Lecture 4

Question 1

where is the major fracture/stress point located?

Answer 1

• between the epidermis and the epidermis of the stratified epithelium

Question 2

stratified epithelial cells divide _____ to the basal membrane

Answer 2

perpendicular

Question 3

what cells are located in the demris

Answer 3

fibroblasts

Question 4

describe the layers of the epithelium

Answer 4

epidermis, EC matrix and? dermis

Question 5

how are adjacent cells connected

Answer 5

• tight junctions, desmosomes and gap junctions

Question 6

do fibroblasts or epithelial cells produce more EC matrix

Answer 6

fibroblast produce more matrix

Question 7

how do cells adhere to their EC matrix?

Answer 7

via adhesion molecules ,

Question 8

what type of junction joins cytoskeleton and integrins

Answer 8

focal adhesion

Question 9

what type of junction joins intermediate filament cytoskeleton and integrins

Answer 9

hemisdesmosomes

Question 10

are focal adhesions or hemidesosomes more stable?

Answer 10

focal adhesions are transient while hemidesmsoomes are stable

Question 11

integrins

Answer 11

Integrins are heterodimeric transmembrane receptors that mediate cell-adhesion

Question 12

hemidesomsome structure

Answer 12

EC matrix connected to integrin connected to pectin connected to intermediate filaments

Question 13

what does the electromicrograph? show us

Answer 13

• pectin and integral antibodies are found in the same place (showing that they are associated), and they are located only with the cells touching the dermis, because those are teh only cells that are connected to the basal membrane?

Question 14

blistering

Answer 14

• caused when epidermis detaches from the epidermis, and the blister becomes filled with EC fluid

Question 15

what are the three types of junctions in cells

Answer 15

• anchoring junctions, occluding junctions, and communicating junctions

Question 16

anchoring junctions

Answer 16

• can be cell-matrix junctions
• can be cell-cell junctions
• mechanically attach cells to their external surroundings
• transmit information back to the cell

Question 17

occluding and communicating junctions

Answer 17

cell-cell juntions

Question 18

what are examples of human connective tissue diseaes

Answer 18

• arthritis (osteoarthritis)
• soft tissue cancer (sarcoma)
• vitamin C deficiency (Scurvy)
• osteogenesis imperfecta

Question 19

what protein is a major component of the ECM

Answer 19

collagen

Question 20

how many types of collagen exist in the human genome

Answer 20

20 types

Question 21

what is the most abundant protein in mammals

Answer 21

collagen (makes up about 1.3 of whole body protein content)

Question 22

collagen features

Answer 22

• insoluble, trimeric structure,
• homotrimeric, heterotrimeric depending on the genes encoding them
• made by fibroblasts

Question 23

structure of collagen

Answer 23

• 3 alpha chain polypeptides