Neoplasia Flashcards
How many cells compose the body? How many different types of cells?
30-40 trillion
200+ different types (epithelial, neurons, RBC, etc)
How many cells die each day in the human body?
100 billion cells die each day and are replaced by new cells
Describe neoplasia.
new, abnormal growth of tissue (uncontrolled)
does not wait for signals for new tissue growth
ignores signals to stop dividing
do not mature normally (differentiate)
do not die off to keep cell count constant
Define the following: adenoma, carcinoma, adenocarcinoma, sarcoma, lymphoma, melanoma, leukemia, blastoma.
adenoma: benign tumor derived from glandular cells
carcinoma: malignant tumor derived from epithelial cells
adenocarcinoma: malignant tumor derived from glandular
tissue
sarcoma: malignant tumor derived from bones or soft tissue
lymphoma: malignant tumor derived from lymphocytes
melanoma: malignant tumor derived from melanocytes
leukemia: malignant tumor of blood-forming tissues
blastoma: malignant tumor derived from precursor cells
How many periods are in the cell cycle?
4 (G1, S, G2, M)
What are quiescent cells capable of doing?
G0, can move into or out of G1
True or false: normally, the number of cells produced is not equal to the number of cells that die
false
number of cells produced=number of cells that die
What happens in each phase of the cell cycle?
G1: cell grows and prepares for DNA replication
S: DNA replication
G2: cell continues to grow and prepare for mitosis
M: cell stops growth and starts division
G0: cell has left cell cycle and stopped dividing
When do checkpoints occur in the cell cycle?
one in G1 (DNA synthesis check) and one in G2 (preparation for mitosis)
-apoptosis occurs if anything goes wrong
What is the significance of R (restriction point)?
cell has committed to the cycle for division
Describe each phase of the M phase.
prophase: condensation of chromatin and disappearance of
nucleus
metaphase: chromosomes align on the metaphase plate
anaphase: chromosomes split and move to the opposite poles
of the cell
telophase & cytokinesis: spindle disappears, nucleus reforms
and mother cell divides into two
daughter cells
What tells a cell to divide?
growth factors (cells only divide when they are told to do so by growth factors)
What are growth factors responsible for?
initiate and maintain transition through G1 to S phase
When does the restriction (R) point occur?
2-3 hours before onset of DNA synthesis
At which point in the cell cycle are growth factors not required?
beyond R point
What are the major checkpoint monitoring molecules?
cyclins
cyclin dependent kinases (CDKs)
p53 (DNA damage)
RB (restinoblastoma)
APC (anaphase promoting complex)
What is cell differentiation?
cells become specialized cells to carry out specific functions
develop certain structures or lose certain structures
What is cell apoptosis?
programmed cell death
no damage to neighboring cells
Which pathway is responsible for mediating cell apoptosis?
caspase signaling pathway
True or false: apoptosis is the same as necrosis and autophagy
false
necrosis: influx of fluid, everything swells and bursts
autophagy: cell consumes its organelles
What happens to a differentiated, “working” cell when it mutates?
they form benign tumors
What happens to an undifferentiated cell when it rapidly divides and mutates?
they form malignant tumors
Describe benign tumors.
cells: similar to normal cells
growth: relatively slow, expanding mass
spread: localized
systemic effects: rare
life-threatening: only in certain locations (brain)
external surface: smooth
capsule: yes
necrosis: no
hemorrhage: no
Describe malignant tumors.
cells: varied in shape and size with large nuclei
growth: rapid growth, no cell adhesion
spread: local and distal metastasis
systemic effects: often
life-threatening: yes, by tissue destruction and spread of tumors
external surface: irregular
capsule: no
necrosis: yes
hemorrage: yes
What are the diagnostic techniques used to diagnose benign tumors?
imaging (X-ray, ultrasound, mammogram, CT, PET, MRI)
tests (blood test, BIOPSY)
scopy (colonoscopy, endoscopy)
What is the treatment for benign tumors?
treatment may not be needed
watch-and-wait
surgery
radiation therapy
What are the diagnostic techniques used to diagnose malignant tumors?
imaging (X-ray, ultrasound, mammogram, CT, PET, MRI)
tests (blood test, BIOPSY)
scopy (endoscopy, colonscopy)
What is the treatment for malignant tumors?
surgery (primary treatment)
chemotherapy
radiation therapy
-the above two can be done before surgery to reduce tumor
size
targeted therapy
immunotherapy
-the above two are not usually given before surgery
What is a CT scan?
computerized tomography
x-ray scan from different angles and computer-processed cross-sectional images