Connective Tissue Flashcards
4 types of connective tissue
connective tissue proper, cartilage, bone, blood and blood forming
connective tissue proper
subdivided into loose and dense, generalized connective tissue made up of cells, extracellular fibers, and extracellular ground substance
cartilage
made of cells and ECM, chondroblasts produce matrix and have a basophilic cytoplasm, avascular
bone
made of cells and ECM, osteoblasts and osteocytes produce matrix, matrix is mineralized by calcium phosphate, type I collagen
blood and blood forming
mast cells, plasma cells, macrophages
connective tissue
made up of support cells and their associated extracellular matrix, functions as an avenue for transport and communication (vascular and innervated)
collagen fibers
flexibility with high tensile strength, secreted by fibroblasts, found in tendons and ligaments
elastic fibers
stretchy, helps restore tissues to normal shape after stretching; found in the lungs, skin, diaphragm, urinary bladder, vocal cords, and blood vessels
reticular fibers
wound repair, supporting framework in large organs such as the liver, spleen, lymph nodes, thymus, and bone marrow
fibroblasts
synthesize and secrete ground substance, very little cytoplasm and elongated nucleus, secrete the ECM components in most tissues, abundant golgi complexes
mast cells
fillopodia to increase surface area, granular cytoplasm, trigger immune and inflammatory responses, typically located near blood vessels so response to secreted substances (histamines) is rapid
plasma cells
mature B lymphocytes for antibody production located in the bloodstream, strong basophilic cytoplasm
adipose
fat, storage of lipids for nutrients, thermoregulation (brown fat/multiocular adipocyte), source of fuel for metabolic processes, thin rim of cytoplasm with a flattened nucleus
macrophages
engulf and digest bacteria and other particulate matter involved in the immune response, attracted to sites of inflammation, granular cytoplasm, come from bone marrow
pericytes
wrap around the endothelial cells that line the capillaries and venules throughout the body
ground substance
a hydrated gel matrix made of water (for communication and transport by diffusion) stabilized by glycosaminoglycans GAC’s
cells that make up connective tissue proper
fibroblasts, mast cells, plasma cells, adipose cells, macrophages, pericytes
function of fibrillar proteins
provide support and are one component of the ECM
two types of dense tissue
dense collagenous and dense elastic
mesenchymal cells and their function
primitive cells derived from the mesoderm, differentiates into various connective tissue cell types,
produces cytokines which influence the differentiation and aging of other cells
how H&E stains active and inactive fibroblasts
active are weakly basophilic (purple) inactive are weakly acidophilic (pink)
arrangement of adipose tissue
lobules surrounded by fibrous septa
function of the basement membrane
anchor down the epithelium to its loose connective tissue underneath
fibronectin
mediates adhesion between cells and ECM, binds collagen to ground substance (glycosaminoglycans)
loose connective tissue
areolar, cushioning layer highly cellular, few fibers, extremely flexible, well vascularized, loose irregular fibers, abundant ground substance
dense connective tissue
fewer cells, mostly fibroblasts, less ground substance, more collagen fibers
dense regular CT
parallel fibers for strong unidirectional stress resistance, ex tendons and ligaments
dense irregular CT
randomly oriented for stress resistance in many directions, ex dermis and organ capsules, less flexible but higher strength
dense regular collagenous
strength of collagen is important, tendons, ligments
dense regular collagenous
strength of collagen is important, tendons, ligaments
dense regular elastic
elasticity is important, aorta, lung, vocal cords
hyaline cartilage
nose, support tissue of the respiratory tract, ends of ribss
elastic cartilage
external ear, epiglottis, larynx
fibrocartilage
intervertebral discs, meniscus of the knee
3 types of cartilage
hyaline cartilage, elastic cartilage, fibrocartilage
type I collagen
dermis, tendons, ligaments, bone, dentin, sclera of the eye
type II collagen
hyaline cartilage, vitreous body of the eye, nose, respiratory tract, ends of ribs, elastic cartilage, articular surfaces of bones
type III collagen
reticular fibers, bone, basement membrane
type IV collagen
basal lamina around smooth and skeletal muscle fibers
elastic tissue
capable of stretching, lungs, skin, urinary bladder, lots of parallel bundles of elastic fibers, Verhoeff’s (Van Geisen) stain identifies elastic fibers as black against a yellow counterstain
reticular tissue
lymphatic system: spleen, lymph nods, thymus, and bone marrow
type III collagen fibers, synthesized by fibroblasts as first step in wound repair
stained black with silver salts
masson’s trichrome stain
muscle stains red, collagen stains blue
oil red O
stains fat, can help identify abnormal fat deposits in disease
hyaline cartilage
most abundant, smooth, nose, support tissue of the respiratory tract, ends of ribs, type 2 collagen only, has isogenous groups
elastic cartilage
similar to hyaline, has isogenous groups, also has elastic fibers not found in hyaline, external ear, epiglottis, larynx
fibrocartilage
made of chondrocytes and dense connective tissue, no perichondrium, difficult to see the lacunae, characteristics in-between hyaline and elastic that resist compression, intervertebral discs, meniscus of the knee
perichondrium
dense connective tissue forming the outer layer of hyaline cartilage
