The Excretory System 9.5 Image from: http://www.buzzle.com/articles/urinary-system-facts.html

Excretory System Two main functions: concentrates wastes & removes them from the body regulates fluids & water within the body

Unicellular Organisms water balance is often maintained by contractile vacuoles video of Paramecium Image: http://greatneck.k12.ny.us/GNPS/SHS/dept/science/krauz/bio_h/images/07_14ContractileVacuole_LP.jpg

Excretion in Earthworms hemolymph is taken into metanephridia ions and waste are reabsorbed & secreted into bladders excess water & wastes exit through pores Image: https://classconnection.s3.amazonaws.com/754/flashcards/566754/png/42.121320592913292.png

Excretion in Grasshoppers grasshoppers & other insects use Malphigian tubules to remove uric acid & other wastes Image: http://www.pleasanton.k12.ca.us/avhsweb/thiel/apbio/review/images/malpig.jpg

Excretion in Birds uric acid is excreted through the cloaca (end of digestive tract), along with feces Image: https://shitmy6yearoldsays.files.wordpress.com/2012/10/bird-poop.png

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 Excretory System the kidneys remove wastes, balance blood pH, and maintain water balance they filter the blood plasma 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 about 1 million nephrons in each kidney Image: http://www.sciencephoto.com/image/395171/530wm/C0097511-Nephron_structure%2C_artwork-SPL.jpg

Review of Structures…

Image from: http://commons. wikimedia

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

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

How is urine formed?

Urine Formation filtration reabsorption secretion (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) move through the walls of the glomerulus your kidneys filter your entire blood plasma 65 times every day! glucose, NaCl, H+ ions, amino acids,

Reabsorption ion pumps reabsorb Na+, K+, Cl- (active) active transport proteins reabsorb pretty much all amino acids, glucose & other nutrients reabsorption of water is by osmosis (passive) and aided by 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.

Proximal Convoluted Tubule microvilli increase surface area ions, gluose, amino acids reabsorbed by passive & active methods water reabsorbed by osmosis Image from: https://humanphysiology2011.wikispaces.com/12.+Urology

Loop of Henle water is reabsorbed in the descending portion ions are reabsorbed in ascending portion (“make medulla salty” as Sal Khan says) Image: https://classconnection.s3.amazonaws.com/471/flashcards/4757471/jpeg/bf9216ee-b2fb-4054-844f-4c88b0e49ad9-147E96763CA798BDAAA.jpeg

Image: http://droualb. faculty. mjc

Distal Tubule & Collecting Duct reabsorption of ions & secretion of H+ and K+ in distal convoluted tubule reabsorption of water in collecting duct some urea reabsorbed (passive) to allow more reabsorption of water

Secretion in the proximal and distal convoluted tubules, and the collecting duct Blood pH maintained through secretion of H+ ions and reabsorption of HCO3- detoxified poisons, water-soluble drugs, nitrogen-containing wastes are all secreted

Resources This is a nice detailed animation that goes through the structure of the kidney & the formation of urine: http://www.sumanasinc.com/webcontent/animations/content/kidney.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)