NUR 339 Exam 19 - Answer G1 cell prepares to make DNA S phase DNA...

NUR 339 Exam 19

• What are the first major phases of the cell cycle?

Answer G1

cell prepares to make DNA S phase DNA synthesis actually takes place G2

prepares for mitosis M phase mitosis occurs 0

resting phase

• In what phase of the cell cycle does mutation typically occur?

Answer S phase

• What are the stages of the cell cycle controlled by?

Answer cyclins (a type of protein), and their inhibitors

• What can defects in the cycle cycle contribute to?

Answer the development of cancer

• Characteristics of benign neoplasms

Answer composed of well differentiated cells that resemble cells of tissues of organ 1 / 3

slow growth rate may become encapsulated usually do not cause death

• Characteristics of malignant neoplasms

Answer cancer atypical cell structure; abnormal nucleus and chromosomes

lose differentiation or resemblance to origin cell (more anaplastic) invade adjacent cells rather than pushing aside more blood supply than normal tissue

• Spread of cancer

Answer direct invasion and extension- local spread, mechanical lysis with enzymes Seeding of CA cells in body cavities

• How does cancer metastasize?

Answer clumps of malignant cells can break off and travel thru blood to a new site(most are killed by the body's defense)

in lymph nodes, cancer may die, grow into mass or remain dormant

• What is a sentinel node?

Answer initial lymph node to which the primary tumor drains

• What is the original tumor called?

Answer primary neoplasm

• What is a metastatic site called?

Answer secondary neoplasm 2 / 3

• What is growth fraction?

Answer ratio of dividing cells divided by G0 cells

• What is doubling time?

Answer time to double total mass of CA cells

• Facts about GF and TD

Answer they are very fast until tumor outgrows blood supply, then slows maybe influenced by hormones

• What are chemotherapeutic drugs more toxic to?

Answer tissues that have a high growth fraction than a low growth fraction

• Proto-oncogenes

Answer normal genes that regulate cell growth and differentiation and are active for only a short time in the cell cycle

• Oncogenes

Answer gene MUTATIONS which become cancer-causing genes; are active continuously and promote unregulated, abnormal and disordered growth

• Oncogenesis

Answer Mechanism by which a normal cell is transformed into cancer cell by random genetic mutation or mutation induced by exposure carcinogens

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