration once in contact with transport epithelium. small solutes that cross the membrane form the filtrate which becomes waste fluid.
-selective reabsorption will take useful molecules and water back to the body fluid using active transport
- solutes left behind are added to filtrate by selective secretion, uses active transport
-excretion: processed filtrate exits as urine.

7. Flatworms
-protonephridia: dead-end tubules connected to external openings that branch throughout the body.
-flame bulbs: have tubule cell, cap cell, tuft of cilia projecting from tubule (during filtration, moving of this draws water/solutes from interstitial fluid to flame bulb to tubule network, filtrate then exits as urine)
-fnc of protonephridia varies in animals. ex osmoregulation in freshwater flatworms, disposal of N wastes in parasitic flatworms.

8. Earthworms
-Metanephridia: excretory organs that collect fluid directly from coelom. each segment of worm has this immersed in coelomic fluid and enveloped by capillary network. internal opening is ciliated (cilia draws in fluid into tubule)
-fnc: excretory ( transport epithelium bordering lumen reabsorbs solutes from urine and returns them to blood, wastes remain in tubule and exit body), osmoregulation (balance water uptake from damp soil thru skin by make urine that is dilute)

9. Insects
-malpighian tubule: remove N wastes, fnc in osmoregulation. extend from dead end tips immersed in hemolymph (circulatory fluid) to openings into digestive tract
-filtration step is absent
- transport epithelium secretes solutes from hemolymph to lumen. water follows the solutes into tubule by osmosis, fluids goes into rectum where most solutes are pumped back into hemolymph and water reabsorption by osmosis. N wastes exit with the feces as dry matter. (adaptation to conserve water)
-adaptation: rectal end of gut enables water uptake from air (water balance)

10. Humans Excretory Organs
-contains 2 kidneys (transport/store urine), 2 ureters (ducts), urinary bladder (sac), urethra (exit thru vagina/ penis), sphincter muscles near junction of urethra and bladder regulate urination
-Urination pathway: kidneys transport it thru ureters where it drained into the bladder where it then exits thru the urethra and empties out of the vagina/penis

11. Kidneys
-contains outer renal cortex, inner renal medulla. each are supplied w/ blood by renal artery and drained by renal vein. within cortex/medulla are tightly packed excretory tubules and blood vessels. inner renal pelvis collects urine from tubules, passes it to bladder.

12. Types of Nephrons
-nephrons (fnc units of kidney) weave b/n cortex/medulla.
-85% of nephrons: cortical nephrons, other: juxtamedullary nephrons ( essential for making urine that's hyperosmotic to body fluids (adaptation for water conservation).

13. Nephron Organization
-filtrate is formed when blood pressure forces fluid from blood in the glomerulus to lumen of the bowman's capsule
-processing occurs as filtrate passes thru proximal/ distal tubule, loop of henle
-collecting duct receives processed filtrate from nephrons , transports to renal pelvis
-each nephron supplied with blood by afferent arteriole (forms capillaries of glomerulus, when these capillaries converge, create efferent arteriole),

14. Blood Filtrate to Urine
1. Proximal tubule - reabsorption is critical for recapture of ions,water, and other valuable nutrients from the huge volume of initial filtrate. Helps in pH regulation.
2. Descending limb of the loop of Henle - has aquaporin proteins to allow for more water to come out since the fluid outside is hyperosmotic to the filtrate.
3. Ascending limb of loop of Henle - impermeable to water, but gets NaCl out. Thin segment gets out NaCl passively. Thick segments gets it out through active trandport.
4. Distal tubule - helps in pH regulation. Maintains balance between K+ and NaCl
5. Collecting duct - hormonal control of permeability and transport determines concentration of urine. urine is made, solutes/water are reabsorbed
-kidneys conserve water by making a dilute urine and reabsorbing salts without letting water follow.

15. Kidney Summation Requires a lot of energy
Helps to conserve more water, and essential nutrients

16. Managing Osmoregulatory Function of Kidney
Nervous system and endocrine system help manage kidneys
antidiuretic hormone (ADH)
A lack or excess of water can change how concentrated the urine needs to be. Hormones can help to regulate this.
ADH - when blood osmolarity rises, ADH increases the epithelium permeability to water in the collecting ducts of kidneys so that less water is wasted. More concentrated urine is created, and blood osmolarity decreases. lower blood Osm has opposite effect

17. Renin-Angiotensin-Aldosterone System
-JGA- specialized tissue consisting of cells of and around the afferent arteriole, supplies blood to glomerulus
-when blood pressure drops, JGA releases renin (enzyme) which starts a chem rxs to cleave angiotensinogen I, which then makes angiotensin II (raises blood pressure by constrict arterioles, stimulates adrenal glands to release aldosterone (acts on nephron's distal tubules/ collecting duct, make them reabsorb Na+/water which in turn inc blood volume/pressure))
A II has multiple fxsto inc blood pressure, thus drugs to block making this will treat hypertension

18. Gout Uric acid build-up in joints Symptoms: Causes: Treatment
sudden joint pain
acute joint tenderness and redness
Causes:
body makes too much uric acid
body is unable to dispose of uric acid
Treatment
painkillers
Daily use of allopurinol or probenecid (decreases uric acid levels in your blood)
uric acid crystals cause joint discomfort. Usually affects the big toe, knee, or ankle joints.

19. Kidney Stones solid mass of small crystals Symptoms: Causes:
Pain in belly area, side of back, groin
blood in urine
nausea
Causes:
build-up of substance in urine which creates crystals that turn into stones
Treatments:
medication
Extracorporeal shock-wave lithotripsy
Percutaneous Nephrolithotomy
-form when urine contains too much of a substance which create small crystals that turn into stones. takes weeks to months to form.
-Calcium, Cystine, struvite, uric acid stones
-symptoms can occur when stones are in the ureters and block urine passage
-symptoms: pain in belly area, side of back and eventually will move to the groin/testicle area, abnormal urine color, blood in urine, chills, fever, nausea, vomiting
-medication used to decrease stone formation, or breakdown/remove substance making the stone. (allopurinol, antibiotics, diuretics, water pills)
-surgery needed if stone is too large to pass on its own, growing, blocking urine so much that it causes infection, pain is not controlled
-extracorporeal shock wave uses sounds or shock waves to break up the stone so it can pass easily thru urine. for stones < 1/2 inch
-percutaneous uses a tube inserted into the kidney thru a small surgical cut to remove larger stones.
-ureteroscopy used on stones in lower urinary tract

20. Works Cited
Reece, Jane B., and Neil A. Campbell. Biology. Boston, MA: Cummings, Print.
"Kidney Stones." PubMed Health. A.D.A.M, Inc, 9/16/11. Web. <
A.D.A.M. "Gout - Causes, Incidence, and Risk Factors." Gout. U.S. National Library of Medicine, 28 June Web. 24 Mar <