Weekâ€2 Quiz Essay Example

Week–2 Quiz Essay Example Week–2 Quiz Essay Week–2 Quiz Essay Cardiovascular System: Peripheral Circulation and Regulation Systemic blood vessels transport blood From the left ventricle through the body to the left atrium. From the left ventricle through the body to the right atrium. From the right ventricle through the body to the left atrium. From the right ventricle through the body to the right atrium. From the left ventricle to the lungs. Which of the following functions is associated with vessels that carry blood directly from arterioles to veins without passing through capillaries? thermoregulation nutrient supply to tissues removal of metabolic waste products from tissues oxygen supply to tissues pH regulation In the pulmonary circulation, the _____ carry blood to the lungs. carotid sinuses pulmonary arteries coronary arteries superior vena cava and inferior vena cava aorta The abdominal aorta divides at L5 to form the two Inferior mesenteric arteries. Common iliac arteries. Superior mesenteric arteries. Femoral arteries. Renal arteries. Blood from the posterior abdominal wall drains into the Hepatic portal vein. Inferior vena cava. Ascending lumbar vein. Mesenteric vein. Hepatic vein. A blood pressure reading of 120/80 would Indicate a diastolic pressure of 120 mm Hg. Have Korotkoff sounds at pressures above 120 mm Hg. Be considered normal for a young adult male. Indicate a systolic pressure of 80 mm Hg. Would be considered hypertensive. In the aorta, The blood pressure and blood velocity are both high. The velocity of blood flow is high, but blood pressure is low. The resistance to blood flow is high, but velocity of blood flow is low. The resistance to blood flow and the blood pressure are both low. Velocity is diminished because the total cross-sectional area is small. In capillary exchange, which of the following statements is true? Most fluid that leaves the arterial end of a capillary reenters the venous end of a capillary. Interstitial fluid normally has a higher osmotic pressure than plasma. Constriction of the precapillary sphincter will increase blood pressure in the capillary. Interstitial protein concentration is normally higher than plasma protein concentration. Most fluid that leaves the arterial end of a capillary enters the lymphatic system. Baron von Quacko, famous tag-team wrestler, has a famous sleeper hold that he uses on his opponents. Using only a single digit on each hand, he presses on his opponents neck until his opponent passes out. What are the structures on which he is pressing and what is the effect? subclavian arteries; blood flow to brain is stopped carotid chemoreceptors; blood pressure increases baroreceptors in carotid sinus; peripheral vasodilation and decreased heart rate vertebral arteries; blood flow to brain is increased jugular vein; blood flow back to heart is decreased Atrial natriuretic factor Is released in response to elevated atrial pressure. Stimulates the release of ADH. Decreases urine production. Stimulates release of aldosterone. Increases blood volume.

Prehistoric Life During the Pliocene Epoch

Prehistoric Life During the Pliocene Epoch By the standards of deep time, the Pliocene epoch was relatively recent, commencing only five million years or so before the start of the modern historical record, 10,000 years ago. During the Pliocene, prehistoric life around the globe continued to adapt to the prevailing climatic cooling trend, with some notable local extinctions and disappearances. The Pliocene was the second epoch of the Neogene Period (23-2.6 million years ago), the first being the Miocene (23-5 million years ago); all of these periods and epochs were themselves part of the Cenozoic Era (65 million years ago to the present). Climate and Geography During the Pliocene epoch, the earth continued its cooling trend from previous epochs, with tropical conditions holding at the equator (as they do today) and more pronounced seasonal changes at higher and lower latitudes; still, average global temperatures were 7 or 8 degrees (Fahrenheit) higher than they are today. The major geographic developments were the reappearance of the Alaskan land bridge between Eurasia and North America, after millions of years of submersion, and the formation of the Central American Isthmus joining North and South America. Not only did these developments allow an interchange of fauna between three of the earths continents, but they had a profound effect on ocean currents, as the relatively cool Atlantic ocean was cut off from the much warmer Pacific. Terrestrial Life During the Pliocene Epoch Mammals. During large chunks of the Pliocene epoch, Eurasia, North America, and South America were all connected by narrow land bridges- and it wasnt all that difficult for animals to migrate between Africa and Eurasia, either. This wreaked havoc on mammalian ecosystems, which were invaded by migrating species, resulting in increased competition, displacement, and even outright extinction. For example, ancestral camels (like the huge Titanotylopus) migrated from North America to Asia, while the fossils of giant prehistoric bears like Agriotherium have been discovered in Eurasia, North America, and Africa. Apes and hominids were mostly restricted to Africa (where they originated), though there were scattered communities in Eurasia and North America. The most dramatic evolutionary event of the Pliocene epoch was the appearance of a land bridge between North and South America. Previously, South America had been much like modern Australia, a giant, isolated continent populated by a variety of strange mammals, including giant marsupials. Confusingly, some animals had already succeeded in traversing these two continents, before the Pliocene epoch, by the arduously slow process of accidental  island-hopping; thats how Megalonyx, the Giant Ground Sloth, wound up in North America. The ultimate winners in this Great American Interchange were the mammals of North America, which either wiped out or greatly diminished their southern relatives. The late Pliocene epoch was also when some familiar megafauna mammals appeared on the scene, including the Woolly Mammoth in Eurasia and North America, Smilodon (the Saber-Toothed Tiger) in North and South America, and Megatherium (the Giant Sloth) and Glyptodon (a gigantic, armored armadillo) in South America. These plus-sized beasts persisted into the ensuing Pleistocene epoch, when they went extinct due to climate change and competition with (combined with hunting by) modern humans. Birds. The Pliocene epoch marked the swan song of the phorusrhacids, or terror birds, as well as the other large, flightless, predatory birds of South America, which resembled meat-eating dinosaurs that had gone extinct tens of millions of years earlier (and count as an example of convergent evolution.) One of the last surviving terror birds, the 300-pound Titanis, actually managed to traverse the Central American isthmus and populate southeastern North America; however, this didnt save it from going extinct by the start of the Pleistocene epoch. Reptiles. Crocodiles, snakes, lizards, and turtles all occupied an evolutionary backseat during the Pliocene epoch (as they did during much of the Cenozoic Era). The most important developments were the disappearance of alligators and crocodiles from Europe (which had now become much too cool to support these reptiles  cold-blooded lifestyles), and the appearance of some truly gigantic turtles, such as the aptly named Stupendemys of South America. Marine Life During the Pliocene Epoch As during the preceding Miocene, the seas of the Pliocene epoch were dominated by the biggest shark that ever lived,  the 50-ton Megalodon. Whales continued their evolutionary progress, approximating the forms familiar in modern times, and pinnipeds (seals, walruses, and sea otters) flourished in various parts of the globe. An interesting side note: the marine reptiles of the Mesozoic Era known as  pliosaurs  were once thought to date from the Pliocene epoch, hence their misleading name, Greek for Pliocene lizards. Plant Life During the Pliocene Epoch There werent any wild bursts of innovation in Pliocene plant life; rather, this epoch continued the trends seen during the preceding Oligocene and Miocene epochs: the gradual confinement of jungles and rain forests to equatorial regions, while vast deciduous forests and grasslands dominated higher northern latitudes, especially in North America and Eurasia.