Connective Tissue and Extracellular Matrix (ECM) Flashcards
What is the extracellular matrix (ECM) comprised of?
Fibers Amorphous ground substance Tissue Fluid
What are the functions of connective tissue?
Structural support Exchange medium between blood and tissues Defense and protection Fat storage
The bulk of cells that produce connective tissue
Fibroblasts
Fibroblast vs Fibrocyte
Fibroblast - actively creating new tissue Swollen rough ER Fibrocyte - maintains status of tissue
Adipocytes
Create adipose tissue, involved in lipid storage
What cell recycles dead red blood cells?
Macrophage, primarily in the spleen
Primary vs secondary lysosomes
Primary - sacks of enzymes Secondary - Primary lysosomes that have been taken up by a macrophage
What cells are primarily involved in the allergic response
Mast cells
Mast cells release mediators that primarily provide what functions?
Vasoactive or increase inflammatory response. (Ex leukotriene C, heparin, histamine)
What cells have the primary function of producing antibodies?
Plasma cells
What do plasma cells exhibit basophilic staining?
They are making a lot of proteins for export. Have a lot of rough ER
T cell Lymphocytes function?
Cell-mediated immunity Differentiate in thymus
B cell Lymphocytes function?
Humoral immune response
What are the first cells that appear in an inflammatory reaction.
Neutrophils
What CT cell has a trilobed nucleus?
Neutrophil
What is the most abundant cell in circulating blood?
Neutrophils
What are the major functions of eosinophils?
Parasite immune response. —release cytotoxins to kill parasite Moderate allergic reaction —release enzymes that cleave histamine and leukotriene C
What CT cell has a bilobed nucleus?
Eosinophil
Where are pericytes found?
Around capillaries
What type of connective tissue is the main component of the umbilical cord?
Mucous CT
What type of connective tissue is found below the epithelium of the intestine?
Loose CT
What is the main difference between Loose CT and Dense irregular CT?
Dense irregular has collagen bundles while loose does not.
Where is dense regular CT found?
Tendons and Ligaments
Where is dense regular elastic CT found?
only in the blood vessels around the heart
What does the extracellular matrix consist of?
Fibers, ground substance, tissue fluid !It is acellular!!!!
What can be found in ground substance?
Proteoglycans, glycoproteins, glycosaminoglycans(GAGs)
What are proteoglycans?
Core protein with covalently linked glycosaminoglycans (GAGs).
What ECM glycosaminoglycan(GAG) is a major component of hyaline and elastic cartilage?
Chondroitin
What does the ECM GAG Hyaluronic acid do?
It is a component of cartilage that helps to maintain the hydration of cartilage by binding H2O.
What two ECM glycoproteins binds to integrins?
Fibronectin and Laminin
What ECM glycoprotein binds to collagen, heparin, and mediates cell adhesion to ECM?
Fibronectin
What ECM glycoprotein is a component of the basement membrane.
Laminin
What is the most abundant protein in the body?
Collagen
What types of collagen are involved in wound healing?
Type 3 first and then it changes to stronger type 1 over time.
Collagen fibers are which type of collagen?
type 1
Reticular fibers are which type of collagen?
type 3
What is the most abundant type of collagen in the body?
type 1
What type of collagen do fibroblasts produce?
type 1
Type 2 collagen is the major component of what?
Hyaline cartilage and some in elastic cartilage
What type of collagen is a basement membrane component?
type 4
What type of collagen anchors the epithelial basement membrane to connective tissue?
type 7
What type of cartilage is found in the hypertrophic zone of developing bones?
type 10 hypertrophic zone – where the development and differentiation of bone takes place
Which type of collagen displays distinct banding?
type 1
What are elastic fibers made of?
Elastin and Fibrillin
What is elastin?
Amorphous structural protein. Contains 2 unusual amino acids (desmosine and isodesmosine)
What protein is the component of peripheral microfibrils around elastic fibers?
Fibrillin
What is Marfan Syndrome?
A genetic defect in fibrillin 1 (a major component of elastin). Basically defective elastin Produces a weakened tunica media of aorta. Arachnodactyly – tall with long arms, legs, fingers, and toes
Ehlers-Danos syndrome
Genetic defect involving peptidyl lysine hydroxylase needed for type 3 collagen synthesis. Results in rupture of large bowel/arteries. Hyper elasticity of skin and hyper mobility of joints.
Osteogenesis imperfecta
genetic defect involving type 1 collagen. Leads to bone fragility
