Adaptive cell and tissue responses

Question 1

Term.
> Refers to a decrease in cell size
> Occurs in response to decrease work demand/ adverse environmental conditions
> Cells revert to a smaller size etc

Answer 1

Atrophy

Question 2

Causes of atrophy (5 groups)

Answer 2

1) Disuse - (skeletal muscles)
2) Denervation - occurs in muscles of paralyzed limb
3) Loss of endocrine stimulation - menopausal women (loss of estrogen > atrophic changes in the uterus
4) Inadequate nutrition - malnutrition can cause atrophic changes
5) Ischemia

Question 3

Term.
> Refers to increase in cell size with increase in tissue mass
> Results from an increased workload imposed on an organ/ body part
> Commonly seen in skeletal muscle tissue which cannot form more cells by mitotic division (cant regenerate)

Answer 3

Hypertrophy

Question 4

Causes of hypertrophy (2)

Answer 4

1) Normal physiological conditions
Greater muscle mass associated with exercise

2) Abnormal pathological conditions:
> Adaptive hypertrophy - eg urinary bladder thickens from continued obstructions of urinary flow
> Compensatory hypertrophy - enlargement of a remaining organ or tissue after a portion has been removed eg. remaining kidney after surgery

Question 5

Term.
> Refers to an increase in the number of cells in an organ or tissue
> Occurs in tissue with cells that are capable of mitotic division eg epidermis, intestinal epithelium/ granular tissue
> a controlled process that occurs in response to an appropriate stimulus/ ceases after stimulus has been removed

Answer 5

Hyperplasia

Question 6

Causes of hyperplasia

Answer 6

Physiological hyperplasia

1) Hormonal - as a result of estrogen stimulation during pregnancy > breasts and uterus enlarges
2) Compensatory - as a result of partial Hepatectomy (partial removal of liver > liver regenerated

Non physiological hyperplasia
1) Hormonal
- W_ as a result of excessive estrogen > Endometrial hyperplasia and abnormal menstrual bleeding
-M_related to the actions of androgens > benign prostatic hyperplasia
2) Growth factors on target tissue
As a result of certain viruses > Warts

Question 7

Term.
> Refers to the reversible changes where one adult cell is replaced with another adult cell type
> Occurs as a result of chronic irritation and inflammation

Answer 7

Metaplasia

example - adaptive substitution of stratified squamous epithelial cells for columnar epithelial cells in trachea as a result of prolonged cigarette smoke
Continued exposure to influences that cause metaplasia > may cause cancer

Question 8

Term.
> Refers to deranged cell growth of a specific tissue/ results in cells that vary in size, shape, organization
> Minor degrees of this condition are associated with chronic irritations/ inflammations
> It is a strongly implicated as a precursor of cancer.

Answer 8

Dysplasia