Cell Adaptations

Question 1

How is the cell cycle controlled?

Answer 1

Regulated by proteins called cyclins, which complex which cyclin dependant kinases, and activated CDKs play a role in phosphorylating proteins

Question 2

How are cylins regulated?

Answer 2

Some growth factors stimulate cyclins and others work by shutting production of CDK inhibitors.

Question 3

What are the different types of cell signalling?

Answer 3

endocrine, autocrine and paracrine

Question 4

What is a Permemant cell population?

Answer 4

Terminally differenitated cells that have left the cell cycle adn cannot replicate

Question 5

What is a example of a stable cell population?

Answer 5

Cardiac tissue, skeltal muscle, neural tissue

Question 6

What is a labile cell population?

Answer 6

Cells can regenerate even if they contain tissues that cannot replicate, and cells are constantly being replaced from stem cells

Question 7

What are some examples of labile cell populations

Answer 7

bone marrow, epitelium

Question 8

What is a stable cell population?

Answer 8

Intermediate between the Permemant and labile cell populations, stem cells are present but normally replicate very slowly

Question 9

What is the regenerative capacity of the liver?

Answer 9

Liver has a very good capcity for regeneration, can regenerate within 7 days in rats.

Question 10

What are the different types of cell adaptation/

Answer 10

Regeneration, Hyperplasia, Hypertrophy, Atrophy and Metaplasia

Question 11

What is cell regeneration?

Answer 11

replacement of cell losses by identical cells within the tissues

Question 12

When does regeneration occur?

Answer 12

Normall process after injury i labile or stable cell populations, if harmful agent removed and there is little damage.

Question 13

What is reconstitution?

Answer 13

The regeneration of a body part

Question 14

What are the examples of reconstitution in mammals?

Answer 14

Children below 4.5 years old can regenerate the tip of a finger if severed cleanly, blood vessels can be reconsitues and rabbit and cats can repair holes in ears

Question 15

What is hyperplasia?

Answer 15

Increase in tissue or organ size due to a increase in cell number

Question 16

What is a example of pathological Hyperplasia?

Answer 16

EPdemral thickening in chornic eczema or psorais, and it occurs secondary to excessive hormonal production.

Question 17

What is hypertrophy?

Answer 17

The increase in size of a tissue or organ without an increase in cell number

Question 18

When can cardiac hypertrophy occur?

Answer 18

In athletes, or those who suffer from hypertension or valvular defects

Question 19

What is atrophy?

Answer 19

Skhrinkag of a tissue or organ due to a aquaired decrease in the number of cells, either by cellular shrinkage or apoptosis

Question 20

What is metaplasia?

Answer 20

Reversible replacement of one adult differentiaated cell type with another adult differentiated cell type

Question 21

Give an example of pathological metaplasia.

Answer 21

Brachial psdueostraifed ciliated columnar epiteal replaced with stratified squamous in ciggaretted smoker, the cells no longer produce muscus and lack cilia.