The crayfish have its nerve cord on the ventral side rather than on the dorsal side. The ventral side is under the Crayfishes' exoskeleton, as opposed to the dorsal side where the exoskeleton is . If it is attacked it will be from the dorsal side and the nerve cord would be snapped easier. The function of the nerve cord is that if it gets attacked by a predator they will go for the top and it will still be able to move.
Answer:
1.Blood pressure in the small capillaries pushes the fluid into a sack called Bowman's capsule. 2. It reabsorbs important nutrients that are in the filtrate. 3. The Loop of Henle descends from the cortex into the medulla and concentrations of salts in the interstitium increases. 4. Salts leave the filtrate using both passive and active diffusion. 5. Waste products ammonia and urea are transported into the filtrate for excretion, while calcium and sodium continue to be reabsorbed and water leaves the nephron. 6. The filtrate empties into collecting ducts, where it combines with filtrate from other nephrons.
1. Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
2. The four most abundant elements in the human body – hydrogen, oxygen, carbon and nitrogen – account for more than 99 per cent of the atoms inside you.