2: Tissue and cell injury Flashcards
What is homeostasis?
Physiological process in which variables within the body are kept within a narrow range
What two processes do cells undergo when they are under increased demand?
Hyperplasia
Hypertrophy
What process do cells undergo when they are under decreased demand?
Atrophy
What process do cells undergo when they are exposed to altered stimuli?
Metaplasia
What is hypertrophy?
Increase in the size of cells
What is hyperplasia?
Increase in the number of cells
Which signals cause a cell to undergo cell division?
Growth factors
Which enzyme is bound to some growth receptors?
Tyrosine kinase
Which protein, other than tyrosine kinase, is bound to some growth receptors?
G-protein
Which pathway involves tyrosine kinase, RAS and RAF?
MAPK/ERK pathway
What are the four stages of the cell cycle, and what happens in each stage?
G1 - protein synthesis
S - DNA replication
G2 - more protein synthesis
M - mitosis
Which enzymes control the progression of the cell cycle?
Cyclin dependent kinases (CDKs)
___ activate CDKs during the cell cycle.
Cyclins
Which protein is activated by CDK4 during G1?
Retinoblastoma (Rb)
What is the protein which controls the main checkpoint in G2?
p53