Intro to cancer Flashcards
(48 cards)
mitosis
-cell splits into 2 genetically identical daughter cells
meiosis
cell splits but keeps only half the genetic chromosomes
-only occurs in sex cells of testes and ovaries
differentiation
normal process where cells change in order to specialize for certain body functions
hyperplasia
increase in number or density of normal cells
-either replicated too fast or arent dying on schedule
metaplasia
change in the normal pattern of cell differentiation
-cell that isnt where it should be
dysplasia
cells differentiate in abnormal ways
What is cancer?
- classification of many diseases
- can affect many different types of cells or body systems
- can affect anyone though there are risk factors
- marked by uncontrolled growth and spread of abnormal cells
What is a tumor?
- also called neoplasm
- a mass of new tissue which grows independently from surrounding tissues and has no function
- cells grow at rates which are uncoordinated
- share properties of parents but altered shape/size/sometimes function
- provide no benefit and may be harmful
Tumors still require..
blood, oxygen, and nutrients
benign tumors are
not cancerous
some characteristics of benign tumors include:
- localized growth
- have solid, well defined borders
- stop growing when they reach the border of other tissues (called inhibition)
- grow slowly and remain stable in size
- usually easy to remove and dont recur
- can still cause problems (crowding, obstruction, etc.)
Malignant tumors
- primarily what we think of when referring to cancer
- grow aggressively and everywhere
- irregular in shape and no defined borders
- cut through other tissue causing injury and crowds out healthy cells
- varying degrees of differentiation from parent cells (minor —> extreme)
malignant cells arise from
- unregulated mitosis
- loss of specialization and differentiation
- no contact inhibition
- progressive mutations leads to greater deviation and sometimes immortality
- altered cell structure/function
- simple metabolic activity, only care about mitosis
- transplantabilty- able to break away and grow somewhere else
- promote own survival- create vascular and support structures for own use- difficult to remove
angiogensis is a
normal body function that creates new blood vessels from old.
A key difference between malignant and benign tumors is
benign tumors do not undergo angiogenesis.
an invasion of cancerous tissue could cause
-pressure atrophy, which means that as the cancer cells grow the healthy tissue dies off
other issues with invasion
- degradation of barriers between tissues
- cancer cells easily separate
- chemotaxis- cells breakdown, drawing phagocytes to clean up; which attracts other cancer cells
The process where cancer cells spread from their primary site to distant organs and tissues
metastasis
How does metastasis occur?
as malignant cells spread they access the vascular and lymphatic systems (even possibly creating their own) allowing for spread to distant parts of the body.
-the majority of cancers have already metastasized by the time they are discovered
Etiology
- several theories have been identified to explain the origins of cancer.
- 2 primary factors central to all
what are the 2 primary theories of the origins of cancer?
- Carcinogens
- immune impairment
carcinogens
- substances which can cause genetic mutation in cells through exposure
- other factors like genetics, immune response, exposure to viruses, etc., all contribute to carcinogens
immune impairment
lessons the body’s ability to fight and control abnormal cell growth
who is exposed to carcinogens?
everyone at some point; can internal or external
internal- inherited mutations, hormones, etc
external- chemicals, substances, viruses
