Cellular Adaptations Flashcards
Cells control signals to do what?
Survive, divide, differentiate, die
Can you see things happening in interphase under and electron microscope or a light microscope?
No
What part of the cell cycle can you see under a light microscope?
M phase (mitosis and cytokinesis)
Which is the most critical checkpoint of the cell cycle, when does this occur?
Restriction point
Near the end of G1
What is the relevance of the restriction point?
Once you pass the restriction point, there is no return
The cell cycle is controlled by what molecules?
Cyclins and CDKs
What is the definition of “hyperplasia”?
Give some examples of physiological and pathological hyperplasia
Increase in the number of cells above “normal”
Phys: Endometrium
Path: Goitre, eczema
What is the definition of “hypertropy”?
Give an example of physiological and pathological hypertrophy?
Increase in the cell size above “normal”
Phys: Skeletal muscle
Path: LV hypertrophy
What is the definition of “atrophy”?
Give some examples of physiological and pathological atrophy
Decrease in the size OR the number of cells below “normal”
Phys: ovarian atropy in post-menopausal women
Path: atrophy of ECM (osteoporosis), aging, atrophy if disuse
What is the definition of “dysplasia”?
What does this often precede?
Abnormal maturation of cells within a tissue, disordered tissue organisation
Malignant neoplasia
What is the definition of “metaplasia”?
Give an example of this
Reversible change of one differentiated cell type to another
Smoking: pseudostratified ciliated columnar epithelium into stratified squamous epithelium
Is tissue atrophy reversible?
Yes but only up to a point
What is the definition of “aplasia”?
Complete failure of a specific tissue or organ to develop
What is the definition of “atresia”?
“No orifice”
Congenital imperforation of an opening (e.g.anus, vagina, small bowel)
What is the definition of “involution”?
Normal programmed shrinkage of an organ (overlap with atrophy)
