Fibrous CT Flashcards
Extracellular Matrix (ECM)
Gel-like substance with embedded protein fibers
In bone, mineralized
Carries oxygen, carbon dioxide, and wastes
3 types of CT
Embryonic
Adult
Special: adipose, cartilage, bone, hematopoietic
Functions of CT
Structural framework
Protection
Supports and interconnects other tissues
Energy storage
Transports fluid, cells, and dissolved chemicals throughout body
Defense against invasion by microorganisms
Cells of CT
Fibroblasts Mesenchymal cells Adipocytes Chondrocytes Osteoblasts Hematopoietic stem cells
Fibroblasts
Produce collagens, proteoglycans, glycoproteins, elastin, and reticular fibers in ECM
Adipocytes
Provide reserve energy source
Closely packed with their nuclei pushed to the side by large fat droplet
Removes lipid from blood, stores it, and releases it into the bloodstream when needed
Mesenchymal cells
Multipotent
CT stem cells
Chondrocytes
Produce and maintain cartilage components
Osteoblasts
Produce bone components
Hematopoietic stem cells
Produce RBCs and immune cells
Fibrous ECM
Collagens
Elastics
Reticular fibers
Collagens
Type I is most common
Fibrils are aligned and cross linked to increase tensile strength
Problems can lead to Ehlers-Danilo’s and Scurvy
Elastin
Stretchable fiber
Tropoelastin
Fibulin-1
Fibrillin 1/2
Reticular fibers
Forms supportive mesh work
Marfan’s Syndrome
AD disease where elastin is weak
Mutation in fibrillin-I gene
Life threatening cardiovascular anomalies
Ground Substance of ECM
Proteoglycans
Hyaluronan
Glycoproteins
Proenzymes
Proteoglycans
Chondroitin sulfates
Heparin sulfates
Keratin sulfates
Glycoproteins
Cytokines
Growth factors
Structural proteins (fibronectin, laminin, tensascins)
Embryonic CT
Rich in ECM and mesenchymal stem cells (more than adult)
Some but not many collagen or reticular fibers
“Warton’s jelly” umbilical cord
Adult mesenchymal stem cells
Multipotent Become fibroblasts muscle cells (skeletal and smooth) Osteoblasts Chondroblasts Adipocytes
Fibrous CT
Loose
Dense
Loose CT
Areolar
Adipose
Reticular
Found immediately beneath membranous epithelia (called lamina propria) and around blood vessels, muscles, and nerves
Areolar CT
Loose
Low density tissue with both fixed and wandering cells
Widespread
Adipose
Fat containing tissue
Reticular
Rich in reticular fibers
Forms an open framework to create a supportive mesh for holding free cells
Liver, bone marrow, lymph nodes, and spleen
Dense CT
Dense irregular
Dense regular
Elastic
Dense irregular CT
Collagen fibers are deposited in a random pattern Dermis Fascia Perichondrium and periosteum Fibroblasts are the principle cell type
Dense regular CT
Collagen fibers are deposited in a highly regular pattern Tendons connecting muscle to bone Fibroblasts=principle cell type Resists pulling forces Poorly vascularized
Elastic CT
Rich in elastin fibers Recoil of tissue following stretching Walls of blood vessels Bronchioles tubes Special ligaments (ligamentum nuchae)
Cell types in loose areolar CT
Fibroblasts Adipocytes Mesenchymal cells Macrophages Mast cells WBCs Plasma cells
Adipose CT
Abundant adipocytes and sparse ECM
Provides reserve energy source and insulates against heat loss
Padding and cushioning for organs
Under skin, around organs, within abdomen, breasts, and buttocks
White fat
Energy storage
Insulating
Cushioning vital organs
Hormone secretion
Brown fat
Key thermogenic tissue
Abundant in newborns; greatly reduced in adults
Macrophages
Differentiate from blood monocytes
Phagocytosis and destruction of bacteria, damaged or sick cells, removal of cell debris, and antigen processing and presentation
Mast cells
Secrete chemicals such as histamine that mediate the allergic response and heparin (anti-coagulant of blood)
Plasma cells
Differentiate from B-lymphocytes
Make antibodies
