Histology Question and Answer Essay Example | Topics and Well Written Essays - 500 words

Histology Question and Answer - Essay Example The common pattern is the presence of three layers – the tunica intima, tunica media and the tunica adventitia from inside out. The tunica intima is the innermost layer, towards the luminal side of the blood vessel and is composed of simple, squamous endothelial cells and the supporting connective tissue. It is separated from the tunica media by the inner elastic lamina. The tunica media is composed of circular smooth muscle interspersed with connective tissue and is separated from the outermost layer by the outer elastic lamina. The tunica adventitia is made up entirely of connective tissue. The walls of the arteries are much thicker than those of the veins as they have to carry the blood pumped by the heart to distant organs which is usually at a higher pressure. The arteries therefore comprise of more elastic tissue in the tunica intima. The medium arteries are more muscular than elastic and the internal elastic membrane is more prominent. The spiral smooth muscle cells of the tunica media assist in the propulsion of blood as well as the maintenance of the blood pressure. The tunica adventitia is composed of collagen as well as elastic fibers and the innermost portion has an external elastic membrane. More elastic and muscular tissue in the arteries serves to sustain the vigorous systolic pressure of the blood and the maintenance of its pressure. The veins, on the other hand have thinner walls. Although they possess the basic histological structure associated with all blood vessels, the three layers are not well demarcated and blend into each other. They have lesser elastic tissue and the tunica adventitia is the thickest layer made up of collagen fibers and longitudinally oriented smooth muscle cells. The tunica intima is modified into loose folds which form pockets or valves to resist the back flow of blood along its journey to the heart. 2. The integument fulfills several roles, including that

Was the Roman Imperial system,particularly its form of government, Research Paper - 1

Was the Roman Imperial system,particularly its form of government, more closely related to the Spartan or Athenian model - Research Paper Example erialism for instance, was often hegemonies rather than annexationists, and there were times when the roman militaries were inactive during the republic. This paper will therefore compare the roman imperial system to the Spartan governing. Ancient Greece for instance, it had four forms of governments namely: Aristocracy, Monarchy, Oligarchy and Direct Democracy. Direct democracy government was exercised in ancient Athens; here citizens of the state were allowed to participate in politically in making decision that seems to be standard to all citizens. While in Ancient Sparta they had an oligarchy form of government, here the state was ruled by citizens who were classified in small groups, the small groups were in charge of the military as well. Sparta had mixed government, as a result of the mixed government state, it had both Oligarchy and democracy; the state of Sparta was hereditary and it was ruled by two kings from the Eurypontid and Agiad families. They were both Heracles descendants and had same authority. This equal authority prevented them from acting against each other. This form of government acted as a model to other poleis, it had three ruling classes, the assembly, council of elders and the Ephorate. In spite of having the mixed government, Sparta was well organized in its rulings. On the other hand, kings were rulers of the Roman city state. The king acted as a supreme ruler and the power he had over his subjects was consolidated by his own negotiation with his gods. In addition as a King, he often ensured that he maintains both his title of supremacy in the military as well as religious authority. However, the ancient government was later broken by the Roman citizens after they expelled their last king; this led to the kingdom of Roman to become a republic, and later processed to be an empire. At this point, the government and religion became one; this came to pass because of Emperor Augustus as well as his successors. Moreover, kings