Session 7 The Pathology Of Trauma Flashcards
(27 cards)
How does skin healing by first intention occur?
- sutured lacerations and splenectomy wound
- haematoma
- minimal granulation tissue
- re epithelisation
How does healing occur by secondary intention?
- larger injuries not suitable for suturing
- haematoma
- large amount granulation tissue
- delayed re epithelisation
- risk of infection
What are the complications of a splenectomy?
Immediate = haemorrhage
Early complications = haemorrhage, infections, raised platelets (thrombosis)
Late complications = infections, prophylaxis needed
What puts you at risk of a DVT?
Immobility Trauma Surgery Splenectomy Smoker
What occurs with an MI?
Chest pain Sudden onset Severe,Central, Crushing pain Increasing troponin ECG will show ST elevation = stemi
What occurs with myocardial repair?
- infarction followed by removal of necrotic tissue by macrophages
- capillary and fibroblast ingrowth from viable edges
- gradual increase in collage = fibrous scar
- no significant regeneration of cardiac myocytes
What can chemical signals make the cell do???
Survive
Divide
Differentiate
Die
How can a cell population increase its numbers?
- shortening the cell cycle
- conversion of quiescent cells to proliferating cells by making them enter the cell cycle
Can cells with damaged DNA replicate?
- checkpoints in cell cycle will stop cells with damaged DNA replicating
- neoplasia = due to changes in genetic material
What is the restriction point?
- a checkpoint of the cell cycle
- cells that pass R point will complete cell cycle = point of no return
- most commonly altered checkpoint in cancer cells
How is the cell cycle controlled?
- cyclins and cyclin dependent kinases
- cyclin dependent kinases become active by binding with cyclins
How can cells adapt?
Hyperplasia
Hypertrophy
Atrophy
Metaplasia - replaced by cells of a different type
In which types of tissue does hyperplasia occur?
- labile/stable tissue
- caused by increased functional demand/hormonal stimulation
- is reversible
- can occur secondary to pathology
- repeated cell division exposes the cell to the risk of mutation and neoplasia
Give physiological and pathological examples of hyperplasia.
Physiological
- bone marrow makes erythrocytes in response to hypoxia
Pathological
- thyroid goitre in iodine deficiency
In which tissue type does cell hypertrophy occur?
- labile/stable
- increased functional demand/hormonal stimulation
E.g skeletal muscle and pregnancy (hypertrophy and hyperplasia), proximal to stenosis in the bowel
Why don’t athletes get cardiac muscle atrophy?
Relative anoxia (absence of oxygen) = little areas of fibrosis appear = cardiac muscle cant work as efficiently = need to rest
Give examples of pathological atrophy
- inadequate blood supply with peripheral vascular disease
- ageing
- pressure: tissues around a enlarging benign tumour
- inadequate nutrition
- cell muscle atrophy
- damage to median nerve
How does osteoporosis occur?
Atrophy of the extracellular matrix
What is metaplasia?
- reversible change of One differentiated cell type to another
- due to altered stem cell differentiation
- in labile or stable tissue
- involves expression of a new genetic programme
What example are there of metaplasia?
Bronchial pseudostratified ciliated epithelium = stratified squamous epithelium due to effect of cigarette smoke
Stratified squamous epithelium = gastric glandular epithelium with persistent acid reflux
Does metaplasia predispose to cancer?
- can be a prelude to dysphasia and cancer
What is aplasia?
Complete failure of a specific tissue/organ to develop
Embryonic development disorder
Used to describe an organ who’s cells have ceased to proliferate
What’s hypoplasia?
Under development of a tissue or organ
In spectrum with aplasia
Not opposite of hyperplasia as congenital
E.g renal, breast, testicular, heart chambers
What’s involution?
Overlaps with atrophy
Normal programmed shrinkage of an organ
Uterus after childbirth
