Kidney and Osmoregulation

U 1 Animals are either osmoregulators or osmoconformers. OSMOREGULATORS: animals that regulate solute concentrations and balances the gain and loss of water. (expend energy) (Terrestrial Animals/ Freshwater Animals/ Boney Fish) OSMOCONFORMERS: animals whose internal solute concentration tends to be the same as the concentrations in the environment. (Marine Invertebrates/ Cartilaginous Fish)

U 2 The Malphigian tubule system in insects and the kidney carry out osmoregulation and removal of nitrogenous wastes.

U 3 The composition of blood in the renal artery is different from that in the renal vein.

U 4 The ultrastructure of the glomerulus and Bowman’s capsule facilitate ultrafiltration. The walls of the capillaries in the GLOMERULUS are FENESTRATED or have small slits. Under the high pressure in the GLOMERULUS only small molecules like salt, glucose, amino acids, vitamins, and nitrogenous wastes such as urea are filtered out of the blood leaving behind larger proteins and blood cells in the blood. The ULTRAFILTRATION is done by a glycoprotein basement membrane and associated specialized cells (PODOCYTES) which prevent large molecules (proteins and blood cells) from entering the filtrate.

U 5 The proximal convoluted tubule selectively reabsorbs useful substances by active transport. SALT IONS- about 80% are actively transported (pumped out using ATP and specialized proteins in the membrane) out of the filtrate into the cells of the tubule then into the intercellular fluid and then onto the peritubular capillary bed. Water- The movement of the salt ions out of the filtrate causes water to flow out down its concentration gradient by OSMOSIS. (80%) (hypotonic hypertonic) Glucose and amino acids- 100% reabsorbtion by active transport back into the blood

U 6 The loop Henle maintains hypertonic conditions in the medulla. The function of the loop of Henle is to create a salt bath concentration in the surrounding medullary fluid. The descending limb of the LOOP is permeable to water but IMPERMEABLE to salt The ascending limb of the LOOP is permeable to salt but IMPERMEABLE to water.

U 9 The type of nitrogenous waste in animals is correlates with evolutionary history and habitat. Based upon an animal’s habitat, specialized adaptations have occurred. Marine organisms (fish, echinoderms, and coelenterates) Release ammonia directly to the surrounding water environment which is quickly diluted. Amphibian larva also release ammonia in this stage but convert to the production of urea after metamorphism. More energy required. Terrestrial (land) organisms: Expend energy to convert ammonia into the less toxic forms of urea or uric acid.

A 1 Consequences of dehydration and over-hydration.

A 2 Treatment of kidney failure by hemodialysis or kidney transplant.

A 3 Blood cells, glucose, proteins and drugs are detected in urinary tests.

S 1 Drawing and labelling a diagram of the human kidney.

S 2 Annotations of a diagram of the nephron.

Animals with a longer loop of Henle generally have thicker MEDULLAS. NOS 1 Curiosity about particular phenomena- investigations were carried out to determine how desert animals prevent water loss in their wastes. Animals with a longer loop of Henle generally have thicker MEDULLAS. Beaver-Semi- Aquatic Rabbit- Terrestrial Sand Rat- Arid