The Circulatory System

Circulatory System –Learning Outcomes

• State the type of tissue the heart is made of• State the function of the heart• State the number of chambers in the heart• Know how the blood flows in the heart• Explain why one side of the heart is thicker

than the other• Explain the importance of the coronary artery• State the function of heart valves• State the function of the 3 blood vessels

• The circulatory system in the human body is made up of the heart and all the associated blood vessels (tubes that carry blood around the body).

The Circulatory System

• Organ which is made out of muscle tissue known as “cardiac muscle”.

• Pumps blood around the body (function).

• Therefore described as a “muscular pump”

• Your heart beats about 100,000 times in one day and about 35 million times in a year.

• During an average lifetime, the human heart will beat more than 2.5 billion times.

The Heart

The Circulatory System

• The circulatory system in the human body is made up of the ______ and the ________ vessels.

• The heart is an organ made of ________. It ________ blood around the body. The blood vessels are a system of _______ that carry blood to all parts of the body.

• The 3 vessels are ________, ________ and capillaries.

• http://www.kscience.co.uk/animations/heart.swf

Blood flow through the Heart

(from lungs)

(TO THE BODY)(TO LUNGS)

(from the body)

Blood flow through the Heart

Cardiac muscle

The heart has 4

chambers!

Deoxygenated bloodOxygenated blood

The “Double Circulatory” System

1. Deoxygenatedblood is pumped from the heart to the lungs

3. The oxygenatedblood is then pumped to the rest of the body

2. The blood receives oxygen and is pumped back to the heart

4. The oxygen leaves the blood and enters body cells. Carbon dioxide enters the blood and it then goes back to the heart

• The LEFT side is thicker than the right side.

• This is because the left side needs to pump blood to the whole body so a greater force is needed.

• Where as the right side only needs to pump blood to the lungs so less force is needed.

Thickness of heart walls

Left side = thicker

Right side = thinner

Coronary artery

The heart is living tissue (muscle) therefore it must have its own supply of oxygen and glucose. The Coronary artery supplies the heart muscle with oxygen and glucose.

Coronary artery

2 minutes – think/pair/share

1. What do people use to listen to the heart?

2. What sound do you hear?

3. What makes this sound?WHAT TO DO:1. Wet some cotton wool with disinfectant and collect a

stethoscope.2. Use the disinfectant and cotton wool to clean the ear pieces.3. Use the larger circle and find your heart

• Place it in the centre• Move it slightly to the left• Move the larger circle slowly up/down until you hear the

“lub-dub” – this is the sound of your HEART VALVES

Listening to a heartbeat

Beats in 10 Seconds Beats per minute

1. Copy and complete the following table (use a pulsometer or stopwatch and your fingers orstethoscope)

2. Work out how many times your heart beats in 1 hour, 1 day and 1 year.

1 Hour = _______ x 601 Day = _______ x 241 year = _______ x 365

Helpful hint under here!

The lower your pulse rate – the FITTER YOU

ARE!

Where to find the valves in the heart

http://www.kscience.co.uk/animations/heart.swf

The treatment for faulty valves

Mechanical valve

Pig tissue valve

Heart Valves

http://www.kscience.co.uk/animations/heart.swf

• The heart has 4 valves.

• Valves help toPREVENT THE BACKFLOW OF BLOOD.

• They make sure the blood flows in one direction.

Valves are like gates which open to let blood through and close to make sure it doesn’t flow backwards.

Open Valves

Closed Valves

The Heart Valves

• There are ______ valves inside the heart

• Each valves ______ to allow ______ to flow in the correct direction

• The valve ______to stop blood from flowing backwards in the ______ direction

• Doctors use a _________to listen to a patient’s heartbeat and check that the ______ are working normally

• If valves do not work properly, a person would not be ______ and have less ______ than they need

• Faulty valves can be ________ with artificial ones.

Watch this video!

• http://www.bbc.co.uk/learningzone/clips/anatomy-and-physiology-of-the-heart/5367.html

2 minutes – think/pair/share

1. Identify ways in which you can keep your heart healthy

2. Why do you need to do this?

• http://www.bbc.co.uk/learningzone/clips/heart-function-and-health/1466.html

• http://www.bbc.co.uk/learningzone/clips/coronary-heart-disease/5700.html

Task

• Copy the title below and use the word bank to below to explain how and whyyou must keep your heart healthy

WORD BANK:

Exercise / salt / blood pressure / high / fatty foods / build up / narrows / regular / coronary

heart disease / heart attack

How to keep your heart healthy

• The blood vessels are tubes which carry blood around the body.

• They are:

Blood vessels

3 types of Blood Vessels

Arteries Veins Capillaries

FUNCTION Carries blood away from the heart

Carries blood to the heart

Site of gas exchange withcells

Description of wall

Valves present?

Pulse present?

The ARTERY

thick muscle and

elastic fibres

Arteries carry blood away from the heart.

The artery has a

pulse

the thick muscle can

contract to push

the blood along.

The VEIN

Veins carry blood towards the heart.

thin muscle and elastic fibres

veins have valves which act to stop the blood from going in the wrong direction.

body muscles surround the veins so that when they contract to move the body, they also squeeze the veins and push the blood along the vessel.

The CAPILLARY

Capillaries link Arteries with Veins

the wall of a capillaryis only one cell thick

they exchange materials between the blood and other body cells.

The exchange of materials between the blood and the body can only occur through capillaries.

• Arteries have a thick muscular wall, veins have a thin muscular wall and capillaries are only 1 cell thick (VERY thin)

• Veins are the onlyvessel to contains valves

Arteries, Capillaries and Veins

Arteries, veins and capillariesArteries carry high pressure blood away from the heart.

They have smaller lumen and no valves.

Veins carry low pressure blood back to the heart. They have thinner, less elastic walls and

have valves to prevent backflow of blood.

Capillaries have thin walls (one cell thick) to allow

glucose and oxygen to pass through. Also used to

connect arteries to veins.

Arteries Veins Capillaries

FUNCTION Carries blood away from the heart

Carries blood to the heart

Exchanges gases and materials (like glucose) between blood and body cells

Description of wall

Valves present?

Pulse present?

3 types of Blood Vessels

THICK muscular

wall

THIN muscular

wall

NO YES

VERY THIN wall - only 1 cell thick

NO

YES NO NO

3 blood vessels

Average pulse rates

Age Pulse (beats per minute)

Newborn 130

3 months 140

6 months 130

1 year 120

2 years 115

3 years 100

4 years 100

6 years 100

8 years 90

12 years 85

Adult 70

Collect graphpaper and turn thisinformation into a

bar graph

You know it isBAR graph becauseyou have one set

of numbers and oneset of words

The words will goat the bottomof the graph

Age (months and years)

Puls

e (b

pm)

3 m

onth

s

6 m

onth

s

9 m

onth

s

10

20

30

0

New

bor

n