Path revision Flashcards
Increase in the number of cells =
Hyperplasia
Increase in the size of cells =
hypertrophy
Cells that cant undergo hyperplasia - only hypertrophy
Cardiac muscle
Skeletal muscle
Nerve
Conditions that don’t have and increased risk of cancer despite hyperplasia =
Benigh prostatic hyperplasia
Apocrine metaplasia
Decrease in cell # occurs via
What changes occur in the cell during apoptosis
Apoptosis
decrease in size, red cytoplasm and condensed nucleus
Decrease in cell size occurs via
Ubiquiten proteosome degradation
Causes of metaplasia
Stress, Vitamin A deficiency,
Dysplasia
Disordered cell growth/proliferation of precancerous cells
Hallmark of reversible cell injury =
Hallmark of irreversible injury =
Hallmark of cell death =
cellular swelling
membrane damage
Loss of nucleus
Necrosis =
what changes are seen in the cell?
Apoptosis =
causes of apoptosis - 2
Death of large groups of cells followed by ACUTE inflammation
cell swelling
Energy dependent (ATP) programmed cell death of single or small groups of cells - NO inflammation. - usually due to lack of oxygen or exposure to toxins/burns
Cell itself activates intrinsic enzymes that degrade the cells’ genomic DNA and nuclear and cytoplasmic proteins.
causes - 1 - normal physiological response 2- due to pathogenesis
eg cells with DNA damage
accumulation of misfolded proteins or due to infections
Types of necrosis (6)
1 - Coagulative - cell shape & organ structure preserved - localised area of coagulative necrosis = infarct (doe not occur in brain)
2 - Liquefactive - brain infarct , abscess, pancreatitis
3- Gangrenous - coagulative necrosis that resembles mumified tissue
4 - Caseous - soft friable necrotic tissue - cheese like - combo of coagulative and liquefactive - TB fungal
5- Fat necrosis - pancreatitis +/- saponification
6 - Fibrinoid - necrotic damage to blood vessel
Apoptosis is mediated by ?
and activated by multiple pathways ?`
Caspases
Intrinsic mitochondrial pathway
Extrinisc receptor - ligand pathway
Cytotoxic CD8 T cell mediated pathway
Free radicals cause damage via
Elimination is via
Peroxidation of lipids
Oxidation of DNA proteins
Antioxidants - glutathionine, Vit A, C and E
Amyloid =
Can be systemic or local
misfolded protein which deposits in the extracellular space
Beta pleated sheet configuration
Congo red stain and green apple birefringence
Primary amyloid =
Secondary amyloid =
AL amyloid - associated with MM derived from immunoglobulin light chain
AA amyloid - derived from serum amyloid protein
Inflammation -
Acute or chronic
Acute inflammation mediators?
Acute - Oedema and neutrophils
Chronic - Lymphocytes and plasma cells
Toll like receptors
Arachidonic acid metabolites
Mast cells
complement
Hageman Factor (F12)
Neutrophil arrival and function
Margination
Rolling
Adhesion
Transmigration and chemotaxis
Phagocytosis
Destruction of phagocytosed material
Resolution
Neutrophils are attracted by bacterial products - ?
IL-8
C5a
LTB4
Chronic granulomatous disease =
poor o2 dependent killing which leads to recurrent infection and granuloma formation with catalase positive organisms - KNOW
- staph aureus
- pseudomonas cepacia
- Serratia marcescens
- No cardia
- Aspergillus
What test is done to screen for CGD?
Nitroblue tetrazolium
T lymphocytes
Produced in the BM as progenitor T cells and further develop in the thymus where they undergo rearrangement and become CD4+ helper T cells or CD8+ cytotoxic T cells
T cells use TCR complex for antigen surveillance
T lymphocytes
Produced in the BM as progenitor T cells and further develop in the thymus where they undergo rearrangement and become CD4+ helper T cells or CD8+ cytotoxic T cells
T cells use TCR complex for antigen surveillance
CD8+ t cells - killing occurs via secretion or perforin
Granuloma =
Caseous granuloma
Non caseous granuloma
Collection of epitheliod histiocytes surrounded by giant cells and rim lymphocytes
Caseating - central necrosis - TB or fungal
Non-caseating - no central necrosis - FB, sarcoid, beryllium, Crohns, Cat scratch
Primary immunodeficiencies (8) -
Di George
Severe combined immunodeficiency
x-linked agammaglobulinemia
Common variable immunodeficiency (CVID)
IgA deficiency - MOST COMMON
Hyper IgM syndrome
Wiskott-Aldrich syndrome
Complement deficiency
Di George = failure of the 3rd and 4th pharyngeal pouches to form normally. 22q11 microdeletion.
Tcell deficiency - lack of thymus and parathyroids
SCID - defective cell mediated and humoral immunity
x-linked agamma - complete lack of immunoglobulin - due to disordered B cell maturation. mutated BRUTON TYROSINE kinase
CVID - low immunoglobulin due to B cell or helper T cell defect
IgA def - low serum and mucosal IgA
Hyper IgM syndrome - Elevated IgM - mutated CD40 on T helper cells or CD40 receptor on B cells. Low IgA, IgG and IgE
Wiskott - Thrombocytopenia
Mutation in the WASP gener
Complement defi - C5-C9 deficiencies - Increased risk of Neisseria infection. C1 inhibitor deficiency - angiooedema