Practical 3: Stromal Changes Flashcards
What processes are involved in tissue damage and repair processes?
Cell proliferation, Fibre production and healing
What are the four alterations to stroma investigated
Sclerosis
Fibrosis
Amyloid
Cirrhosis
What is sclerosis?
A pathological condition in which a tissue has become hard and which is produced by overgrowth of fibrous tissue and other changes (as in arteriosclerosis) or by increase in interstitial tissue and other changes (MS)
Give two conditions where sclerosis occurs
Artherosclerosis
Nephrosclerosis
What happens in nephrosclerosis?
There is a gradual destruction of glomerular function and structure
What happens in atherosclerosis
The process of progressive thickening and hardening of the walls of arteries from fat deposits on their inner living
Define fibrosis
(3)
The formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process
This can be a reactive, benign, or pathological state
In response to injury, this is called scarring, and if fibrosis arises from a single cell line, this is called a fibroma
Define amyloid
(5)
An abnormal extracellular protein, which is derived from many precursor proteins and gives rise to a condition called Amyloidosis
It is deposited extracellularly as a homogenous acellular substance and is most commonly found in the walls of blood vessels, beneath the endothelial linings
The progressive nature of deposition may result in occlusion of vessels and destruction of parenchyma with loss or organ function
The condition may be systemic or localised. In systemic conditions, amyloid is deposited in a wide variety of tissues and organs such as kidneys, spleen, liver, adrenal glands and heart
In localised form it is present only in the organ involved
What are foam cells?
A type of macrophage that localise to fatty deposits on blood vessel walls, where they ingest low-density lipoproteins and become laden with lipids, giving them a foamy appearance
Define cirrhosis
Defined histologically as a diffuse hepatic process characterised by fibrosis and conversion of the normal liver architecture into structurally abnormal nodules
What are three names for stromal tissue
Supporting tissue -> parenchymal
Acinar
Glial (in the nervous tissue)
Write about glomerulosclerosis
Affects blood vessels of kidney including those of the glomerulus
Caused by hypertension or diabetes
Glomeruli in cortex are affected
Loss of tubules -> replaced by stroma
Glomeruli are blocked by scar tissue in response to continuous high blood pressure which causes blood to be pushed out into the nephron -> fibrin is then laid down
Hyaline change -> clear ‘glassy’ like
Also problem with blood vessels in the kidney (bad prognosis if this happens)
Patient’s filtration is affected
Renin-angiotensin-aldosterone system is turned on -> causes a rise in blood pressure and volume -> inappropriate response -> damages more glomeruli
Write about artherosclerosis
Disease process driven by foam cells (pathogenomic cell)
Foam cell goes behind intima which results in deposition of scar tissue which can cause a thrombis
Thrombis can break odd and cause an embolism
Foam cells ingest lipid so we can stain for them with Oil Red O
Causes intima remodelling which can cause a stroke -> huge amount of inflammation
Lymphocytes and macrophages can be seen
No room for blood to flow
Can usually barely see the intima but in this disease it takes up most of the lumen
Fat accumulates in intima to cause a cholesterol cleft
Give an example of fibrosis
Fibroadenoma of the breast
Fibroadenoma of the prostate
Write about fibroadenoma of breast
Increased stroma causes a firm lump in breast
