Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Pathology PPT 3 Hypertension Lecture Notes
HYPERTENSION
Pathological classification-
BENIGN (ESSENTIAL) HYPERTENSION-
? left ventricular hypertrophy
? left ventricular dilatation
? disease of arterioles and small arteries
MALIGNANT HYPERTENSION-
? markedly raised diastolic blood pressure, and progressive renal disease
? Give rise to many consequences
Etiological factors-
? Essential hypertension or idiopathic (92-95%)
? Secondary hypertension-
oRenal causes
oEndocrine causes
oCardio-vascular
oStress
oPsychogenic
Regulators of blood pressure
Etiopathogenesis of Essential hypertension
Essential hypertension-
? Genetic factors-
oSingle gene disorder
oMultiple gene disorder
? Environmental factors
Single gene disorder-
? CYP11B2 gene-aldosterone synthase
? CYP11B1
? SCNNIB
Multiple gene disorder-
? Angiotensinogen and angiotensin receptor gene
? Prorenin receptor gene
Essential hypertension pathogenesis-
Etiopathogenesis of secondary hypertension
1- renal causes
? Reno-vascular
? Renal parenchymal
? Excess renin secretion- nephroblastoma
2-Endocrine causes-
? Cushing syndrome
? Pheochromocytoma
3-oral contraceptive
? Angiotensinogenangiotensin2-> increase blood pressure
Pathogenesis in secondary hypertension
1-Renovascular hypertension
2-Hypertensive heart disease
Genesis of renovascular hypertension
Hypertensive heart disease
Genetic aspect of hypertension
Gene classification
? renin-angiotensin-aldosterone system(MAJORITY)
? sodium system genes
? signal transduction system genes
? endothelial system genes
? neurohormonal and adrenergic genes
The renin-angiotensin-aldosterone system
? REN gene located at the 1q32
? Angiotensinogen (AGT) gene located on chromosome 1q42-43
? angiotensin-converting-enzyme (ACE) is located on chromosome
17q23
? AGTR1 gene-located at chromosome 3q21-25
? AGTR2 gene is located on the X-chromosome
? CYP11B2 gene coded for aldosterone synthase ,located on
chromosome 8q22
Other genes
? ECE1 gene- chr 1
? HYT3 gene ?chr 2
? AGTR1A gene on chromosome region 3q21-q25, Caucasians
? adducin-1 (ADD1) on chromosome band 4p16.3 has been associated
with salt-sensitive essential HT
? HYT6-high renal function on chromosome 5p
? CYP3A5 gene on chromosome band 7q22.1
? NOS3 gene-7q36 pregnancy-induced HT
? Locus in chromosome 11q- Mexican-Americans
? HYT4 gene- chromosome 12 -Chinese family
CONSEQUENCES OF HYPERTENSION
? KIDNEY
? BRAIN
? HEART
? EYE
? Hyaline arteriolosclerosis. Arterioles show homogeneous, pink hyaline thickening
with associated luminal narrowing
? Hyperplastic Arteriolosclerosis. severe hypertension; laminated ("onion-skin")
thickening of the walls
MORPHOLOGY
Hyaline arteriolosclerosis Hyperplastic Arteriolosclerosis
Hypertensive changes in Kidney
Benign nephrosclerosis-
? Gross-
?fibrosed and contracted kidney
?Also called granular contracted kidney
? Microscopy-
?hyaline arteriosclerosis
?Tubular atrophy
?Interstitial fibrosis
?Glomerulosclerosis
?Periglomerular fibrosis
? Malignant nephrosclerosis-
Gross- Flea bitten kidney (multiple red colored pin point dots)
Microscopy-
? necrotising arteriolitis
? Hyperplastic arteriolitis (onion skin)
KIDNEY Malignant hypertension (flea bitten)
KIDNEY(malignant hypertension)
Renal arteriolar wall in malignant hypertension
Hypertensive changes in heart
1-Narrowing of the arteries-coronary heart disease (CHD)
2-Thickening and enlargement of the heart-Left ventricular
hypertrophy(LVH)
Gross-
? Early stage- concentric hypertrophy of myocardium
? Late- cardiomegaly
Microscopy-
? Early- enlargement of myocyte
? Late stage-disorganised arrangement of myocyte with variable size
HEART
Atherosclerotic plaque cause IHD
Hypertensive encephalopathy
? Cerebral edema
? Cerebral infarct
? Lacunar infarct
? Intracerebral hemorrhage
? Petechial hemorrhage
? Fibrinoid necrosis of arteriole
Lacunar infarct Cerebral infarct
Cerebral infarct(12? 24hrs)
Hypertensive retinopathy
Retinal changes-
? Narrowing of arterioles
? Flame shaped hage
? Waxy exudates
? Micro infarction of nerve fibre(cotton wool spot)
? papilloedema
Hypertensive retinopathy
cotton-wool spot
This post was last modified on 07 April 2022