RAT-1 CHAPTER FIVE Flashcards
What is the major distinguishing factor between connective tissue and other tissue types (epithelium, muscle, and nerve)
the major constituent of connective tissue is the extracellular matrix
What are the major tissue types found in connective tissue proper
- fibroblasts
- plasma cells
- lymphocytes
- eosinophilic leukocytes
- neutrophilic leukocytes
- macrophages
- mast cells and basophilic leukocytes
- adipocytes
List the major components of the extracellular matrix
protein fibers and ground substance
Describe the function of fibroblasts
the major cell of connective tissue that synthesize and secrete most components of the ECM
Describe the function of macrophages
they function in ECM turnover, phagocytosis of dead cells and debris, and antigen presentation to lymphocytes
Describe the function of mast cells
release various vasoactive agents and other substances during inflammatory or allergic reactions
Describe the function of plasma cells
abundant secretion of specific antibodies (immunoglobin)
Describe the function of heparin
acts locally as an anticoagulant
Describe the function of histamine
promotes vascular permeability and smooth muscle contraction
What are the three major fiber types found within the extracellular matrix
- collagen
- reticular fibers
- elastic fibers
What are the three major groupings or classifications of collagen molecules
- fibril-forming collagens
- network-forming collagens
- linking/ anchoring collagens
Describe the general structure of type I (pro)collagen fibers
they assemble to form extremely strong fibrils, which are then bundled further by other collagens into larger units called collagen fibers
Describe the cellular organelles involved in the formation of (pro)collagen molecules and the site of collagen fiber formation
RER: the site where initial pro-collagen alpha chains are assembled
ER: three alpha chains are selected, aligned, and stabilized by disulfide bonds at their carboxyl terminal and are folded as a triple helix
ECM: where further assembly into fibrils occurs after pro-collagen secretion
golgi: packaging of soluble pro-collagen in secretory vesicles
secretory vesicles: assisted by microtubules and microfilaments and transport soluble pro-collagen molecules to the cell surface
State the major type of collagen molecules found in collagen
collagen type I
State the major type of collagen molecules found in reticular fibers
collagen type III
Which type of fibers provide greater tensile strength
type I collagen fibers
Give examples of where collagen fibers are most abundant
cornea, blood vessels
Give examples of where reticular fibers are most abundant
liver and endocrine glands, stroma of hemopoietic tissue (bone marrow), the spleen, and lymph nodes
What is the classification of type III collagen fibers
network-forming
What is the classification of type I collagen fibers
fibril-forming
What is the function of elastic fibers
provide structural support to the extracellular space of connective tissues, they provide elasticity and resilience to connective tissue
List the major components of ground substance
glycosaminoglycans (GAGs), proteoglycans, multiadhesive glycoproteins
Describe the structure of GAGs
long polymers of repeating disaccharide units, some are synthesized in the ECM and others in the golgi complex
Describe the structure of proteoglycans (PGs)
core protein that has various number and combinations of GAGs covalently attached, they are synthesized in the RER, mature in the golgi apparatus, and are secreted from the cell by exocytosis
