Connective Tissue

Question 0

Cite examples to explain connective tissue functions such as binding, support, protection etc.

Answer 0

Provide substance and form to the body and organs
Provide a medium for diffusion of nutrients and waste
Attach muscle to bone (tendon) and bone to bone (ligament)
Provide a cushion between tissues and organs
Defend against infection
Aid in injury repair

Question 1

Define the term ‘connective tissue’

Answer 1

Encompasses the major structural constituents of the body, linking together muscle, nerve and epithelial tissue in a structural way but also providing support in metabolic and physiological ways

Question 2

Describe and discuss the function of extracellular matrix, e.g. the constituents of ground substance and the collagen, reticular and elastic fibres which may lie within it

Answer 2

Ground substance - glycosaminoglycan (GAG) (-ve charge attracts water), glycoproteins, hyaluronate proteoglycan aggregates = gel-like matrix, firm jelly
Fibres - collagen, reticular, elastic

Question 3

Explain the differences between loose and dense connective tissues, in terms of their cellular and extracellular components, relating these differences to tissue function

Answer 3

Loose (adipose, blood, areolar CT):
Cells - fibroblasts, macrophages, mast cells, adipocytes, plasma cells
EX material - ribbon like collagen fibres, elastic fibres, watery
Dense regular (tendons, ligaments):
Cells - parallel rows of flattened fibroblasts
EX material - parallel rows of densely packed collagen
Dense irregular (dermis):
Cells - fibroblasts, macrophages
EX material - thick, wavy bundles of collagen, elastic fibres, reticular
Reticular (liver, spleen, kidney, lymph nodes, bone narrow):
Cells - reticular cells, large oval nuclei, lymphocytes, macrophages
EX material - reticular fibres

Question 4

Classify different types of loose and dense connective tissues

Answer 4

Embryonic
Mesenchyme (embryonic origin):
Cells - spindle-shaped, large nuclei
EX material - reticular fibres
Whaton’s jelly/Mucous CT (umbilical cord):
Cells - fibroblasts, oval nuclei
EX material - collagen bundles, irregular

Question 5

List the common cell types found in connective tissue (fibroblasts, macrophages and mast cells) describing their function

Answer 5

Fibroblasts - abundant RER, synthesise and secrete ground substance and fibres within ground substance, produce procollagen, important in wound healing (formation of scar tissue)
Macrophages - phagocytic, professional antigen presenting cells
Mast cell - contain abundant granules of heparin (anti-coagulant) and histamine
Pericytes - contractile cells
Adipose - white (store lipids), brown (generate heat)
Leukocyte a