Download First Law of Motion: Inertia

Chapter 7:
Circulatory System
How do oxygen & nutrients get to your muscle
cells?
What makes up the circulatory system?
Your blood, blood vessels, and heart
Blood delivers oxygen and nutrients to your
muscle cells through a system of tubes, or pipes,
called blood vessels.
Define blood vessels
Blood vessels are tubes, or pipes that
carry blood around your body.
How does the heart work?
Your heart itself is a muscle. It expands (gets
bigger) and contracts (gets smaller). When your
heart expands, it fills with blood. When it
contracts, it squeezes out the blood into your
blood vessels.
What is your heart rate?
The number of times your heart beats in one minute
is called your heart rate.
What are the two types of blood cells?
Red blood cells and white blood cells
There are 3 major types of blood vessels in your body, which make up the huge network of
blood vessels that carry blood to every part of your body. Name and explain each type of
vessel:
Arteries – carry blood from your heart to your cells.
Capillaries – the smallest, thinnest, and most numerous blood vessels. They branch off from the smallest
arteries.
Veins – the blood vessels that carry blood from the capillaries back to your heart.
Why does your heart beat faster when you exercise?
Your body’s cells – especially your muscle cells – need more energy when you
exercise. To make more energy, they need more oxygen and nutrients. Your heart
pumps faster so it can deliver more blood to your muscle cells.
How do your heart muscles “know to work faster?
When waste builds up in your blood (because your muscles are working hard),
your brain sends messages to your heart muscles. These messages “tell” them to
work harder and faster.
Why does your face get so red when you exercise?
The blood vessels that supply your skin expand so more blood can flow through them. When the warmed
blood moves into your skin, it makes your face look red.
How can you keep your circulatory system healthy?
Exercise at least 3 times per week.
Eat healthy food.
Don’t smoke.
What have you done to keep your circulatory system healthy today?
Ate healthy and exercised in PE class!