Lecture 3: Connective Tissue Flashcards
What prevents CT from being exposed to outside environment?
It is separated from outside by an epithelium
CT cells are separated from each other by what?
EC matrix
_______ is a gel-like substance with embedded protein fibers; in bone, it is mineralized
ECM (extracellular matrix)
What types of material are carried by ECM?
O2, CO2, nutrients, and wastes
What are the 3 major categories of connective tissue?
Embryonic CT
Adult CT
Special CT
What is the major type of adult CT?
Fibrous
Adult fibrous CT can be subdivided into what 3 categories?
Loose (areolar) CT
Dense Regular CT
Dense Irregular CT
What are the 4 types of special CT?
Adipose
Cartilage
Bone
Hematopoeitic
What are some functions of CT?
Structural framework of body
Protection (dermis, bones)
Supports and interconnects other tissues
Energy storage
Transports fluids, cells, and dissolved chemicals through body
Defense against invasion by microorganisms
_____________ are cells of connective tissue that produce collagens, proteoglycans, and glycoproteins
Fibroblasts
_____________ cells are connective tissue stem cells
Mesenchymal
_____________ are cells of connective tissue that store and release fats
Adipocytes
_____________ are cells of connective tissue that produce and maintain cartilage components
Chondrocytes
_____________ are cells of connective tissue that produce bone components
Osteoblasts
_____________ cells are cells of connective tissue that produce RBCs and immune cells (e.g. Macrophages, mast cells, lymphocytes, plasma cells)
Hematopoietic stem
What fibrous component of ECM CT resists tension?
Collagen
There are several types of collagen but which one is most common?
Type I
What fibrous component of ECM CT is a stretchable fiber?
Elastin
What fibrous component of ECM CT contains type III collagen forms a looser, but supportive meshwork?
Reticular fibers
Where might you find a lot of elastin?
In the lungs; important for expansion/contraction of the tissue
Where might you find a lot of reticular fibers?
Lymph nodes, bone marrow, and spleen
Scurvy is due to insufficient __________, which is a required co-factor in cross-linking ________ fibers.
Vitamin C; collagen
[thus collagen is weakened and there is overall weak CT in the body]
Marfan’s syndrome is an autosomal dominant disorder where _______ is weak
Elastin
[due to mutation in fibrillin-I gene, a component of tropoelastin]
What 3 systems does Marfan’s syndrome primarily affect?
Ocular
Skeletal
Cardiovascular (aneurysms, mitral prolapse)
What disease results in defects in collagen synthesis leading to weak collagen fibers?
Ehlers Danlos Syndrome
T/F: Type I collagen fibrils are aligned and crosslinked to increase tensile strength
On electron micrographs, banding of collagen fibrils is obtained due to fibril alignment
True
What are the 3 major types of amorphous ground substances associated with ECM CT?
Proteoglycans
Hyaluronan
Glycoproteins
What are the 3 major proteoglycans?
Chondroitins
Heparans
Keratans