Connective Tissue and Epithelial Tissue

Question 1

definition of connective tissue

Answer 1

any supporting tissue that lies between other tissues and consists of cells embedded in a relatively large amount of extracellular matrix

Question 2

where does connective tissue come from?

Answer 2

mesodermal origin

Question 3

definition of fibroblasts?

Answer 3

common cell type found in connective tissue which secrete an extracellular matrix rich in collagen.

Question 4

give 6 of the structural features of fibroblasts

Answer 4

microtubules 
filaments
junctions
heterogeneity
ageing
contraction and motility

Question 5

definition of extracellular matrix?

Answer 5

a complex network of polysaccharides and proteins secreted by cells

Question 6

function of extracellular matrix?

Answer 6

support cells
growth factors
development

Question 7

describe the structure of collagen

Answer 7

• long, stiff triple stranded helical structure

- at least 25 types of collagen

Question 8

what can an excess of collagen cause?

Answer 8

• scleroderma

- oral submucosa fibrosis

Question 9

what can insufficient levels of collagen cause?

Answer 9

• osteogenesis imperfecta
• Ehlers-Danlos syndrome
• Collagenopathy

Question 10

definition of epithelium?

Answer 10

protective and secretory tissue of closely packed cells that form a surface or lines a cavity or tube

Question 11

functions of oral mucosa epithelium?

Answer 11

• protection of underlying tissue
• permeability barriers
• protect from fluid loss and ingress of harmful agents

Question 12

definition of cell proliferation?

Answer 12

an increase in number of cells as a result of cell division

Question 13

how is cell proliferation controlled?

Answer 13

receptors
signalling
extracellular matrix
phosphorylation

Question 14

definition of a growth factor?

Answer 14

polypeptides that control animal cells growth and differentiation

Question 15

definition of a transcription factor?

Answer 15

a protein that regulates the activity of RNA polymerase

Question 16

where is the cell proliferative unit found?

Answer 16

in the basal cell layer

Question 17

definition of differentiation?

Answer 17

process by which cells or tissues undergo change towards a more specialised form or function

Question 18

definition of cytoskeleton?

Answer 18

system of protein filaments in the cytoplasm of a eukaryotic cell that gives the cell shape and the capacity for directed movement

Question 19

describe the structure of keratin?

Answer 19

• low and high molecular weight keratins pair
• basic and neutral keratins pair
• type I and type II

Question 20

Type I keratin?

Answer 20

smaller and acidic

Question 21

Type II keratin?

Answer 21

larger and basic