Connective Tissues

Question 1

connective tissue cells are separated from each other by

Answer 1

extracellular matrix

Question 2

extracellular matrix (ECM)

• what is it
• what is it like in bone
• what does it carry

Answer 2

gel-like substance with embedded protein fibers

• in bone it is mineralized
• carries O2, CO2, nutrients, and wastes

Question 3

3 types of adult fibrous connective tissues

Answer 3

loose (areolar)
dense regular
dense irregular

Question 4

6 functions of connective tissues

Answer 4

1. structural framework of body
2. protection
3. supports and interconnects tissues
4. energy storage (adipose)
5. transports fluids, cells, chemicals
6. defense against microorganisms

Question 5

fibroblasts

- what do they produce

Answer 5

produce collagens, proteoglycans, glycoproteins

Question 6

mesenchymal cells

Answer 6

connective tissue stem cells

Question 7

adipocytes

Answer 7

store and release fats

Question 8

chondrocytes

Answer 8

produce and maintain cartilage components

Question 9

osteoblasts

Answer 9

produce bone components

Question 10

hematopoietic stem cells

Answer 10

produce red blood cells and immune cells

• macrophages
• mast cells
• lymphocytes
• plasma cells

Question 11

function of collagens in ECM

Answer 11

resists tension

Question 12

function of elastins in ECM

Answer 12

stretchable fibers, assembly of tropoelastin, fibulin-1, fibrillins 1/2

Question 13

function of reticular fibers in ECM

Answer 13

forms supportive meshwork

Question 14

type 1 collagen fibers

Answer 14

aligned and cross-linked to increase tensile strength

Question 15

Ehlers-Danlos syndrome

Answer 15

abnormal collagen synthesis leading to weak collagen fibers

Question 16

Scurvy

Answer 16

due to vitamin C deficiency; vitamin C is a cofactor in cross-linking collagen fibers
- weakens connective tissue

Question 17

Marfan’s syndrome

Answer 17

autosomal dominant disorder where elastin is weak; caused by mutation in fibrillin-1 gene

• targets ocular, skeletal, and cardiovascular systems
• patients tend to be tall with long arms/legs

Question 18

features of embryonic connective tissue

Answer 18

rich in ECM and mesenchymal stem cells; some collagen and reticular fibers

Question 19

“Warton’s Jelly”

Answer 19

embryonic connective tissue in the umbilical cord

Question 20

adult mesenchymal stem cells

Answer 20

multipotent stem cells that differentiate into a variety of cell types:

• fibroblasts
• muscle cells
• osteoblasts
• chondroblasts
• adipocytes

Question 21

areolar tissue

Answer 21

a type of loose connective tissue; low density tissue with both fixed and wandering cells; widespread

Question 22

adipose tissue

Answer 22

a type of loose connective tissue; fat containing tissue

Question 23

reticular connective tissue

Answer 23

a type of loose connective tissue; rich in reticular fibers; forms an open framework to create a supportive mesh for holding free cells
- meshwork also houses blood cells and immune cells outside blood and lymph vessels

Question 24

dense irregular connective tissue

• how are the fibers arranged
• example

Answer 24

fibers are deposited in a random pattern

- ex: dermis of skin

Question 25

dense regular connective tissue - how are the fibers arranged - function - vascularization? - example

Answer 25

fibers are deposited in a highly regular patterns; resists pulling forces; poorly vascularized - ex: tendons connecting skeletal muscle to bone

Question 26

elastic connective tissue

Answer 26

dense connective tissue rich in elastin fibers; allows recoil of tissue following stretching

Question 27

what are the three types of fixed cells in loose areolar connective tissue

Answer 27

fibroblasts adipocytes mesenchymal cells

Question 28

what are the four types of wandering cells in loose areolar connective tissue

Answer 28

macrophages mast cells leukocytes/lymphocytes plasma cells

Question 29

functions of loose connective tissue

Answer 29

- support and bind other tissues - hold body fluids - defense against infection

Question 30

where is loose connective tissue found

Answer 30

- beneath membranous epithelia | - around blood vessels, muscles, and nerves

Question 31

function of adipose connective tissue

Answer 31

- provides reserve energy source and insulates against heat loss - supports and protects organs

Question 32

where is adipose connective tissue found

Answer 32

under skin, around organs, within abdomen, breasts and buttocks

Question 33

white fat | - functions

Answer 33

functions in energy storage, insulation, cushioning vital organs, and hormone secretion

Question 34

brown fat - functions - babies vs adults

Answer 34

key thermogenic tissue, abundant in newborns, greatly reduced in adults

Question 35

where is reticular connective tissue found

Answer 35

liver, bone marrow, lymph nodes, spleen

Question 36

where is dense irregular connective tissue found

Answer 36

dermis of skin, capsules surrounding internal organs, perichondrium and periosteum, fascia

Question 37

what is the principle cell type of dense regular CT

Answer 37

fibroblasts

Question 38

where is elastic CT found

Answer 38

blood vessel walls, bronchiole tubes, special ligaments (ligamentum nuchae)

Question 39

function of fibroblasts

Answer 39

produce the collagen, elastin, reticular fibers, proteoglycans, and glycoproteins in the ECM

Question 40

adipocytes - micrograph appearance - function

Answer 40

closely packed cells with nuclei pushed to the side by large fat droplet; removes lipids from blood and stores it and releases it into the bloodstream when needed - provides reserve energy source

Question 41

macrophages

Answer 41

differentiate from monocytes; function is phagocytosis and destruction of bacteria/damaged cells/sick cells, removal of debris, and antigen processing and presentation

Question 42

mast cell

Answer 42

secrete chemicals such as histamine that mediate the allergic response and heparin (an anti-coagulant of blood)

Question 43

plasma cells

Answer 43

differentiate from B-lymphocytes; produce antibodies that mediate immunity

Question 44

3 types of proteoglycans

Answer 44

- chondroitin sulfates - heparan sulfates - keratan sulfates

Question 45

hyaluronan

Answer 45

links proteoglycans into large link | - found a lot in cartilage

Question 46

integrin receptors

Answer 46

transmembrane linkers between ECM and cells | - used by migrating cells and epithelial cells

Question 47

syndecans

Answer 47

single transmembrane domain proteins that are thought to act as coreceptors

Question 48

CD44

Answer 48

cell surface adhesion receptor that is highly expressed in many cancers

Question 49

dystroglycans

Answer 49

cell adhesion receptor that connects ECM to cells