Connective Tissue II

Question 1

Fibroblasts/Fibrocytes

Answer 1

• The principal cell types found in connective tissue. They are also the most numerous cell fond in CT
• Functions:
  
  • Secretion and maintenacne of CT matrix
  • Secretion of precursor fibrous molecules
  • Secretion of the amorphous contents of hte matrix,including the glycosaminoglycans

Question 2

Resident Cells in Fibrous CT

Answer 2

• In addition to fibroblasts and fibrocytes, a large number of other kinds of cells are often found in fibrous connective tissues
• Common types of cell residents include:
  
  • Macrophages-derived from manocytes
  • Mast cells
  • Plasma cells -activated B cells whic hare in the process of secreting immunoglobulins

Question 3

Macrophages

Answer 3

• Ovoid or indented heterochromatic nucleus
• Irregular in shape with blunt processes :
  
  • Wandering macrophages are somewhat oval in shape
  • Fixed macrophages are more irregular in shape with long processes
• Capable of amoeboid movement
• Part of mononuclear phagocytic system(originally called the reticular activiating system– RAS)
• Extensive Golgi , rER,sER,mitochondria, secretory vesicles, and lysosomes
• May fuse with other macrophages to form large multinucleated phagocytic foreign body giant cells
• Derived from bone marrow manocytes
  
  • main functoin is to eat , and use phagocytoes to chow down on foreign particles that they find

Question 4

Where are macrophages found?

Answer 4

• Wandering in blood(monocytes)
• connective tissue(istiocytes)
• Liver sinusoids(Kupffer cells)
• Sinusoids of spleen, lymph nodes , bone marrow(perialveolar macrophages)
• Alveoli of lungs(dust cells)
• Central nervous system(microglia)
• Assocaited with bone reabsorption(osteoclasts)

Question 5

Answer 5

Macrophages

Question 6

Mast Cells

Answer 6

• Irregularly oval in outline
• Small spherical/ovoid nuclei often masked by membrane-bound granules
• Stain with toluidine blue
• Large metachromatic granules with histamine,ECF-A, SRS-A and heparin
  
  • ECF-A(eosinophil chemotactic facor) attracts eosinophils and neutrophils
  • SRS-A(slow reacting substance of anaphylaxis) similar to histamine but has a more sustained effect
  • Heparin from mast cells is a poor anticoagulant and is probably involved in helping clear plasma lipids
• invovled in hypersensitive response to allergens
  
  • Edema,shock,pain,hypercoagulation,fever
• membranes release leukotrienes
• Found near small blood vessels:
  
  • Target of histamine and SRS-A
• Absent from spleen
• Found in mucosal surfaces and in connective tissues

Question 7

Plasma Cells

Answer 7

• Activated B lymphocytes
• Resemble lymphocytes but are larger
• Large pale nuclei with “clock face”distribution of heterochromatin
  
  • Spherical and typically offset
• Prominent Golgi and extensive RER
• Rare in connective tissue
• Frequently occur in:
  
  • Serous membranes
  • Lymphoid tissue
  • Lamina propria of gut tract

Question 8

Lymphocytes

Answer 8

• Diamter ranges from 6 to 8 um
• Numerous in lamina propria of respiratory and GI tract
• Charecterized by relatively large,heterochromatic nucleus surrounded by thin rim of cytoplasm

Question 9

Answer 9

Dense Regular Connective Tissue

Question 10

Answer 10

White Fibrous Connective tissue

Question 11

Answer 11

Areloar Connective Tissue

Question 12

Answer 12

Elastic Connective Tissue

Question 13

Answer 13

Adipose Tissue