Cellular Adaptation

Question 1

Define cell adaptation

Answer 1

Reversible changes in number size phenotype metabolic activity or functions of cells in response to changes in their environment

Question 2

Classify adaptations

Answer 2

Hyperplasia
Hypertrophy
Atrophy
Metaplasia

Question 3

Hyperplasia def and classify

Answer 3

Increase in the no of cells in an organ or tissue usually resulting in increased volume of organ or tissue in response to stimulus
Types
Physiological:
1.hormonal
2. Compensatory
Pathological

Question 4

Causes of hyperplasia

Answer 4

Physiological
1. Hormonal: glandular tissue of female breast during pregnancy puberty or lactation
Uterine endometrium during pregnancy
2. Compensatory
In partial hepatectomy of liver
Remaining kidney after unilateral nephrectomy

Pathological
Endometrial hyperplasia in granulosa tumor of ovary
Benign prostatic hyperplasia

Question 5

Clinical imp of hyperplasia

Answer 5

Constitutes a fertile soil in which cancerous proliferation may eventually arise

Question 6

Causes of hypertrophy

Answer 6

Physiological..
Increased workload ie bulging muscles of body builders 1.Hormone induced
Uterus during pregnancy breast during lactation
2. Pathological hypotrophy hypertrophy of cardiac muscle in hypertension

Question 7

Both hypertrophy and hyper
Plasia

Answer 7

Uterus during pregnancy

Question 8

Metaplasia def and examples

Answer 8

It is a reversible change in which one differentiated cell type is replaced by another cell type of similar nature
it is of 2 types
epithelial Metaplasia
Connective tissue metaplasia
Epithelial metaplasia:
Squamous-
columnar to sq( resp tract in chr irritation cigarette smokers ciliated columnar to strat sq)
Transitional to sq( urinary bladder in long standing chr inflammation calculi)
Columnar
Sq to columnar( barette esophagus)
Columnar to columnar( epitheium of stomach is replaced by intestinal type epithelium)

Question 9

Metaplasia is a double edged sword

Answer 9

Metaplasia Causes two harmful effects at the same time
they are:
1. in respiratory tract although the epithetial lining becomes more durable, important mechanisms of protection against infection like mucous secretion And ciliary action of epithelial cells is lost.
2.the influences that predispose to metaplasia if persistent can initiate malignant transformation in metaplastic epithelium. Eg scc in resp tract can occur from metaplastic sq cell

Question 10

Mechanism of metaplasia

Answer 10

1. Reprogramming of local tissue stem cells
2. Colonization of differentiated cell populations from adjacent sites

Question 11

Condition where fibromlast is converted to osteoast

Answer 11

Myositis ossificans