ECM

Question 1

ECM

Answer 1

Function: Different per tissue use

Ex: filtration in kidneys but gives strength to tendons

Question 2

Epithelial tissue

Answer 2

Little ECM in these cells

also known as basement membrane or basal lamina

Question 3

Components of ECM

Answer 3

1. ) Proteoglycans
2. ) Fibrous Proteins
3. ) Adhesive Proteins

Question 4

Proteoglycans

Answer 4

Found:

1. ) Mucus
2. ) Synovial fluid

Chondroitin sulfate and hyaluronic acid
(Precursor is glucosamine)

Question 5

Fibrous Proteins

Answer 5

Provide structure

Made up of amino acids

Types of fibrous proteins in ECM:

1. ) Collagen
2. ) Elastin

Question 6

Collagen

Answer 6

Most abundant protein in the body

Function:

1. ) resist force
2. ) different types vary for structural role
3. ) ECM function: support and strength

Question 7

Type 1 Collagen

Answer 7

Most Abundant

Location: bones, skin, tendons

Question 8

Type 2 Collagen

Answer 8

Location: hyaline cartilage

Body specific location: end of ribs, larynx, trachea and bronchi

Component for filtration in kidneys: Basement membrane and eye lens

Question 9

Elastin

Answer 9

Rubber like connective tissue

Location:

1. ) lung
2. ) large arteries
3. ) elastic ligaments

Question 10

Osteogenesis Imperfecta

Answer 10

Brittle bone

Inherited: mutation in collagen gene

Type 1: most common and increased risk for fractures before puberty

Type 2: lethal around birth

Question 11

Ehlers-Danlos Syndrome

Answer 11

Genetic defect of fibril collagen

Effects joints and some affects skin

Question 12

Marfan Syndrome

Answer 12

Autosomal dominant: gene mutation necessary for elastin

Features: long limbs, near-sighted, tall stature, abnormal joint mobility

Question 13

Antitrypsin Deficiency

Answer 13

WBC in lungs produce elastase (elastase digests elastin)

Destruction of elastin in lungs

Question 14

Cell adhesion

Answer 14

Cell-cell

Cell-matrix: adhesion receptors in the cell membrane bind to the ECM

Use for adhesions: viral infections, cardiovascular disease, bone and joint issues

Protein and carbs are important in forming these interactions.

Question 15

CAMs

Answer 15

Transmembrane proteins that are embedded in the plasma membrane

Homophilic binding: CAM on 1 cell can bind to same type of CAM on adjacent cell

Heterophilic binding: CAM can bind to different type of CAM on adjacent cell

Question 16

Types of CAMs

Answer 16

1. ) Cadherins
2. ) Selectins
3. ) Immunoglobulin superfamily
4. ) Intergrins

Question 17

Cell junctions

Answer 17

Anchoring junctions

1. ) Adherens
2. ) Desmosomes
3. ) Hemidesmosomes

Tight junctions: control flow of ions

Gap junctions

Question 18

Anchoring junctions

Answer 18

1. ) Adherens: Join actin bundles between cells
2. ) Desmosome: anchors filaments between cells
3. ) Hemidesomosome: anchors filaments to basement membrane

Question 19

Tight Junctions

Answer 19

Holds epithelial cells together and prevents leakage (leaky gut)

Question 20

Cell Adhesion molecules

Answer 20

1. ) cadherins
2. ) integrins
3. ) selectins
4. ) immunoglobulin superfamily

Question 21

Cadherins

Answer 21

Holds cells together to maintain integrity of tissue

Binding site: Bind to ______ on another cell

Some are inside the cells

CALCIUM is required for binding

Long lasting bond

Question 22

Integrins

Answer 22

Receptors are in hemidesmosomes

Regulate cell-to-cell and cell-to-ECM adhesions

Very weak

Ligands:

1. ) cell-to-cell: binds to members of the immunoglobulin superfamily
2. ) Cell-to-ECM: binds to arginine-glycine-aspartic acid residue in collagen and fibronectin

Important for signaling

1. ) outside-in
2. ) Inside-out

Question 23

Selectins

Answer 23

Short term

Cell-to-cell adhesions

Function:

1. ) Mediate WBC migration to areas of inflammation
2. ) Important for the immune system

_____ on one cell binds to lectin on another cell

Question 24

Immunoglobulin Superfamily

Answer 24

Cell-to-cell adhesion

Function:
1.) promote adhesion of WBC to endothelium of blood vessels during injury

Includes:

1. ) Intercellular adhesion molecules (ICAM)
2. ) Vascular cell adhesion molecules (VCAM)

Question 25

Fibronectin

Answer 25

Fundamental adhesive protein in connective tissues.

Three binding domains:

1. ) cell
2. ) proteoglycans
3. ) collagen

Question 26

Laminin

Answer 26

Fundamental adhesive protein in epithelial tissues.

Question 27

Extravasation

Answer 27

Migration of cells from circulation into the tissue

Process:

1. ) Rolling
2. ) Activation
3. ) Firm arrest
4. ) Diapedesis- movement of the leukocyte thru the endothelial layer

Slide 39 ECM