Cancer A&P

Question 1

what is the cell cycle?

Answer 1

–series of events that occurs during the growth and development of a cell
–regulates duplication of genetic information
–assures that daughter cells are structurally identical to the parent cell

Question 2

four phases of cell cycle

Answer 2

–G1
–S
–G2
–M
G0

Question 3

G1

Answer 3

–cell prepares to make DNA
–RNA and protein synthesis and cell growth

Question 4

S

Answer 4

–DNA synthesis occurs
–2 separate sets of chromosomes arise (one for each daughter cell)

Question 5

importance of restriction point in cell cycle

Answer 5

–under normal conditions, all cell proliferation is regulated by the restriction point
–chemo drugs are designed to attack cells that are proliferating rapidly
–by using drugs that inhibit completion of the restriction point, normal cells can’t proliferate and are protected from chemo treatments

Question 6

G2

Answer 6

–DNA synthesis ceases
–cell prepares for mitosis

Question 7

M

Answer 7

–cell actually divides

Question 8

G0

Answer 8

–resting phase
–not part of the cell cycle
–cells can remain in G0 for days, weeks, or years

Question 9

which cells don’t divide?

Answer 9

–neurons
–skeletal muscle cells

Question 10

which cells divide slowly?

Answer 10

liver cells

Question 11

which cells divide rapidly?

Answer 11

GI epithelial cells lining GI tract

Question 12

undifferentiated stem cells

Answer 12

can be triggered to enter cell cycle and produce parent cells

Question 13

parent (progenitor) cells

Answer 13

–continue dividing and reproducing
–examples: blood cells, skin cells, liver cells

Question 14

well-differentiated cells

Answer 14

–do not normally divide and reproduce
–examples: neurons and cells of skeletal and cardiac muscle

Question 15

what causes cell proliferation to speed up?

Answer 15

–tissue injury
–tissue loss

Question 16

three basic cell proliferation properties

Answer 16

(1) intracellular control of proliferation
(2) contact inhibition
(3) rate of cell proliferation

Question 17

intracellular control of cell proliferation

Answer 17

–cells are controlled by an intracellular mechanism that tells them when they need to regenerate
–there is a balance in cell proliferation and cell degeneration/death
–cell proliferation occurs when there is a need for more cells, to replace dead or dying cells

Question 18

contact inhibition

Answer 18

–normal cells respect the boundaries of other cells and tissues
–normal cells do not invade cells or tissues outside of their own territory

Question 19

rate of cell proliferation

Answer 19

–differs with each cell type
–examples of rapid proliferation: hair follicles, bone marrow, epithelial linings of GI tract
–examples of slow proliferation: cartilage, liver

Question 20

cell differentiation

Answer 20

the process in which proliferating cells are transformed into different and more specialized cell types

Question 21

apoptosis

Answer 21

–molecules on cell surface changes
–this allows healthy cells (macrophages) to recognize, engulf, and dismantle the dying cell before it falls apart

Question 22

stem cells

Answer 22

when triggered by some physiologic event:
–they jump into cell cycle
–begin proliferation and differentiation

Question 23

stem cells and cancer

Answer 23

it is the mutation of cells at some point in the differentiation process from a stem cell to adult cells that cancer cells are formed

Question 24

benign

Answer 24

–grow slowly
–well-defined capsule
–not invasive
–well-differentiated
–low mitotic index
–do not metastasize

Question 25

malignant

Answer 25

--grow rapidly --not encapsulated --invade local structures and tissues --poorly differentiated --high mitotic index --can spread distantly