| What are the 4 primary functions of excretion? | Maintenance of internal levels of inorganic solutes.
Maintenance of plasma water volumes.
Removal of non-nutritive or harmful substances.
Maintenance of osmotic balance. |
| What are the two types of excretory organs? | Epithelial and tubular excretion |
| How do epithelial organs excrete and control waste? | Lined with special membrane mechanisms to remove waste and regulate solutes and water such as aquaporins. |
| When does tubular excretion become more beneficial to an organism? | As body size increases epithelial excretion becomes less effective as an excretion method so larger more complex organisms tend to have more tubular excretory organs. |
| What are the 4 main physiological aspects of excretory organs? | Filtration, forms primary urine, using ultrafiltration.
Secretion, of specific waste products.
Reabsorption, water, solutes and nutrients after primary urine formed.
Osmotic concentration, definitive urine. |
| What are the specialised cells for salt exchange known as? | Chloride cells |
| What family has no specialised excretory organs, are osmo-regulators and have renette glands which act as an entrance for water where it is transported and salts are secreted. | Nematodes. |
| What organism uses tubule excretion and flame cells (protonephirida). Has cilia in cells that draws fluid across the membrane and to move fluid through the tubules for excretion? | Pathyhelminthes |
| What is the name of an insects excretory organ? | Malpighian tubules |
| What order has antennal glands, a single tube in their head near second antenna, where fluid enters from the blood into the end sac and moves through a labyrinth of spongy tissue and nephiridal canals where ions are reabsorbed. | Crustaceans. |
| which order have tubular nephrida organised as 'kidneys', that collect liquid from the coelom and dump it into the mantle cavity or directly outside the organism? | Molluscs. |
| What is the hormone used by vertebrates to control water reabsorption? | Anti-diuretic hormone. |
| How much filtrate is made by a human kidney each day and what is the final volume of urine? | ~180L of filtrate and 1.2L of urine. |
| How do birds store urine? | Urine is drained from their kidneys straight into the cloaca |
| What are the porperties of ADH? | Secreted by the pituitary gland, to modulate water reabsorption based on blood plasma water concentration. |
| What are the qualities of freshwater teleosts kidneys? | They have a large glomerulus, therefore a high filtration rate 4ml / kg / hour, a high urine flow rate and, dilute urine due to the high uptake of ions. |
| What are the qualities of marine teleost kidneys? | They have a reduced or absent glomerulus, there for a low filtration rate 0.5ml / kg/ hour, a low urine flow rate and ions actively secreted into their urine. |
| What is the function of chloride cells? | To actively pump chloride and sodium ions out of the internal environment of marine teleosts and vise versa for freshwater teleosts. |
| Which order has two types of nephron: ventral and dorsal nephrons, which both have glomerulus and only the ventral has nephrons. A high glomerular filtration rate and high urine flow rate. | Amphibians |
| how much of an amphibians primary filtrate is reabsorbed? | 1/2 |
| How much of an amphibians ions are reabsorbed? | 99% |
| Which order uses urea as a primary osmolyte? | Elasmobranchs |
| What is the role of an osmolyte? | An osmolyte main role is to maintain the integrity of the cell by affecting the viscosity, melting point and ionic strength of the aqueous solution. |
| What is the purpose of the loop of henle and how does it length change its function? | The loop of henle's main function is for water reabsorption on the descending limb and ion reabsorption on the ascending limb to ensure as much of both are taken up as necessary, in arid zones mammals have a larger loop to ensure that they can take-up as many ions as possible in a stressful environment. |
