Britannica Student Encyclopedia - 2010

in the urine by tightening nearby

muscles. When the muscles relax, urine

passes out of the bladder. It flows

through a tube called the urethra and

out of the body. This process is called

urination.

Problems with the Urinary

System

Like other parts of the body, the organs

of the urinary system may become

infected. This can make urination painful.

Several diseases can cause the kidneys

to stop working correctly.Wastes

then build up in the body and make the

person sick.

If the kidneys fail, doctors may use a

technique called dialysis to remove

wastes from the blood. In dialysis the

patient’s blood travels out of the body,

through a cleaning machine, and back

into the body. Doctors may also transplant

a healthy person’s kidney into the

patient.

Urinary Systems in Other

Animals

Like humans, most animals with a backbone

have kidneys and a bladder. However,

in birds, reptiles, and amphibians,

urine collects in a chamber called a

cloaca before leaving the body. Solid

waste also collects in the cloaca. Unlike

the watery urine of mammals and fish,

the urine of birds and reptiles is white

and thick. The urine of land insects is

solid.

#More to explore

Digestive System • Kidney

Humans and frogs both have kidneys and a

bladder in their urinary systems. Frogs and

other amphibians have a cloaca as well.

BRITANNICA STUDENT ENCYCLOPEDIA Urinary System 41

 

Uruguay

Uruguay is a small country on the east

coast of South America. Uruguay’s capital

is Montevideo.

Geography

Uruguay is the second smallest country

in South America, after Suriname. Uruguay

borders Brazil in the north and

Argentina in the west. To the southeast

is the Atlantic Ocean. To the south is a

part of the Atlantic called the Rio de la

Plata.

Hills and plains cover most of the land.

The Uruguay River runs along the border

with Argentina. The largest river

system in Uruguay is the Rio Negro. A

dam on this river created the Embalse

del Rio Negro, the largest lake in the

country.

Uruguay has mild winters and warm

summers. Rain is heaviest in the

autumn.

Plants and Animals

Tall prairie grasses cover most of Uruguay.

The country has few forests. Alder,

willow, eucalyptus, and poplar trees and

aloe plants grow near the rivers.

Some pumas and jaguars live in Uruguay.

Other native animals include

foxes, deer, wildcats, and large rodents

called capybaras. Caimans, which are

similar to alligators, live in the Uruguay

River. Uruguay’s birds include vultures,

parakeets, and flamingos.

People

Most Uruguayans have Spanish or Italian

ancestors. Mestizos, or people with

mixed European and American Indian

roots, form a small group. A smaller

number of people have African roots.

Almost all Uruguayans speak Spanish.

Roman Catholicism is the main religion.

Most people live in cities. Montevideo is

many times larger than Salto, the

second-largest city.

A gaucho (South American cowboy) herds

cattle in central Uruguay.

42 Uruguay BRITANNICA STUDENT ENCYCLOPEDIA

 

Economy

Most Uruguayans work in services,

including banking, communications,

and tourism. However, agriculture is

very important to the economy. Large

herds of cattle and sheep live on the

grasslands. The animals provide beef,

wool, leather, and dairy products.

Uruguay sells these products to other

countries. Farmers also grow rice,

wheat, corn, oranges, and sugarcane.

Fishing is another source of food.

Uruguay’s factories produce fuels,

chemicals, beverages, machinery, and

other goods.

History

A group of American Indians known as

the Charrua lived in the Uruguay region

hundreds of years ago. Spanish explorers

arrived in 1516, but they did not settle

the land.

Banda Oriental

The Spanish called the area the Banda

Oriental del Uruguay. The name means

“east bank of the Uruguay River.” Bands

of gauchos, or Spanish cowboys, hunted

the stray cattle that roamed through the

region. But the gauchos did not form

permanent settlements.

In 1680 the Portuguese set up a town in

the Banda Oriental. The Spanish

founded the city of Montevideo in 1726

and attacked the Portuguese. By the late

1770s the Spanish had driven out the

Portuguese.

In 1810 Spain’s American colonies

began fighting for independence. People

in the Banda Oriental defeated the

Spanish. However, Brazil soon took over

the Banda Oriental. After several years

of war the Banda Oriental finally won

independence in 1828. The new country

was called Uruguay.

Independence

Civil war erupted in Uruguay soon after

independence and continued for about

70 years. Uruguay became a stable

democracy in the early 1900s. In the

1960s a terrorist group called the

Tupamaros began trying to overthrow

the government.

The military took control of the government

in 1973. The military defeated the

Tupamaros, but it also ruled very

harshly. The military government jailed,

tortured, or killed many people who

disagreed with it. A democratic government

finally replaced the military leaders

in 1985.

..More to explore

Montevideo

The Punta del Este is a popular place for

vacations in southern Uruguay. Hotels line

the beaches along the Atlantic Ocean.

Facts About

URUGUAY

Population

(2008 estimate)

3,350,000

Area

68,037 sq mi

(176,215 sq km)

Capital

Montevideo

Form of