Cuestionario: Understanding Atherosclerosis Formation and Risks — 16 preguntas

1. Which process is primarily involved in the initiation of atherosclerosis related to endothelial dysfunction and LDL oxidation?

A. LDL particles cross the endothelium and become oxidized under it

B. Vasodilation increases, reducing blood flow to the vessel wall

C. Smooth muscle cells migrate from media to the intima

D. Endothelial cells proliferate and form a thickened intima

Answer: (A)

Explicación

The initiation of atherosclerosis involves endothelial dysfunction that allows LDL cholesterol to cross the endothelium and become oxidized beneath it. Oxidized LDL plays a key role in attracting immune cells and promoting lesion formation.

2. At what age do fatty streaks typically begin to form in arteries, according to the revision sheet?

A. 10-20 years old

B. 30-40 years old

C. 50-60 years old

D. 60-70 years old

Answer: (A)

Explicación

Fatty streaks, the earliest lesions in atherosclerosis, typically start forming in individuals aged 10-20 years, establishing the beginning stage of the disease.

3. What is the hallmark feature of foam cells in the development of fatty streaks in atherosclerosis?

A. Platelets adhering to damaged endothelium

B. Macrophages loaded with oxidized LDL

C. Smooth muscle cells accumulating calcium

D. Endothelial cells proliferating rapidly

Answer: (B)

Explicación

Foam cells are macrophages that have ingested oxidized low-density lipoprotein (LDL). They appear as lipid-laden macrophages within the arterial intima and are the hallmark feature of early fatty streaks in atherosclerosis. These foam cells contribute to the formation of fatty streaks, which are the earliest visible lesions in atherogenesis.

4. Which component is primarily responsible for creating the fibrous cap in atherosclerotic plaques?

A. Vascular smooth muscle cells (VSMC)

B. Foam cells

C. Endothelial cells

D. Cholesterol crystals

Answer: (A)

Explicación

VSMCs migrate into the intima and produce collagen, forming the fibrous cap that stabilizes the plaque.

5. Which process best describes the role of vascular smooth muscle cell (VSMC) migration and collagen production in the development of atherosclerotic plaques?

A. VSMC migration induces lipid accumulation and collagen degradation that weaken the plaque

B. VSMC migration causes foam cell formation and collagen production results in plaque erosion

C. VSMC migration allows cells to reach the intima and produce collagen, forming a fibrous cap over the lipid core

D. VSMC migration leads to plaque rupture while collagen production causes plaque stabilization

Answer: (C)

Explicación

VSMC migration is a crucial step in atherogenesis where smooth muscle cells move from the media to the intima, where they produce collagen and other extracellular matrix components. This collagen forms a fibrous cap that stabilizes the plaque, preventing rupture. Therefore, the correct process involves VSMC migration reaching the intima and producing collagen, which contributes to plaque stability.

6. According to the facts provided, which of the following is considered a major risk factor for atherosclerosis?

A. High LDL cholesterol levels

B. Low blood pressure

C. Regular physical activity

D. Adequate sleep

Answer: (A)

Explicación

High LDL cholesterol is a major risk factor because it leads to fatty deposits beneath the endothelium, promoting plaque formation.

7. What is the primary structural feature of a stable atherosclerotic plaque that contributes to its stability?

A. A large necrotic lipid core

B. A thin fibrous cap with lots of lipids

C. High infiltration of macrophages

D. A thick fibrous cap rich in collagen

Answer: (D)

Explicación

A stable atherosclerotic plaque is characterized by a thick fibrous cap that is rich in collagen, which provides mechanical strength and reduces the likelihood of rupture. In contrast, unstable plaques tend to have a thin fibrous cap with a large lipid core and are more prone to rupture leading to thrombosis.

8. What feature primarily distinguishes unstable plaques from stable plaques?

A. Large lipid/necrotic core

B. High collagen content

C. Rich in VSMCs

D. Presence of a fibrous cap

Answer: (A)

Explicación

Unstable plaques are characterized by a large lipid/necrotic core, making them more prone to rupture compared to collagen-rich stable plaques.

9. In the context of plaque rupture and thrombosis, which is most accurately described as a characteristic of unstable plaques?

A. Rich in collagen and smooth muscle cells, making them stable surface coverings

B. Having a thick fibrous cap that prevents rupture

C. Lipid-rich and soft, making them prone to fissuring or rupture

D. Predominantly calcified, reducing the risk of rupture

Answer: (C)

Explicación

Unstable plaques are typically lipid-rich and soft, making them vulnerable to fissuring or rupture. These plaques have a thin fibrous cap and a large necrotic core, which predisposes them to rupture, leading to thrombosis. In contrast, stable plaques usually have a collagen-rich fibrous cap that provides stability and reduces the likelihood of rupture.

10. According to the revision sheet, what percentage of arterial narrowing typically causes symptomatic ischemic disease?

A. Greater than 70-75%

B. Less than 50%

C. Exactly 50%

D. Less than 25%

Answer: (A)

Explicación

Critical stenosis causing symptoms is generally defined as greater than 70-75% narrowing of the artery, impairing blood flow.

11. Which of the following best characterizes a stable atherosclerotic plaque?

A. Plaque prone to rupture due to high lipid content

B. Plaque with significant calcification and necrosis

C. Lipid-rich core with a thin fibrous cap

D. Collagen-rich, fibrous cap that covers a lipid core

Answer: (D)

Explicación

A stable atherosclerotic plaque is characterized by a fibrous cap rich in collagen that covers a core of lipids and necrotic material, making it less prone to rupture. The thick collagen cap provides structural integrity, reducing the risk of fissuring or rupture, unlike unstable plaques that are lipid-rich and have a thin fibrous cap.

12. Which pathological event is most directly responsible for causing thrombosis in atherosclerotic arteries?

A. Plaque rupture exposing the necrotic core

B. Formation of foam cells

C. Endothelial dysfunction without rupture

D. Lipid accumulation in the intima

Answer: (A)

Explicación

Plaque rupture exposes the necrotic core to blood, activating clotting and leading to thrombosis, which can cause vessel occlusion.

13. Which of the following best describes the relationship between critical stenosis and ischemic symptoms?

A. Ischemic symptoms typically occur when arterial stenosis exceeds 70-75% of lumen narrowing.

B. Ischemic symptoms only develop in the presence of unstable plaques, regardless of stenosis severity.

C. Ischemic symptoms are most common when stenosis is less than 50% owing to early plaque formation.

D. Critical stenosis always results in immediate ischemic symptoms regardless of other factors.

Answer: (A)

Explicación

Ischemic symptoms usually manifest when arterial lumen narrowing exceeds 70-75%, as this level of stenosis significantly impairs blood flow. When the stenosis is less severe, collateral circulation or residual flow often prevents symptoms. Therefore, the critical threshold for symptom development is generally in the >70-75% range of vessel narrowing, making option one correct.

14. Which of the following best describes the pathological process leading to angina in coronary artery disease?

A. Formation of occlusive thrombus from a disrupted plaque leading to transient or persistent ischemia

B. Gradual narrowing of coronary arteries due to fibrous tissue proliferation, reducing blood flow during increased activity

C. Sudden rupture of an unstable atheromatous plaque causing immediate vessel occlusion

D. Chronic vasospasm of coronary arteries unrelated to plaque formation

Answer: (A)

Explicación

Angina in coronary artery disease often results from the rupture of an unstable atheromatous plaque, leading to thrombus formation and subsequent obstruction of blood flow. The process typically involves plaque disruption rather than mere gradual narrowing or vasospasm alone. The rupture exposes thrombogenic material, activating clot formation that can suddenly occlude the vessel, causing ischemic chest pain.

15. Which cerebral artery is most commonly involved in large vessel strokes leading to significant neurological deficits?

A. Anterior cerebral artery

B. Basilar artery

C. Middle cerebral artery

D. Posterior cerebral artery

Answer: (C)

Explicación

The middle cerebral artery is the most commonly affected cerebral artery in large vessel strokes, accounting for a significant proportion of ischemic strokes. It supplies large portions of the lateral cerebral cortex, including areas responsible for motor and sensory functions of the face and limbs. Occlusion often leads to contralateral hemiparesis and sensory loss, aphasia if in dominant hemisphere.

16. Which of the following best describes the main pathological process leading to claudication in peripheral artery disease?

A. Infection of arterial walls leading to abscess formation

B. Spasm of peripheral arteries causing transient ischemia

C. Sudden arterial rupture causing hemorrhage

D. Gradual narrowing of arteries due to atherosclerotic plaques leading to reduced blood flow during exercise

Answer: (D)

Explicación

Claudication results from gradual narrowing of peripheral arteries caused by atherosclerotic plaques, which reduces blood flow during increased demand such as exercise. This ischemia manifests as pain or cramping in the affected limbs. The process is primarily due to atherosclerosis, not rupture, spasm, or infection.