Transcript Unit 1: The Body in Action

Principles of Anatomy and
physiology
structure and function of the CV
system
Kevin Browne
Starter Activity
In pairs, write down as many structures of the
cardiovascular system as you can.
Once you get stuck, begin to ask other students
who you are sat near to.
Learning Objectives
For all students to:
• Identify the 3 main structures of the
cardiovascular system.
• Identify the 4 main chambers of the heart.
• List at a minimum of 4 specific structures of
the heart (not including the 4 main chambers)
• For students to list 4 names of blood vessels
Introduction
The cardiovascular system can also be called the
circulatory system.
This system is the major transport system in the
body by which food, oxygen and all other
essential products are carried to the tissue
cells, and their waste products and carbon
dioxide are carried away. (Barker et al, 2007)
The Circulatory System
The circulatory system is also known as the cardiovascular system.
It consists of…
1. Blood
2. Blood Vessels
3. The Heart
True or false
• The heart helps get rid of waste products in
the body
• There are 8 types of blood vessels in the body
• de-oxgenated blood is on the left hand side of
the heart
• Carbon dioxide helps the heart to beat
• Different blood vessels are different sizes but
have the same function
The Heart
The heart is the centre of the cardiovascular
system. It is a hollow organ situated in the
left-hand side of the chest, below the
sternum, and is about the size of a closed fist.
It is a muscular pump, the purpose of which is to
drive blood into and through the arteries in
order to deliver blood to your tissues and
working muscles.
The Heart Cont.
The heart is surrounded by a sac known as
pericardium. This is a twin-layered sac, with its
cavity filled with pericardial fluid, the purpose
of which is to prevent friction as your heart
continually moves through beating
How are your ART skills?
Activity 1
Individually you have to draw the structure of
the heart.
Worksheet
The Heart
The four chambers of the heart have special names:
An upper chamber is called an atrium (plural: atria).
right
atrium
right
ventricle
left
atrium
left
ventricle
A lower chamber is called a ventricle.
The Heart
Here are some other important parts of the heart:
The walls
are made of
cardiac
muscle.
The wall
dividing the
left and
right sides
of the heart
is called the
septum.
The semi-lunar
valves prevent
expelled blood
flowing back into
the heart.
Bicuspid
(mitral) valve
Tricuspid
valve
These two valves
prevent blood flowing
back into the atria
from the ventricles.
New PP
The heart as a pump
The heart
Blood enters the heart through several major blood vessels.
The blood moves through the chambers of the heart and is pumped out via blood vessels. The
valves prevent the blood flowing the wrong way.
blood
vessels
valves
chambers
right
left
Blood from the body enters the
right side of the heart, where it is
pumped to the lungs. Blood from
the lungs enters the left side of
the heart, before it is pumped to
the rest of the body.
What are the stages in the cardiac
cycle?
Blood Vessels
There are 5 different types of blood vessels.
Students are in 2 groups, and you have 2
minutes to come up with the answer. First
group to write all 5 down and give to the
teacher wins.
Blood Vessels
There are 5 main blood vessels:
• Arteries
• Arterioles
• Capillaries
• Veins
• Venules
Arteries
The Major Blood Vessels
Veins
Arteries
Arteries carry blood away
from the heart, and carry
oxygenated blood (except
pulmonary artery).
Arteries have good
elasticity and
contractibility.
They have thick muscular
walls to carry blood at high
speeds under high
pressure
Thick outer wall
Thick inner layer of
muscle and elastic fibres
Narrow central tube (lumen)
Arterioles
• Arterioles have thinner walls than arteries.
These vessels control blood distribution by
changing their diameter.
• Are essentially responsible for controlling
blood flow to the capillaries.
Capillaries
Capillaries form an extensive
network that connects
arteries and vein by uniting
arterioles and Venules.
They are the smallest of all
blood vessels and are very
narrow and thin. This is
essential to allow diffusion
of oxygen and nutrients
required by the cells of the
body
wall only one cell thick
Veins
Veins return deoxygenated blood
to the heart. They have thinner
walls than arteries and have a
relatively large diameter.
When blood finally reaches the
veins, blood is flowing slowly
and at a low pressure.
Therefore contracting muscles
push the thin walls of the veins
inward to help squeeze the
blood back to the heart
thin outer
wall
thin inner layer of
muscle and elastic
fibres
wide central tube (lumen)
Venules
• They have thinner walls than arterioles. They
collect blood leaving the capillaries and
transport it to the veins
Blood vessels
There are three types of blood vessels, as shown in this
magnified part of the circulatory system.
blood to the
heart
blood from
the heart
vein
artery
carries blood
away from
the heart
carries blood
back into
the heart
carries blood to
and from the
body’s cells
Why are there different types of blood vessels?
Blood vessels
Click on this work sheet on the blog
How does blood go around the body?
PULMONARY CIRCULATION
CARRIES BLOOD FROM THE HEART TO THE
LUNGS AND BACK AGAIN
SYSTEMIC CIRCULATION
CARRIES BLOOD FROM THE HEART TO THE
REST OF THE BODY AND BACK AGAIN
The Cardiovascular system
The circulatory system
Deoxygenated
blood is
pumped from
the heart to the
lungs through
the pulmonary
artery.
Deoxygenated
blood returns to
the heart
through the
vena cava.
lungs
body’s
cells
Oxygenated
blood returns
to the heart
through the
pulmonary
vein.
Oxygenated
blood is pumped
at high pressure
from the heart to
the body through
the aorta.
The double circulatory system
The pulmonary circulation carries:
deoxygenated blood from the
heart to the lungs
lungs
oxygenated blood back from the
lungs to the heart, ready to be
pumped out to the body.
The systemic circulation carries:
oxygenated blood to the rest of
the body through the arteries
deoxygenated blood back to the
heart through the veins.
body’s
cells