Connective Tissue – General/Blood

Question 1

General characteristics of connective tissues

Answer 1

Few cells, large amounts of extracellular matrix, provides structural support, stores metabolites, defense/protection of the body (immunity, inflammatory, allergic reactions), repairs other tissues

Question 2

Collagen characteristics

Answer 2

Most abundant protein in the body; flexible/tensile strength; produced by fibroblasts

Question 3

Collagen type I

Answer 3

Can form collagen bundles; found in [dermis, tendons, ligaments, fascia, bone, most connective tissue]

Question 4

Collagen type II

Answer 4

found in cartilage

Question 5

Collagen type III

Answer 5

Assemble into reticular fibers

Question 6

Collagen types IV

Answer 6

Sheet like mesh-work that is found in the basal lamina

Question 7

Reticular fibers

Answer 7

Made of type III collagen, cross-link to form reticular tissue

Question 8

Elastic fibers

Answer 8

Made of elastin and fibrillin, responds to stretch/distention

Question 9

Elastin

Answer 9

hydrophobic domain, cross-linked by covalent bonds, fibers have variable lengths OR lamellar layers (like in blood vessels)

Question 10

Fibrillin

Answer 10

Thin microfibrils that surrounds developing elastic fibers

Question 11

Hyaluronic acids

Answer 11

Do not attach to protein cores to form proteoglycans, but will attach to existing proteoglycans to create a hydrophilic aggregate

Question 12

Role of proteoglycans

Answer 12

Forms aggregates with hyaluronic acids to create a “gel” that resists compression without losing compressibility

Question 13

Multiadhesive glycoproteins

Answer 13

Cross-links collagen, ECM, and cells; stabilizes/binds ECM to transmembrane integrins; BINDING SITES

Question 14

2 types of multiadhesive glycoproteins

Answer 14

Fibronectin and Laminin

Question 15

Fibronectin

Answer 15

Most abundant glycoprotein, contains binding sites for ECM molecules

Question 16

Laminin

Answer 16

Present in the basal membrane, contains binding sites

Question 17

Types of resident cells

Answer 17

Fibroblasts, Adipocytes, Macrophages, Mast Cells

Question 18

Fibroblasts

Answer 18

Principle type of resident cell, produce components of the ECM, Types: active, inactive, myofibroblasts, mesenchymal

Question 19

Active fibroblasts

Answer 19

Abundant cytoplasm/RER/Golgi and has euchromatic nucleoli, commonly in loose connective tissue

Question 20

Inactive fibroblasts

Answer 20

Limited cytoplasm, heterochromatic, common in dense connective tissue

Question 21

Myofibroblasts

Answer 21

Have the ability to contract, are commonly found in wound sites

Question 22

Mesenchymal fibroblasts

Answer 22

present in embryonic connective tissue, give rise to many types of connective tissue

Question 23

Adipocytes

Answer 23

Store energy as fat, produce hormones; Types: unilocular, multilocular

Question 24

Unilocular adipocytes

Answer 24

Most common type, forms white adipose tissue, usually large lipid droplet with a flattened nucleus

Question 25

Mulitlocular adipocytes

Answer 25

Rare in adults, multiple fat droplets and a large amount of mitochondria, generates heat, aka brown adipose tissue

Question 26

Macrophages

Answer 26

Phagocytic cells derived from monocytes, have a kidney-shaped nucleus – functions: phagocytosis of bacteria/senescent cells/cell debris, presents antigens to immune cells, produces cytokines to active the immune system

Question 27

Mast cells structure

Answer 27

Largest cells in connective tissue, oval w/ centrally placed nucleus, many big basophilic granules, surface contains IgE receptors

Question 28

Mast Cell Functions

Answer 28

Mediates Inflammatory/hypersensitivity reactions: activates during first exposure to antigen, IgE activation causes degranulation of mast cells

Question 29

Effects of histamines

Answer 29

Vasodilation, increase in vascular permeability, bronchoconstriction, increase in mucous production

Question 30

Types of transient cells

Answer 30

Plasma cells, Leukocytes

Question 31

Plasma cells

Answer 31

Antibody producing cells derived from B-lymphocytes, most numerous in areas of inflammation, have a "clock-face" pattern

Question 32

Types of Leukocytes

Answer 32

aka WBCs, Lymphocytes, monocytes, neutrophils, eosinophils, basophils [Everyone's Blood Needs More Leukocytes]

Question 33

Lymphocytes

Answer 33

Round, dark heterochromatic | Produce antibodies/regulate immune response

Question 34

Monocytes

Answer 34

Kidney shaped nucleus (is a macrophage when enters tissue), phagocytic cell

Question 35

Neutrophils

Answer 35

phagocytes for bacteria | elongated, segmented, multi-lobed nucleus

Question 36

Eosinophils

Answer 36

React to parasitic infections | Intense staining granules and bi-lobed nucleus

Question 37

Basophils

Answer 37

Rare cells that are involved with allergic response | Bi-lobed nucleus and basophilic granules

Question 38

Embryonic connective tissue

Answer 38

Mesenchyme and Mucous connective tissue

Question 39

Mesenchyme tissue

Answer 39

Forms a 3D network, abundant in ground substance, but has few collagen/reticular fibers

Question 40

Mucous connective tissue

Answer 40

Found only in umbilical cord (aka Wharton's jelly) | large amounts of hyaluronic acid

Question 41

Loose connective tissue

Answer 41

Highly cellular, thin/relatively sparse collagen type I fibers, abundant ground substance, large amounts of transient cells, acts as a filter tissue

Question 42

Dense connective tissue

Answer 42

Lots of collagen type I fibers, little ground substance

Question 43

Dense regular connective tissue

Answer 43

Densely packed collagen bundles, oriented in the same direction, have many inactive fibroblasts

Question 44

Dense irregular connective tissue

Answer 44

Collagen bundles are in different directions, fibroblast are mostly inactive, resists stress in all direction

Question 45

Specialized connective tissue

Answer 45

Adipose, reticular, cartilage, bone

Question 46

Reticular tissue

Answer 46

loose connective tissue found in the stroma of organs | Has thin, branching, interconnected threads