Connective Tissue

Question 1

Connective tissue classification

Answer 1

1. 2 types: regular & irregular
2. Regular → dense regular
3. Irregular→ areolar, dense irregular, adipose
4. Most CT are avascular

Question 2

Areolar connective tissue (Loose connective tissue)

Answer 2

1. “Packing” material
2. Most generalized, extensively in the body
3. Binds structures together while allowing movement
4. Mesh work of thin collagen and elastin fibers interlaced irregularly
5. Found in submucosa, subcutaneous tissue, eyelids, penis, scrotum, labia
6. Connects muscles, vessels, nerves with other structures

Question 3

Dense irregular connective tissue

Answer 3

1. Less flexible, more resistant to stress
2. Fewer cells (fibroblasts); predominance of collagen in bundles without definite orientation
3. Found in reticular dermis, capsules of organs, testis, sclera, periostea, perichondria

Question 4

Adipose connective tissue

Answer 4

1. Serves as an energy store, thermal insulator, shock absorber
2. Found in female breast, bone marrow, retro-orbital fat, around kidneys, foot
3. Does not stain well with H&E
4. Is a component of superficial fascia
5. Not a major component of the matrix
6. WAT → shock + thermo
   BAT → only thermo

Question 5

Dense regular connective tissue

Answer 5

1. Displays interweaving, increases structural stability, allows some stress, resistant to axial forces
2. ↑ fibrous tissue; collagen with regularly oriented fibres forming sheets/bundles
3. Sheets → found in fascia, vessels, nerves, aponeuroses
4. Bundles → found in ligaments, tendons

Question 6

What are the connective tissue cell types?

Answer 6

1. Fibroblasts
2. Myofibroblasts
3. Adipocytes
4. Chondrocytes → does not synthesise collagen
5. Osteoblasts
6. Osteocytes
7. Defense cells (mast cells, macrophages, all WBCs)

Question 7

Cartilage

Answer 7

1. Two types of cells: chondroblasts and chondrocytes
2. Chondroblasts are derived from primitive mesenchymal cells
3. Both secrete fibres of the matrix
4. Nourishment is maintained by blood vessels in the perichondrium
5. Specialized hyaline cartilage forms articular cartilage

• 3 types of Cartilage:
  → hyaline cartilage: contains ↓ collagen (trachea & bronchi, costal cartilages, nasal septum, larynx, articular cartilages)
  → fibrocartilage: contains ↑ collagen (intervertebral discs, pubic symphysis)
  → elastic cartridge: contains ↑ elastic fibers (epiglottis, eustachian tube)

Question 8

Components of connective tissue and their properties

Answer 8

1. Protein fibers → important for tensile strength
2. Myofibrils → contract wound edges
3. Fibroblasts → secrete actin
4. Collagen → forms the joint capsule
5. Adipose tissue → shack absorbance ( soles, palms, glutes, synovial membrane)

Question 9

Joints

Answer 9

1. Synovial joints are the most mobile joints in the body

Types:
→ condyloid joint = 1st metacarpophalangeal
→ hinge joint = knee
→ ball and socket joint = radiohumeral
→ synovial plane joint = proximal tibiofibular, carpometacarpal
→ fibrous joint = distal tibiofibular, b/w tooth & tooth socket
→ primary cartilaginous joint = union b/w epiphysis & diaphysis on a long bone
→ secondary cartilaginous joint = intervertebral joints