4 Cellular Adaptations - Variations in Growth - Neoplasia

Vocabulary flashcards based on lecture notes about cellular adaptations and variations in growth (neoplasia).

Cellular Adaptation

Modifying metabolism or growth pattern to better equip cells for survival in response to physiological or pathological stimuli.

Labile Cells

Cells constantly divide to replenish those that are lost (short lifespan, high mitotic rate).

Stable Cells

Cells able to divide but will only do so occasionally (long lifespan, low mitotic rate); require special stimulation to divide.

Permanent Cells

Cells that have lost/have very little ability to divide (cells need to be maintained for life).

Hyperplasia

The increase in mass of an organ due to an increase in the number of its specialized constituent cells.

Hypertrophy

The increase in mass of an organ due to an increase in the size of its specialized constituent cells.

Atrophy

The decrease in mass of an organ due to a decrease in the size and/or number of its specialized constituent cells.

Agenesis

Failure of an organ to develop at all from its primordia.

Aplasia

A sudden cessation of growth leading to decreased mass of tissue and defective development of the organ.

Hypoplasia

Tissue fails to attain full size (deficient growth) leading to decreased mass of tissue & incomplete development of organ.

Metaplasia

A fully differentiated adult cell changes into another more resilient but less specialized fully differentiated adult cell type, in response to chronic injury.

Dysplasia

An abnormal growth and differentiation with loss of regularity of cells, loss of normal orientation and relationship to one another (i.e. abnormal tissue organisation).

Hamartoma

A focal overgrowth of normal cells found in a tissue in which these cells ARE usually present.

Choristoma (Ectopia)

A focal overgrowth of normal cells found in a tissue, in which these cells are NOT usually present.

Neoplasia

Process which leads to the formation of an abnormal, uncontrolled new growth of tissue, which has no coordinated useful function in the body. The abnormal mass is called a NEOPLASM (TUMOUR).

Clinical Classification (of tumors)

Describes behaviour of tumour and its effect on the patient.

Histogenetic Classification (of tumors)

Describes the tissue origin of tumour.

Morphological Classification (of tumors)

Describes the appearance of tumour.

Benign Tumours

Slow growing, surrounded by CT capsule, Well supported by abundant stroma, No infiltration/invasion of normal tissue, do not spread, Easily treated, good prognosis.

Malignant Tumours

Rapidly growing, not encapsulated, Scanty stroma, fragile blood vessels, Infiltration and invasion of normal tissue, May spread to distant parts (metastasis), Not as easily treated, usually bad prognosis.

Metastasis

The process whereby malignant tumours spread from their site of origin to distant parts of the body forming secondary masses.

Primary Tumour

One that is growing at the site of origin.

Secondary Tumour

One that is growing distant from the site of origin (retaining the histological characteristics of the tissue in which it arose).