Giraffe Coloring Sheet

---

---

Learning what is special about a giraffe’s heart is made possible by the award-winning science curriculum from Apologia

---

What Is Special About a Giraffe’s Heart?

Giraffes are not the kind of creature that can walk by unnoticed. They are the tallest land animal in the world, and their long necks and towering height make them stand out in any crowd.

Adult giraffes can be 13 to 19 feet tall. A giraffe’s neck alone can be about 6 feet long. Even baby giraffes, called calves, start out tall at around 6 feet the day they are born.

With heads held so high, you might wonder: what is special about a giraffe’s heart that keeps it alive and well way up there?

If you have ever stood up quickly and felt dizzy, you know what can happen when blood does not reach your brain fast enough. We might think a giraffe would get dizzy all the time as it raises its head from the ground to far above our heads. But God designed giraffes in a very special way so that does not happen.

A big part of that design is the giraffe’s heart.

A Giraffe’s Extra Strong Left Ventricle

Like our hearts, a giraffe’s heart has four chambers. Two of those chambers are called ventricles: a right ventricle and a left ventricle. Blood flows through these chambers and is pumped out to the body.

• The right ventricle pumps blood to the giraffe’s lungs. This is a short trip.
• The left ventricle has a much harder job. It has to pump blood through the rest of the body and all the way up the long neck to the brain.

In our bodies, the distance between our hearts and brains is not that far. In a giraffe, the brain can be over six feet above the heart. Blood has to travel a long way upward, working against gravity.

So what is special about a giraffe’s heart that makes this possible?

God designed the left ventricle of a giraffe’s heart with extra thick walls. It is like a super muscle. This powerful chamber can generate the strong pressure needed to send blood all the way up the giraffe’s neck to its brain.

God also tuned a giraffe’s heartbeat just right for this job. A giraffe’s heart spends extra time filling with blood between beats. So when the heart squeezes, there is a lot of blood ready to be pumped out in one strong push.

All of this means a giraffe’s heart can send plenty of oxygen-rich blood up to its brain so it does not get dizzy, even with its head held so high.

Why a Giraffe’s Head Does Not Explode When It Drinks

Now imagine this same powerful heart when a giraffe lowers its head down to the ground to take a drink.

The heart is still pumping very strongly. Only now the blood is flowing down the neck instead of up. Without another special design, all that pressure could cause serious damage. The blood could rush into the giraffe’s head and cause its brain to be overloaded.

But God thought of that too.

God created special valves in the blood vessels in a giraffe’s neck. These valves act like tiny doors in the veins.

• When a giraffe lowers its head, the valves close.
• This keeps too much blood from rushing into the brain all at once.

Instead of flooding the brain, the extra blood sits behind the closed valves, like water held back by a door.

God also designed the blood vessels beneath a giraffe’s brain to be able to expand like a water balloon. These stretchy vessels can safely hold the extra blood until the giraffe raises its head again.

When the giraffe lifts its head back up, the stored blood flows back down toward the heart, and the heart goes on pumping strongly to send blood up to the brain again.

This system allows a giraffe to lower and raise its head safely without getting dizzy and without its head being harmed by all that pressure.

What Giraffes Teach Us About Engineering

When we look at what is special about a giraffe’s heart, neck, and blood vessels, we see an amazing work of engineering. This connects to something called irreducible complexity.

Irreducible means nothing can be removed or made simpler.
Complexity means something has many parts.

So irreducible complexity means something has many parts and needs all of those parts at the same time to keep working. If you remove even one piece, the whole thing fails.

You can see this in everyday objects:

• A bicycle brake needs the lever, cable, and pads. Take away one part, and your bike will not stop.
• A flashlight needs the bulb, battery, and switch. Remove one piece, and the light will not turn on.

The same idea shows up in the giraffe’s design. Its heart and blood system are not simple. They have many parts that must work together:

• An extra strong left ventricle
• A heart rhythm that allows extra filling time
• Valves in the neck that close at the right moment
• Stretchy blood vessels beneath the brain that can expand and hold blood

If the giraffe did not have a strong left ventricle, it could not pump blood up to its brain and would die.
If it did not have the special valves in its neck, its head could be damaged when it bent down to drink.
If the blood vessels beneath the brain could not expand, they could burst under pressure.

All of these pieces are needed at the same time. This is not a simple system that can work with parts missing. It is irreducibly complex.

Nature is full of these kinds of designs. They remind us that God is a wise and powerful Creator who thought of every detail.

As Psalm 104:24 says:

“How many are your works, Lord!
In wisdom you made them all;
the earth is full of your creatures.”

And Revelation 4:11 reminds us:

“You are worthy, our Lord and God,
to receive glory and honor and power,
because you made all things.
Everything existed and was made,
because you wanted it.”

So the next time you see a picture or video of this tall and gentle creature, you can remember what is special about a giraffe’s heart. God engineered its powerful heart, clever valves, and stretchy blood vessels so it can live every day with its head held high.

Learn more about the giraffe’s incredible design on our giraffe podcast for kids: