chap 3 cell cycle and cancer Flashcards
what is differentiation
taking on a cellular fate
what are the 3 germ layers
endoderm
mesoderm
ectoderm
what happens once a cell has differentiated and then divides
the 2 new cells should follow their DNA instructions and function as the old cell once did, as a member of a tissue
what is cellular clock
after a certain amount of time or certain number of cell divisions, cells die
apoptosis
programmed cell death
how is cell death hastened
?
free radical detoxification slows as our organelles age
what limits the amount of times mitosis can occur in a cell line?
peices of telomeres, DNA structures on the ends of chromosomes, break off during mitosis
replacement is limited
what is cancer?
uncontrolled division and spread of cells in the body
what is neoplasm?
abnormal mass of growing cells
a more general term for cancer
kinds of neoplasm?
benign tumors
malignant tumors
what is a benign tumor?
cells are encapsulated, growing but not spreading
cells functions correctly in the wrong body area like fat tumors
can be successfully removed before they pressure on other organs
what is a malignant tumor?
cancerous
lack of tumor suppression genes
unregulated cell growth
what happens if a mistake is made during mitosis?
some sections of DNA sense it and halt the replication process, killing the abnormal cell
what happens if you dont have tumor suppression genes?
cells with improper DNA sequences can survive mitosis. they can then divide uncontrollably and give rise to cancer
what are carcinogens?
agents that cause mutations in DNA?
examples of carcinogens
radiation
mechanical trauma
viral infections
chemicals (tobacco, saccharine)
what happens during unregulated cell growth
cells no longer respond to normal control mechanisms
no longer heed to normal signals that regulate cell cycle
no longer exhibit density-dependent inhibition
dont stop dividing when growth factors are depleted
what does density dependent stand for?
contact
what is metastasis?
cells spreading through the body
how does cancer kill?
by displacing and putting pressure on normal tissues, cutting off their blood supply and or interrupting organ function
diagnosis and treatments of cancer
biopsy
surgical removal
x-ray treatment of surround area to kill metastasized cells
chemotherapy to find and destroy escaped cells
