connective tissue Flashcards
Describe the characteristics that define connective tissue and the common features of
connective tissue
Cells embedded in large quantities of extracellular matrix composed of protein fibres, amorphous
ground substance and tissue fluid.
Describe the major functions of connective tissue
Space filler and mechanical support.
Attachment and protection
Highway for nutrients
Main fat store and calcium store
Site of many immunological defence reactions
Discuss the cell types that form connective tissue
soft connective tissue - Tendons, ligaments, mesentery, stroma of
organs, dermis of the
skin, etc
hard connective tissue - bone and cartilage
blood and lymph - specialised form
what are the components of the connective tissue
cells
extracellular matrix
what is the extracellular matrix
the space between the cells in the connective tissue
what is the type of connective tissue determined by
the types and relative amount of cells and extracellular matix
what cells are present in connective tissue
resident cells - fibroblasts and adipose cells
osteocytes - cells of bone
chondrocytes - cells of cartilage
what are fibroblasts
elongated cells wiht tapered ends that are distributed and produce and maintain extracellular matrix
what is the composition of the extra cellular matrix
mainly fibroblasts
why are fibroblasts important in wound repair
they are able to divide after tissue damage
what are adipose cells
fat cells - single giant fat droplet and with release of fatty acids into bloodstream which provides energy for other cells
what is the largest store of energy in the body
adipose tissue
where is the adipose tissue located around the body
subcutaneous layers help shape body, deposits in form of pads that act as a shock absorber
help to fill up space between tissue
describe how wounds heal in terms of connective tissue
myofibroblast (cell between a fibroblast and smooth muscle cell) cause wound to contract by rpoducing collagen fibres and tugging on them to draw wound closed
what are immigrant cells
leukocytes- commonly found in loose connective tissue, which migrate from blood stream and increase in number at sites of inflammation and infection
mast cells - originate from type of leukocyte, contain granules of heparin, histamine and substances that stimulate inflammation and attract white blood cells.
what do leukocytes do
migrate from blood
- neutrophils leave the blood stream in response to infection
2.eosinophils are found in increased number during allergic reaction and parasitic diseases
describe macrophages
derived from monocytes in bone marrow
circulate blood before migrating into connective tissue to rapidly transform into macrophages
can proliferate locally
describe mast cells
largest cell in connective tissue
describe lymphocytes
leukocytes that are widely scattered in connective tissue
appear as small nucleus with no cytoplasm
plasma cells
- Rare in connective tissue - numerous at sites of infection.
- large oval cells rich in rER.
- basophilic cytoplasm are responsible for the synthesis of antibodies found in the blood stream.
they neutralise harmful antigens, render toxins harmless, promote phagocytosis and as a result protect the body from micro-
organisms.
what are the transient cells in connective tissue
Fibroblast
Plasma cells
Lymphocytes
Macrophages
Neutrophils
Eosinophils
Erythrocytes
how do you determine the type of connective tissue
the relative amounts of
fibres - collagen, reticular, elastic fibres
ground substances - amorphus, space occupying material mad eof unbranched polysaccharides (GAGS)
tissue fluid
describe collagen fibres
most abundant protein in body
synthesised in fibroblasts and is formed from 3 polypeptide chains
inelastic
type 1 - tensile strength
reticular fibres
thin made of a special type of collagen (type iii)
form support network in many organs
