Unit 1 Carinogenesis

Question 0

What are the primary causes of atrophy?

Answer 0

1) disuse
2) denervation
3) loss of endocrine stimulation
4) inadequate nutrition
5) ischemia or decreased blood flow

Question 1

What is cellular adaptation?

Answer 1

Changes in cells as a result of increased work demands or threats to survival. They can change:

• size (atrophy and hypertrophy)
• number (hyperplasia)
• and form (metaplasia)

Normal cellular adaptation occurs in response to appropriate stimulus and ceases when the need for adaptation ceases
dysplasia

Question 2

What are the cellular changes that produce atrophy?

Answer 2

Decrease in work demands or adverse environmental conditions decrease the oxygen consumption of the cells and protein synthesis. This produces:
- decreased number and size of organelles including mitochondria, myofilaments, and endoplasmic reticulum structures

Question 3

What is hypertrophy and what cellular changes produce this?

Answer 3

• An increase in cell size, producing an increase in functioning tissue mass.
• Due to increased workload in tissues that cannot adapt to increased wordload due to mitotic division (producing more cells). Common in cardiac and skeletal muscle cells.
• Additional actin and mysosin filaments, cell enzymes and ATP are synthesized.
• Can result from normal physiologic or abnormal pathologic conditions.
• Adaptive hypertrophy = thickening of bladder due to obstruction, myocardial hypertension due to valvular hrt disease or HTN
• Compensatory hypertrophy = enlargement of remaining organ or tissue after a portion is removed or inactivated, e.g., kidney

Question 4

Describe the process by which cells begin to hypertrophy.

Answer 4

In the heart:

a) biomechanical and stretch sensitive mechanisms
b) neurohomormonal mechanisms (e.g., release of hormones, growth factors, cytokines, and chemokines)

Question 5

What is hyperplasia and what tissues are capable of it?

Answer 5

• Epidermis
• Intestinal epithelium
• Glandular tissue

Stimulus can be:

• physiologic, hormonal (breast and uterine enlargement in pregnancy due to estrogen release) and compensatory (regeneration of liver after surgical removal), also important in wound healing by connective tissue (fibroblasts)
• nonphysiologic, due to excessive hormonal stimulation or effects of growth factors on target tissues (e.g., estrogen overproduction = endometrial hyperplasia and abnormal menstrual bleeding); benign metastatic hyperplasia due to androgrens, skin warts are caused by GF by certain viruses, including HPV)

Question 6

What is metaplasia?

Answer 6

Reversible change in one adult cell type to another (e.g., epithelial mesenchymal)

• response to chronic irritation and inflammation
• substitution of cells that are better able to survive
• cell types stay within primary tissue type (e.g., epithelial to epithelial, not to a connective tissue cell)
• can predispose someone to cancer formation
• e.g., stratified squamous to ciliated columnar in a habitual smoker

Question 7

What is dysplasia?

Answer 7

Deranged cell growth of a specific tissue resulting in cells that vary in size, shape and organization. Associated with irritation and inflamation.

• Most frequently found in metaplastic squamous epithelium of respiratory tract and uterine cervix,
• Abnormal but potentially reversable
• Usually found adjacent to foci of cancerous cells