Cellular adaptation to stress

Question 1

Define Atrophy

Answer 1

Decreased size of organ due to decreased size of cells

Question 2

Define Hypertrophy

Answer 2

Increased size of organs due to increased size of cells

Question 3

Define Hyperplasia

Answer 3

Increased size of organ due to increased Number of cells

Question 4

Define Metaplasia

Answer 4

Reversiblle transformation of cells caused by reprogramming of stem cells

Question 5

Define dysplasia

Answer 5

Abnormal disordered non-neoplastic prolifration of Mucosa & epidermis

Question 6

examples of physiological Localized atrophy

Answer 6

• Uterus & breasts after menopause
• Thymus gland after puberty

Question 7

Examples of Physiological Generalised atrophy

Answer 7

Old age –> Senile atrophy

Question 8

Examples of pathological localised Atrophy

Answer 8

• disuse –> immobilisation of muscles after fracture
• Hormonal path. atrophy: atrophy of breast after excision of Ovaries
• Vascular path. atrophy: Atherosclerosis –> ischemia –> Renal & Brain atrophy
• Neuropathic atrophy: poliomyelitis
• Pressure atrophy: Tumor or aneurysm

Question 9

Examples of pathological generalised Atrophy

Answer 9

increased catabolism:
* Malignant tumor
* Thyrotoxicosis
* cachexia

Decreased anabolism:
* Malnutrition & Starvation (marasmus)

Question 10

Examples of physiological hypertrophy

Answer 10

• Striated muscles of Athletes 🏋
• Pregnent uterus

Question 11

Examples of Pathologcial Hypertrophy

Answer 11

• Kidney enlargement after surgical removal of the other one (compensatory)

Increase size ofMuscle coat of hollow organs caused by increased intralumenal pressure (Adaptive):
* Left ventricular hypertrophy due to Hypertension or aortic valve stenosis
* Bladder hypertrophy caused by bilhariziasis, tumor, stone

Question 12

examples of physiological hyperplasia

Answer 12

• Mammary glands/ genital organs at puberty (or endometrium during pregnency) –> (Hormonal)

Compensatory:
* Liver after partial hepatectomy
* Bone marrow after hemorrhage

Question 13

examples of Pathological hyperplasia

Answer 13

• Mammary gland & endometrium during repeated anovulatory cycles (follicle doesnt ovulate –> increase estrogen ) or thyrotoxicosis
• Lymphoid hyperplasia from Antigen stimulation

Question 14

Examples of Squamous metaplasia

Answer 14

• Respiratory mucosa in smokers
• Columnar epithelium of gall bladder & Bile duct by stone
• Transitional mucosa (bladder & ureter) by bilhariziasis or stone

Question 15

Examples of Intestinal Metaplasia

Answer 15

• edges of peptic ulcer or gastritis, from columnar —> mucous secreting cells with goblet cells
• Barret’s esophagus (glandular metaplasia): stratified squamous epithelium –> columnar epithelium

Question 16

Define Leukoplakia

Answer 16

keratinised squamous metaplasia forming irregular white patches

Question 17

Example of Mesenchymal Metaplasia

Answer 17

Traumatic myositis ossificans: bone formation in Muscles after intramuscular hemorrhage

Question 18

Sites of Dysplasia

Answer 18

• Mucus membranes
• epidermis

Question 19

Gross morphology of Dysplasia

Answer 19

Non-specific growth appearance

can only be identified under microscope

Question 20

Microscopic morphology of dysplasia

Answer 20

Signs of anaplasia/Atypia:
* Loss of polarity (normal cell arrangement)
* diffuse (involves full thickness of epithelium)
* Pleomorphism (different shapes and sizes)
* Hyperchromatism (bigger nucleus)
* Mitosis (clear mitotic figures)

NO INVASION of basement membrane (thus not tumor)

Question 21

other name for dysplasia

Answer 21

Intra-epithelial neoplasm

Question 21

describe grading of Dysplasia:

Answer 21

Mild/reversible/Low grade:
* affects lower basal 1/3 of epithelium

Severe/High grade/preinvasive:
* affects lower 2/3 or full thickness of epithelium
* AKA Carcinoma Institu (CIS)