Pathology - Blood Vessles Flashcards
List the vasoconstrictors that determine vascular resistance.
Angiotensin II Catecholamines Thromboxane Leukotrienes Endothelin
Define hypertension.
Clinically defined hypertension is a sustained diastolic pressures >89mmHg or systolic pressures >139mmHg.
Malignant hypertension is characterised by a systolic >200mmHg, diastolic >120mmHg, retinal haemorrhage and renal failure.
List the vasodilators that determine vascular resistance.
Kinins
Prostaglandins
Nitric oxide
Adenosine
Blood volume is affected by:
Sodium load
Mineralocorticoids
Natriuretic factors
Hypertension is associated with which 2 forms of small arteriolar disease?
Hyaline arteriosclerosis:
Increased SMC synthesis with pink hyaline arteriolar wall thickening.
Hyperplastic arteriosclerosis:
Concentric laminated thickening. Necrotising arteriolitis.
What are the 3 patterns of arteriosclerosis?
Arteriolosclerosis: S-M sized vessels
Monckeberg medial sclerosis: Medial calcification in muscular arteries occurring after the age of 50. Doesn’t cause ischaemia by itself!
Atherosclerosis:
Most frequent and clinically important.
Major classic RF for cardiovascular disease?
Family history Smoking Diabetes Hypercholesterolaemia Hypertension
Apart from the major RF, what are 5 additional contributing factors to cardiovascular events?
Inflammation Hyperhomocysteinuria Metabolic syndrome Lipoprotein a Haemostatic markers
Describe the pathogenesis of atherosclerosis:
- Endothelial injury or dysfunction
- Monocyte and platelet adhesion
- GF release and SM recruitment
- SMC and ECM proliferation
- M➰ and SMC take up cholesterol
- Necrosis of fatty core.
How do lipids worsen EC dysfunction?
Increased circulating lipids encourage formation of local oxygen free radical formation, which worsens EC and SMC dysfunction.
Moreover, oxidised LDLs are ingested by M➰ creating pro-inflammatory foam cells.
Complicated plaques include plaques which exhibit:
Calcification
Haemorrhage
Fissuring
Ulceration.
Most cases of MI are associated with critical or subcritical stenoses?
Sub critical!
Unstable plaques are characterised by:
Large, deformable lipid cores
Thin fibrous caps
Increased inflammatory content.
What are the 3 pathological changes underlying aneurysmal disease?
- Poor intrinsic quality of the matrix. Marfans, scurvy etc.
- Imbalance of matrix synthesis and degradation. For example in vasculitides or inflammation.
- Loss of SMC in the media or a change in SMC matrix synthesis via ischaemia or degeneration.
AAA rupture rate when 5-6 cm?
11% per annum
AAA rupture rate when >6cm?
25% per annum
AAA operative mortality when electively versus emergently performed?
5% elective. 50% emergent.
Classification of Aortic Dissection?
Type A: Involve ascending aorta.
Type B: Distal lesions, usually distal to subclavian.
Type A is worse and requires operative management.
What is MPO-ANCA?
A.K.A p-ANCA
Anti myeloperoxidase ANCA. Directed against lysosomal constituents in neutrophils. Associated with microscopic polyangiitis and Churg-Strauss syndrome.
What is PR3-ANCA?
A.K.A c-ANCA
ANCA directed against neutrophil azurophilic granule constituent. Associated with Wegener’s granulomatosis.
Which vasculitides are thought to involve T-cell mediated hypersensitivity?
Giant Cell Arteritis (Takayasu…)
Kawasaki disease
Wegener’s granulomatosis
Beurger disease.
Characteristics of juvenile haemangiomas?
Present at birth ~1/200
Grows rapidly for a few months
Begins regressing at 1-3 years
Most disappear by the age of 7.
Where might cavernous haemangiomas form?
Skin, liver, CNS, other viscera.
Cavernous haemangiomas in the cerebellum, brainstem, and eyes associated with angiomatous or cystic lesions in the pancreas and liver suggest…
von Hippel Lindau disease.
