ct Flashcards
provides a matrix that supports and physically
connects other tissues and cells together to form the
organs of the body
CT
CT major constituent is the
extracellular matrix (ECM)
which consist of protein fibers and ground
substance
CT o originate from
,
o originate from embryonic mesenchyme,
CT originate from embryonic mesenchyme,
embryonic mesenchyme,
a tissue developing mainly from the middle layer of
the embryo
mesenchymnme
o produce and maintain most of the tissue’s
extracellular components.
o the key cells in connective tissue proper
o originate locally from mesenchymal cells and are
permanent residents of connective tissue.
o Synthesize and secrete collagen
fibroblast
o the most common cells in connective tissue proper
fibroblast
macrophages, plasma cells, and mast cells, originate from
hematopoietic stem cells
o abundant and irregularly branched cytoplasm,
o Ovoid nucleus, large and pale staining w/ fine
chromatin
o Larger cell
o Euchromatic nucleus
active fibroblast
o “fibrocyte”
o smaller than the active fibroblast
o acidophilic cytoplasm
o a darker, elongated, more heterochromatic nucleus
o smaller spindle shape
Quiescent Cell
- Active Chromatin
- Pale Stain
euchromatin
- Inactive Chromatin
- Darker Stain
HETEROCHROMATIN
o Targets fibroblast
o influence cell growth and differentiation.
growth factors
o Fibroblasts involved in wound healing
o have a well-developed contractile function
and are enriched with a form of actin also
found in smooth muscle cells.
myofubroblast
o Also from Mesenchymal
o “fat cell”
o found in the connective tissue of many organs.
adiipocyte
o specialized for cytoplasmic storage of lipid as
neutral fats, or for the production of heat.
o Nucleus pushed to the side
adipocyte
o Tissue with a large population of
adipocytes
o serves to cushion and insulate the
skin and other organs
adipose CT
have highly developed phagocytic ability and
specialize in turnover of protein fibers and removal
of apoptotic cells, tissue debris, or other particulate
material, being especially abundant at sites of
inflammation.
MACROPHAGE
are large oval or irregularly shaped cells of
connective tissue
MAST CELL
Has a characteristics of metachromasia, which
means that they can change the color of some basic
dyes from blue to purple or red.
MAST CELL
o Blue color due to many basophilic granules which
contains heparin
o Function for inflammatory and tissue repair
o Release bioactive substances
MAST CELL
o a sulfated GAG that acts locally as an anticoagulant
HEPARIN
promotes increased vascular permeability and
smooth muscle contraction
Histamine
✓ Serine proteases
o which activate various mediators of inflammation
Are polypeptides directing activities of leukocytes
and other cells of the immune system
Cytokine
✓ Eosinophil and neutrophil chemotactic factors
o which attract leukocytes
are converted to prostaglandins, leukotrienes, and
other important lipid mediators of the inflammatory
response.
✓ Phospholipid precursors
mast cells that are especially numerous near the
small blood vessels in skin and mesenteries
➢ Perivascular Mast Cell
Mast cells in the tissue that lines digestive and
respiratory tracts
➢ Mucosal Mast Cell
Also known as allergic reaction which is inhibited
after the release of certain chemical mediators
stored in mast cells
➢ Immediate hypersensitivity reaction
o large, ovoid cells have basophilic cytoplasm
o pale nucleus, spherical and eccentric
o clock face nucleus appearance
o nucleus has heterochromatin and euchromatin
region
o 10-20 days life span
PLASMA CELL
o Derived from Lymphocyte
PLASMA CELL
o comprise a population of wandering cells in
connective tissue.
o Migrate from blood vessels via ??????
o They function in connective tissue, don’t return to
blood and then undergo ????
o Found between endothelial cell
o Abundant in ????? tissue of ????
LEUKOCYTE
Via diapedesis
Undergo apoptosis
Abundant in CT of digestive tract
o elongated structures formed from proteins that
polymerize after secretion from fibroblasts
FIBER
o Most abundant fibers
o constitute a family of proteins selected during
evolution for their ability to form various extracellular
fibers, sheets, and networks,
o extremely strong and resistant to normal shearing
and tearing forces.
o key element of all connective tissues, as well as
epithelial basement membranes and the external
laminae of muscle and nerve cells.
o major product of fibroblasts
o family of 28 collagens
COllagen
4 GRPS OF COLLAGEN
4 Groups: fibril forming, fibril associated, anchoring
fibril, network forming
o Forms structure as tendons, organs, capsules and
dermis
FIBRIL FORMING COLLAGEN
o Bind the surface of collagen fibrils to the
components of ECM
Fibril Associated
o Bind Basal Lamina
Anchoring Fibril
o Assemble in meshwork
o Constitutes a major structural component of basal
lamina
NETWOEK FORMING
o consist mainly of collagen type III, which forms an
extensive network of thin fibers
o support of many different cells.
o Very thin
o Found associated with hematopoietic tissue (blood
forming cells)
RETICULAR FIBERS
o thinner than the type I collagen fibers and form
sparse networks interspersed with collagen bundles
in many organs
o seen in walls of blood vessels
o has elastin that can bend or stretch fibers
o ability to stretch but not elasticity
o have rubberlike properties that allow tissue
containing these fibers, such as the stroma of the
lungs, to be stretched or distended and return to
their original shape
o
o a composite of fibrillin, which forms a network of
microfibrils, embedded in a larger mass of cross
linked elastin
ELASTIN FIBERS
Transparent and rich in water
o Act as both lubricant and barrier
o allows diffusion of small molecules
GROUND SUBSTANCE
3 CLASS OF GROUND SUBSTANCE
Has 3 classes : GAGs, :Proteoglycans, Multi
adhesive glycoprotein
long polymers of repeating disaccharide units,
usually a hexosamine and uronic acid.
GAGs
- also known as hyaluronic acid
are the largest GAG located and synthesized
in golgi
Hyaluronan
have attached GAGs that often comprise a greater
mass than the polypeptide core
Proteoglycans
proteoglycan has Has 4 main GAGs: d
ermatan sulfate, chondroitin
sulfates, keratan sulfate, and heparan sulfate
- key proteoglycan in all basal laminae.
Perlecan
very large, having a core protein heavily
bound with chondroitin and keratan sulfate chains
-
Aggrecan
o Have more proteins than sugar
o have multiple binding sites (multiadhesive) for cell
surface integrins and for other matrix
macromolecules.
➢ Multiadhesive glycoprotein
- with binding sites for integrins, type IV
collagen and providing adhesion for epithelial and
other cells providing adhesion for epithelial and
other cells.
Laminin
- a 235-270 kDa dimer synthesized
largely by fibroblasts, with binding sites for collagens
and certain GAGs, and forms insoluble fibrillar
networks throughout connective tissue
Fibronectin
of the blood caused by the
pumping action of the heart, which forces water out
across the capillary wall T
hydrostatic pressure
produced by plasma
proteins such as albumin, which draws water back
into the capillaries
Colloid osmotic pressure
Function as structural (bone), Transportation
(blood, lymph), Protection (cartilage and bone),
storage of energy (adipose), protection from
microorganism (diff. type of cells)
ct
ct types
Has 5 classifications: Connective tissue proper,
fluid, support, embryonic, adipose
broadly classified as “loose” or “dense” (according to
arrangement of collagen present/)
ct proper
Also called areolar tissue - - - -
Thick layer (lamina propria) forming a layer
beneath the epithelial lining of many
organs and filling the spaces between
fibers of muscle and nerve
contains cells, fibers, and ground
substance in roughly equal parts
delicate consistency, flexible and not very
resistant to stress.
Equally, randomed cells (fibroblast), fiber (collagen), and ground substance
loose ct
has similar components as loose
connective tissue, but with fewer cells,
mostly fibroblasts, and a clear
predominance of bundled type I collagen
fibers over ground substance - -
protects organs and strengthens them
structurally.
Tight or close arrange
dense Connective Tissue -
bundles of collagen fibers appear
randomly interwoven - - -
no definite orientation.
Provides resistance to stress from all
directions.
Example include the deep dermis layer of
skin and capsules surrounding most
organs.
dense irrreg ct
consists mostly of type I collagen bundles
and fibroblasts aligned in parallel - -
dense regular connective tissue -
characterized by abundant fibers of type III collagen
known as reticulin which supports various types of
cells.
o their loose disposition provides a framework with
specialized microenvironments for cells in
hemopoietic tissue and some lymphoid organs
reticular tissue
o Mucus connective tissue
o Embryonic type
o principal component of the fetal umbilical cord
o gelatinous, with sparse collagen fibers and scattered
fibroblasts
o similar to the tissue found in the vitreous chambers
of eyes and pulp cavities of young teeth.
Mucoid Tissue
2 type of adi[pose
white and brown
3 main type of fiber
o 3 main types: collagen, reticular, and elastic fibers.
o Responsible in secreting antibodies
Plasma cell
Also occurs as fenestrated sheets called
elastic
lamellae
o Type I, II, III, V, XI
Fibril forming
o Type IX, XIII, XIV
Fibril associated
o Type VII, IX, XII, XIX
Anchoring fibril
o also known as Wharton’s Jelly
Mucoid tissue
o Type X, IV
Network forming
