2The Kidneys Excrete metabolic wastes Maintain homeostasis (6 ways) Supplied by renal arteries , drained by renal veinsThe kidneys remove waste from the blood, then excrete them as urine. The urine is transported passively to the ureters, urine carried down the ureters to urinary bladder by peristalisis and gravitational forces.
3Anatomy of the Kidney Located on the back wall of the abdominal cavity Surrounded by fat for protection (they easily bruise); caps on top are the adrenal glandsRibs protect the upper half of the kidneysFilter/clean blood with structures called nephrons (functional units)There are ~ 1 million nephrons per kidney
4Urination The process of eliminating urine from the body ADD THESE NOTES TO THE BOTTOM OF YOUR PAGE:The process of eliminating urine from the bodyAlso known as MicturationA sphincter muscle controls the opening to the bladderIs under nervous control
8ExcretionThe Removal of waste products from the body
9What types of wastes does the Human Body produce? Primary Metabolic Wastes incl:Carbon DioxideWaterAmmoniaMineral SaltsThe Main Excretory Organs are the lungs,kidneys, rectum and skinPrimary metabolic waste – means:
10Some Major Organs and their waste products Primary WasteSecondary WasteKidneyUrine through water,N2 wastes, saltsCarbon dioxide,HeatRectumFood wastes, bacteriaFecesCarbon dioxide, heat, water, salts, and methane!LungsCarbon dioxideWater vaporSkinSweat = urea, water, saltLook up the deal on methane
11Consequences if Fluid Intake is not equal to Fluid output High fluid output can occur due to many reasons:Consumption of diuretics or kidney malfunction (examples of diuretics….? Write them down)Large amounts of perspiration (sweating)Increased exhalation (exercise)Prolonged bouts of diarrheaThese conditions along with low fluid intake can lead to ? Dehydration
12DehydrationWhen body’s fluid output is greater than fluid input – body attempts to restore homeostasis:If output exceeds intake by (% of dehydration occurring or % of total body mass)1% : thirst sensation to get lost fluids replaced5%: pain and collapse to conserve water, exhalation is reduced10%: death!!
13Roles of the Liver in Excretion Transforms toxins (ex. Alcohol and heavy metals) into soluble compoundsTransforms hazardous products of protein metabolism into safer productsAmmonia is converted to urea, and also: ketonesLook up heavy metals, and ketones
14TWO Major Roles of the Kidney 1. Excretion of Nitrogenous and other wastes – making and releasing urine2. Maintaining Homeostasis – by many different ways (see other handout)
15Composition of Urine Water – 95% - from food and drinks PLUS N – Urea – 2% - from detoxified ammoniaN – Uric Acid – broken down nucleic acids (DNA)N – Creatinine – 1.5% - from muscles as they work (involved with ATP being used)Excess salt ions – 1.4% - from food and drinksN – Ammonia – 0.05% from breaking down proteins (amino acids ammonia)Detoxified means – liver converting ammonia into urea
16Composition of UrineN – Ammonia – 0.05% from breaking down proteins (amino acids ammonia)N – Ketones – .03% - from broken down body fat (higher in diabetics and ppl losing body fat)N – Urochrome – .02% - from broken down red blood cells – is what gives urine its yellow color
18How The Kidney Maintains Homeostasis 6 waysRead the pageFun quiz afterwards!??
19T/F ?? The Kidneys clean blood by filtering it 2. T/F ?? The Kidneys can put sugar into urine if there’s too much sugar in the blood3. T/F ?? The kidneys make more urine when the blood doesn’t have enough water4. T/F ?? The kidneys can put more salt in the urine if the blood is too salty5. Osmoregulation is a) Regulation of the water content of the bloodb) Regulation of the salt content of the bloodc) Regulation of the water content in the urined) Regulation of the salt content in the urinee) All of the above
206. T/F ?? [OH –] ions are acid ions 7. What kind of ions will the urine contain after a person eats lemons and oranges? (Acid or Base??)Y/N ?? Can the kidney control how many red blood cells are in theblood?9. How does the kidney do this?10. T/F ?? The kidneys help to balance the composition of blood by adding or subtracting things to the urine.
21T/F ?? The Kidneys clean blood by filtering it TrueT/F ?? The Kidneys can put sugar into urine if there’s too much sugar in the bloodT/F ?? The kidneys make more urine when the blood doesn’t have enough waterFalseT/F ?? The kidneys can put more salt in the urine if the blood is too salty5. Osmoregulation is e) All of the above
22T/F ?? [OH –] ions are acid ions FalseWhat kind of ions will the urine contain after a person eats lemons and oranges? (Acid or Base??)AcidY/N ?? Can the kidney control how many red blood cells are in theblood?YesHow does the kidney do this?By releasing the hormone Erythroproteinwhich tells the bone marrow to make more rbc’sT/F ?? The kidneys help to balance the composition of blood by adding or subtracting things to the urine.True