The term' Peristalisis, which pumps blood towards the head in the open circulatory system of insects, also means 1. muscular conctractions that push food through the digestive system
2. air flowing into and out of the lungs
3. skeletal muscle contracting and relaxing to move a bone up and down

Kidney stones are tiny crystals of calcium or magnesium that block the narrow sections of the excretory system. which symptoms would a person with kidney stones experience? a. inability to store urine; pain in the bladder b. inability to store urine; pain in the urethra c. reduced urine flow; pain in the bladder d. reduced urine flow; pain in the urethra