btec national sport unit 5 the body in action the cardiovascular system dale embleton the body in...

BTEC NATIONAL SportUNIT 5 THE BODY IN ACTION

The Cardiovascular System

Dale Embleton

THE BODY IN ACTION


The cardiovascular system

What you need to learn …• The structure of the cardiovascular system

– The blood– The heart and valves– The blood vessels

• The functions of the cardiovascular system– Heart contraction– Cardiac cycle– Pathway of blood




The cardiovascular system consists of the heart, blood and blood vessels, and is also referred to as the circulatory system of the body.



The circulatory system consists of three parts• The blood – in which materials are carried to and

from the tissues• The heart – the muscular pump that pushes

blood to the working muscles• The blood vessels (venules, veins, arteries,

arterioles and capillaries) – the routes by which the blood travels to and through the tissues, and back to the heart



Key points

• Arteries carry oxygenated blood away from the heart

• Veins carry de-oxygenated blood back to the heart

• Capillaries connect veins and arteries


STRUCTURE


The cardiovascular system: BLOOD

Functions of blood• Carries nutrient substances absorbed from the intestine

to the tissues• Carries oxygen to the tissues• Carries waste products from the tissues to the kidneys

and liver• Returns carbon dioxide from the tissues to the lungs• Regulates body temperature• Distributes hormones and other agents • Fights bacterial infection through the white cells and

antibodies


The cardiovascular system: BLOOD

• Plasma– Liquid

• Erythrocytes– O2 and CO2

• Leucocytes– Immune

• Platelets– Blood clots

Monocyte

LymphocytePlatelets

Doughnut-shaped

red blood cells

Granulocyte or phagocyte

with lobed nucleus

See Handout and complete worksheet 45

A closer look at the structure of blood …


The cardiovascular system: HEART

The heart• Situated in the left-hand side of the chest• Muscular pump whose purpose is to drive the

blood into and through the arteries, to deliver it to the tissues and working muscles

• Considered as two separate pumps• Two chambers on the right, and two chambers

on the left side– What are they?



Structure of the Heart• Surrounded by sac known as the

pericardium, which prevents friction as the heart beats.

• Heart wall is made of:– Epicardium (outer layer)– Myocardium (strong middle layer)– Endocardium (inner layer)

• Right separated from left by Septum



The structure of the heart and blood vessels

Task

1. In pairs research and complete work sheets 42, 43 and 44



The heart functions (continued)

• Right atrium receives de-oxygenated blood from the body

• Right ventricle pumps it to the lungs

• Left atrium receives oxygenated blood from the lungs

• Left ventricle pumps oxygenated blood to the body



Lungs

Body(non-lung tissues)

Pulmonaryvein

Leftheartpump

AortaVena cava

Pulmonaryartery

Pulmonary circulation

Systemic circulation

Rightheartpump

Circulation of Blood



The heart valves• The heart has 4 valves• Choose 1• Using books/web, draw these valves

– Identify their location – What is their function?– When will they open and close?

• Present to the class


The Cardiovascular System: BLOOD VESSELS

• Complicated network of blood vessels

• 96 kilometres of arteries, arterioles, capillaries, venules and veins.

• Their structure relates to their function

• Next two slides and handout have more information on the blood vessels

• Page 218-19


The cardiovascular system: BLOOD VESSELS

Elasticfibres

Musclelayer

Roundlumen

Lining

Ovallumen

Fibroustissue

(a) Artery (b) Vein (c) Capillary

Singlelayer

of cells

Redcells

1. 3 groups

2. Explain the structure of these blood vessels using a diagram and labels

SRUCTURE


The cardiovascular system: BLOOD VESSELS

Main blood vessels and their functions• Aorta – Main artery of the body carrying oxygenated

blood to the body tissues• Pulmonary artery – Carries deoxygenated blood from

the lungs back to the heart• Superior vena cava – Receives deoxygenated blood

from the upper body to empty into the right atrium of the heart

• Inferior vena cava – Receives deoxygenated blood from the lower body to empty into the right atrium of the heart

See Handout for further information and complete worksheet 45


FUNCTIONSOF THE

CARDIOVASCULAR SYSTEM


THE HEART’S CONTRACTION

• Contraction causes blood to move• The SA (sinoatrial) node is the pacemaker

– Endocardial of right atrium

• 60-100 beats per minute• AV node (septal wall of right atria) slows

impulse between the atria and ventricles to allow time for contracting atria to fill ventricles.– What would happen otherwise?


CARDIAC CYCLE

• “The period from the beginning of one heart beat to the beginning of the next”

• Two distinct phases– Systole– diastole

• Using textbook handout, complete Worksheet 47,question 1 and 2


• Cardiac output = rate at which blood leaves the heart

• Stroke volume = volume of blood that leaves the heart with each beat

• CO = SV X HR

• Complete worksheet 47 and 48


PATHWAY OF BLOOD

• There are 3 modes of circulation that transports blood through the body.– Pulmonary– Systemic– Coronary

• Summarise these in a few sentences on your Handout

• Now complete worksheets 46


PATHWAY OF BLOOD…cont….

Blood Pressure

• The blood is always under pressure

• Without it where would the blood in your body be?

• It therefore enables the blood to gravitate upwards in the body and through capillaries.

• Worksheet 49


THE PULSE

• Where can you find a pulse?

• Why?

• What is it a measure of?

• Healthy adults = ______ - _______ bpm


BLOOD POOLING

• This is where blood is not returned to the heart and lungs for re-oxygenation.

• Fainting may occur………– Why?......what has this got to do with gravity?

• Blood may pool in your cardiovascular system– Low blood pressure– Terminating activity without a recovery phase.



What you need to learn …• The structure of the cardiovascular system

– The blood– The heart and valves– The blood vessels

• The functions of the cardiovascular system– Heart contraction– Cardiac cycle– Pathway of blood

btec national sport unit 5 the body in action the cardiovascular system dale embleton the body in...

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