BISC220 exam4review spring09

BISC220 exam4review spring09 - BISC 220 SI Exam 4...

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Diana, TJ, Sarah, Brenda b i s c 2 2 0 s i l e a d e r s @ g m a i l . c o m 1 OSMOREGULATION & EXCRETION As homeostatic processes, (1) ___________ manages the body’s solute & water concentrations while (2) _________ eliminates waste. (1) Osmoregulation is dependent on the passive diffusion of water, known specifically as ____________. Water moves from areas of low / high osmotic pressure to areas of low / high osmotic pressure. (2) Different nitrogenous waste products are secreted depending on where an organism lives. N waste product Ammonia Urea Uric acid Advantages Disadvantages Organisms Excretory systems have tubules with large surface areas facilitating water & solute exchange with the environment. produce urine. Urine formation is the net result of _______________ of body fluid, _______________ of needed materials, and _______________ of nonessential or excess substances. In an equation: _______________ _______________ + _______________ = _______________ (tubule body fluid) (body fluid tubule) MAMMALIAN KIDNEY Which is not a function of the human excretory kidney? a. regulate H 2 0 and ion concentrations c. eliminate toxic wastes e. All are functions. b. maintain plasma volume and blood pressure d. secrete renin & erythropoeitin All mammals including humans have ____ kidneys. Each kidney is divided into the outer ____________ (A), the ____________ (B), and the renal ____________, which transmits urine to the ____________via the ____________ before the urine is expelled through the ____________. The functional unit of the kidney is the __________; a juxtamedullary one is shown below. Show the osmolarity gradient with an arrow pointing towards the region where the interstitial fluid is most concentrated. 1. __________________: podocytes & pores allow small molecules to nonselectively leave this capillary network & enter lumen of (6). 2. __________________: brings blood to kidneys from aorta 3. __________________: Na + , HCO 3 - actively reabsorbed; H 2 0 passively reabsorbed; K + , H + actively secreted into tubule 4. __________________: ___________limb permeable to H 2 0, allow passive reabsorption of H 2 0; Na + reabsorbed (passive then active) in ____________ limb, which is not permeable to H 2 0; role= concentrate interstitial fluid 5. __________________: delivers blood to (1) 6. __________________: filtration occurs here - cuplike structure surrounding (1) 7. __________________: Na + , nutrients actively reabsorbed; H 2 0, HCO 3 - , K + passively reabsorbed; H + actively secreted; NH 3 passively secreted 8. __________________: leads to pelvis; Na + 2 0 passively reabsorbed in (B) region only Why does urea diffuse out? Where does the most selective reabsorption occur?
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This note was uploaded on 09/09/2010 for the course BISC 13141 at USC.

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BISC220 exam4review spring09 - BISC 220 SI Exam 4...

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