Water Balance & Excretion 9.4 & 9.5

Osmoregulation process of actively regulating the osmotic pressure of bodily fluids and cells hyperosmotic (hypertonic) hypoosmotic (hypotonic) isoosmotic (isotonic)

Homework: p.445 #11. Explain the difference between the terms “hypertonic” and “hyperosmotic”.

Unicellular Organisms water balance is often maintained by contractile vacuoles video of Paramecium: http://www.youtube.com/watch?v=mTXRcbjuYGU

Excretion eliminating waste is important for all living organisms (Image from: http://www.cartoonstudio.co.uk/Pages/kmeters1.html)

Types of Waste Our bodies eliminate wastes through various organs: lungs (CO2) large intestine (solid wastes) liver (transforms toxins for removal) kidneys (soluble wastes) Lungs - CO2 Large intestine - solid wastes Liver - transforms toxins Kidneys - soluble wastes

Nitrogenous Wastes mostly from deamination animals that live in water can remove ammonia with lots of water mammals, some reptiles, most amphibians form urea birds and some invertebrates produce uric acid

Homework: p.445 #4. Explain the advantages & disadvantages for terrestrial animals of creating urea rather than other forms of nitrogenous waste. #5. Why is it an advantage for birds to create uric acid as their nitrogenous waste compound? (Think of flight.)

Human Excretory System Image from: http://cabeijo.com/39245025_human-excretory-system-facts.html

Renal Blood Flow) blood is brought to the kidneys by the renal arteries filtered blood leaves the kidneys through the renal veins (Image from: http://www.revolutionhealth.com/articles/blood-supply-to-the-kidneys/tp13026

The Urinary System kidneys can hold up to 25% of the body’s blood at a time kidneys filter the blood urine (with wastes and toxins) is conducted to the bladder through the ureters

Kidney Structure Basic structure: cortex medulla renal pelvis (Image from: http://www.yalemedicalgroup.org/stw/Page.asp?PageID=STW028984)

Kidney Kiwi Found this website of a medical illustrator on December 6, 2011 (Images from: http://drawbones.com/2009/01/dissection-of-the-kidney-kiwi/

Kidney Kiwi Dissection

Nephron the functional unit of the kidney is the nephron there are about 1 million nephrons in each kidney

Image from :http://kcfac. kilgore. cc. tx

(Image from: http://www. medical-illustrations Afferent Arrives…Efferent Exits

Other links… Khan academy…this video starts off with the structure of the kidney & nephron, then goes into detail about the formation of urine (covered in 9.5) http://www.khanacademy.org/video/the-kidney-and-nephron?playlist=Biology

How is urine formed?

Urine Formation filtration reabsorption secretion Simple overview of urine formation: http://www.pennmedicine.org/encyclopedia/em_DisplayAnimation.aspx?gcid=000136&ptid=17 (Image on previous slide from: http://www.mountainside-medical.com/products/Urine-Specimen-Cup ,-Sterile.html

Filtration higher blood pressure in glomerulus water, ions, smaller dissolved molecules (glucose, amino acids, urea) can move through the walls of the glomerulus your kidneys filter your entire blood plasma 65 times a day glucose, NaCl, H+ ions, amino acids,

Reabsorption ion pumps reabsorb Na+, K+, Cl- (active) active transport proteins reabsorb amino acids, glucose filtrate becomes hypoosmotic to interstitial fluid, so water is reabsorbed by osmosis and through aquaporins If you produced 120 mL of urine a minute… (your bladder’s stretch receptors signal to your brain when there is 200mL of urine; can hold up to 600-800) Osmotic gradient created by glucose, amino acids moves water back to blood.

Where? a lot of reabsorption occurs in the proximal convoluted tubule filtrate with high concentration of urea and other wastes enters loop of Henle and then distal convoluted tubule: more water and ions (Na+& Cl-)are reabsorbed

Where (cont’d)? collecting ducts are permeable to water but not salt ions, so more water is reabsorbed at bottom of medulla, urea is reabsorbed through passive urea transporters

Secretion H+ ions (active) to adjust blood pH (HCO3- is also reabsorbed to balance) products of detoxified poisons (passive) water-soluble drugs (passive) nitrogen-containing wastes (such as small amounts of NH3) in the proximal and distal convoluted tubules

Animations Narrated animation on urine formation; good amount of detail: http://davisplus.fadavis.com/scanlon6e/Animations/animations.cfm?exercise=NephronFiltration&title=Nephron%20Filtration Narrated animation of structure & function; quite detailed: http://bcs.whfreeman.com/thelifewire/content/chp51/51020.html

Kidney Disorders

Urinalysis can be used to detect many metabolic and kidney disorders as well as urinary tract infections urine can be assessed using a dipstick or at a laboratory

Multiple Test Dipstick (Image on next slide from: http://lifeinthefastlane.com/education/investigations-tests/urinalysis/

Diabetes Mellitus Type 1 - body cannot produce insulin Type 2 - cells fail to use insulin properly gestational - hormones of pregnancy interfere with action of insulin urinalysis would show high levels of glucose (and greater volumes of urine)

Kidney Stones caused by precipitation of minerals, can be alkaline or acidic VERY painful (Image from: http://healthcareguide4u.blogspot.com/2009/05/kidney-stones.html)

Kidney Stones - Treatment time… lithotripsy (shock-wave therapy) ureteroscopy (and placement of stent or surgical removal of stone) (Images from: http://www.freeclinicproject.org/the-natural-way-of-passing-kidney-stones

Dialysis for low-functioning kidneys, dialysis machine can filter blood (Image from: http://www.nocturnaldialysis.org/LOWBP.LRG.htm)

(Image from: http://www.metrohealth.org/body.cfm?id=1452)

Homework: p.454 #2. What may be the reasons that the body normally uses two kidneys? #3. Describe the flow of blood into and out of the kidneys. Compare the contents of the blood when entering and exiting the kidneys. #9. What would be the result on the body if Na+, K+, and Cl- were not reabsorbed in the kidneys?