PP 2 Circulation 1

Transport system to carry oxygen and nutrients to all of the cells in the body.

Takes away waste products (like CO2)Heart pumps blood continuouslyUses a network of blood vessels (to the cells /

at the cells / back to the heart)

(In diagrams – red = oxygenated blood – blood that has oxygen & blue = deoxygenated blood – blood that is carrying CO2))

Circulatory System

From the Heart – pumps blood to (at the same time):

1. Aorta – an artery that carries blood (oxygenated) out of the heart and then through smaller arteries to the rest of the body.

2. Pulmonary artery (actually a vein)- carries (deoxygenated) blood to the lungs.

The process

To the heart from the body at the same time:1. Pulmonary vein: (actually an artery)

carries oxygenated blood to the heart from the lungs.

2. Vena Cava – carries the rest of the deoxygenated blood from the body to the heart.

The process

Double circulatory system – If you follow 1 blood cell – you will notice that it is in the heart 2 times. One as oxygenated blood and the other as deoxygenated blood in 1 cycle.

Oxygenated blood gives O2 to the cells and becomes deoxygenated (has CO2) when it comes back to the heart

O2 is needed for cell respiration

The process continued

The heat has valves that allow the blood to flow only in 1 direction.

The veins also have valves that stop the blood to flow backwards.

Blood flows out of the heart in Arteries (like the Aorta) under high pressure

Blood flows back to the heart in Veins (Vena Cava) under low pressure.

One way flow / blood pressure

Blood moving out of the heart is under high pressure.

As it gets further away from the heart the pressure reduces.

When pressure is high – the movement of the blood is fast

When pressure is low – movement of the blood is slower

Double Circulation

Structure of the heart

Aorta

RightAtrium

LeftAtrium

RightVentricle

LeftVentricleSeptum

Vena Cava

Tricuspid Valve

Semi Lunar valve

Bicuspid Valve

Pulmonary Vein

Pulmonary Artery

Heart is made of cardiac muscles that contract and relax

60 heart beats per minute (on an average)Energy for the heart comes from fatty acids

rather than glucose (glucose is for the rest of the body)

Fatty acids are brought to the heart via Coronary arteries (that supplies nutrients to the heart)

Function of the heart (muscular contactions /Working of the valves)

contractionRight Side:Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.

Left Side:The pulmonary vein empties oxygen-rich blood, from the lungs into the left atrium.

Heart valves: The tricuspid and bicuspid valves stay shut until the right and left atriums are full. The pressure of the blood being full in the atrial chambers pushes the valves open and then the ventricles fill up.

contraction Right Side:Blood flows from your right atrium into your right ventricle through the open tricuspid valve. When the ventricles are full, the tricuspid valve shuts. This prevents blood from flowing backward into the atria while the ventricles contract (squeeze).Left Side:Blood flows from your left atrium into your left ventricle through the open mitral valve. When the ventricles are full, the mitral valve shuts. This prevents blood from flowing backward into the atria while the ventricles contract (squeeze).Heart Valves: The tricuspid and bicuspid valves stay open till the ventricles are full.

When the ventricles contract, the pressure of the blood pushing against the bicuspid and tricuspid valves force it to shut. This allows the atrial chambers to fill again as Blood is coming in via the Vena cava and the pulmonary vein.

contraction

Right Side:Blood leaves the heart through the semilunar valve, into the pulmonary artery and to the lungs.Left Side:Blood leaves the heart through the aortic valve, into the aorta and to the body.This pattern is repeated, causing blood to flow continuously to the heart, lungs and body.

When the ventricles are full, they force the Semilunar valves to open. This forces the blood into the Aorta (from the left ventricle) and into the Pulmonary Artery (from the right ventricle).

Coronary Arteries -Deliver blood to muscles of the heart

Disease – these arteries are blocked or damaged and therefore can not supply the heart with the nutrients it needs.

How?- Cholesterol builds up in the walls partly

blocking the arteriesÞWalls of the arteries – less elastic (unable to

expand and contract as normal).

Coronary Heart Disease

Þ Increases the chances of blood clot near the blocked area. The blood clot can move into a narrow area of the artery.

When the heart is unable to get blood and nutrients due to this it stops functioning properly.

This is a heart attack.

contiued

Heart viewed from the front of the Body with Pericardium Removed

Aorta

Left Pulmonary Artery

Superior VenaCava

Right PulmonaryArtery

Left Pulmonary veins

Coronary Artery

Coronary VeinAnterior VenaCava

Causes Preventative Measures• diet in high saturated fats cause cholesterol to be deposited in the coronary arteries•Too much salt in diet•Smoking•Stress

• regular exercise• well balanced diet• less salt• no smoking

Causes and prevetative measures