The Circulatory System - Algonquin and Lakeshore Catholic

 The circulatory (or
cardiovascular) system is
the transport system of the
body and has four major
1. Transportation of O2 and
2. Transportation of wastes
and nutrients
3. Transportation of
4. Maintain body
Structure of the Circulatory System
 A circulatory system
consists of three parts:
1. A fluid in which
materials are
transported (i.e. blood)
2. A system of vessels to
transport the fluid all
over the body (i.e.
arteries and veins)
3. A pump (i.e. heart)
Interesting Facts
 No cell in your body is
more than two cells away
from a blood vessel.
 There are 96 000 km of
blood vessels in your body
to sustain your 100 trillion
 Your heart beats around 72
times a minute and in your
lifetime it will pump
enough blood to fill two
ocean tankers!
Two Systems in One
 The left and right side of
your heart do different
 The right side of your heart
pumps blood to the lungs
to exchange CO2 for O2 in
the pulmonary circuit.
 The left side of your heart
pumps oxygen rich blood
around your body in the
systemic circuit.
 Blood moving through the
heart is the cardiac circuit.
Heart Structure
 The wall separating the left
and right sides of your
heart is known as the
 Each side has a thin walled
atrium to collect blood
above a more muscular
ventricle that pumps
 Between the different
regions of the heart are
valves to ensure blood only
flows in one direction.
Heart Sounds
 The heart beat is actually
controlled within the heart
itself by two bundles of
 The sinoatrial (SA) node
acts as a pacemaker
causing the atria to
contract while the
atrioventricular (AV) node
ensures the ventricles
contract a moment later.
 The sound we hear is
caused by the closing of
the heart valves.
 The “lub” is from the
shutting of the valves
between the atria and
ventricles when blood is
moved from the top to the
bottom of the heart.
 The “dub” is the closing of
the valves between the
ventricles and the arteries
that leave the heart.
Blood Vessels
 Arteries carry blood away
from the heart and have
thicker walls to withstand
the greater pressure of
 Veins take blood back to
the heart and have valves
to ensure one way blood
 Capillaries are the junction
of arteries and veins where
gases and nutrients are
exchanged with body cells.
(from heart)
(to heart)
Tracing the Path Blood Takes
around the Body
1) What are the four functions of a circulatory system?
2) What are the three main parts to a circulatory
3) What are two differences between an Atrium and a
4) Using three different points of criteria, compare
arteries, veins and capillaries.

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