Cellular Adaptations Question And Answers

Cellular Adaptations Important Notes

1. Terms

Cellular Adaptations terms

Cellular Adaptations Long Essays

Question 1. Hypertrophy

Hypertrophy Definition: Hypertrophy is an increase in the size of parenchymal cells resulting in enlargement of the organ/tissue, without any change in the number of cells.

Hypertrophy Etiology:

Hypertrophy is caused by increased functional demand or by hormonal stimulation.

Hypertrophy Etiological types:

It may be classified into:

  • Physiologic hypertrophy: Enlarge the size of the uterus in pregnancy.
  • Pathologic hypertrophy: Hypertrophy of cardiac muscle: In cardiovascular disease.
    • Systemic hypertension
    • Aortic valve disease
    • Mitral insufficiency.
  • Hypertrophy of smooth muscle:
    • Cardiac achalasia (in the esophagus)
    • Pyloric stenosis (in the stomach)
    • Muscular arteries in hypertension.
  • Hypertrophy of skeletal muscle:
    • A hypertrophied muscle in athletes and manual laborers
  • Compensatory hypertrophy: This may occur in an organ when the contralateral organ is removed.
    • After nephrectomy on one side in young patients there is compensatory hypertrophy of the kidney as well as nephrons on the other side.

Morphologic features:

  • The affected organ is enlarged and heavy.
  • There is an enlargement of muscle fibers as well as of nuclei

Question 2. Metaplasia

Metaplasia Definition:

Metaplasia is defined as a reversible change of one type of epithelial or mesenchymal adult cells to another type of adult epithelial or mesenchymal cells, usually in response to abnormal stimuli.

Metaplasia Types:

Metaplasia is divided into the following two types.

  1. Epithelial
  2. Mesenchymal.

1. Epithelial Metaplasia:

  • Squamous metaplasia There is a transformation of various types of epithelium into squamous epithelium due to chronic irritation
  • For example:
    • In bronchus in chronic smokers.
    • In uterine endocervix in prolapse of the ureters and in old age.
    • In renal pelvis and urinary bladder in chronic infections.
  • Columnar metaplasia: There is the transformation of various epithelia into columnar epithelium.
  • For example:
    • Intestinal metaplasia in healed chronic gastric ulcer.
    • In Barrett’s esophagus, normal squamous epithelium changes to columnar.

2. Mesenchyme metaplasia: There is the transformation of an adult type of mesenchymal tissue to another.

  • Osseous metaplasia: Osseous metaplasia is the formation of bone in fibrous tissue, cartilage, and myxoid tissue.
  • For example:
    • In the arterial wall in old age (Monchkeberg’s medial calcific sclerosis]
    • In soft tissues in myositis ossifications.
    • In cartilage of larynx and bronchi in elderly people.
    • In fibrous stoma of the tumor.
  • Cartilaginous metaplasia: In the healing of fractures, cartilaginous metaplasia may occur where there is undue mobility.

Cellular Adaptations

Read And Learn More: Pathology Question And Answers

Question 3. Hyperplasia

Hyperplasia Definition:

  • Hyperplasia is an increase in the number of parenchymal cells resulting in enlargement of the organ/tissue.
    • Hyperplasia occurs due to the increased recruitment of cells from the resting phase of the cell cycle to undergo mitosis when stimulated.
    • Hyperplasia persists as long as the stimulus in present.

Hyperplasia Etiology:

Hyperplasia may occur due to physiologic and path-logic causes.

1. Physiologic hyperplasia: The two most common types are.

Cellular Adaptations Physiological Hyperplasia

2. Pathologic hyperplasia: Due to excessive stimulation of hormones or growth factors.

Cellular Adaptations Pathologic Hyperplasia

Cellular Adaptations Short Question And Answers

Question 1. Atrophy

Atrophy Definition:

Atrophy may be defined as the decrease in the number and size of parenchymal cells of an organ or its parts which was once normal.

Atrophy Causes:

Cellular Adaptations Atrophy Causes

Question 2. Anaplasia

Anaplasia Definition:

  • Anaplasia is a lack of differentiation and is a characteristic feature of most malignant tumors.
  • Depending upon the degree of differentiation, the extent of anaplasia is also variable i.e., poorly differentiated malignant tumors have a high degree of anaplasia.

Result of Anaplasia:

  • Loss of polarity
  • Pleomorphism
  • N: C ratio changes from 1:5 to 1:1
  • Anisonucleosis.
  • Hyperchromatism.
  • Prominent nucleolus
  • Tumor giant cells
  • Chromosomal abnormalities.

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