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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 is also known as the cardiovascular system.It consists of…
3. The Heart1. Blood 2. Blood Vessels
The Circulatory System
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
The HeartThe four chambers of the heart have special names:
A lower chamber is called a ventricle.
An upper chamber is called an atrium (plural: atria).
rightatrium
rightventricle
leftatrium
leftventricle
The HeartHere 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.
These two valves prevent blood flowing
back into the atria from the ventricles.
Bicuspid (mitral) valve
Tricuspid valve
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.
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
Narrow central tube (lumen)
Thick inner layer of muscle and elastic fibres
Thick outer wall
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
VeinsVeins 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
wide central tube (lumen)
thin inner layer of muscle and elastic fibres
thin outer
wall
Venules
They have thinner walls than arterioles. They collect blood leaving the capillaries and transport it to the veins
Blood vesselsThere are three types of blood vessels, as shown in this magnified part of the circulatory system.
Why are there different types of blood vessels?
blood from the heart
blood to the heart
arterycarries blood
back intothe heart
carries blood away fromthe heart
carries blood to and from the body’s cells
vein
How does blood go around the body?
PULMONARY CIRCULATIONCARRIES BLOOD FROM THE
HEART TO THE LUNGS AND BACK AGAIN
SYSTEMIC CIRCULATIONCARRIES BLOOD FROM THE
HEART TO THE REST OF THE BODY AND BACK AGAIN
The circulatory system
body’scells
lungsDeoxygenated blood is pumped from the heart to the lungs through the pulmonary artery.
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.
Deoxygenated blood returns to the heart through the vena cava.
The double circulatory system
oxygenated blood to the rest of the body through the arteries
deoxygenated blood back to the heart through the veins.
The pulmonary circulation carries:
deoxygenated blood from the heart to the lungs
oxygenated blood back from the lungs to the heart, ready to be pumped out to the body.
The systemic circulation carries:
lungs
body’scells