CONNECTIVE TISSUE Flashcards
What does connective tissue do?
connects various issues of the body and gives them support
Where does connective tissue develop from?
mesoderm and mesenchyme
What does connective tissue contain?
cells, fibers, ground substance
What are the cells that makeup the connective tissue?
fibroblast, adipose, macrophages, mast, undifferentiated mesenchyme, plasma, blood, pigment
Describe the fibroblast cells?
What is their role?
spindle shaped, round nucleus, basophilic cytoplasm
also called fibrocytes in resting stage
production and maintenance of fibres and ground substances
Describe adipose cells?
What is their role?
large lipid vacuole, thin cytoplasm, flat & periphery nucleus
cells singly or in groups
specialized for synthesis and storage of fats
Describe macrophages.
What is their role?
Fusiform, stellate or spheroidal in shape
phagocytotic in nature
cytoplasm contains granules and vacuoles
Describe Plasma cells.
What is their role?
cart wheel shaped nucleus
found: lamina propia in digestive and respiratory tract
lymphoid tissue
function: manufacture of antibodies, provides resistance to the body
Describe Mast cells.
What is their role?
connective tissue & along blood vessels
secretes histamine and serotonin
Describe undifferentiated mesenchymal cells
along blood vessels
precursor of all types of cells
Describe pigment cells.
melanocytes
epidermis of skin
protect skin from harmful effects of sun’s rays
Describe blood cells
lymphocytes and neurophils
migrated from blood stream
What are the three types of fibres?
Collagen, elastic, recticular
Where are collagen fibres found?
All types of connective tissue
What is one property of collagen fibres?
inelastic and great tensile strength
Describe the structure of collagen fbres?
made up of collagen
individual fibres are unbranched
fibres run in bundles, split into branches
each fiber contains fine subunits: tropocollagen
What are collagen fibres synthesized by?
fibroblast
What is used in the staining of collagen fibres and what colour are they stained?
fresh fibres- colourless
hematoxylin and eosin- pink stain
What are collagen fibres treated with and what is the result?
dilute acetic acid
swollen = gelatin
Type I collagen fibres?
thickest fibers, seen in bones, tendons, dermis of skin
Type II collagen fibres?
found in the cartilages, vitreous body of eye
Type III collagen fibres?
seen in spleen, lymph nodes, bone marrow, also called reticular fibers
Type IV collagen fibres?
seen the basement membrane
Type V collagen fibres?
fetal tissues, blood vessels
What is one property of elastin fibers?
Highly elastic, can stretch to up to 150% of their resting length
Where are elastin fibers found?
ligamentum nuchae, ligamentum flavum
walls of large arteries
What are elastin fibers synthesized by?
fibroblasts
Describe the structure of elastin fibers
contain protein elastin
can run individually, branched, anastome with each other
yellowish in groups
if broken ends will retract or recoil
What is used in the staining of elastin fibres and what colour are they stained?
hematoxylin and eosin- purple stain
What are collagen fibres treated with and what is the result?
boiled and treated with acetic acid however no change
What are reticular fibres and where are they found?
Type III collagen fibres
Found in spleen, liver, lymph nodes, bone marrow, thymus, endocrine glands
Describe the structure of reticular fibers.
Fine branching fibres form network- reticulum
What is used in the staining of recticular fibres and what colour are they stained?
silver staining methods
What is ground substance?
semisolid gel aka intercellular space
Describe the structure of ground substance.
cells and fibers embedded in it
consists of water, carbohydrates (mucopolysaccharides), proteins (glycoproteins)
What re the classifications of connective tissue?
Loose connective tissue
Dense connective tissue
What are the types of loose connective tissue?
areolar, adipose, myxomatous, reticular
What is areolar tissue?
contains bundles of collagen fibres and scattered individual elastic fibers
fibroblast cells are the most cells present
e.g. superficial fascia