The Circulatory System

The Circulatory System

Learning Goals

1. I know the structure and function of the circulatory system.

2. I know the diseases and disorders of the circulatory system.

3. I understand the blood flow and parts of the heart.

Circulatory SystemA transport system that has four main functions:

1. Transport oxygen and carbon dioxide to and from the cells of the body

2. Transport nutrients to cells and waste from the cells

3. Transport hormones throughout the body4. Maintain body temperature

Three Main Components

1. The pump – the heart2. Fluid – the blood3. Blood vessels (arteries, veins and capillaries)

THE HEART

• Size of your first• Pumps blood through vessels• 4 chambers (2 atria and 2 ventricles)• Thick muscular walls – The left side of the heart is

more muscular than the right. Why?• Controlled by electric signals from the brainSinoatrial node (SA node) is the pacemaker of the

heart.

BLOODThe Components of Blood:1. Plasma - 55% of the blood volume

- 92% of plasma is water, the rest contains minerals (sugar, protein, fat, salts)

2. Red Blood Cells - has hemoglobin (red) - Carries oxygen to the cells - No nucleus

3. White Blood Cells – Carried to infected tissues to fight bacteria and virus’

4. Platelets – cell fragments (no nucleus) that help clot the blood.

BLOOD VESSELS3 Types:1. Arteries – Largest vessels

- Carry blood away from the heart- Have thick muscular walls* The largest artery is the aorta

2. Veins – Thinner muscular walls- Carry blood back to the heart- Valves to prevent backflow

Blood Vessels Continued3. Capillaries – Smallest blood vessels

- Site of gas exchange between blood and cells (diffusion)

- Connect arteries and veins

Atherosclerosis • Artery wall thickens as a result of the accumulation of fatty

materials such as cholesterol• Caused by damage to the innermost layer of the artery:

- High levels of cholesterol and fat in the blood.- High Blood Pressure- Cigarette Smoke

• Wall thickens artery diameter gets smaller less blood flow decreases oxygen circulation.

• Blood clot can form. If it cuts off oxygen supply to the brain – stroke. If it cuts off oxygen supply to the heart – heart attack.

Varicose Veins• Swollen, twisted and sometimes painful veins filled with

an abnormal collection of blood.• Causes – Valves do not function properly, allowing blood

to stay in the vein. Blood pools and causes swelling. – Standing for a long time can lead to varicose veins. Why?

• Treatment – Avoid standing for too long, raise your legs, wear elastic support pressure stockings.

- Surgery: Vein Stripping removes the varicose veins in the legs. Usually only if severe pain or skin sores. - Sclerotherapy: Medicine is injected into the veins, which make them shrink. Less invasive, improves appearance.

Disease/Disorder

Cause Symptoms/Diagnosis

CORONARY ARTERYDISEASE

-Coronary artery delivers oxygen to heart muscles-Partial blockage of plaque (cholesterol, calcium, etc)-Caused by genetics or poor lifestyle choices

- Symptoms include dizziness, tiredness, burning/pain in chest or arms- Angiogram: fluorescent dye is injected into the bloodstream (X-Ray)

HEART ATTACK

-Coronary arteries become completely blocked (by plaque or blood clot)- Heart muscle cells don’t receive oxygen or nutrients Heart stops pumping and heart tissue starts to die

-Symptoms vary: chest pain, shortness of breath, anxiety, dizziness.-Blood test (specific proteins)- Electrocardiogram (ECG): Measures electrical signals from heart beat

Disease/Disorder

Cause Symptoms/Diagnosis

LEUKEMIA - Bone marrow makes abnormal white blood cells that divide out of control- Can be caused by genetic diseases, radiation, smoking

-Swollen lymph nodes, frequent infections-Diagnosed by blood test and then bone marrow biopsy

ANEMIA -Lack of healthy red blood cells or hemoglobin (iron)- Due to blood loss, destruction or faulty cells.

-Less oxygen transportation causes fatigue- Diagnosed by blood test

• The circulatory system is a transport system that is made up of the blood, the heart, and the blood vessels.

• It’s function is to move oxygen and nutrients to the cells of the body and remove carbon dioxide and wastes.

• Heart disease is the group of conditions that affect the functioning of the heart.

• Angiograms and electrocardiograms are important technologies that help diagnose abnormalities in the circulatory system.

Summary

Homework

• Page 87 #3, 4, 5, 7 and 8

THE CIRCULATORY SYSTEM (Part II)

Learning Goal

1. I understand the blood flow and parts of the heart.

Heart Rate Activity

Heart Rate – The number of beats per minute (bpm)1. Take your resting heart rate (neck next to your

windpipe or wrist). Count the beats for 15 seconds than times that by 4- Should be between 60-100

2. Do jumping jacks for 2 minutes. Take your heart rate again.

Why did we see these results?

Let’s Take a Look at the Blood Flow through the Heart

YouTube clip: Blood Flow through The Heart

http://www.youtube.com/watch?v=Rj_qD0SEGGk