Fibrous Connective Tissue

Question 1

What are the 4 major types of connective tissue?

Answer 1

Fibrous CT, Cartilage CT, Bone CT, Blood CT

Question 2

What are the functions of connective tissue?

Answer 2

Structural framework for body, protection, defense against microorganisms, supports and interconnects other tissues, energy storage, transports fluids, cells, and dissolved chemicals throughout the body

Question 3

What are the 3 basic fibers found in the ECM?

Answer 3

Collagen, Elastic fibers and Reticular fibers

Question 4

What type of collagen is the most common?

Answer 4

Type 1

Question 5

What is the main job of collagen?

Answer 5

Resist tension

Question 6

List the properties of type 1 collagen

Answer 6

Fibrils are aligned and crosslinked to increase the tensile strength; made of 2 alpha1 chains and 1 alpha2 chain that are processed and then crosslinked on the surface of the cell

Question 7

How does scurvy affect collagen?

Answer 7

Scurvy is a vitamin C deficiency, and vitamin C is needed in order to crosslink collagen fibers. This deficiency results in weakened collagen and CT

Question 8

What are the symptoms of scurvy?

Answer 8

Bleeding gums, loss of teeth, easy bruising and poor healing

Question 9

What is Ehlers Danlos Syndrome?

Answer 9

ABnormal collagen synthesis due to mutations in the collagen or collagen synthesis genes = overly flexible joints
It results in weakened collagen fibers

Question 10

What are elastic fibers?

Answer 10

Protein fibers that are elastic and recoil back to original state when stretched

Question 11

What are elastic fibers made up of?

Answer 11

Tropoelastin, fibulin 1, fibrillin 1, fibrillin 2

Question 12

What are reticular fibers?

Answer 12

They form a meshlike supportive network around structures

Question 13

What is something reticular fibers connect?

Answer 13

Connective tissue to basement membranes

Question 14

What is ground substance?

Answer 14

An amorphous, gel-like substance in the extracellular space that contains all components of the ECM BESIDES the fibrous materials (collagen, elastin)

Question 15

Why is ground substance important?

Answer 15

It carries oxygen, carbon dioxide, nutrients and waste

Question 16

What are the fixed cell types found in loose areolar CT?

Answer 16

Fibroblasts, adipocytes, mesenchymal cells

Question 17

Function of fibroblasts?

Answer 17

Produce collagens, proteoglycans, and glycoproteins

Question 18

Function of adipocytes?

Answer 18

Stores and releases fats

Question 19

Function of mesenchymal cells?

Answer 19

CT stem cells

Question 20

What are the wandering cell types found in loose areolar CT?

Answer 20

Macrophages, mast cells, leukocytes/lymphocytes, plasma cells

Question 21

Difference between fixed and wandering cells?

Answer 21

Fixed are permanent and wandering cells are actively migrating

Question 22

What is the function and location of loose CT?

Answer 22

Support and bind other tissues, hold body fluids, defense against infection
Found beneath membranous epithelia

Question 23

Principle cell type of Dense connective tissue?

Answer 23

Fibroblasts

Question 24

What is the purpose of proteoglycans and hyaluronans?

Answer 24

Sugar molecules in the ground substance that hold water and are responsible for resisting compressive forces

Question 25

What is the purpose of glycoproteins?

Answer 25

In the ground substance, can protect proteins from destruction, serve as signaling molecules and serve as structural molecules for the ground substance to be built

Question 26

Subclasses of loose CT?

Answer 26

Areolar, Adipose, and reticular

Question 27

Describe loose adipose CT

Answer 27

Abundant adipocytes and sparse ECM, provides energy reserve and insulates against heat loss, also provides protection to organs by cushioning

Question 28

What are the 2 types of loose adipose CT?

Answer 28

White fat and brown fat

Question 29

Purpose of white fat?

Answer 29

Energy storage, insulation, cushion for vital organs and hormone secretion

Question 30

Purpose of brown fat?

Answer 30

Thermogenic tissue (produces heat), abundant in newborns and reduced in adults

Question 31

Describe loose reticular CT?

Answer 31

Rich in reticular fibers, creates a supportive mesh for holding free cells
Found in the liver, bone marrow, lymph nodes and spleen where meshwork it forms houses blood cells and immune cells

Question 32

2 types of Dense CT?

Answer 32

Regular and irregular

Question 33

Describe Dense irregular CT?

Answer 33

High fibrous density with fibers in a RANDOM pattern

ex. dermis of skin, fascia, surrounding internal organs

Question 34

Describe Dense regular CT?

Answer 34

ECM tightly packed with fibers REGULARLY arranged, resists tension, poorly vascularized, wavy appearance when not in tension
ex. tendons, ligaments, aponeuroses, dense fascia, joint capsules

Question 35

Describe elastic CT?

Answer 35

High number of elastic fibers that allow stretching

ex. blood vessel walls, bronchiole tubes, nuchal ligament

Question 36

Marfan’s syndrom

Answer 36

Autosomal dominant disorder = elastin is weak! due to mutation in fibrillin 1 gene
Targets ocular, skeletal (long arms and legs) and cardiovascular (life threatening aneurysms)

Question 37

Difference between embryonic and adult CT?

Answer 37

Embryonic is high in mesenchymal cells and ECM but low fibril count
Adult is high in fibrils and their mesenchymal cells are differentiated into other cell types

Question 38

How do cells interact with the ECM?

Answer 38

Integrin receptors, syndecans, CD44, growth factor receptors, cytokine receptors

Question 39

What are integrin receptors?

Answer 39

Transmembrane receptors that bind ECM components and initiate signaling cascades using RTK mechanisms

Question 40

Epithelia and CT combine to form membranes, list the 4 types

Answer 40

Mucous, serous, cutaneous, synovial