Connective Tissue

Question 1

What is connective tissue?

Answer 1

Characterized by large amounts of intracellular substance with very few cells

Question 2

Connective tissue consists of…

Answer 2

• cells
• extracellular fibers
• ground substance

Question 3

What are the 3 types of connective tissue?

Answer 3

• embryonic connective tissue
• connective tissue proper
• specialized connective tissue

Question 4

What are the types of embryonic connective tissue ?

Answer 4

• mesenchyme

- mucus

Question 5

What are the types of connective tissue proper?

Answer 5

Loose connective tissue

Dense connective tissue
-irregular

-regular

Question 6

What are the types of specialized connective tissue ?

Answer 6

Adipose tissue

Blood

Bone

Cartilage

Question 7

What are loose (areolar) connective tissue ?

Answer 7

• Contains more cells than collagen fibers
• Located in mucosa and submucosa of various organs
• Surrounds:
• muscles
• nerves
• blood vessels

Question 8

Describe connective tissue proper

Answer 8

-dense connective tissue

• contains more collagen fibers than cells
  
  • regular dense connective

Tissue
-collagen fibers are preferentially oriented

• regular dense connective tissue
  
  • collagen fibers
    
    • randomly oriented
• reticular fibers
• found in dermis of skin

Question 9

Where are connected tissue proper found?

Answer 9

• Tendons
• ligaments
• cornea

Question 10

What are the most abundant fibers of connective tissue?

Answer 10

Collagen fibers

Question 11

How does collagen fibers appear?

Answer 11

Appear wavy
-variable width

-intermediate length

Stain easily with Eosin (Acid dye)

Question 12

What are the functions of reticular fibers?

Answer 12

Supporting framework for cellular constituents of tissue & organs

Form supporting stroma in hemopoietic and lymphatic tissues (not thymus)

In these cases: fibers surround the cells and isolate them

Question 13

What are reticular fibers?

Answer 13

-closely related to collagen

• composed of type III collagen
  
  • Also may have some type IV collagen

Fibers are about 20 nm diameter

Question 14

What are the function elastic fibers?

Answer 14

Enable tissues to stretch and distend

Prevents tearing

Question 15

What are elastic fibers ?

Answer 15

Elastic fibers are thinner than collagen

-In large amounts, give a yellowish color to tissues

-fibers are interwoven with collagen
Prevents tearing

Question 16

What are the functions of ground substance?

Answer 16

“Glue”- binds cells to fibers

“Lubricant” - allows ease of motion (pathway for cell migration)

“Barrier” - physical prevention of bacteria and microorganisms

Tissue tensile strength

Question 17

What is ground substance?

Answer 17

-occupies the space between cells and fibers

• clear, viscous substance
  
  • high water content
• Appears amorphous in light micrographs
  
  • stains with PAS stain
  • always lost in H &E preps

Consists largely of:

• Proteoglycans
• Hyaluronic acid

Question 18

Types of cells and their numbers reflect their…

Answer 18

Functional activity

Question 19

Connective tissue cells are classified as:

Answer 19

• Fixed

- Wandering

Question 20

What are the functions of fibroblasts ?

Answer 20

Principal cell of connective tissue
-Main cell involved in wound repair

Synthesize
-collagen

• elastin
• reticular fibers
• complex carbohydrates of ground substance

Question 21

Describe macrophages

Answer 21

• possess a large indented or kidney-shaped nucleus
• ingestion and degradation of foreign matter
• Stimulation of the immune response by immune presentation
• fixed and wandering

Question 22

Where are macrophages derived from?

Answer 22

Derived from monocytes in the bone marrow

Question 23

Macrophages are difficult to identify unless…

Answer 23

They display obvious phagocytosis

Question 24

What are mast cells?

Answer 24

• Oval, cytoplasm filled with basophilic granules

- Storage of chemical mediators of inflammatory response

Question 25

Mast cells are distributed mainly in

Answer 25

- area of small blood vessels. - capsules of organs - within organs near vessels

Question 26

Where are mast cells absent from and why?

Answer 26

Absent from brain and spinal cord -protects them from damage due to edema and allergic reactions

Question 27

What are adipose cells?

Answer 27

Specialized to store fat Differentiate from: - fibroblasts - mesenchymal cells - occur singly or in groups - brown or white

Question 28

Lymphocytes exist in two functional cell types:

Answer 28

T lymphocytes- cell-mediated immunity B lymphocytes- production of antibodies

Question 29

What do B lymphocytes produce?

Answer 29

In the presence of antigens, B lymphocytes divide to produce: - more B lymphocytes - large clones of cells that mature into PLASMA CELLS

Question 30

What are plasma cells?

Answer 30

Derived from B lymphocytes Limited migratory ability Relatively large -20 um Ovoid Much basophilic cytoplasm Synthesis of antibodies

Question 31

How long do plasma cells last?

Answer 31

Lives 10-30 days

Question 32

What are the functions of eosinophils, monocytes and neutrophils?

Answer 32

These cells rapidly migrate from blood to connective tissue - Response to injury and inflammation - especially neutrophils followed by monocytes

Question 33

What is indicated by eosinophils, monocytes and neutrophils?

Answer 33

Their presence indicates an acute inflammatory reaction

Question 34

What are Basophils?

Answer 34

-basophilic granules- cytoplasm - Release of histamine from basophilic granules - enhances vascular response in insect bites

Question 35

What is scurvy and what causes it?

Answer 35

Degeneration of connective tissue- lack of vit. C

Question 36

What is lipoma?

Answer 36

Benign tumor of adipocytes

Question 37

What is the Ehlers-Danlos type IV disease?

Answer 37

Deficiency of type III collagen | -rupture of arteries and intestine

Question 38

How was keloid formed?

Answer 38

Local swelling caused by abnormal amount of collagen | -scars