Session 9: Connective tissue

Question 1

What are the 3 characteristics of collagen fibers?

Answer 1

1. Flexible
2. Strong
3. Bundles of thread-like subunits

Question 2

What is an aberration that can develop due to insufficient collagen synthesis?

Answer 2

Scurvy

Question 3

What are the 5 types of soft CT?

Answer 3

1. Aerolar
2. Adipose
3. Mesenchymal
4. Reticular
5. Gelatinous

Question 4

What are the 2 populations/types of CT cells?

Answer 4

1. CT immigrated (wandering/transient) cells

2. CT associated (resident/fixed) cells

Question 5

Name the 5 CT associated cell types/resident cell population types.

Answer 5

1. Macrophages
2. Mast cells
3. Adipose (fat)
4. Fibroblasts
5. Stem cells

Question 6

Name the 4 types of CT immigrating cells/wandering cell population.

Answer 6

1. Plasma cells
2. Lymphocytes
3. Granulocytes
   
   • nuetrophils
   • basophils
   • eusinophils
4. Monocytes

Question 7

What are the 3 types of CT according to development?

Answer 7

1. Embryonic CT
2. CT proper
3. Specialized CT

Question 8

What are the 2 types of embryonic CT?

Answer 8

1. Mesenchyme

2. Mucous

Question 9

What is the function of fibroblasts?

Answer 9

Formation of fibers and amorphous ground substance

Question 10

What are the 4 functions of macrophages?

Answer 10

1. Phagocytic cells
2. Secretory functions
3. Immune response
4. Formation of foreign body giants by
   fusion

Question 11

What are the 2 functions of adipose tissue?

Answer 11

1. Source of energy

2. Insulation

Question 12

What is adipose surrounded by?

Answer 12

Thin cytoplasm layer

Question 13

What are the 2 functions of mast cells?

Answer 13

1. Divide mitotically

2. Secretory granules secrete heparin and histamine

Question 14

What are the functions of heparin and histamine respectively?

Answer 14

Heparin- anti-coagulant

Histamine- causes vasodilation w/ increase in small vessels permeability

Question 15

What is the function of the plasma cells?

Answer 15

Produce antibodies

Question 16

What is the function of lymphocytes?

Answer 16

Immunological function

Question 17

What is the function of granulocytes?

Answer 17

Have white blood cells w/ basilophils, eusinophils and neutrophils

Question 18

What are the 3 types of extracellular fibers?

Answer 18

1. Elastic
2. Collagen
3. Reticular

Question 19

Describe the 7 steps of protein synthesis.

Answer 19

1. mRNA is produced for every alpha chain 
   @ the nucleus
2. Course ER synthesizes alpha chains 
3. Trans vesicles carry procollagen 
    molecules Golgi Apparatus
4. Procollagen molecules are packed into 
    secretory vesicles in the GA
5. Microtubuli and microfilaments convey 
    secretory vesicles to the surface 
6. Procollagen molecules are released 
    into the extracellular space 
7. Procollagen is transformed into 
    insoluble collagen

Question 20

Compare white and brown adipose (fat)

Answer 20

WHITE

• uniocular
• lipids stored in 1 large drop
• cytoplasm arranged in thin ring around periphery
• flattened nucleus at periphery
• range from white => dark yellow
• less and smaller mitochondria in cytoplasm
• richly vascularized
• almost all organs, except for eyelids, penis, scrotum, external ear
• E source
• Shock absorber

                                  VS 

BROWN

• multiocular
• lipids stored in numerous vesicles
• lots of eosinophilic cytoplasm
• large accentric nucleus
• brown due to blood capillaries & mitochondria
• more & larger mitochondria
• more blood capillaries
• mainly in embryo & newborn; abundant in hibernating animals
• produce heat

Question 21

How do mast cells cause an allergy?

Answer 21

• They release vasoactive and immuno-active substances at the mast cell surface after antigen-antibody interaction
• These substances may cause immediate hypersensitivity reactions, allergy and anaphylaxis.

Question 22

What is the function of a pericyte?

Answer 22

Can differentiate into smooth muscle cells, osteoblasts, fibroblasts, adipocytes and endothelium.

Question 23

Name the 5 substances released by basophil during an allergic reaction.

Answer 23

1. Histamine
2. Heparin
3. NCF (neutrophil chemotactic factor)
4. ECF (eosinophil chemotactic factor)
5. Peroxidase

Question 24

Describe the development of scurvy.

Answer 24

• Lack of certain nutritional factors
• Lack of Vitamin C results in scurvy
• Vitamin C is a co-factor for proline-
  hydroxylase , which is essential for
  normal collagen synthesis
• Absence of Vitamin C: fibroblasts
  synthesize defective collagen
• General degradation of connective
  tissue
• Periodontal ligament that holds teeth in
  place degrades and teeth are lost

Question 25

What types of cells produce collagen?

Answer 25

Fibroblasts

Question 26

Name the 4 types of cells that produce reticular fibers.

Answer 26

1. Fibroblasts 2. Reticular cells 3. Schwann cells 4. Smooth muscle cells

Question 27

Name the 2 types of cells that produce elastic fibers.

Answer 27

1. Fibroblasts | 2. Smooth muscle cells

Question 28

Name the 2 types of connective tissue populations/cell groups.

Answer 28

1. Resident cell population (associated cells) | 2. Wandering/transient cell population (immigrating cells)

Question 29

Name the 3 types of diseases caused by mast cells.

Answer 29

1. Immediate hypersensitivity reactions 2. Allergy 3. Anaphylaxis

Question 30

What is the function of pericytes?

Answer 30

Can differentiate into smooth muscle cells, osteoblasts, adipocytes, fibroblasts, and endothelium.

Question 31

Name 9 substances released by mast cells.

Answer 31

1. Histamine 2. Heparin 3. ECF 4. NCF 5. Leukotrienes 6. Serine proteases 7. Interleukines 8. Tumor necrosis factor 9. Prostaglandin D