Body Plan 06: Connective Tissue and Cartilage

Question 1

Mesenchyme

Answer 1

Embryonic connective tissue with lots of ECM and migrating cells; derives from mesoderm

Question 2

What can mesenchyme cells differentiate into?

Answer 2

Mesothelial cells, Endothelial cells, smooth muscles, osteoblasts, osteoclasts, chondroblasts, adipocyte, fibroblast

Question 3

Fibroblasts

Answer 3

Secrete fibril ECM and ground substances

Question 4

Fibrocytes

Answer 4

Inactive fibroblast

Question 5

Collagen

Answer 5

A main structural protein found in many connective tissues

Question 6

What are the main reasons for variation in collagen?

Answer 6

1) Genetic differences in amino acid sequence
2) Whether they form fibrils, fibers, or bundles
3) Differences in amounts of carbohydrate linked to hydroxylysine

Question 7

Collagen Type 1

Answer 7

A bundle of collagen, consists of a bunch of type 3 collagen. Found in bone, tendon, skin, dentin

Question 8

Collagen Type 2

Answer 8

A fibril of collagen. Found in hyaline cartilage

Question 9

Collagen Type 3

Answer 9

A fiber of collagen, consists of a bunch of type 2 collagen. Flexible network in organs that change size

Question 10

Reticular fibers

Answer 10

Collagen type 3 fibers. Only visible through silver staining

Question 11

Collagen Types 4 and 7

Answer 11

Molecular forms of collagen that assemble into sheets. Type 4 becomes basal membrane and type 7 becomes anchoring fibrils

Question 12

Scurvy

Answer 12

Vitamin C deficiency, results in decreased assembly of type 1 collagen

Question 13

Osteoporosis imperfecta

Answer 13

A point mutation changing one nucleotide in the genetic coding for type 1 collagen

Question 14

Elastic Fibers

Answer 14

ECM fibers in structures that deform then recover shape. Found in the dermis, lungs, arteries, elastic ligaments of the spinal cord, and the bladder

Question 15

What are the components of elastic fibers?

Answer 15

Microfibrils and tropoelastin

Question 16

Marfan Syndrome

Answer 16

Mutation in fibrilin gene that prevents scaffoling of the elastic fibers, leading to dilation of the root of the aortic artery and aortic aneurysms

Question 17

What immune cells are found in connective tissue?

Answer 17

Macrophages, dendritic cells, mast cells, leukocytes (specifically, neutrophils, eosinophils, lymphocytes)

Question 18

Mast cells

Answer 18

Connective tissue counterpart of basophils

Question 19

Plasma cells

Answer 19

Terminally differentiated B lymphocytes. Can be found in lamina propria of mucosa

Question 20

Macrophages

Answer 20

Develop from monocytes after migrating into tissue; phagocytotic; antigen-presenting cells

Question 21

Adipocytes

Answer 21

Lipid storages that develop from lipoblasts from mesenchyme

Question 22

White adipose tissue

Answer 22

Store energy and are about 20-25% of body weight

Question 23

Brown adipose tissue

Answer 23

Non-shivering heat production, not found much in adults

Question 24

What are the four types of connective tissue?

Answer 24

Loose connective tissue, elastic connective tissue, dense connective tissue, cartillage

Question 25

Loose connective tissue

Answer 25

Allows for movement and houses immune defense cells. It is loose to accommodate for moving things and smooth muscle contraction

Question 26

Mucosa

Answer 26

The mucous membrane, consisting of epithelial lining, underlying connective tissue, and muscularis mucosae

Question 27

Serosa

Answer 27

Single layer of squamous mesothelial cells with underlying loose connective tissue that lines celomic cavities

Question 28

Dense connective tissue

Answer 28

Transmit tensile forces from muscles to bones; includes tendons and ligaments

Question 29

Elastic connective tissue

Answer 29

Consists of elastic fibers, stores and returns energy

Question 30

Cartilate tissue

Answer 30

Avascular connective tissue that can bear stress without permanent distortion. Comes in three types (1, 2, and elastic fibers)

Question 31

How is cartilage molecularly organized?

Answer 31

The chondroitin sulfate side chains of the proteoglycan electrostatically bind to the collagen fibrils, forming a cross-linked matrix

Question 32

Hyaline cartialge

Answer 32

Most prominent type of cartilage in body, mostly type 2 cartilage

Question 33

Elastic cartilage

Answer 33

Maintains shape after deformation, consists of type 2 cartilage and elastic fibrils. Found in ear and larynx

Question 34

Fibrocartilage

Answer 34

Dense regular connective tissue with cells in lacunae, consisting mainly of type 1 cartilage. Found in places where hyaline cartilage is not available

Question 35

Perichondrium

Answer 35

Layer of dense irregular connective tissue that surrounds the cartilage of developing bone

Question 36

Chondroblast

Answer 36

Immature cartilage producing cell

Question 37

Where do chondrocytes usually reside?

Answer 37

In lacunae inside the Territorial/capsular matrix

Question 38

Interstitial cartilage growth

Answer 38

Chondrocytes secrete ECM and become confined to their lacunae. Only viable in young, smaller bones

Question 39

Appositional cartilage growth

Answer 39

Perichondrium cells secrete fiborous element around cartilage. Chondrocytes in perichondrium secrete ECM , sealing themselves off

Question 40

Ground substance

Answer 40

a fluid, gelatinous component of extracellular matrix that is rich in glycosaminoglycans, proteoglycans, and glycoproteins