[B] 1.65 Disturbances in cell division

Question 1

Stages of mitosis

Answer 1

1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. Telophase
6. Cytokinesis

Question 2

Normal mitosis: Causes

Answer 2

• Reaction to environmental stimuli (neighbouring cells)
• Growth factor
• Blood vessel injury
• Deficient oxygen supply

Question 3

Causes of normal mitosis: Growth factor (steps taken)

Answer 3

1. Produced in the cell, exits to the intercellular area
2. Strongly controlled process
3. Sensed by an adequate receptor
4. Interaction - Changes in the receptor-molecule function
5. Signal to the nucleus - preparation to mitosis
   
   • Supervision by protoonco- and suppressor molecules

Question 4

Causes of normal mitosis: Blood vessel injury

Answer 4

• Thrombocytes - Platelet-derived GF (PDGF)
• Fibroblast proliferation

Question 5

Causes of normal mitosis: Deficient oxygen supply

Answer 5

• RBCs - Vascular Endothelial GF (VEGF)
• New capillaries are formed

Question 6

Cell cycle

Answer 6

• Series of events in a eukaryotic cell btw. one cell division and the next
• Four distinct phases
  
  • Regulated by cyclins
• Temporarily or reversibly stopped

Question 7

Somatic cell types

Answer 7

1. Vegetative intermitotic cells
2. Differentiating intermitotic cells
3. Reversible postmitotic cells
4. Fix postmitotic cells

Question 8

Vegetative intermitotic cells

Answer 8

• Basal epithelial cell
• Haemoblasts
• Basal cells of the Lieberkühn crypts
• Spermatogonia

Question 9

Differentiating intermitotic cells

Answer 9

• Precursor WBCs
• Spermatocytes

Question 10

Reversible postmitotic cells

Answer 10

• Hepatocytes
• Tubular epithelial cells of the kidney
• Endothelial cells
• Adventitial cells

Question 11

Fix postmitotic cells

Answer 11

• Neurocytes
• Erythrocytes

Question 12

Possible disturbances in cell division

Answer 12

• Endomitosis
• Multinucleated giant cells
• Syncytial giant cells
• Mitosis doesn’t start
• Decreased rate
• Increased rate
• Deviant, out of the ordinary

Question 13

Endomitosis

Answer 13

• Nuclei and cytoplasms are not separated
• Polyploidy
• Giant cells with one nucleus: Large than normal nucleus & cytoplasm
  
  • Regenerating Tissues
  • Megakaryocyte

Question 14

Multinucleated giant cells

Answer 14

• Nucleus duplicates
• Cytoplasms are not separated during mitosis

Question 15

Syntitial giant cells

Answer 15

Several similar cells fuse

Question 16

Physiological forms of multinucleated giant cells

Answer 16

• Osteoclasts (multinucleated)
• Placental giant cells
• Megakaryocytes (endomitosis)

Question 17

Pathological cell division

Answer 17

Intense proliferation

• Regeneration, inflammation, tumour

Question 18

Types of intense proliferation of cells

Answer 18

• Smudge-cell (endomitosis)
• Langhans - Horseshoe arrangement
• “Foreign body”
• Sterberg’s - Similar to foreign body giant cell
• Touton - Lipid accumulation in the cytoplasm

Question 19

What is shown?

Answer 19

Langhans-type giant cell

Question 20

What is shown?

Answer 20

Foreign body type giant cell

Question 21

What is shown?

Answer 21

Touton type giant cell

Question 22

What is shown?

Answer 22

Syntitial giant cells

Question 23

Pathological forms: Giant cells in tumours

Answer 23

• Giant cell sarcoma
• Hodgkin-lymphoma
  
  • Reed-Sternberg type giant cell

Question 24

Defective mitosis

Answer 24

• Resting cell-secunder effect
  
  • Fragmented chromosomes
  • Abnormal reunition
• During mitosis - Primer effect
  
  • Multipolar spindle