Biology 2201 Unit 3

Circulatory System Disorders P 323 - 328

Circulatory System Disorders

1. Hypertension

2. Atherosclerosis

3. Arteriosclerosis

4. Coronary Blockage

1. Hypertension • Called “High Blood Pressure”

• Known as the “silent killer”

– Condition where a person has a chronically elevated blood pressure. • Ex: 145/90 = high blood pressure.

• Causes

– Diet high in salt. • Causes blood to retain more water thus

increasing pressure. – Diet high in Cholesterol

• Arteries can become clogged resulting in high blood pressure.

– Lack of exercise (inactivity) – Stress – Caffeine, Nicotine, Alcohol – Age (as you get older blood pressure increases) – Heredity (runs in the family) – Smoking – Obesity

2. Atherosclerosis

• A narrowing of the arteries. • This causes a reduction in flow of blood to and from heart. • Cause • Buildup of cholesterol plaques on the inside of arteries.

• Atherosclerosis can Cause:

a. Heart attack

b. Stroke

Cholesterol Plaque

3. Arteriosclerosis • “Hardening of arteries”.

– Arteries lose their elasticity.

– Arteries narrow and become thick.

– Blood flow is reduced.

– Blood clots (thrombus) can form and cause strokes or heart attacks when the break off and move to the heart or brain.

– A moving blood clot is called an Embolism.

• Cause

– Buildup of cholesterol plaques under the lining of arteries over several years.

3. Stroke

• Stroke: Loss of blood flow to brain tissue causing cell death.

• Causes: Any one of the above and others

• Effect on Body: loss of brain function and/or motor control (paralysis), death.

4. Coronary Blockage • A blockage of the Coronary Artery of the Heart.

– Caused by Cholesterol buildup in the coronary artery.

– Reduces blood flow to the heart resulting in a heart attack.

Treatments for Circulatory Disorders

1. Clot Prevention medications

2. Clot Busting Medications

3. Angioplasty

4. Coronary Bypass

1. Clot Prevention Medications

Aspirin

– Works by keeping platelets from “sticking” together. This prevents blood clots.

2. Clot Busting Drugs

• Also known as thrombolytic drugs.

– Thrombus = Blood Clot

1. t-PA (Tissue Plasminogen activator)

• Converts plasminogen into Plasmin.

• Plasmin “dissolves” blood clots.

• Used on patients suffering a “stroke” or heart attack because of a clot.

• Works best if used within first 3 hours of stroke.

3. Angioplasty • Sometimes called “Balloon Angioplasty”.

– Used to treat a narrow or clogged artery.

– The artery is “opened” up by stretching it.

• How it works

– Doctor inserts a tiny needle with a balloon on the end into the clogged artery.

– The balloon is inflated. The artery is stretched.

– The balloon is deflated and removed when procedure completed.

Stents

• A “Stent” is a wire mesh inserted in a narrow artery that helps to keep it open.

4. Coronary Bypass

• A surgery performed to “go around” or bypass a blocked artery near the heart.

• A new path is created around the blockage.

• A healthy blood vessel is attached at one end “before” the blockage and at another end “after” the blockage.

• Blood flows around the blockage.

A triple Bypass surgery

Homework

• Read pages 324 – 329 of MHR

• Answer Q # 4 on page 328

• Answer Q # 10 on page 329