Connective Tissue Flashcards
Function of Connective Tissue
connect suspend, give form, subdivide insulation and storage defend provide nutrition repair and regeneration
Resident cells
stay in connective tissue
formed by embryonic mesenchyme cells
ex. fibroblasts, reticular cells, adipocytes, mesenchymal cells, macrophages, mast cells
Transient Cells
come and go
formed by hematopoietic stem cells
ex. plasma cells, leukocytes: neutrophils, eosinophils, basophils, lymphocytes
fibroblasts
form collagenous, elastic and reticular fibers of the matrix
Macropages
come from blood monocytes once in CT called macrophages
resident phagocytic cell of CT
proliferate quickly
ground substance
amorphous, formed by principal cells of tissue, contains GAGs, Proteoglycans, glycoproteins
tissue fluid
a solution that bathes and surrounds the cells and fibers, comes from plasma of blood
Collagen fiber
white, very tensile and strong, do not stretch
most numerous fibers in CT and bone
extracellular scleroprotein fibers composed of fibrils usually arranged in bundles of indefinite length
Types of Collagen Type 1
found in bone, dentin, dermis, tendons; resists tensile forces
Types of Collagen Type 2
forms fibrils found in cartilage, resists compression
Types of Collagen Type 3
reticular fibers found in stroma of expandable organs- spleen, lymph node, liver CV system, lymphatics
Types of Collagen Type 4
basement membranes (basal laminae
Collagen Synthesis
synthesized by- fibroblasts, chondroblasts, osteoblasts, odontoblasts
procollagen is formed in fibroblast, cleaved to tropocolagen outside the cell and then assembled into collagen
vitamin c is an important cofactos
Elastic Fibers
individual branching and anastomosing
pink in HE
yellow, weak and elastic, stretch and recoil
tiny in loose CT and longer in big ligaments
Reticular Fibers
form fine network reticulum that can be stained silver
type 3 is synthesized by reticular cells
support system of organs with a lot of cells like liver
reticulocytes
reticular cell that produced reticular fibers
Ground substance properties
allow for binding of water, resisting compressive forces, cell adhesion to fibers, cell migration, barrier to bacterial/venom penetration
Proteoglycans
formed by covalently linking GAGs to protein core
may regulate passage of molecules and cells in he intercellular space and in chemical signaling between cells
stain with basic dyes if high concentration
structural glycoproteins
proteins with attached carbs
help attach cells to each other and to extracellular matrix
ex. fibronectin, laminin, osteonectin, chondronectin
Connective Tissue Fluid
solution of nutrients, dissolved gases derived from plasma
bathes matrix and cells with nutrients, aids in removing waste
fluid dynamics maintain proper balance
lymphatics important in fluid movement and prevention f edema
Embryonic Connective Tissue
mesenchyme comes from mesoderm and gives rise to adult CT
gel like due to ground substance, few fibers and star shaped mesenchymal cells
Loose Connective Tissue
areolar CT
ubiquitous tissue
loosely arranged
cellular constituents vary with loaction
Dense Connective Tissue
Irregular and regularly arranged densely packed fibers strong tissues very strong found in tendons, ligaments and cornea
Reticular Connective Tissue
network of fine collagen fibrils
formed by reticulocytes, liver cells, smooth muscle cells or Schwann cell
found in most tissue, principal CT in lymphatic
Adipose Connective Tissue
composed of adipocytes- cells with basement membrane
functions
energy storage
endocrine- produce leptin which has regulatory effect on body fat (proportional to body fat, signals brain its had enough to eat)
White Adipose TIssue
unilocular fat cells- one lipid droplet
energy storage, insulation, hormone ‘leptin’ secretion
Brown adipose tissue
need special stain
multiocular fat cells- several lipid droplets
many mitochondria
found in hibernating and newborn animals
