Connective Tissue

Question 1

What are the three main components of connective tissue?

Answer 1

cells, fibers, and ground substance

Question 2

What are fibroblasts/fibrocytes?

Answer 2

cells that help to form fibers of connective tissue
(collagen, elastin, and reticular fibers)

Question 3

What are fibroblasts that are able to contract called?

Answer 3

myofibroblasts

Question 4

What are reticular cells?

Answer 4

type of fibroblast that make reticular fibers

Question 5

Where are reticular cells found?

Answer 5

lymph nodes and bone marrow

Question 6

What are the function of adipocytes?

Answer 6

storage and metabolism of lipids

Question 7

What are macrophages?

Answer 7

defensive cells of connective tissue
-made in bone marrow
-monocytes when they enter the tissue would become macrophages or dendritic cells
-phagocytosis
-specific defense mechanism
-antigen presenter to T cells

Question 8

Fibers in connective tissue

Answer 8

-collagen
-elastic
-reticular

Question 9

Characteristics of collagen fibers:

Answer 9

-fibrous proteins
-secreted into extracellular
-tensile strength to matrix

Question 10

Characteristics of elastic fibers:

Answer 10

long, thin fibers that form branching network in ECM
-help connective tissue stretch and recoil

Question 11

Characteristics of reticular fibers:

Answer 11

short. fine collagenous fibers that branch extensively to form a delicate network

Question 12

What is the extracellular material of CT

Answer 12

ground substance
-many fibers are embedded in

Question 13

How many types of collagen are there?

Answer 13

At least 28

Question 14

Type I collagen

Answer 14

90% of collagen
-in loose and dense connective tissue

Question 15

Type II collagen

Answer 15

collagen in hyaline (joints) and elastic cartilage (ears and nose)

Question 16

Type III collagen

Answer 16

seen in lymph nodes and bones
-reticulin fibers
-made by reticular cells
agyrphilic (stain black with silver stain)

Question 17

Type IV collagen

Answer 17

in the basement membrane
-dense, sheet like form of ECM

Question 18

Type V collagen

Answer 18

in cornea, placenta, and dermo-epidermal junctions
-Ehlers-Danlos syndrome

Question 19

Type VII collagen

Answer 19

special anchoring fibrils that link ECM to basement membrane

Question 20

Steps of collagen synthesis

Answer 20

-first made as procollagen of three alpha chains that form a triple helix
-packed into secretory vesicles and secreted into ECS
-extracellular modification to form tropocollagen monomers
-polymerization of tropocollagen into collagen microfibrils
-several microfibrils combine to form larger collagen fibers to make up collagen bundle

Question 21

Characteristics of elastic fibers:

Answer 21

highly branched, random coiling pattern

Question 22

What makes elastic fibers?

Answer 22

fibroblasts

Question 23

What are elastic fibers first made as?

Answer 23

tropoelastin

Question 24

What are the two components of elastic fibers?

Answer 24

elastin and fibrillin

Question 25

What is elastin?

Answer 25

protein core similar to collagen

Question 26

What is fibrillin?

Answer 26

A structural glycoprotein

Question 27

Three types of non-filamentous molecules?

Answer 27

laminin, entactin, and tenascin

Question 28

What is laminin?

Answer 28

sulfate glycoprotein; major component of basement membrane

Question 29

What is entactin?

Answer 29

sulfated glycoprotein; bind with laminin

Question 30

What is tenascin?

Answer 30

bind with extracellular matrix; important in cell migration during the formation in developing nervous system

Question 31

What is Marfan's syndrome?

Answer 31

autosomal dominant condition resulting in abnormal elastic fibers -tall stature, long limbs, and long, thin fingers -enlarged aorta

Question 32

What is ground substance?

Answer 32

Amorphous, transparent material with properties of semi-fluid gel

Question 33

What are GAGs?

Answer 33

negatively charged polysaccharides made of repeating disaccharide units present in every mammalian tissue -most are sulfated -most bind to proteins to make proteoglycans

Question 34

Characteristics of the sugars present in GAGs:

Answer 34

one is always an amino sugar

Question 35

Lysosomal storage disease can cause____

Answer 35

non-functional or insufficient break down of GAGs

Question 36

What are some types of GAGs?

Answer 36

-Hyalunronic acid -Chondrotitin sulfate -Keratan sulfate -dermatan sulfate -heparan sulfate

Question 37

Where is hyaluronic acid found?

Answer 37

connective tissue

Question 38

Where is chondroitin sulfate found?

Answer 38

cartilage and bone

Question 39

Where is keratan sulfate found?

Answer 39

cartilage, bone, cornea, and intervertebral disk

Question 40

Where is dermatan sulfate found?

Answer 40

dermis, skin, blood vessels, and heart valves

Question 41

Where is heparan sulfate found?

Answer 41

basement membrane, lung, and liver

Question 42

Characteristics of GAGs:

Answer 42

-negatively charged due to sulfate and carboxyl side group -incompressibility of water providers tugor pressure -reinforced with fibrous proteins

Question 43

Characteristics of hyaluronic acid:

Answer 43

-predominant GAG in loose connective tissue -no sulfated groups -do not form proteoglycans itself, just bind with them -bacteria produce hyaluronidase to break down hyaluronic acid

Question 44

Characteristics of loose connective tissue:

Answer 44

-sparse fibers and abundant ground substance -viscous, gel-like consistency -supportive function -beneath epithelia and around nerves and vessels

Question 45

Characteristics of dense connective tissue:

Answer 45

-provide structural support -abundant fibers, moderate number of cells, less ground substance

Question 46

Two types of dense connective tissue:

Answer 46

Regular and irregular

Question 47

Regular connective tissue:

Answer 47

collagen fibers oriented parallel to each other

Question 48

irregular connective tissue:

Answer 48

collagen fibers oriented randomly

Question 49

Types of specialized connective tissue

Answer 49

bone, blood, cartilage, adipose tissue, hematopoietic tissue, and lymphatic tissue

Question 50

Characteristics of adipose tissue:

Answer 50

contain adipocytes -derived from lipoblasts -very active, has rich blood supply -energy storage, thermoregulation, and as shock absorber

Question 51

White fat

Answer 51

in dermis and around intraperitoneal organs -up to 20% in males and 25% in females

Question 52

Brown fat

Answer 52

highly specialized, present in infants and hibernating animals -thermoregulation -located around adrenals -large number of mitochondrias