Flashcards in Connective Tissues Deck (15):
Classification of connective tissues.
Liquid= blood and lymph.
Skeletal= bone and cartilage.
Proper= Fibrous (loose and dense irregular+regular)
Specialised 9reticular, pigment, mucous, adipose white+brown)
Functions= trophic, supporting. Heat inducing, heat forming, depot o liposoluble vitamins.
White adipose= unilocular, white/yellow colour, capillary networks, adults, nerves terminate on the blood vessels, storage of lipids.
Brown adipose= multilocular, abundant mitochondria, red-brown colour, intensive vascularisation, newborns and hibernating mammals, oxidation rate is high, nerves terminate on blood vessels and adipocytes.
Reticular cells, macrophages
Reticular fibres= argirophilic, Col.III
Found in- stroma of bone marrow, spleen, lymph nodes, liver sinusoid, adipose tissues, smooth muscle, Islets of Langerhans.
Loose connective tissue.
Less fibres, more cells, more ground substance.
Dense connective tissues.
More fibres, less cells, more ground substance.
Regular- Collagen fibres are parallel. Found in tendons, ligaments, aponeuroses.
Irregular- collagen fibres are random. Found in reticular layer of dermis, capsules of internal organs, submucosa of GI and respiratory tracts, mucosa of urinary bladder.
Mucous Connective tissue.
AKA Wharton's jelly.
Mostly hyaluronic acid, fibroblasts.
Found in umbilical cord.
Pigment connective tissue.
Has loose connective tissue with pigment cells.
Found in iris and choroid.
Cells of connective tissues.
1. Transient = plasma cells, macrophages, leukocytes.
2. Resident = fibroblasts, fibrocytes, adipocytes, mast cells, macrophages, myofibroblasts.
Intercellular substances of Connective Tissues.
1. Fibres = collagen, elastic and reticular.
2. Glycosaminoglycans = non-sulphated (HA), sulfated (keratin S, chondroitin S, heparan S, dermatans S, heparin).
3. Proteoglycans = aggrecans, syndecans, decorin, betaglycan.
4. Glycoproteins = osteonectin, laminin, entactin, tenascin, chondronectin, fibronectin.
Found in connective and mucous tissue.
Primary mediators - heparin, histamin, proteases (tryptase, chymase), eosinophilic and neutrophilic chemotactic factors.
Secondary mediators - Leukotriens, tromboxanes, prostaglandins (arachnoid acid precursors), PAF, TNF - A, bradykinins, IL-4,5,6
Cell boundaries are obscure.
Fibrocytes are smaller, ovoid, acidophilic, darker stained.
Active has 1-2 nuclei.
Functions of macrophages.
Phagocytosis (chemotaxis, adhesion, uptake, digestion)
Metabolism of lipids and iron.
Secretions of macrophages.
Mediators of inflammation and immunomodulators
Inhibitors of fibrinolysis.
Antigen presenting macrophages.
Characteristics = low phagocytosis, no lysosomes, S100 protein and ATPase
Interdigitating cells in thymus
Follicular cells in lymph nodes
Langerhan cells in skin