Transcript Excretory Green

Excretory System
Sarah Norton
Giselle Lehman
Cam Hansel
Urinary System
FUNCTION: remove waste and excess water from
blood and get it out of the body in the form of urine;
counters unwanted shifts in the volume and
composition of extracellular fluid (8)
Urine Formation Helps Maintain
Homeostasis
- excretion regulates the water content (to ensure the
correct amount is the body) in the blood by producing
hypotonic or hypertonic urine (compared to blood plasma)
(3)
• in summer, water is lost through sweat--> urine is
hypertonic (8)
• no water loss from sweating in winter--> urine is
hypotonic (8)
- urine formation counters shifts in volume and
concentration of solutes and foreign substances (like
drugs) (3)
- excretion regulates pH of the blood by removing waste (3)
The Kidney
STRUCTURE:
• in the rib cage, next to the spine, have 2 (4)
• small (about 10 cm), bean-shaped (8)
FUNCTION:
• filters used/unwanted water, minerals, and urea (waste)
from blood--returns all but 1% to blood (8)
• makes that 1% into urine (~1.5 liters a day) (8)
• blood pressure regulation (by secreting enzyme renin)
(9)
• controls production of erythropoietin, which controls red
blood cell production (4)
• regulates the volume, composition and pH of body fluids
(1)
• regulates calcium absorption via vitamin D (4)
The Nephron
- tiny filtering units in the kidney, millions in cortex (8)
- purifies and filtrates blood (7)
- the whole nephron is made of the Renal
Corpuscle (glomerulus + Bowman's capsule) and the Renal
Tubule (proximal convoluted tubule+ loop of Henle) (7)
-Glomerulus: ball formed of small blood capillaries (glomerular)
-Bowman's capsule: nephron starts here, double-walled
epithelial cup that holds the glomerulus (7)
-proximal convoluted tubule:absorbs and regulates the
potassium, calcium, sodium and pH of filtrate and secretes
natural acids into filtrate (7)
-loop of Henle: U-shaped tube, concentrates salt of the tissue
around it (7)
-Distal Tubule: adjustment stage, can lead to urine that is
highly dillute, concentrated or in between (8)
-Collecting Duct: leads to kidney's central cavity then into an
ureter (8)
The Nephron
Filtration
• blood is filtered by osmosis and diffusion
in glomerulus (2)
• driven by heart's contractions
• blood enters through the glomular capillaries
(glomerulus) in the nephron
• blood pressure filters blood when it forces water and
solutes (except proteins) out of the glomerular
capillaries.
• this protein-free solution moves into the proximal
tubule
• filtered fluid in the Bowman's capsule is isotonic (2)
[all from source 2 and 8]
Tubular Reabsorption
• happens in tubules; sodium is pumped out through active
transport in loop of Henle and proximal tubule (8)
• reclamation (reabsorption) of water (80%), glucose,
electrolytes, amino acids, sodium, potassium, etc-restores their concentrations in blood
• done by capillary network around tubules
• osmosis and active transport (for glucose, amino acids).
• then filtrate's water and solutes move into peritubular
capillaries.
[all from source 2 and 8]
Tubular Secretion
• as the tubular filtrate drains, toxic substances(not filtered
in the glomerulus) are secreted through the blood and
tubular wall into the filtrate (in the opposite direction of
reabsorption)
• cells in the tubule wall accept solutes then secrete them
into the nephron wall
• filtered waste products make urine
[all from source 2 and 8]
How does this relate to diabetes?
- the kidney filters waste from the blood
- in diabetes there is an excess of glucose in blood
because of a lack of insulin
- extra glucose is considered waste gets filtered from blood
in kidney
- the kidneys make that glucose (waste) into urine and thus
it becomes a symptom of diabetes that glucose appears in
the urine
References
1. "Anatomy and Physiology."Welcome to Kaskaskia College Faculty Homepages. N.p., n.d. Web. 4
Nov.
2010.
<http://kconline.kaskaskia.edu/bcambron/Biology%20117/Anatomy%20and %20Physiology.htm>.
2."Excretion And Osmoregulation In Man, Functions Of The Kidney Tutorvista.com."Tutorvista.com - Online
Tutoring, Homework Help for Math, Science, English from Best Online Tutor. Tutorvista, 2010. Web. 04
Nov. 2010. <http://www.tutorvista.com/content/biology/biology-ii/excretion-and-osmoregulation/excretionand-osmoregulation-man.php>.
3. Franklin Institute, . "Excretory System: Poison Protection."The Human Heart. Unisys, 2010. Web. 4 Nov
2010. <http://www.fi.edu/learn/heart/systems/excretion.html>.
4."How Your Kidneys Work." National Kidney Foundation. National Kidney Foundation, 2010. Web. 04 Nov.
2010. <http://www.kidney.org/kidneydisease/howkidneyswrk.cfm>.
5. Lucile Packard Children's Hospital at Stanford. "Anatomy and Function of the Urinary System." Packard
Children's Hospital at Stanford LPCH: Northern California Children's Hospital . N.p., n.d. Web. 4 Nov. 2010.
<http://www.lpch.org/DiseaseHealthInfo/HealthLibrary/transplant/urinaryant.html>.
6. Nelson, Robert . "Excretory System | Untamed Science."Biodiversity Web and Ecogeek Community |
Untamed Science. N.p., n.d. Web. 4 Nov. 2010. <http://www.untamedscience.com/biology/humanbiology/excretory/excretory-system>.
7. "Nephron." COE - Main. N.p., n.d. Web. 4 Nov. 2010.
<http://coe.fgcu.edu/faculty/greenep/kidney/nephron.html>.
8.Starr, Cecile, and Ralph Taggart. Biology The Unity and Diversity of Life. 9th ed. Pacific Grove, CA:
Brooks/Cole, 2001. 750-753. Print.
9. "Your Urinary System and How It Works." National Kidney and Urologic Diseases Information
Clearinghouse. Aug. 2007. Web. 04 Nov. 2010. <http://kidney.niddk.nih.gov/kudiseases/pubs/yoururinary/>.