Excretion http www youtube comwatch va QZa NXNro
Excretion http: //www. youtube. com/watch? v=a. QZa. NXNro. VY
Excretion removal of metabolic waste Protein and nucleic acid metabolism nitrogen containing compounds does not include feces is what your body did not use, therefore not metabolic waste
Excretion is an example of homeostasis Prevent build up of toxic wastes within our body Contribute to water balance in our body
Organs Responsible for Excretion
Composition of Urine solution of metabolic waste Water (mostly) urea and uric acid salts organic compounds
Compounds within asparagus are metabolized Produce a byproducts that contain sulfur
fluid for urine comes from filtered blood extracellular fluid (ECF)
Forms of Nitrogenous Waste Urea Ammonia Uric Acid
deamination – removal of amine group Occurs in the liver Byproducts are sent to the kidneys for further processing
Urea product of two other waste molecules ammonia, NH 3 (very toxic) carbon dioxide, CO 2 Where does the ammonia come from? amine group from amino acids
Ammonia ammonia released when liver breaks down proteins 0. 005 mg NH 3 is lethal reacts with CO 2 to produce less toxic urea 100 000 x less toxic than NH 3
Uric Acid product of nucleic acid breakdown specifically of purine bases
Role of Kidneys 1. Removal of wastes Urea, uric acid and other materials are filtered through the kidney and excreted 2. Water balance average person loses 2 L of liquids a day suggested to consume 2 L H 2 O / day
Excretion: Ameoba remove waste and excess water through a contractile vacuole.
Excretion: Fish can excrete ammonia directly through their gills.
Excretion: Birds excrete uric acid directly with feces.
Excretion: Earthworms capillary network bladder collection tubule nephrostome nephridiopore
Renal System AKA The Kidney
Role of Kidney 1. 2. 3. 4. 5. blood filtration waste excretion acid / base balance blood pressure regulation hormone secretion
Kidney Structure renal cortex – outside of kidney; location of Bowman’s capsule renal medulla (lobes) – middle of kidney; location of loop of Henle renal pelvis – location of the ends of collecting ducts
Kidney Blood Flow Blood enters the kidney through the renal artery. renal arteries stem from the aorta Carry oxygenated blood Filtered blood exits the kidney through the renal veins flow into the inferior vena cava Carry de-oxygenated blood
Nephron Functional unit of the kidney Responsible for the formation of urine A million nephrons make up the kidney
Blood and the Nephron Blood from renal artery is filtered through nephrons. Nephrons collect liquid to be excreted Filtered blood is returned to renal vein
Renal artery The renal artery is split into afferent arterioles. blood brought to glomerulus; a capillary bed. blood leaves through the efferent arterioles no veins involved Efferent arterioles are the beginning of a network of peritubular capillaries, that wrap around the nephron.
Glomerulus and Bowman’s Capsule Efferent Arteriole Afferent Arteriole Filtrate
From the bowman’s capsule: fluids to become urine flow to narrow proximal tubule urine flows through loop of Henle urine flows through distal tubule Urine from multiple nephrons flow into the collecting duct.
Urine Flow Urine leaves the renal pelvis through the ureters and travels to the bladder. Fluid leaves the body through the urethra. When ~200 m. L of urine has collected in the bladder, the walls stretch and signals are sent to the brain. At ~600 m. L, urine will involuntarily be released. ureters
Nephron Structure efferent arteriole proximal tubule glomerulus Bowman’s capsule distal tubule collucting duct afferent arteriole Loop of Henle
Urinary System aorta inferior vena cava renal cortex renal medulla renal artery renal vein kidney ureter bladder urethra renal pelvis nephrons ureter
Question Athletes now undergo random urine testing for drugs. Describe the pathway of drugs through the urinary system, from the time they enter the glomerulus until they are excreted in the urine.
Classwork/Homework Review Khan Academy Video: http: //www. youtube. com/watch? v=cc 8 s. Uv 2 Sua. Y 7. 3 – Pg. 345 #1 -4, 6 7. 4 – Pg. 348 #1 -3
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