1. Circulatory System Disorders
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Circulatory System Disorders
Circulatory system disorders are also known as cardiovascular disease (CVD). CVD is the leading cause of death in most Western countries
Examples of CVD include:
Atherosclerosis
Hypertension
Heart Valve Disease
Stroke, Heart Attack, and Aneurysm
North American diseases
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2. Atherosclerosis UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Atherosclerosis
atherosclerosis: an accumulation of soft masses of fatty materials, particularly cholesterol, beneath the inner linings of arteries
accumulation of soft masses of fatty materials (e.g., cholesterol) beneath the inner linings of arteries.
Deposits of these materials are called plaque
Plaque narrows arteries by protruding into the blood vessel; this results in restricted blood flow
Plaque can also cause platelets to adhere to the arterial wall, forming a clot
If the clot remains stationary, it is called a thrombus
If the clot dislodges, it is called an embolus
Thromboembolism is a clot that has been carried in the blood and has become lodged in a blood vessel
Figure 10B Coronary arteries and plaque. Atherosclerotic plaque is an irregular accumulation of cholesterol and fat. When plaque is present in a coronary artery, a heart attack is more likely to occur because of restricted blood flow.
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3. Atherosclerosis UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Atherosclerosis
accumulation of soft masses of fatty materials (e.g., cholesterol) beneath the inner linings of arteries.
Deposits of these materials are called plaque
Plaque narrows arteries by protruding into the blood vessel; this results in restricted blood flow
Plaque can also cause platelets to adhere to the arterial wall, forming a clot
If the clot remains stationary, it is called a thrombus
If the clot dislodges, it is called an embolus
Thromboembolism is a clot that has been carried in the blood and has become lodged in a blood vessel
atherosclerosis: an accumulation of soft masses of fatty materials, particularly cholesterol, beneath the inner linings of arteries
accumulation of soft masses of fatty materials (e.g., cholesterol) beneath the inner linings of arteries.
Deposits of these materials are called plaque
Plaque narrows arteries by protruding into the blood vessel; this results in restricted blood flow
Plaque can also cause platelets to adhere to the arterial wall, forming a clot
If the clot remains stationary, it is called a thrombus
If the clot dislodges, it is called an embolus
Thromboembolism is a clot that has been carried in the blood and has become lodged in a blood vessel
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4. Hypertension UNIT B Hypertension is high blood pressure.
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Hypertension
Hypertension is high blood pressure.
Under the age of 45 years, blood pressure above 130/90 mm Hg is considered abnormally high
Called “the silent killer” because it may not be detected until a stroke or heart attack occurs
Occurs secondary to a narrowing of arteries due to atherosclerosis
Narrowed arteries cause an increase in blood pressure, since more force is needed to move blood through the blood vessels
Treatment involves vasodilators (which dilate blood vessels) and diuretics (which decrease blood volume by increasing urine)
Two genes assoc: angiotension- plasma protein covereted to vascoeonstricotr
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5. Heart Valve Disease UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Heart Valve Disease
Heart valve disorders result in the backflow of blood, and range from mild to severe.
Heart valves can be malformed at birth, or they can degenerate due to age or infections
Result from narrowing (stenosis) of the aortic valve opening, or from mitral valve prolapse (abnormally thickened leaflets of the mitral valve protrude into the left ventricle)
Treatment involves repair of faulty valves in open-heart surgery or replacement with artificial valves or valves from an animal or deceased human
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6. Stroke, Heart Attack, Aneurysm
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Stroke, Heart Attack, Aneurysm
Stroke
Occurs when an arteriole in the brain bursts or is blocked by an embolus (a clot that has been dislodged)
Results in lack of oxygen (due to impaired blood flow) to the brain, causing a portion of the brain to die
Paralysis or death can result
Symptoms of stroke include numbness in the hands or face, difficulty speaking, or temporary blindness
stroke: a cerebrovascular accident resulting when an arteriole in the brain bursts or is blocked by an embolus
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7. UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Heart Attack
When a coronary artery becomes partially blocked, angina pectoris occurs, resulting in a squeezing or burning sensation in the chest
When a coronary artery is completely blocked, a portion of the heart muscle dies due to lack of oxygen, and a heart attack (myocardial infarction) occurs
Treatment includes vasodilators (nitroglycerin) to dilate blood vessels
angina pectoris: occurs when a coronary artery becomes partially blocked; characterized by a squeezing or burning sensation in the chest
heart attack: occurs when a coronary artery is completely blocked, causing a portion of the heart muscle to die due to lack of oxygen; also called a myocardial infarction
Nitroglycerin is a vasodilator, a medicine that opens blood vessels to improve blood flow. It is used to treat angina symptoms, such as chest pain or pressure, that happens when there is not enough blood flowing to the heart.
Angina – chest pain
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8. UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Aneurysm
Occurs when there is a ballooning of a blood vessel, most often the abdominal aorta or the arteries leading to the brain
Atherosclerosis and hypertension can weaken the wall of the artery to the point that an aneurysm develops
If the aorta bursts, about 50% of victims die before reaching the hospital
Treatment involves replacing the damaged or diseased portion of the vessel with a synthetic graft
aneurysm: the ballooning of a blood vessel, most often the abdominal aorta or the arteries leading to the brain
Heart Attack, stroke and aneurysm are Assoc with atherosclerosis and hypertension
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9. Treatment for Cardiovascular Disorders
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Treatment for Cardiovascular Disorders
Coronary Bypass Operations
Involves grafting arteries to bypass an obstructed coronary artery
A segment from another blood vessel in the body is stitched to one end of the aorta; the other end is stitched to a coronary artery past the point of obstruction
Figure Bypassing blocked coronary arteries. This is a 3-D scan of the heart of a patient who received a triple bypass operation. The surgeon has bypassed two blocked arteries using vessels removed from another part of the body and used an existing artery that branches off the left subclavian artery to bypass a third blocked artery.
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10. UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Stem Cells
Stem cells may be used to regenerate heart muscle that has been damaged by a heart attack
Stem cells injected directly into the damaged heart muscle of mice and rats differentiated into new heart muscle cells and new blood vessels
A “bioartificial” human heart has been grown by a research group by using cardiac muscle cells from a cadaver as a “scaffold” for human stem cells
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11. Angioplasty involves inserting a catheter into a clogged artery.
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Clearing Clogged Arteries
Angioplasty involves inserting a catheter into a clogged artery.
When the catheter reaches the site of the clogged artery, a balloon is inflated to force the vessel open
A stent is a metal mesh tube that inflates, expands, and locks the balloon into place.
Some stents are coated with medications that inhibit inflammation and scar formation
Figure Angioplasty with stent placement. a. A plastic tube (catheter) is inserted into the coronary artery until it reaches the clogged area. b. A metal stent with a balloon inside it is pushed out the end of the plastic tube into the clogged area c. When the balloon is inflated, the vessel opens, and the stent is left in place to keep the vessel open.
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12. Dissolving Blood Clots
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Dissolving Blood Clots
Thromboembolisms can be treated with tissue plasminogen activator (tPA)
Converts plasminogen to plasmin, an enzyme that dissolves blood clots
Aspirin can be prescribed for individuals with symptoms of angina or stroke
Reduces stickiness of platelets and lowers the probability of clot formation
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13. Heart Transplants and Artificial Hearts
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Heart Transplants and Artificial Hearts
Heart transplants
The need for hearts to transplant is greater than the supply
A left ventricular assist device (LVAD) can be implanted in the abdomen of patients waiting for an implant
A tube passes blood from the left ventricle to the LVAD, which pumps it into the aorta
Figure Human Heart. This human heart being cradled in the hands of a surgeon is about to be transplanted into a person whose own heart no longer functions properly.
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14. Heart Transplants and Artificial Hearts
UNIT B
Chapter 10: Circulatory System and Lymphatic System
Section 10.8
Heart Transplants and Artificial Hearts
Artificial hearts
A total artificial heart (e.g., AbioCor) contains:
An internal battery
A controller (regulates pumping speed)
An external battery (powers the device by passing electricity through the skin)
A pump moves silicon hydraulic fluid between the left and right sacs to force blood out of the heart and into the pulmonary trunk and aorta
Figure A total artificial heart. The AbioCor replacement heart is designed to be implanted within the chest cavity.
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