Histology - CT proper & Cartilage

mesenchyme

the CT of the developing embryo, made of mesenchymal cells, pluripotent, have all 3 fiber type but are fine and not very visible, abundant ground substance

pluripotent

have the potential to differentiate into many different cell types

collagen type 1

coarse, fibril forming collagen, found in skin, bone, tendons, ligaments, orange/orange pink on H&E and blue on truchrome

collagen type 2

fine, fibril forming collagen, in cartilage and spinal cord

reticular fibers

same thing as collagen type 3, fibril forming, silver or immunostaining, lymphoid organs,

collagen type 4

network forming, located in BM, synthesized by epithelium

loose CT

also called areolar CT, always irregular, has fibroblasts, all three fibers present but type 1 is most visible, ground substance slightly less abundant than mesenchyme

dense irregular CT

always irregular, has fibroblasts, all three fibers present but type 1 is most visible, larger bundles than in loose, les abundant ground substance

dense regular CT

two types: collagenous and elastic; always regular, all 3 fibers but most visible are large bundles of type 1 and elastic fibers respectively, collagenous tendons and elastic ligaments

reticular CT

reticular cells and fibers, found throughout body, mesh like supportive framework for soft organs

adipose tissue

two types, white and brown, made of adipocytes, have a delicate network of collagen and reticular fibers

white adipose tissue

unilocular, found throughout body, varies in abundance depending on condition of animal

brown adipose tissue

multilocular, less abundant and location tends to be regional

chondroblast

cells that actively secrete cartilage matrix and are capable of division

chondrocytes

not actively dividing and secreting, suspended in cartilage matrix which they maintain

chondroclasts

osteoclasts that break down calcified cartilage

fibroblasts

found along outer surfaces of cartilage, produce fibers

fibers in hyaline and elastic cartilage

type 2 collagen

fibers in fibrocartilage

type 1 cartilage

fibers in elastic cartilage

elastic fibers

ground substance for cartilage

glycosaminoglycans, glycoproteins, chondroitin sulfate and keratin sulfate, hyaluronic acid

hyaluronic acid

binds multiple aggrecan monomers to form large aggregates called aggrecan aggregates

hyaline cartilage

most bone forming sites in fetus and young animals, type 2 collagen, more basophilic due to acidic GAGs

elastic cartilage

external ear, auditory canal, auditory tube, have elastic fibers

perichondrium

region which separates from and physically binds cartilage to surrounding non-collagenous tissue, surrounds all cartilage except at articular surfaces/articular cartilage

fibrocartilage

intervertebral discs and attachments of certain tendons and ligaments, collagen type 1 fibers, no perichondrium

chondroblasts

divide and synthesize matrix in response to hormones or bone repair

interstitial growth

growth within the inside, chondroblasts divide and form multicellular lanunae, daughter cells secrete matrix around and between each other, causing expansion from within cartilage

appositional growth

growth upon the surface, chondroblasts form from stem cells in the perichondrium and secrete matrix onto cartilage surface