Download Open Circulatory System

Journal 2/2/17
What do cells need to survive?
Objective
To learn how animals get
oxygen and nutrients to
cells
Tonight’s Homework
Get vocab definitions for the
Circulatory system page
Circulatory Systems
Cells need energy, nutrients and oxygen to
work. As they work, they generate waste
materials and gases.
Cells need to get their nutrients from
somewhere. The job of the circulatory system is
to provide a way for every cell to get the
nutrients it needs and to get rid of everything it
doesn’t.
There are 3 kinds of circulatory system:
- Diffusion
- Open
- Closed
Circulatory Systems
Diffusion
If every cell in a creature is right up next to the
air or water, we don’t need a circulatory system
Each cell can get what it wants and get rid of
what it needs on its own.
Sponges are made of only 2 layers of cells.
An outside and an inside. They have a
“skeleton” between the layers.
Every cell has access
to the water, and it
takes care of
nutrients and oxygen
that way.
Circulatory Systems
Flatworms and jellyfish work the same way.
They’re made of only a few layers of cells, so
every cell can get oxygen and nutrients on its
own.
This system has limitations. You can’t make a
very complex creature this way before you have
cells that can’t get to the water or air on their
own.
Outside
These in the middle have
no way of getting nutrients!
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Inside
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Circulatory Systems
This is where blood comes in. The job of blood is
to carry nutrients and oxygen to cells, and to
carry away that waste.
The simplest is the Open Circulatory System
In this kind of system, there’s one tube that
blood flows through and a simple heart. After
blood leaves the
tube, it flows
freely inside the
creature until
it finds its way
back to the tube.
Circulatory Systems
Open circulatory systems are less efficient
because some blood can deliver nutrients and
oxygen and then take a while to get back to the
heart.
Insects make up for this with their special
respiration system (which we’ll get to later).
Circulatory Systems
Closed Circulatory System
In a closed system, blood always stays in tubes.
It’s pumped away from the heart to the lungs
where it gets fresh oxygen. In most animals, it
then comes
back to the
heart where it
gets pumped
out to the
rest of the body.
Circulatory Systems
The blood vessels head to literally every cell in
your body so the cells can get what they need.
Arteries always head away from the heart, veins
always head towards the heart.
Arteries almost always carry fresh oxygen and
have high pressure.
Veins almost always carry waste or carbon
dioxide and have low pressure.
Circulatory Systems
Circulatory Systems
The job of the
circulatory system is to
get nutrients and
oxygen to each cell and
to carry waste away
from each cell.
Diffusion systems
Open systems
Closed Systems
DIAGRAM
Circulatory
Vocab: <define each>
Diffusion
Artery
Capillary
Vein
Pulmonary Circulation
Portal Circulation
Atrium
Ventricle
3 types of circulation
Exit Question
What is the job of the circulatory system?
a) To carry nutrients to cells
b) To carry oxygen to cells
c) To carry waste away from cells
d) A and B
e) All of the Above
f) None of the above