anatomy unit 4 digestive and excretory systems excretory notes
TRANSCRIPT
Unit 5 Notes: The Urinary/Excretory
System
(1) Main Organs•Kidneys•Ureters•Bladder•Urethra
(2) Functions• Filter blood•Remove impurities, toxins,
excess nutrients•Reabsorb needed water +
nutrients
(3) Kidney Functions• Excretion of nitrogenous wastes•Maintain water concentration of
blood•Maintain electrolyte
concentration of blood• Regulate blood pH (H ion levels)
(4) Ureter, Bladder & Urethra Function
• Ureters = Tubes which carry filtered “liquid waste” towards the bladder.• Bladder = Storage tank for filtered
“liquid waste”.• Urethra = Tube which allows filtered
“liquid waste” to exit body.
(5) Kidneys & Blood Supply• Kidneys use 20% of body’s blood• Renal Artery = Entering
oxygenated blood• Renal Vein = Exiting deox. Blood
• All blood is filtered through nephrons.
(6) Nephrons• 2 Main Structures:–Glomerulus Bundle of capillaries w/
blood to be filtered.
–Renal Tubule Tubes following capillaries, which collect filtered contents•Bowman’s Capsule = Portion of tubule
where initial filtration and absorption occurs
(7) Urine Formation• Filtration: – Water + Small Solutes are forced through capillary
walls into Bowman’s Capsule.
• Reabsorption:– Water, Glucose, Amino Acids & Ions that were filtered
out are actively transported back into capillaries and blood.
• Secretion:– H ions, K ions, urea, and drugs/toxins are forced
through capillary walls into renal tubule.
(8) Anatomy of Urine Formation
• Filtration Bowman’s Capsule of Renal Tubule• Reabsorption Proximal Tube,
Loop of Henle & Distal Tubule of Renal Tubule• Secretion Distal Tubule of Renal
Tubule
(9) Nitrogenous Wastes• Urea: Byproduct of protein
metabolism in the liver.• Uric Acid: Byproduct of nucleic
acid metabolism.• Creatinine: Byproduct of creatine
metabolism in muscle tissue.
(10) Regulating Drops in Blood Pressure
• Antidiuretic Hormone (ADH) from Pituitary:– Increases water reabsorption from renal tubule.
• Aldosterone from Kidney:– Increases water retention in blood by
reabsorbing more sodium from renal tubule.
• Angiotensin II from Blood:–Causes vasoconstriction, increasing blood
pressure
(11) Don’t Pee It Out…• Glucose Chill out on sweets OR Diabetic?!
• Protein Increased Physical Activity & Pregnancy OR Hypertension & Nephron Disease?!
• Pus Urinary Tract Infection
• Blood Kidney Stones, Infection, Trauma, Anemia ?!
• Bile Liver Disease?!
(12) Kidney Dialysis• Used in hospitals when kidneys fail (stop working)• Blood is filtered through mechanical pump +
tubing which regulates contents
• Causes for Kidney Failure:–Repeated kidney infections–Physical Trauma–Heavy Metal / Chemical poisoning– Low Blood delivery (arteriosclerosis)