EXCRETORY SYSTEM Flashcards
(15 cards)
Explain the following terms:
• De-amination
• Ultra-filtration
• Selective re-absorption
A:
• De-amination: Removal of excess amino acids by the liver, forming urea.
Ultra-filtration refers to the filtration of fluid from the blood in the nephron, glomerulus under pressure.
• Selective re-absorption: Reabsorption of useful substances from the glomerular filtrate as it passes down the kidney tubules.
Q: State one function each for:
• Kidneys
• Lungs
A:
• Kidneys: Remove nitrogenous waste.
• Lungs: Remove carbon dioxide.
Q: Name three structures in the dermis of mammalian skin. Explain how the body cools when overheated.
A:
• Structures: Hair follicle, sweat gland, blood capillary.
Cooling mechanism:
Increased sweating causes heat loss by evaporation, vasodilation lets heat escape from blood, and metabolism slows to reduce heat production.
Q: Define excretion and name two excretory products from:
• Lungs
• Kidneys
• Skin
A:
• Excretion: Removal of metabolic waste from the body.
• Lungs: Carbon dioxide, water vapor.
• Kidneys: Urea, excess salts.
• Skin: Urea, salts.
Q: Name three urinary system disorders and their remedies.
A:
• Kidney stones: Surgery or chemotherapy.
• Weak bladder: Chemotherapy.
• Enlarged prostate: Surgery or chemotherapy.
Q: State four functions of the mammalian skin and a related structure for each.
A:
• Excretion: Sweat gland.
• Thermoregulation: Sweat gland, erector muscle.
• Protection: Horny layer, melanin.
• Sensitivity: Nerve endings.
Q: Name two excretory products of plants and describe how urine is formed in humans.
A:
• Plant excretory products: Tannins, alkaloids.
Urine formation:
Blood is filtered in Bowman’s capsule, useful substances are reabsorbed, and waste forms urine in tubules.
Q: Match each excretory product with its site of formation.
• Carbon dioxide
• Water:
Sweat
Urine
Urea,bile pigment,cholesterol
• Carbon dioxide: Body tissues
• Water: Body cells
• Sweat: Sweat gland/skin
• Urine: Kidney
• Urea, bile pigment, cholesterol: Liver
Q: Why do animals have specialized excretory organs while plants do not?
A:
• Animals produce waste quickly and must eliminate toxins.
• Plants reuse or store excretory products.
Q: Describe how plants excrete excess water and oxygen.
A:
• Excess water: Diffuses into air spaces and exits through stomata.
• Oxygen: Diffuses out of leaf cells and escapes through stomata.
Describe how the skin carries out excretion and protection.
• Excretion: Sweat glands remove excess water, salts, and urea.
• Protection: Cornified layer prevents bacteria entry; melanin absorbs UV rays.
State the precise location of the Loop of Henle and one of its functions.
• Location: Medulla of the kidney.
• Function: Creates a concentration gradient, reabsorbs water and nutrients.
Define homeostasis and state three conditions where it occurs.
• Homeostasis: Maintaining a stable internal environment.
• Conditions:
• Regulation of body temperature
• Blood glucose levels
• Blood pressure/osmotic balance
Name four human excretory organs and a waste excreted by each.
• Skin: Sweat (salt, urea, water)
• Liver: Bile pigments
• Lungs: Carbon dioxide
• Kidneys: Urine (urea, salts)
Q: Distinguish between excretion and egestion.
Excretion: Removal of metabolic waste from body cells (e.g. urea, CO₂).
• Egestion: Removal of undigested food through the anus (e.g. feces).
