Connective Tissue

Question 1

How connective tissue is developed?

Answer 1

Originates from the mesenchyme, which develops from mesoderm

Question 2

Characterstics of connective tissues

Answer 2

1. Various TYPES of cells present
2. Rich in extracellular matrix
3. Originates from mesenchyme
4. Poor cells present
5. No district boundary / no basal lamina

Question 3

Functions of connective tissues

Answer 3

1. Protect - physical (bones) and immunological defense (cells of immune system n blood)
2. Repair
3. Support to form framework of body tissue
4. Storage ( water n electrolyte in ecm) & ( fats in adipocyte)
5. Transport (O2, CO2, Enzyme, hormone)

Question 4

Compositions of connective tissue

Answer 4

1. Cells = fixed and wandering

2. Ecm = ground substance and fiber

Question 5

Fixed cells in connective tissue

Answer 5

1. Fibroblast
2. Adipocyte
3. Mesenchymal cell (undifferentiated)
4. Mast cells
5. Macrophage

Question 6

What is fibroblast

Answer 6

1. Principal cell of connective tissue
2. Responsible for synthesis of fibers, collagen and the complex carbohydrates of ground substance
3. Main cell involved in cell repair

Question 7

Adipose cell / adipocyte

Answer 7

1. Lipid droplets
2. Primarily as triglycerides
3. Specialised for storage of fat and for heat production

Question 8

What is macrophage

Answer 8

Derived from monocyte
Major line of defense against infection
Eg: phagocytosis, antigen presenting and presentation
Can be identified using India ink

Question 9

Mast cells

Answer 9

1. Filled with basophilic secretory granules
2. Important role in immediate hypersensitivity response (anaphylactic shock)
3. Storage for mediators for inflammatory response
   
   • mediators : a. Histamine - increase permeability of blood vessels
     B. Heparin - anticoagulant
     C. Serine protease - tryptase n chymase

Question 10

Wandering cells

Answer 10

Basically the leukocytes

Basophils - release histamine for inflammatory responses - bi/trilobed nucleus - blue

Eosinophil - modulate allergy inflammatory responses - bi lobed - pink

Neutrophils - bacteria infection - pink

Monocyte - kidney shaped nuclei
Lymphocyte - B cell, T cell, natural killer - largest nucleus

Question 11

What is plasma cell

Answer 11

1. Derived from hematopoietic stem cells
2. Have basophilic cytoplasm
3. Nucleus having clock- face appearance
4. Secretes antibody

Question 12

Fibers in connective tissues

Answer 12

1. Reticular fiber
2. Elastic fiber
3. collagen fiber

Question 13

Describe collagen fiber

Answer 13

1. Tough
2. Provide tensile strength
3. Synthesized by fibroblast, chondroblast, osteoblast
4. Stain with eosin

Question 14

Reticular fiber

Answer 14

1. mainly type III collagen
2. Arranged in mesh like pattern or network
3. Supportive network of soft flexible tissues
4. Major fiber in liver, kidney, and hematopoietic tissue ( bone marrow, spleen)
5. Visible with silver stain only

Question 15

Elastic fibers

• -characteristics
• function
• arrangements
• staining
• distribution

Answer 15

1. Thin, small
2. Allow stretching
3. Arranged in branching pattern to form 3D network
4. Stain with eosin but not well
5. Found in legamentum flava of vertebral column, vocal folds n elastic arteries.

Question 16

Ground substances

• characteristics
• composition
• function

Answer 16

1. Highly hydrophilic, colourless, viscous complex.
2. Consist of
   A. Glycoaminglycan (GAG)
   B. Proteoglycan
   C. Adhesive glycoproteins
3. Medium for molecules passage and metabolites exchange
4. Barrier for pathogen penetration

Question 17

Types of connective tissue

Answer 17

1. Connective tissue proper
   
   • loose cn
   • dense cn
     ✔️ Regular
     ✔️Irregular

2. Supporting cn
✔️Cartilage
 ✔️Reticular
 ✔️Elastin
✔️Bone

3. Specialised cn
   ✔️Adipose tissue
   ✔️Blood
   ✔️Hematopoietic tissue
4. Embryonic cn
   ✔️Mucous cn