Excretion and osmoregulation

In this section (IB Topic 11.3)

- Osmoregulation

- Malpighian tubules

- Kidney structure: cortex, medula, pelvis, ureter

- Renal vessels: renal artery vs renal vein

- Ultrafiltration: glomerulus and Bowman's capsule

- Nephron reabsorption (convoluted tubules, loop of Henle and collection duct)

- ADH and osmoreceptors (hypothalamus)

- Types of nitrogenous waste

- Urinalysis: glucose, protein, conductivity, pH, monoclonal antibodies and microscopy (see lab)

- Kidney failure treatment: dialysis vs transplant

The excretory system is a passive biological system that removes excess, unnecessary materials from the body fluids of an organism, so as to help maintain internal chemical homeostasis and prevent damage to the body.

Vocabulary and crossword!

11.3 Vocabulary.pdf

Crossword

Osmoregulation in paramecium

Osmoregulation_paramecium_worksheet.pdf

Answers here

Osmoregulation_conformers_worksheet.pdf

Answers here.

Malpighian tubules (insects)

The Malpighian tubule system (named after Marcello Malpighi) is a type of excretory and osmoregulatory system found in some insects, myriapods, arachnids, and tardigrades. The system consists of branching tubules extending from the alimentary canal that absorbs solutes, water, and wastes from the surrounding hemolymph. The wastes then are released from the organism in the form of solid nitrogenous compounds. Wastes such as urea and amino acids diffuse through the walls, while ions such as sodium and potassium are transported by active pump mechanisms. Water follows by osmosis and it all merges in the hindgut. Uric acid form precipitates and ions are actively absorbed by the rectum, along with water via osmosis. Uric acid is left to mix with feces, which are then excreted. (From Wikipedia Contributors).