form and func

• ertythrocytes
• transport oxygen (attached to hemoglobin) and catalyze the conversion of CO₂ and H₂O to H₂CO₃
• mature red blood cells lack a nucleus which maximizes hemoglobin content and their ability to transport oxygen

• leukocytes
• 5 major groups of disease-fighting cells that defend the body against infection

• blood clotting
• factors involved in clotting are fibrinogen...and released in active form fibrin
• threads of fibrin protein form a network that stops blood flow

liquid portion of the blood that contains dissolved substances

helps maintain homeostasis in organisms by regulating water balance and by removing harmful substances

absorbtion and excretion of water and dissolved substances (solutes) so that proper water balance is maintained between the organism and its surroundings

• hypoosmotic with environment-less salty than the surrounding water. water is constantly lost by osmosis.
• fish constantly drink, rarely urinate, and secrete accumulated salts out through gills

• hyperosmotic-saltier than their surrounding
• water constantly diffused into the fish
• rarely drink, constantly urinate, and absorb salts through gills

• found in the cytoplasm of protists (paramecia and amoeba)
• accumulate water, merge with the plasma membrane, and release the water into the environment

• found in planaria
• distributed alone a branched tube system that permeates the flatworm
• body fluids are filtered across the flame cells, hose internal cilia move the fluids through the tube system
• wastes are exreted from the tube system through pores exiting the body

• chemical breakdown of food into smaller molecules
• cell digestion is accomplished by intracellular digestion
• in most animals, food is too large to engulfed by cells so it is first digested in a gastrovascular cavity by extracellular digestions then absorbed by individual cells

• starch broken down to glucose
• protein broken down to amino acids
• fats broken down into glyceral and fatty acids
• nucleic acids broken into nucleotides

• mouth
• pharynx
• esophagus
• stomach
• small intestine
• large intestine

• gastrin
• secretin
• cholecystokinin

• produced by cells in stomach lining when food reaches the stomach or when the nervous system sense the availability of food
• enters blood stream and stimulates other cells of the stomach to produce gastric juices

• produced by the cells lining the duodenum when food enters
• stimulates the pancreas to produce bicarbonate which, when deposited into the small intestine, neutralizes the aciditiy of the chyme

• produced by the small intesting in response to the presence of fats
• stimulates the gallbladder to release bile and the pancreas to release its enzymes