Differences and similarities of a fjord and an estuary?

Both firth and fjord are now generally defined as an arm of the sea. The difference is crucial - a firth (or fjord) is made up of undiluted sea water, but an estuary has a gradation of salt water dilution from fully salt water at its mouth to fresh water at its head, and experiences tidal fluctuations

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

photosynthesis makes the glucose that is used in cellular respiration to make atp. the glucose is then turned back into carbon dioxide, which is used in photosynthesis. while water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.