C.h.l.o.e..docx

Chloe Adrianne A. Gimena

II-Rose

The Structure and Function of the Digestive System Mouth The mouth is the beginning of the digestive tract; and, in fact, digestion starts here when taking the first bite of food. Chewing breaks the food into pieces that are more easily digested, while saliva mixes with food to begin the process of breaking it down into a form your body can absorb and use.

Esophagus Located in your throat near your trachea (windpipe), the esophagus receives food from your mouth when you swallow. By means of a series of muscular contractions called peristalsis, the esophagus delivers food to your stomach.

Stomach The stomach is a hollow organ, or "container," that holds food while it is being mixed with enzymes that continue the process of breaking down food into a usable form. Cells in the lining of the stomach secrete strong acid and powerful enzymes that are responsible for the breakdown process. When the contents of the stomach are sufficiently processed, they are released into the small intestine.

Small intestine Made up of three segments — the duodenum, jejunum, and ileum — the small intestine is a 22-foot long muscular tube that breaks down food using enzymes released by the pancreas and bile from the liver. Peristalsis also is at work in this organ, moving food through and mixing it with digestive secretions from the pancreas and liver. The duodenum is largely responsible for the continuous breaking-down process, with the jejunum and ileum mainly responsible for absorption of nutrients into the bloodstream. Contents of the small intestine start out semi-solid, and end in a liquid form after passing through the organ. Water, bile, enzymes, and mucous contribute to the change in consistency. Once the nutrients have been absorbed and the leftover-food residue liquid has passed through the small intestine, it then moves on to the large intestine, or colon.

Pancreas The pancreas secretes digestive enzymes into the duodenum, the first segment of the small intestine. These enzymes break down protein, fats, and carbohydrates. The pancreas also makes insulin, secreting it directly into the bloodstream. Insulin is the chief hormone for metabolizing sugar.

Liver The liver has multiple functions, but its main function within the digestive system is to process the nutrients absorbed from the small intestine. Bile from the liver secreted into the small intestine also plays an important role in digesting fat. In addition, the liver is the body’s chemical "factory." It takes the raw materials absorbed by the intestine and makes all the various chemicals the body needs to function. The liver also detoxifies potentially harmful chemicals. It breaks down and secretes many drugs.

Gallbladder The gallbladder stores and concentrates bile, and then releases it into the duodenum to help absorb and digest fats.

Colon (large intestine) The colon is a 6-foot long muscular tube that connects the small intestine to the rectum. The large intestine is made up of the cecum, the ascending (right) colon, the transverse (across) colon, the descending (left) colon, and the sigmoid colon, which connects to the rectum. The appendix is a small tube attached to the cecum. The large intestine is a highly specialized organ that is responsible for processing waste so that emptying the bowels is easy and convenient. Stool, or waste left over from the digestive process, is passed through the colon by means of peristalsis, first in a liquid state and ultimately in a solid form. As stool passes through the colon, water is removed. Stool is stored in the sigmoid (S-shaped) colon until a "mass movement" empties it into the rectum once or twice a day. It normally takes about 36 hours for stool to get through the colon. The stool itself is mostly food debris and bacteria. These bacteria perform several useful functions, such as synthesizing various vitamins, processing waste products and food particles, and protecting against harmful bacteria. When the descending colon becomes full of stool, or feces, it empties its contents into the rectum to begin the process of elimination.

Rectum The rectum (Latin for "straight") is an 8-inch chamber that connects the colon to the anus. It is the rectum's job to receive stool from the colon, to let the person know that there is stool to be evacuated, and to hold the stool until evacuation happens. When anything (gas or stool) comes into the rectum, sensors send a message to the brain. The brain then decides if the rectal contents can be released or not. If they can, the sphincters relax and the rectum contracts, disposing its contents. If the contents cannot be disposed, the sphincter contracts and the rectum accommodates so that the sensation temporarily goes away.

Anus The anus is the last part of the digestive tract. It is a 2-inch long canal consisting of the pelvic floor muscles and the two anal sphincters (internal and external). The lining of the upper anus is specialized to detect rectal contents. It lets you know whether the contents are liquid, gas, or solid. The anus is surrounded by sphincter muscles that are important in allowing control of stool. The pelvic floor muscle creates an angle between the rectum and the anus that stops stool from coming out when it is not supposed to. The internal sphincter is always tight, except when stool enters the rectum. It keeps us continent when we are asleep or otherwise unaware of the presence of stool. When we get an urge to go to the bathroom, we rely on our external sphincter to hold the stool until reaching a toilet, where it then relaxes to release the contents.

Chloe Adrianne A. Gimena

II-Rose Parthian Empire

The Parthian Empire (247 BC – 224 AD), also known as the Arsacid Empire (Modern Persian: ‫ اشکانیان‬Ashkāniān), was a major Iranian political and cultural power in ancient Persia. Its latter name comes from Arsaces I of Parthia who, as leader of the Parni tribe, founded it in the mid-3rd century BC when he conquered the Parthia region in Iran's northeast, then a satrapy (province) in rebellion against the Seleucid Empire. Mithridates I of Parthia (r. c. 171–138 BC) greatly expanded the empire by seizing Media and Mesopotamia from the Seleucids. At its height, the Parthian Empire stretched from the northern reaches of the Euphrates, in what is now south-eastern Turkey, to eastern Iran. The empire, located on the Silk Road trade route between the Roman Empire in the Mediterranean Basin and Han Empire of China, became a center of trade and commerce. The Parthians largely adopted the art, architecture, religious beliefs, and royal insignia of their culturally heterogeneous empire, which encompassed Persian, Hellenistic, and regional cultures. For about the first half of its existence, the Arsacid court adopted elements of Greek culture, though it eventually saw a gradual revival of Iranian traditions. The Arsacid rulers were titled the "King of Kings", as a claim to be the heirs to the Achaemenid Empire; indeed, they accepted many local kings as vassals where the Achaemenids would have had centrally appointed, albeit largely autonomous, satraps. The court did appoint a small number of satraps, largely outside Iran, but these satrapies were smaller and less powerful than the Achaemenid potentates. With the expansion of Arsacid power, the seat of central government shifted fromNisa, Turkmenistan to Ctesiphon along the Tigris (south of modern Baghdad, Iraq), although several other sites also served as capitals. The earliest enemies of the Parthians were the Seleucids in the west and the Scythians in the east. However, as Parthia expanded westward, they came into conflict with the Kingdom of Armenia, and eventually the late Roman Republic. Rome and Parthia competed with each other to establish the kings of Armenia as their subordinate clients. The Parthians soundly defeated Marcus Licinius Crassus at the Battle of Carrhae in 53 BC, and in 40–39 BC, Parthian forces captured the whole of the Levant, excepting Tyre, from the Romans. However, Mark Antony led a counterattack against Parthia and several Roman emperors invaded Mesopotamia during the Roman-Parthian Wars. The Romans captured the cities of Seleucia and Ctesiphon on multiple occasions during these conflicts, but were never able to hold onto them. Frequent civil war between Parthian contenders to the throne proved more dangerous than foreign invasion, and Parthian power evaporated when Ardashir I, ruler of Estakhr in Fars, revolted against the Arsacids and killed their last ruler, Artabanus IV, in 224 AD. Ardashir established the Sassanid Empire, which ruled Iran and much of the Near East until the Muslim conquests of the 7th century AD, although the Arsacid dynasty lived on through the Arsacid Dynasty of Armenia. Native Parthian sources, written in Parthian, Greek and other languages, are scarce when compared to Sassanid and even earlier Achaemenid sources. Aside from scattered cuneiform tablets, fragmentaryostraca, rock inscriptions, drachma coins, and the chance survival of some parchment documents, much of Parthian history is only known through external sources. These include mainly Greek and Roman histories, but also Chinese histories prompted by the market for Chinese goods in Parthia. Parthian artwork is viewed by historians as a valid source for understanding aspects of society and culture that are otherwise absent in textual sources.

Sassanid Empire The Sassanid Empire (also spelled Sasanid Empire, Sassanian Empire, or Sasanian Empire), known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran, was the last preIslamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651. The Sassanid Empire, which succeeded the Parthian Empire, was recognized as one of the two main powers in Western Asia and Europe, alongside the Roman Empire and its successor, the Byzantine Empire, for a period of more than 400 years.

The Sassanid Empire was founded by Ardashir I, after the fall of the Arsacid Empire and the defeat of the last Arsacid king, Artabanus IV. It lasted until Yazdegerd III lost control of his empire in a series of invasions from the Arab Caliphate. During its existence, the Sassanid Empire encompassed all of today's Iran, Afghanistan, Iraq, Syria, the Caucasus (Armenia, Georgia, Azerbaijan, and Dagestan), southwestern Central Asia, part of Turkey, certain coastal parts of the Arabian Peninsula, the Persian Gulf area, and areas of southwestern Pakistan, even stretching into India. The native name for the Sassanid Empire inMiddle Persian is Eran Shahr which means Aryan Empire. According to legend, the vexilloid of the Sassanid Empire was the Derafsh Kaviani. It was also hypothesized that the transition toward the Sassanid Empire represents the end of struggle of ethnic proto-Persians with their close migrant ethnic relatives, the Parthians, whose original homeland was in modern-day Central Asia. The Sassanid era, during Late Antiquity, is considered to have been one of Persia's/Iran's most important and influential historical periods, and constituted the last great Iranian empire before the Muslim conquestand the adoption of Islam. In many ways, the Sassanid period witnessed the peak of ancient Persian civilization. Persia influenced Roman civilization considerably during the Sassanid period. The Sassanids' cultural influence extended far beyond the empire's territorial borders, reaching as far as Western Europe, Africa, China and India. It played a prominent role in the formation of both European and Asian medieval art.

Roman Empire The Roman Empire (Latin: Imperium Romanum) was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean. The 500-year-old Roman Republic, which preceded it, had been weakened and subverted through several civil wars. Several events are commonly proposed to mark the transition from Republic to Empire, including Julius Caesar's appointment as perpetual dictator (44 BC), the Battle of Actium (2 September 31 BC), and the Roman Senate's granting to Octavian the honorific Augustus (4 January27 BC). Roman expansion began in the days of the Republic, but the Empire reached its greatest extent under Emperor Trajan: during his reign (98 to 117 AD) the Roman Empire controlled approximately 6.5 millionkm2[7] of land surface. Because of the Empire's vast extent and long endurance, the institutions and culture of Rome had a profound and lasting influence on the development of language, religion, architecture, philosophy, law, and forms of government in the territory it governed, particularly Europe, and by means of European expansionism throughout the modern world. In the late 3rd century AD, Diocletian established the practice of dividing authority between four coemperors, in order to better secure the vast territory, putting an end to the Crisis of the Third Century. During the following decades the Empire was often divided along an East/West axis. After the death of Theodosius I in 395 it was divided for the last time. The Western Roman Empire collapsed in 476 as Romulus Augustus was forced to abdicate to the Germanic warlord Odoacer. The Eastern Roman or Byzantine Empire ended in 1453 with the death ofConstantine XI and the capture of Constantinople by the Ottoman Turks led by Mehmed II.