Circulatory System Basics

Circulatory System

• The circulatory system is a way for the body to move essential items like oxygen, nutrients, and cell wastes around the body.
• It's comparable to carrying groceries from the store to your house, but instead, the body uses blood vessels to transport these items.

Blood Vessels

• Blood vessels are tube-like structures that resemble roads, but are inside the body.
• If all the blood vessels in the body were laid out in a line, they would stretch over 60,000 miles, circling the earth almost two and a half times.
• Blood vessels contain blood, which is a mixture of oxygen, nutrients, and wastes that need to be transported throughout the body.
• Oxygen is essential for cells to function, and cells are the basic structures that make up every part of the body.

Heart

• The heart is a muscular organ that pumps blood through the blood vessels, keeping it moving throughout the body.
• The heart is located in the left side of the chest and is about the size of a fist.
• The heart is made up of two interior pumps: one that pulls blood in and another that pumps it out.
• The heart pumps blood in a continuous circle, from the heart to the body and back to the heart, which is why it's called the circulatory system.

How It Works

• When cells work, they produce carbon dioxide as a waste product, which is dumped into the blood.
• The heart takes this waste-filled blood and sends it to the lungs, where it can be breathed out.
• When you breathe in, oxygen enters the blood, making it oxygen-rich.
• This oxygen-rich blood goes back to the heart, which pumps it around the body, supplying cells with fresh oxygen.
• The heart beats around 70 times per minute when you're resting, but increases its rate during exercise to supply cells with more oxygen.

Learn about the circulatory system's role in transporting essential substances like oxygen, nutrients, and waste products throughout the body.