10.8 Circulatory System Disorders

Question 1

What is atherosclerosis?

Answer 1

an accumulation of soft masses of fatty materials, particularly cholesterol, beneath the inner linings of arteries

this is called plaque

Question 2

What does plaque tend to do?

Answer 2

protrude into the lumen of the vessel and interfere with the flow of blood

Question 3

When does atherosclerosis begin in most instances?

Answer 3

begins in early adulthood and develops progressively through middle age, but symptoms may not appear until an individual is 50 years or older

Question 4

What can plaque cause platelets to do?

Answer 4

adhere to the irregular arterial wall, forming a clot

clot remains stationary: THROMBUS
clot dislodges and moves along with the blood: EMBOLUS

Question 5

What is thromboembolism?

Answer 5

a clot that has been carried in the bloodstream but is now lodged in a blood vessel

MUST BE TREATED OR SERIOUS COMPLICATIONS CAN ARISE

Question 6

What is hypertension?

Answer 6

high blood pressure

Question 7

What is considered abnormally high blood pressure under the age of 45? In older people?

Answer 7

under 45: 130/90 mm Hg

older: 140/95 mm Hg

Question 8

Why is hypertension sometimes called “the silent killer”?

Answer 8

it may not be detected until a stroke or heart attack occurs

Question 9

When does hypertension most often occur?

Answer 9

secondary to a narrowing of a person’s arteries from atherosclerosis

Question 10

What does forcing blood through narrowed arteries over time create?

Answer 10

additional pressure on the circulatory system that can damage the blood vessels, heart, and other organs

Question 11

What medications are used to treat hypertension?

Answer 11

diuretics, vasodilators, and various drugs that improve heart function

Question 12

What do diuretics do?

Answer 12

reduce the blood volume by increasing urine output

Question 13

What do vasodilators do?

Answer 13

dilate the blood vessels

Question 14

How does heart valve disease occur?

Answer 14

• heart valves can be malformed at birth
• more commonly, they degenerate due to age or infections to the point where they no longer prevent the backflow of blood

Question 15

What is the most common infection that leads to heart valve disease?

Answer 15

a narrowing (stenosis) of the aortic valve opening is the most common, followed by mitral valve prolapse

Question 16

What is mitral valve prolapse?

Answer 16

abnormally thickened “leaflets” of the mitral valve protrude back into the left ventricle

Question 17

How can faulty valves be repaired?

Answer 17

• open-heart surgery
• replaced, using either artificial valves or valves removed from an animal (usually a pig) or deceased human
• surgeons can thread a compact artificial valve through an artery in the leg, thus avoiding open-heart surgery

Question 18

How does a stroke occur?

Answer 18

when an arteriole in the brain bursts or is blocked by an embolus

lac of oxygen causes a portion of the brain to die, and paralysis or death can result

Question 19

How can a person be forewarned of a stroke?

Answer 19

by a feeling of numbness in the hands or the face, difficulty in speaking, temporary blindness in one eye

Question 20

What is a stroke also called?

Answer 20

cerebrovascular accident

Question 21

What is angina pectoris?

Answer 21

a squeezing or burning sensation in the chest when a coronary artery becomes partially blocked

Question 22

What happens when a coronary artery is completely blocked?

Answer 22

a portion of the heart muscle dies due to lack of oxygen, and a myocardial infraction (HEART ATTACK) occurs

Question 23

What drugs can help treat angina pectoris?

Answer 23

nitroglycerin or related drugs dilate blood vessels and help relieve pain

Question 24

What is an aneurysm?

Answer 24

the ballooning of a blood vessel, most often the abdominal aorta or the arteries leading to the brain

Question 25

How can an aneurysm develop?

Answer 25

atherosclerosis and hypertension can weaken the wall of an artery to the point that an aneurysm develops

Question 26

How is it possible to replace a damaged or diseased portion of a vessel, such as an artery?

Answer 26

with a synthetic graft wireless sensors that can be implanted along with these grafts, to help doctors monitor changes in pressure that may signal an aneurysm that is about to burst, are being developed

Question 27

What is coronary bypass surgery?

Answer 27

common way to treat an obstructed coronary artery surgeon usually takes a segment from another blood vessel and stitches one end to the aorta and the other end to a coronary artery past the point of obstruction

Question 28

What if veins are used instead of arteries in coronary bypass surgery?

Answer 28

they must be placed in reverse orientation due to the presence of valves

Question 29

What is still common after successful coronary bypass surgery with veins?

Answer 29

common for blockages to recur in the transplanted veins within 5-7 years

Question 30

How can heart muscle that has been damaged by a heart attack be regenerated?

Answer 30

using stem cells studies show that stem cells injected directly into the damaged heart muscle will differentiate into new heart muscle cells, as well as new blood vessels

Question 31

How did scientists grow a human heart?

Answer 31

starting with a cadaver heart, removing the cardiac muscle cells, then exposing the "scaffold" of blood vessels and connective tissues to human stem cells

Question 32

Why has the amount of patients receiving bypass surgery decreased?

Answer 32

increased usage of angioplasty and stent placement

Question 33

What happens with angioplasty?

Answer 33

a cardiologist threads a catheter into an artery in the groin or upper part of the arm and guides it through a major blood vessel toward the heart when the tube arrives at the region of plaque in an artery, a balloon attached to the end of the tube is inflated, forcing the vessel to open, followed by removal of the tube

Question 34

Why might the artery part of angioplasty not always remain open?

Answer 34

the trauma can cause smooth muscle cells in the wall of the artery to proliferate and close it

Question 35

What is the form of angioplasty more often used?

Answer 35

once a cylinder of expandable metal mesh called a stent is in place, a balloon inside the stent is inflated, expanding it, and locking it in place

Question 36

What are the most common types of stents implanted in patients' arteries?

Answer 36

drug-eluting stents, which are coated with medications designed to inhibit inflammation and scar formation

Question 37

What is tissue plasminogen activator?

Answer 37

medical treatment for thromboembolism this drug converts plasminogen into plasmin

Question 38

What is plasmin?

Answer 38

an enzyme that dissolves blood clots

Question 39

What is tPSA also being used for?

Answer 39

thrombolytic stroke patients, but with limited success because some patients experience life-threatening bleeding in the brain

Question 40

What is aspirin for and what does it do?

Answer 40

people who have symptoms of angina or stroke - reduces the stickiness of platelets and thereby lowers the probability that a clot will form - protects against first heart attacks, but there is no clear support for taking Aspirin everyday to prevent strokes in symptom-free people some physicians recommend taking a low dosage of Aspiring everyday

Question 41

What can help patients waiting for a heart transplant?

Answer 41

a left ventricular assist device implanted in the abdomen - a tube passes blood from the left ventricle to the device, which pumps it to the aorta - a cable passes the device through the skin to an external battery the patient totes around

Question 42

What is the AbioCor?

Answer 42

a total artificial heart - an internal battery and controller regulate the pumping speed, and an external battery powers the device by passing electricity through the skin - a rotating centrifugal pump moves silicon hydraulic fluid between left and right sacs to force blood out of the heart into the pulmonary trunk and the aorta - exterior is made of mainly titanium, but the valves and membranes inside the ventricles are made of plastic, which has held up in testing to beating 100,000 times a day for years