Tissue Renewal and Repair lecture

Question 1

Mechanisms regulating cell populations are due to increase and decrease what?

Answer 1

Stem cell input
Cell death
Rate of proliferation
Rates of differentiation

Question 2

What is the G1 phase?

Answer 2

Presynthetic

Question 3

What is the G2 phase?

Answer 3

Premitotic

Question 4

What is the S phase?

Answer 4

DNA synthesis

Question 5

What is the M phase?

Answer 5

Mitotic

Question 6

What is cell growth initiated by?

Answer 6

Binding of signaling agent to a specific receptor frequently located on the plasma membrane

Question 7

What are the three types of receptors?

Answer 7

Receptors with intrinsic kinase activity
Receptors without intrinsic kinase activity
GPCRs

Question 8

What is embryonic stem cell therapy?

Answer 8

Therapeutic cloning using ES cells and stem cell therapy using induced pluripotent stem cells

Question 9

What is Therapeutic cloning using ES cells?

Answer 9

The diploid nucleus of an adult cell from a patient is introduced in a enucleated oocyte

Question 10

What is stem cell therapy using induced pluripotent stem cells?

Answer 10

The cells of a patient are placed in culture and transduced with genes encoding transcription factors

Question 11

What does a zygote from from?

Answer 11

The union of a sperm and egg whic divides to form a blastocyte and the inner cell mass of that generates the embryo (known as the embryonic stem cells)

Question 12

What happens as pluripotent cells differentiate?

Answer 12

They give rise to cells with more restricted developmental capacity and generate stem cells that are committed to specific lineages

Question 13

Where are skin stem cells located?

Answer 13

The bulge area of the air follicle, in sebaceous glands and in the lower layer of the epidermis

Question 14

Where do small intestine stem cell reside?

Answer 14

Near the base of a crypt, above Paneth cells

Question 15

Where are liver stem (progenitor) cells located? (Oval cells)

Answer 15

Canals of Hering (structures that connect bile ducts with paraenchymal hepatocytes)

Question 16

Where are corneal stem cells located?

Answer 16

Limbus region between the conjunctiva and the cornea

Question 17

What are the major components of the extracellular matrix?

Answer 17

Collagens & elastins
Adhesive glycoproteins
Proteoglycans and hyaluronan

Question 18

What are the phases of cutaneous wound healing?

Answer 18

Inflammation, Proliferation and Maturation

Question 19

What happens during inflammation?

Answer 19

Clot formation and chemotaxis

Question 20

What happens during proliferation?

Answer 20

Re-epithelialization, provisional matrix

Question 21

What happens during maturation?

Answer 21

Collagen is deposited just before…

Collegan matrix and wound contraction

Question 22

What happens in angiogenesis?

Answer 22

Endothelial cells from the pre-exisitng vessels become motile and proliferate to form capillary sprouts
EPCs are mobilized from the bone marrow and may migrate to a site of injury where they differentiate and form mature netwrok

Question 23

What happens in healing of thin wounds?

Answer 23

Small amounts of granulation tissue and formation of a thin scar with minimal contraction

Question 24

What happens in healing of thick wounds?

Answer 24

Large amounts of granulation tissue and scar tissue and would contraction

Question 25

What is regeneration?

Answer 25

Restitution of normal structure

Question 26

What is repair?

Answer 26

Scar formation

Question 27

What is fibrosis?

Answer 27

Tissue scar

Question 28

What happens when there is a persistent stimulus?

Answer 28

Activation of macrophages and lymphocytes
Growth factors cause proliferation of fibroblast, endothelial cells and fibrogenic cells
Cytokines cause increase collagen synthesis or decrease in metallioproteinase activity with decrease collagen degradation both of which lead to fibrosis