connective tissue Flashcards
provides a matrix that supports and physically connects tissues to form organs of the body
connective tissue
what is the major constituent of connective tissue?
extracellular matrix
where does connective tissue originate?
embryonic mesenchyme
where does macrophages, plasma cells, and mast cells originate from?
hematopoietic stem cells
consists of population of undifferentiated cells; generally elongated but with large chromatic nuclei that indicated high level of synthetic activity
mesenchyme
permanent resident of connective tissue; produce and maintains most of the tissue’s extracellular component
fibroblast
what does the fibroblast synthesize and secrete?
collagen, elastin, glycosaminoglycans, proteoglycans, multiadhesive glycoproteins
rapidly closing wounds are induced by?
myofibroblasts
extracellular fibers and ground substance
fibroblasts
serves as antibodies
plasma cells
various immune defense functions
lymphocytes
modulate allergic/vasoactive reactions and defense against parasites
eosinophil
high eosinophil indicates?
parasitic infection
phagocytosis of bacteria
neutrophil
elevated neutrophil indicates?
bacterial infection
phagocytosis of ECM components and debris; antigen processing and presentation to immune cells; secretion of growth factors, cytokines, and other agents
macrophages
pharmacologically active molecules
mast cells and basophils
what has high levels in cases of allergy
basophil
storage of neutral fats
adipocytes
kidney shaped nucleus; 10-30 um in diameter
macrophages
macrophage in connective tissue
histiocytes
macrophage in bone marrow
monocytes
macrophage in liver
kupffer cells
macrophage in CNS
microglial cells
macrophage in skin
langerhans cells
macrophage in bone
osteoclast
oval or irregularly shaped cells of connective tissue; 7-20 um in diameter filled with basophilic secretory granules
mast cells
sulfated glycosaminoglycan that acts locally as an anticoagulant
heparin
promotes increased vascular permeability and smooth muscle concentration
histamine
activate various mediators of inflammation
serine proteases
attracts leukocytes
eosinophil and neutrophil chemotactic factors
release of certain chemical mediators which are stored in mast cells promotes what?
type 1 hypersensitivity
lymphocyte-derived, antibody producing cells; responsible for the synthesis of immunoglobulin antibodies
plasma cells
where are plasma cells derived from?
B lymphocytes
average life span of plasma cells
10-20 days
also present in cases of inflammation like plasma cells
leukocyte
what are the major signs of inflamed tissues include?
redness and swelling with heat and pain
in some cases of inflammation there is a presence of?
swelling (edema)
elongated structures which are formed from proteins that polymerize after the secretion of fibroblast
fibers
most abundant, formed by proteins of the collagen family
collagen
three main types of fibers
collagen, reticular, elastic fibers
most abundant protein in the human body, 30% of its dry weight
collagen
two important amino acids in formation of collagen
glycine and proline
3 groups of collagens
fibrillar collagens, network or sheet-forming collagens, anchoring collagens
collagens type I, II, and III; have polypeptide unit that aggregate to form large fibrils
fibrillar collagens
type IV collagen have subunits produced by epithelial cells and are major structural proteins of external laminae and all epithelial basal lamina
network or sheet-forming collagen
short collagens that link fibrillar collagens to one another and to other components of ECM
anchoring collagen
skin, tendon, bone, dentin; resistance to tension
type I collagen
cartilage, vitreous body; resistance to pressure
type II collagen
skin, muscle, blood vessels, frequently together with type I; structural maintenance in expansible organ
type III collagen
fetal tissues, skin, bone, placenta, most interstitial tissues; participates in type 1 collagen function
type V collagen
cartilage; participates in type II collagen function
type XI collagen
Fibril forming collagens are:
type I, II, III, V, and XI
all basal and external laminae; support of epithelial cells; filtration
type IV collagen
hypertrophic cartilage involved in endochondral bone formation; increase density of the matrix
type X collagen
Network forming collagens are:
type IV and X collagen
epithelial basement membranes; anchors basal laminae to underlying reticular lamina
type VII collagen
Cartilage, vitreous body; binds various proteoglycans; associated with type II collagen
type IX collagen
placenta, skin, tendons; interacts with type I collagen
Type XII collagen
placenta, bone; binds with type I collagen fibrils, with types V and XII, strengthening fiber formation
type XIV collagen
serves as supportive stroma for parenchymal secretory cells and rich microvasculature of the liver and endocrine glands
reticular fibers
highly hydrated, transparent, and a complex mixture of glycosaminoglycans, proteoglycans, and multiadhesive glycoproteins
ground substance
allows diffusion od small molecules and acts as lubricant and barrier to invaders
ground substance
distributed in the umbilical cord, synovial fluid, vitreous humor, and cartilage
hyaluronic acid
distributed in the cartilage, bone, cornea, skin, notochord, aorta; high levels of interaction mainly with collagen type II
chondroitin 4-sulfate
distributed in the cartilage, umbilical cord, skin, aorta; high levels of interaction mainly with collagen type II
chondroitin 6-sulfate
distributed in skin, tendon, aorta (adventitia); low levels of interaction; mainly with collagen type I
dermatan sulfate
distributed in aorta, lung, liver, basal laminae; intermediate levels of interaction, mainly with collagen type III and IV
heparan sulfate
distributed in cartilage, nucleus pulposus, annulus fibrosus
keratan sulfate
what are the four major GAGs found in proteoglycans?
dermatan sulfate, chondroitin sulfates, keratan sulfate, and heparan sulfate
supports microvasculature, nerves and immune defense cells
loose connective tissue
protects and supports organs; resists tearing
dense irregular connective tissue
provide strong connections within musculoskeletal system; strong resistance to force
dense regular connective tissue
contains stem/progenitor cells for all adult connective tissue cells
mesenchyme
supports and cushions large blood vessels
mucoid connective tissue
supports blood forming cells, many secretory cells, and lymphocytes in most lymphoid organs
reticular connective tissue
