Understanding pathophysiology CH37 Flashcards
how do iritants damage the skin?
direct cytotoxicity, lipid barrier removal, cell membrane damage, breakdown of proteins
what happens when iritants penetrate stratum corneum?
keratinocytes release cytokines and stimulate MHC antigens which promote inflamation
what is the major mediator in inflamation?
tumor necorsis factor-alpha
What is cancer?
Cancer is an uncontrolled proliferation (growth and multiplication) of cells that can arise from any cell type in the body.
what is Hypertrophy ?
Hypertrophy refers to an increase in size (of a cell or organ), which is not always detrimental.
what are Benign tumours ?
Benign tumours do not possess the properties of malignant tumours. They are usually well encapsulated, the cells and tissues appear normal in structure, and they do not spread to regional lymph nodes or distant locations.
how are cancers distinguished?
Cancers ( or malignant tumours) are distinguished from benign tumours by their more rapid growth rates and alterations in microscopic appearance, such as loss of cell differentiation and absence of normal tissue organisation.
what is Carcinogenesis?
Carcinogenesis is the process by which normal cells transform into malignant cells; it is not one single event that causes cancer to develop, but a series of events that cause cells to transform into cancerous cells.
what are carcinomas?
Cancers arising in epithelial tissue
what are adenocarcinomas?
cancers arising from ductal or glandular epithelium
what are lymphomas?
Cancers of lymphatic tissue
what are leukemias?
cancers of blood-forming cells
what are the three types of mutations to genes that occur in cancer?
oncogenes, tumour-suppressor genes, and DNA repair genes.
what are Proto-oncogones genes?
Proto-oncogones are genes that code for proteins in a cell to help regulate normal cell growth. A change in the DNA sequence of a proto-oncogene gives rise to an oncogene , which subsequently results in loss of normal cell regulation.
what are Tumour-suppressor genes?
Tumour-suppressor genes are responsible for slowing or stopping cell division, in order to initiate either the repair of faulty DNA, or to initiate apoptosis. In this way, they ensure that abnormal cells are either corrected or destroyed.
