Craft study sheet Flashcards
Atresia
Absence of an opening…pig pic
Agenesis
Absence of organ and primordial tissue
Aplasia
Absence because of failure of growth. Still have primordial tissue
Hypoplasia
Failure to develop to normal size.
Hyperplasia
- Response to ext. stimulus
- Regression with stim. Remov.
- Normal cells
- Organized tiss. Struct.
- Non-clonal cell expansion
Neoplasia
- No direct stimulus needed
- No regression with stimulus removal
- Abnormal cells with genetic modifications
- Effaces normal tissue
- Clonal cell expansion
Parenchyma
Neoplastic cells constituting tumor
Stroma
Reactive tissue around parenchyma
Benign tumor
- Gross and microscopic non-invasive features
- Well dileneated
- Often have capsule
- Expansile growth
- Amendable to sx
Malignant tumor
- Infiltrate growth
- Invasive and destructive to surrounding tissues
- Metastasis
Anaplasia
Lack of differentiation
Hallmark of malignancy
Anaplasia
Schirrous response (desmoplasia)
Abundant fibrous stroma, carcinomas
Differentiation
Extent which neoplastic cells resemble corresponding normal parenchymal cells (morphologically and functionally)
Pleomorphism
Variation in size and shape of cells
Oncogenes
Promote autonomous cell growth in cancer cells
Proto-oncogenes
Normal genes regulate cell growth and differentiation
Oncoproteins
Abnormal proteins encoded by oncogene that usually inactivate regulatory processes.
Most reliable features of malignancy
- Metastasis
2. Local invasion
Common routes of metastasis
- Direct seeding of body cavities (peritoneal cavity)
- Lymphatic spread (carcinomas)
- Hematogenous spread (sarcomas)
4 genetic targets
- Proto-oncogenes
- Tumor suppressor genes
- Apoptosis regulating genes
- DNA repair genes
Metastatic cascade
- Loosening cell-to-cell contact
- Degradation of BM/ECM
- Attachment to novel ECM components
- Migration
- Intravasation
- Embolic spread
- Adhesion to endothelium
- Extravasation
- Angiogenesis
- Growth
Cancer mechs of immune evasion
- Growth of antigen negative variants
- Reduction of MHC molecule expression
- Production of immunosuppressive/immunoreg molecules
Direct acting chemical carcinogens
- Require no metabolic conversion
- acylating agents
Indirect acting carcinogens
-Require metabolic conversion
Radiation carcinogenesis
UV light (sun) Ionizing radiation (x rays)
Microbial carcinogenesis
- Chronic tissue damage and inflammation
- hepatitis; helicobacter pylori
Paraneoplastic syndrome def
Symptoms occurring at sites distant to neoplasm or metastasis
Ex neoplastic syndromes
- Hypercalcemia
- Hypertrophic osteoarthropathy
- Endocrinopathy
Grading of neoplasms
Based on degree of differentiation of tumor cells
