Disorders of blood vessels and blood pressure

Question 1

What is hyperlipidemia?

Answer 1

elevated lipids (cholesterol, phospholipids, triglycerides) in the blood

Question 2

What is an apoprotein?

Answer 2

a protein that transports lipids in blood because lipids are not water-soluble

Question 3

What is a lipoprotein?

Answer 3

when lipids bind to an apoprotein they are called lipoproteins, they vary in density (influenced by protein content)

Question 4

What is HDL?

Answer 4

high density lipoprotein, it has a high density because of a high protein content

Question 5

What is LDL?

Answer 5

low density lipoprotein, it has a low density due to a lower protein content, it therefore has a higher lipid content, this type is bad

Question 6

Define atherosclerosis.

Answer 6

formation and deposition of a soft paste in the ateries

Question 7

What does atherosclerosis cause?

Answer 7

• atherosclerosis causes the formation of fibrofatty lesions called atheromas in the intima of larger arteries
• as lesion grows, the patency of the artery is decreased
• this decreases perfusion of the tissue the artery supplies

Question 8

Define ischemia.

Answer 8

local inadequacy of perfusion due to an obstructed blood vessel

Question 9

Define infarction.

Answer 9

Cell death related to ischemia.

Question 10

Atherosclerosis is a process that occurs over decades and the lesions change over time. Name and describe the 3 different lesions seen in atherosclerosis.

Answer 10

1) fatty streak - yellowish discolouration
2) fibrous atheromatous plaque - further deposition of cells, lipids and smooth muscle cells
3) complicated lesion - there are changes in the lumen of the blood vessel and a build up in the lumen which now has the potential to be dislodged

Question 11

What is the pathophysiology of atherosclerosis.

Answer 11

• begins with endothelial injury (risk factors)
• this allows lipids to enter/accumulate into the intima, triggers inflammation
• inflammatory cells migrate into the tissue (monocytes bind and enter endothelium, become macrophages, oxidize lipids, releasing free radicals, engulf oxidized lipids and become foam cells, free radicals cause injury, foam cells release growth hormone causing smooth muscle to proliferate)
• foam cells degenerate, release contents forming an atheroma (formation of necrotic core)
• in later stages, endothelium ruptures, collagen is exposed - platelets contact and begin the clotting cascade… form a thrombus
• the thrombus can break off and cause problems

Question 12

Which blood vessels are most often affected by atherosclerosis?

Answer 12

1) abdominal aorta and iliac arteries
2) proximal coronary arteries
3) thoracic aorta, femoral and popliteal arteries
4) internal carotid arteries

Question 13

What is hypertension?

Answer 13

persistently elevated blood pressure that does not return to normal, clinically persistent blood pressure more than 140/90 mmHg

Question 14

Why is hypertension bad?

Answer 14

• heart must work harder, requires more oxygen, more susceptible to injury/disease
• high pressure can damage endothelium, causing atherosclerosis
• high pressure can damage capillaries in retina, glomerulus
• high pressure makes it more likely a plaque will break off… PE, CVA
• high pressure also increases likelihood that vessels break, causing hemorrhagic stroke

Question 15

What are 4 major ways that blood pressure is controlled?

Answer 15

1) arterial baroreceptors (in carotid and aorta to protect brain and coronary circulation)
2) RAAS
3) vascular autoregulation
4) blood volume (regulation of fluid volume by the kidney with the help of ADH and aldosterone)

Question 16

What is normal blood pressure?

Answer 16

under 120/80 mmHg

Question 17

What are the categories and related ranges of hypertension?

Answer 17

high normal:
120-139 systolic and/or 80-90 diastolic

stage 1/mild:
140-159 systolic and/or 90-99 diastolic

stage 2/moderate:
160-179 systolic and/or 100-109 diastolic

stage 3/severe:
over 180 systolic or over 110 diastolic

Question 18

What is the difference between primary and secondary hypertension?

Answer 18

primary or essential hypertension is idiopathic (90% of cases)

secondary hypertension has an identifiable cause… like renal disease

Question 19

In most hypertension, both systolic and diastolic pressures are elevated. Explain who might be affected by systolic hypertension and why they would only experience elevated systolic pressure.

Answer 19

• people over 50 years old because of vessel degeneration and atherosclerosis
• vessel compliance is reduced, can no longer stretch to accommodate the increased pressure during systole

Question 20

What are three other types of hypertension?

Answer 20

1) white coat hypertension - hypertension in clinical setting
2) gestational hypertension - elevated blood pressure during pregnancy
3) malignant hypertension - sudden, marked elevations in blood pressure with diastolic pressure over 120 mmHg

Question 21

Hypertension is usually asymptomatic except for one sign - what is it?

Answer 21

elevated blood pressure

Question 22

When hypertension does have signs and symptoms, what are they? What do they indicate?

Answer 22

• fatigue
• palpitations
• am headaches
• blurred vision
• dizziness

signs of long-term damage from hypertension on other organs and tissues

Question 23

What is target organ damage?

Answer 23

complications associated with hypertension that affect the heart, brain, kidneys, eyes, and blood vessels

Question 24

What is a palpitation?

Answer 24

sensation of a forceful, irregular heart beat

Question 25

How is hypertension treated?

Answer 25

1st - lifestyle modifications
2nd - if this doesn’t work after a few months, add diuretic medication
3rd - if this doesn’t work, add a second medication: calcium channel blocker, angiotensin II receptor blocker, ACEI

Question 26

What is peripheral vascular disease?

Answer 26

disorder of the circulation of the extremeties

Question 27

What are the two types of PVD?

Answer 27

1) acute arterial occlusion - when there is an acute disruption to perfusion, usually from a thrombus or embolus
2) atherosclerotic occlusive disease - the gradual development of an atheroma impedes perfusion, can lead to ischemia and tissue damage

Question 28

How does PVD manifest?

Answer 28

acute arterial occlusion: sudden onset of 5 p’s = pulselessness, palor, polar, pain, paraesthesia

atherosclerotic occlusive disease: intermittent claudication (pain from ischemia when walking), edema caused by venous or lymphatic stasis (fluid and wast accumulates)

Question 29

Who has increased incidence of atherosclerotic occlusive disease? Why?

Answer 29

• increased incidence in elderly and those with diabetes mellitus
• atherosclerosis manifests later in life
• vascular damage is a chronic complication of DM

Question 30

How does the body react/compensate for peripheral vascular disease? Is it effective?

Answer 30

• vasodilating (doesn’t work)
• switching to anaerobic metabolism (good if short term)
• form new blood vessels around the occlusion - collateralization (takes time)

Question 31

What happens if PVD is not treated?

Answer 31

ulceration and gangrene… amputation

Question 32

What is an aneurysm?

Answer 32

A localized dilation in an artery that does not return to normal/is permanent.

Question 33

What causes an aneurysm?

Answer 33

degenerative changes in a vessel wall

Question 34

What are some risk factors for aneurysms?

Answer 34

hypertension, atherosclerosis, congenital defects

Question 35

What are the three types of aneurysms? Describe them?

Answer 35

1) fusiform - bulge around entire circumference of vessel
2) saccular - bulge on 1 side of the vessel only
3) dissecting - blood flows between 2 layers of the blood vessel to cause a bulge

Question 36

Where do aneurysms commonly (generally) occur and why?

Answer 36

• bend in a vessel
• bifurcation in a vessel
• where vessel lacks external support

why? because the vessel is subject to higher pressure in these areas

Question 37

What are common sites of aneurysms?

Answer 37

• abdominal and thoracic aorta
• femoral artery
• iliac artery
• popliteal artery

Question 38

What are the complications associated with aneurysms?

Answer 38

• rupture and hemorrhaging
• applies pressure to adjoining structures
• thrombosis
• embolism