Connective Tissue (CT) Flashcards
What are the roles of CT proper?
Maintains and supports structure and communicates
Mediates exchange
plays a role in immune response, inflammation and tissue repair
What are the components of CT Proper?
Extracellular Matrix (ECM) & fibers functionally apart of ECM
Cells (resident vs visiting)
What are the two major components of the ECM?
ground substance
fibrous proteins embedded throughout the ground substance
What determine the properties of CT?
Extracellular matrix
What is ground substance?
largely proteoglycans (proteins, GAGs, linked to hyaluronic acid) attract water to create a hydrated gel
What are structural glycoproteins?
Connect the compoents of the ECM to each other including the cells and fibers
Fibronectin, fibrillin
What are Type I Collagen Fibers?
Most abundant type
found in ligament, tendon, fascia, joint capsules, bone
What is Type I collagen fiber structure?
Bundled, cross-linked structure makes it exceptionally strong and resilient to tensile forces
What are the resident cells of CT?
Fibrocytes or fibroblasts
Mesenchymal cells
What is the function mesenchymal cells?
aka stem cells, differentiate into fibroblasts fro growth or when there is damage to a connective tissue structure
what is the function of fibroblast?
responsible for producing and secreting all of the components of the ECM
What are the visiting cells of CT?
Macrophage
Mast cell
Plasma cells
What are the function of macrophages?
picks up debri
identify foreign substances within tissue and present them to the b lymphocytes (plasma cells)
pro inflammatory; can secrete substances that can start an inflammatory cascade
What are the functions of mast cells?
Produce and secrete vasoactive types of substances; starting an allergic response Cause blood vessels to dilate and causes localized swelling
Heparin: anticoagulant, makes blood within vessels thinner
what are the function of plasma cells?
Produce antibodies
What are the characteristics of Loose CT?
most abundant CT proper, sparse fibers, fat cells, blood vessels, increased cells and ground substance
What is the function of Loose CT?
Fluid nature makes it easy for visiting cells to diffuse in and out of blood vessels and into surrounding tissue
Space occupying protective tissue (shock absorbing)
what are the characteristics of dense irregular CT?
densely packed with Type 1 collagen (multidirectional arranged) some elastic fibers as well
What are the functions of dense irregular CT?
Withstand tension form different directions but also somewhat flexible
What are the functions of dense regular CT?
To provide maximum tensile strength; resist pull
What are the characters of dense regular CT?
highly packed fibers within the ECM
Where is Dense Irregular CT found?
Found in dermal layer, sheaths around tendons, bursa and nerves
Where is Dense Regular CT Found?
Found in ligaments, musculotendinous units, and aponeuroses
What does the Hierachical Structure of Collagen within tendon emphasize?
The collagen fibers need to be able to both resist very efficiently the tendon that is being created by the muscle and be able to pull on the bone levers
What disorders are caused by elastic fibers?
Can be damaged by UV light (affects skin elasticity)
Loss of elastin in respiratory system causes emphysema
what disorders are caused by Collagen fibers?
Ethlers-Danlos Syndrome
osteogenesis imperfect
What re the most common clinical symptoms of Ethlers-Danlos syndrome?
joint hyper mobility and skin hyper elasticity
what assessment is used to test for Ethlers-Danlos Syndrome?
Beighton scale
What is the most common symptom of osteogenesis imperfect?
blue sclera, weak joints
What are examples of CT Proper?
Loose (areolar)
Dense: irregular/regular
What are examples of specialized CT?
adipose
cartilage
bone
hematopoietic tissue in bone marrow
