2011.4.1Cardiovascular System V2

7/28/2019 2011.4.1Cardiovascular System V2

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Cardiovascular


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The circulatory system is also referred to asthe cardiovascular or vascular system

Controls the steady circulation of the blood through

the body by the heart and blood vessels (veins andarteries )

It consists of the heart, arteries, veins and capillariesfor the distribution of blood throughout the body


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The Cardiovascular system works

well with:

The Respiratory system

The Lymphatic system


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Main functions

Transportation

Transport oxygen, nutritive materials, water to cells, carbon dioxideand other waste products to the organs of excretion.

Protection Protect through the action of white blood cells and through the

production and transportation of antibodies.

Maintenance

Maintain constant internal environment of the body.

Regulation Regulate body temperature, water and other substances in the body

and co-ordinate the body through the distribution of hormonesfrom endocrine system to the cells which they influence.

pg 28


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Systemic and Pulmonary

circulation

With each beat, the heart pumps blood into two closedcircuits;

SYSTEMIC and PULMONARY (lungs)


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SYSTEMIC SYSTEMIC

LEFT SIDE OF THE HEART

RECEIVES FRESHLY OXYGENATED BLOOD FROM THE LUNGS.

Left ventricle ejects blood into the aorta and the blood then

flows into separate streams distributing all organsthroughout the body except for the air sacs in the lungs.


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PULMONARY PULMONARY;

RIGHT SIDE OF THE HEART

The pump for pulmonary circulation RECEIVES DEOXYGENATED BLOOD returning from the systematic

circulation.

Blood ejected from the right ventricle flows into the pulmonarytrunk, which branches into pulmonary arteries that carries blood tothe left and right lungs.

Blood unloads Carbon Dioxide (CO2) which is exhaled and picks upOxygen (O).

The freshly oxygenated blood then blows into pulmonary veins andreturns to the left atrium.


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The

HeartA muscular, coneshaped organthat keeps theblood moving

within thecirculatory

system

It is often

referred to as thebodys pump

It is enclosed by amembrane

known as the

pericardium


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The heart Is a muscle (cardiac

muscle)which is approxthe size of a clenched

fist. It weighs approx 250g

and is located in thechest cavity

In a normal resting statethe heart beats 72 to 80times per minute

The heart has fourchambers.

Two atria ( upper chambers )

right atrium & left atrium

Two ventricles (lower chambers)

Right ventricle & left

ventricle

The sides of the heart aredivided by the septum


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Valves between the chambers allow the blood to flowin only one direction.

Pulmonary circulation TO THE LUNGS Deoxygenated blood enters the heart from 3

sources Superior and Inferior vena cava and thecoronary sinus to the right atrium.


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PULMONARY CIRCULATION Blood passes from the RIGHT ATRIUM into the

RIGHT VENTRICLE through a valve called theTRICUSPID VALVE 3 point.

Right Ventricle blood passes from the Right Ventricle

through the pulmonary semi lunar into a large arterycalled the PULMONARY TRUNK which divides intothe right and left pulmonary arteries.


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Systemic circulation FROM THE LUNGS

Oxygen rich blood FLOWS from the lungs viapulmonary veins and returns to the LEFT ATRIUM andthen passes through the bicuspid valve into the leftventricle where it is ejected into the AORTA.


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Systole

Systole; the term systole means contraction

Is when the atria or the ventricles of the heart contract.


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Diastole Diastole means dilation or expansion.

Is when the atria or ventricles of the heart relax,expand or dilate.


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The difference between systole

and diastole

Systole- Contraction of the atria or ventricles

Diastole- Expansion or relaxation of atria or ventricles


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Blood vesselsThe blood vessels transport the blood around the body

and can be divided into three main types:

1.Arteries2. Capillaries

3. Veins


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Blood vesselsArteries Veins

Are thick-walled, muscular,flexible tubes.

Carry oxygenated bloodaway from the heart to thecapillaries (except pulmonaryartery).

The largest artery in the bodyis the aorta

Do not have a valves.

Have a pulse

Are thin-walled bloodvessels that are less elastic

than arteries.

Carry blood containing wasteproducts from the variouscapillaries towards the heart

(except pulmonary veins). Havevalves to prevent back

flow

Do not have a pulse.


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Capillaries Capillaries are minute, thin walled blood vessels that

connect the smaller arteries to the veins.

Arterioles the smallest arteries. Venules the smallest veins

They bring nutrients to the cells and carry away wastematerials

They connect arterioles to venules

Capillaries have no valves.


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Blood Adult human body contains 4-5 litres of blood 1/20 of the

bodys weight.

Blood is approx. 80% water.

It is a sticky & salty substance, with a normal temperature of 36degree Celsius .

Blood consists of blood cells (45%) and blood plasma (55%).

Blood cells include: red blood cells

white blood cells Platelets

Plasma

haemoglobin.


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Blood cells

Red blood cells White blood cells Also called Red corpuscles

or Erythrocytes.

Are produced in the red bonemarrow.

Contain haemoglobin, acomplex iron protein thatgives the blood its bright redcolour.

Main function is to carryoxygen to body cells andtissues.

Women have slightly lowerhaemoglobin levels that men.

Also called Whitecorpuscles or Leukocytes.

Produced in bone marrow,lymph tissue and spleen.

Main function is fightinfection by absorbing anddigesting disease-causingorganisms.

Some white blood cellsproduce antibodies.Antibodies are proteins thatattach to foreign materials

which enter the body.


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Platelets Plasma

Also known as Thrombocytes Platelets are the blood parts that

form clots to stop bleeding. When an injury tears open a

blood vessel, platelets stick tothe vessel wall around theopening.

Fibrinogen then sticks to the

platelets forming a tangled webof thin fibres. The fibres catchmore platelets and blood cells,forming a clot. The clot plugsthe opening and stops thebleeding.

Consists of 90% of water and10% dissolved materials.

Clear yellowish fluid thatcarries nutrients to the body.

Contains Fibrinogen, theprotein that assists plateletsin blood clotting.

Main function is to carryfood and secretions to thecells and to remove carbondioxide away from the cells.

Blood Cells


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Red blood cells White blood cells


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Platelets and Fibrinogen


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Blood

Plasma (55%) Blood cells

(45%)

Water (90%) Dissolved substances (10%) Red cells White

cells

Platelets

Proteins Mineral salts Food Materials (glucose,

amino acids, fatty acids,

glycerol)

Waste products (carbon

dioxide, urea)

Hormones

Antibodies Hormone

Clotting proteins

Composition of Blood


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Homework/revision1. Name the functions of the heart.2. What are the 4 chambers of the heart called?3. What is Systole and Diastole?4. Which side of the heart does de-oxygenated blood flow into?5. Draw a simple flow chart of the blood circulation from when it

enters into the right Atrium6. How is the blood carried around the body? Name 3 blood

vessels7. Name 2 differences between Arteries and Veins8. What is blood made up of?9. What is the percentage of blood cells to plasma?10. What does plasma consist of? Name the percentages and the

components of plasma

Documents

2011.4.1Cardiovascular System V2