Connective Tissue

Question 1

What are the types of Connective Tissue?

Answer 1

1. Cells
   
   • resident
     
     • mesenchymal cell
     • adipocyte
     • fibroblast
   • transient/immigrating
     
     • macrophage
     • blood
2. Fibers
   
   • collagen
   • reticular
   • elastic
3. Ground substance

Note: Does not line a body surface!

Question 2

What are the 3 main classifications of Connective Tissue?

Answer 2

1. Emryonic
   
   • mucous CT
   • mesenchyme
2. Adult Proper

• Loose
• Dense
  
  • regular (parallel)
  • irregular

3. ​​Special

• reticular
• elastic
• adipose
• cartilage
• bone
• hematopeitic (blood)

Question 3

What are the 2 kinds of embryonic connective tissue?

Answer 3

• Mesenchyme
  
  1. loose CT network
  2. from mesoderm & neural crest
  3. stellate or spindle shaped
  4. ground substance
  5. resident cells = mesenchymal
• Mucous CT
  
  1. hyaluronic acid
  2. cells are spindle shaped
  3. Wharton’s jelly
  4. resident cells = fibroblasts

Question 4

What are the 2 characteristics of Adult CT Proper?

Answer 4

1. Loose (areolar)
   
   • cells > fibers
   • pathway for lymphatics, nerves, blood
     
     • can find lots of transient material in it
   • abundant ground substance
   • resident cell = fibroblast
   • predominant collagen = type I
2. Dense
   
   • fiber > cells
   • predominant collagen = type I
   • named for arrangement of fibers
     
     • dense regular (parallel)
     • dense irregular

Question 5

What type of connective tissue is this?

Answer 5

Loose CT

• Looks washed out
• Has lots of transient material in it

Question 6

What type of connective tissue is this?

Answer 6

Dense Irregular CT

• Collagen bundles
  
  • No obvious orientation
• Resistance to stress in ALL directions
• Capsules of organs
  
  • part of dermis, submucosa
  • can have fibroblasts & neurons in it

Question 7

What type of connective tissue is this?

Answer 7

Dense Regular CT

• Parallel collagen bundles
  
  • fibroblasts
• Tendons, ligaments, cornea

Question 8

What is this?

Answer 8

Connective Tissue Tumor:

Fibrosarcoma

• Lots of cells
• Little organization

Question 9

What type of tissue is this?

Answer 9

White adipose tissue

• One lipid droplet
• Resident cell = adipocytes
• Functions:
  
  • energy storage
  • cushion/insulation
• No direct innervation

Question 10

What type of tissue is this?

Answer 10

Brown adipose tissue

• multiple lipid droplets
• resident cell = adipocytes
• present in newborns
• mostly absent in adults
• Functions:
  
  • heat production
  • more vascular
  • direct innervation

Question 11

What type of tissue is this?

Answer 11

Reticular Tissue

• Lymph node

Question 12

What type of tissue is this?

Answer 12

Elastic Tissue

• Abundant elastic fibers or laminae
• Smooth muscle cells
• Example: Aorta

Question 13

What are the 3 types of resident cells?

Answer 13

• Mesenchymal cell
  
  • Stellate (star-shaped)
• Fibroblast cell
  
  • spindle-shaped
• Adipose cell
  
  • Signet-ring-shaped

Question 14

What type of resident cell is this?

Answer 14

Mesenchymal Cells

• Undifferentiated
  
  • differentiate into multiple cell types:
    
    • fibroblasts, chrondoblasts, osteoblasts
• Star or spindle shaped
• Euchromatic nucleus & prominent nucleolus
• Surrounded by ground substance

Question 15

What type of resident cell is this?

Answer 15

Fibroblasts

• Makes component of EC matrix:
  
  • collagen
  • elastic fibers
  • reticular fibers
• Also makes:
  
  • proteoglycans & glycosaminoglycans
  • glycoproteins: fibronectin & laminin
• Flattened nuclei
• Spindle shaped
• Leads to scar tissue
  
  • becomes contractile myofibroblasts

Question 16

What type of resident cell is this?

Answer 16

Adipocytes

• Ring shaped
• Thin cytoplasm
• Filled w. lipid
• Nucleus = compressed

Question 17

What are the 7 types of Transient Cells?

Answer 17

1. Macrophages
   
   1. engulfs bacteris
2. Mast Cells
   
   1. allergic reactions
   2. granules
3. Eosinophil
   
   1. granules
   2. multilobed nucleus
4. Neutrophil
   
   1. wound healing
   2. granules
5. Basophil
   
   1. lots of granules
6. Lymphocyte
   
   1. large nucleus
7. Plasma cell
   
   1. no granules

Question 18

What type transient cell is this?

Answer 18

Macrophages (in lung alveoli)

• Phagocytosis
  
  • engulf material
  • Ag processing
  • Derived from blood monocytes
  • large, oval eccentric nucleus
• In many tissues
  
  • histiosytes in CT
  • kupffer cells in liver
  • dust cells in lung
  • microglia in CNS
• Pathology:
  
  • aggregation causes multinuclear GIANT cells

Question 19

What type of transient cell is this?

Answer 19

Mast Cells

• Derived from hematopoietic stem cells in bone marrow
  
  • different lineage than basophils
• Allergy/hypersensitivity
• Unilobed nucleus
• Granules (can be basophilic or eosinophilic or metachromatic)
  
  • Histamine
    
    • Protoglycan (PG): increase vascular permeability & contraction of smooth muscle
  • Heparin
    
    • PG: anticoagulant
  • Eosinophil or neutrophil chemical factors
  • Cytokines
  • Phospholipid precursors
    
    • to make PG & leukotrienes
• Metachromatic due to heparin
  
  • PG: highly sulfated
• Have IgE receptors
  
  • initates allergic response when Ag binds

Question 20

What type of transient cell is this?

Answer 20

Plasma Cells

(look like mast cells, but NO granules)

• Derived from B lymphocytes
• Secretes antibodies
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