The circulatory system of the human body is composed of many large and small blood vessels that transport blood throughout the body. The largest artery in the human body is the aorta. This blood vessel is responsible for pumping oxygenated blood from the left side of the heart to the head and body. The aorta is attached to the left ventricle of the heart.
Although there are many different species of both wallabies and kangaroos that span a wide range of sizes, wallabies only tend to weigh between four pounds and 53 pounds (2 kg to 24 kg) and grow a mere 12 inches to 24 inches (30 cm to 104 cm) tall, not including their tails [source: Wallaby].
The Wall is a colossal fortification which stretches for 100 leagues (300 miles) along the northern border of the Seven Kingdoms, defending the realm from the wildlings who live beyond. The Wall is reported to be over 700 feet tall and is made of solid ice.