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18 Cards in this Set
- Front
- Back
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1. Electrolytes |
* An electrolyte is a compound that dissociate into ions when dissolved in water * Cells require precise concentrations of Na+, Cl-, K+, Ca^2+... to function normally The chemical reactions that make life possible occur in an aqueous solution. If the balance of water and solutes in a solution is disturbed, those chemical reaction may stop. |
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Osmoregulation |
organisms actively regulate osmolarity to achieve homeostasis o Many organisms respond to osmotic stress by osmoregulating (ex: marine bony fish) |
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Osmoconformation |
organisms do not actively regulate the osmolarity of tissue (they conform to the osmolarity of the environment instead) blood isotonic with seawater (ex: jellyfish, cartilaginous fish) |
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How do marine bony fish, freshwater fish, insects, and terrestrial animals gain/lose water and electrolytes? |
Marine Fish *Seawater is hyperosmotic is comparison to marine fish tissue — seawater contains more solutes * Marine fish are under osmotic stress because they lose water and gain solutes * 1. Marine fish lose water by osmosis and gain electrolytes by diffusion Freshwater Fish Freshwater is hypo-osmotic in comparison to freshwater fish tissue — the solution outside contains fewer solutes. 2. Freshwater fish are under osmotic stress because they gain water and lose solutes 3.
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5. Terrestrial Animals Constantly Lose Water to the Environment • Water can be gained via eating, drinking, and cellular respiration (metabolic water), and is lost via breathing and evaporation. Electrolytes can be gained via food, and are lost primarily in the urine and feces. 6.
Terrestrial Insects regulate the amount of H_2O + electrolytes excreted.
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* Malpighian tubules |
* Pre-urine passes to the hindgut where it is modified before excretion. The hindgut facilitates selective reabsorption of electrolytes and H_2O. |
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* Hemolymph |
* is the circulatory fluid of animals with open circulatory systems. The fluid is not confined to blood vessels. |
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1. In terrestrial mammals, osmoregulation occurs primarily through what organ? What is the functional unit of the kidney? |
1. Terrestrial Mammals Osmoregulation occurs primarily through the kidney Most of the kidney’s mass is made of nephrons — the basic functional units of the kidney |
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The Nephron |
* A nephron has four major parts, empties into a collecting duct, and is served by blood vessels Urine formation begins in the renal corpuscle and ends in the collecting duct |
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1. What is the sequence of filtrate flow in the kidney? |
1. Renal corpuscle 2. Proximal tubule 3. Loop of Henle 4. Distal tubule Collecting duct |
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RENAL CORPUSCLE |
• The renal corpuscle filters blood, and forms a “pre-urine” filtrate consisting of ions, nutrients, wastes, and water |
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PROXIMAL TUBULE |
* The proximal tubule has epithelial cells that reabsorb nutrients, valuable ions, and water from the filtrate into the bloodstream * The epithelial cells have many microvilli facing the lumen, and also contain many mitochondria Ion and water movement is driven by a “master gradient” |
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LOOP OF HENLE |
• The loop of Henle establishes a strong osmotic gradient in the interstitial fluid surrounding the loop. Osmolarity increases as the loop descends |
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DISTAL TUBLE |
• The distal tubule is the most distal portion of the nephron and is responsible for the reabsorption of sodium, water and secretion of hydrogen potassium. |
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COLLECTING DUCT |
* The collecting duct leaks urea — the solute that is most responsible for the steep gradient in the space surrounding the nephron o Urea concentration is high in the interstitial fluid in the inner medulla o Urea concentration is lower in the outer medulla The innermost section of the collecting duct is permeable to urea |
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How do humans get rid of nitrogenous waste safely and efficiently? |
Kidneys and Kidney Failure electrolyte balances in the body
• If kidneys do not work properly, harmful wastes can accumulate in the body. In addition, blood pressure may rise, excess fluid will be retained, and you might not make enough red blood cells |
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What forces water and small molecules out of the glomerulus and into Bowman’s capsule? |
Renal Corpuscle *(A) The renal corpuscle consists of Bowman’s capsule and the glomerulus. (B) The capillaries in the glomerulus have pores and are surrounded by cells that have filtration slits. Blood pressure forces water and small molecules out of the capillaries, through the slits, and into Bowman’s capsule. |
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1. What is the function of ADH? Aldosterone? |
1. Regulation Aldosterone — released by the adrenal glands when Na+ levels are low o Activates Na+/K+ -ATPase pumps so reabsorption of Na+ occurs o Water follows by osmosis Antidiuretic hormone (ADH) — released by the brain when dehydration occurs |
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bio |
sucks |
