Connective Tissue Flashcards
What is the Function
Form and support to the body and organ
Connect and anchor parts of organs
medium for exchange of nutrients oxygen and waste products
aids the defense and protection
stores fat for cushioning and thermoregulating
what does connective tissue arises from
embryonically from the mesoderm
what does the head connective tissue originates
neural crest extoderm
what are the two types of cells of connective tissue
resident
migrant
what is the extracellular matrix composed of
protien fibers
amorhous ground
tissue fluid
how much extracellular matrix
alot
what does areolar mean
loose
what is a resident cell
cells which a permanent component of connective tissue
examples of resident cell
fibroblasts , adipocytes and stem cells
what is migrant cell
cell present in the blood
they can spexicalise and migrate to become a part of connective tisuse
what is an example migrant cell
macropghaes , plasma and mast cells
what are the types of fibres
collagen , elastic and reticular fibres
what are some trypes of ground substance
Glycosaminoglycans (GAGs)
proteoglycans
glycoporitens
what resident cells of soft and hard connective tissue
soft - fibroblasts and adipocytes
hard - osteocytes and chondrocytes
where is only fibroblasts found
only in dense regular connective tissue ~ tendon
what is the shape of fibroblasts
elongated cells with tapered ends
what is the function of fibroblasts
synthesis and secretions of ground substances
what is fibrocyte (activity
fibrocytes - mature connective tissues these cells are relatively inactive and immoblie
what is active fibroblasts
repair they rapidly proliferate and become active fibroblasts to form new ECM fibres and ground substances
how many nucules was the fibroblasts
one elliptical nucules usually euchromatic
what is the phillic of active or inactive
weakly basophillic - active
inactive - weakly acidphillic
why is the fibroblasts in some nucleus plae or dark
DNA is active opened up and active transciprtion and translation
cytoplasmic process are coloured dark which means the cell cytpolasm contain protiens basophillic nature
What is the function adipose cells
specialised for storage of netural fats
why is it called signet ring apperance
cytoplasm is dispalced to the peripheral region of cell by single large fat droplet
nucleus flattened and and surronded by a small amount of cytoplasm
how many fat droplets in one adipose cells
one fat droplet
why does the adipose cell look empty
xlyene washes away or dissolves the fat droplet present in teh adipose cells and leave an empty space within the cell
where are leukocytes
white blood cell
what is the two forms granulocytes
neutrophils and eosinophils
what is neutrophils
leaves the bloodstream as a first reponse to infection while the eosinophils enter the connective tissue in an event of allergic reaction or in reponse to a parasticic inection
what is eosinophils
increase in number during allergic reason and parasitic diseases
what is macrophages dervied from (2)
from monocytes in the bone marrow
some dervie from mesenchyme
how do the macrophages migrate
circualte in the blood before migrating into the connective tissue where they rapdily transform into macropahges
where do macrophages proliferate
locally
what are mast cells dervied from
bone marrow precursors
what does the location of mast cells near small blood vessels allow
them to perform many sentiel function for host defense
hat is the function of mast cells
release potent inflammatory mediators ~ histamine and anticogulant heparin chemotatic factors cytokines and metabolism of arachindonic acid that act on different tissue
what is herparin
anticagoulent while hisatmine icnreases the permeability of small blood vessels and in the airways it causes increase mucus production and smooth muscles contraction
what is lymphocytes
widley scatteed in connective tissue and are the smallest cells
what is the composition of the lymphocyte
small nucleus with almost no cytoplasm surronding it
where is plasma cells found
lamina propia of gastrointestinal tract
what is the nuclear chromastin of lymphcoytes
moslty condense and herechomatic alternting with light areas - clock face apperance
what does plasma cells
easily syntehsis protiens
produce antibodies that are released locally and circualte the blood
what is plasma cells dervied from
B lymphocytes and are kown to tbe reponsible to produce the antobodies
what are the plasma riched with
rich in rough endoplasmic reticulum and this is one of the characteristic of the cells that produce prtiens
what does antibodies produced by plasma cells help do what
neutalize harmful antigens, render toxins harmless, promote phagocytosis and as result protection the body from microoragism
what is mesenchyme
embryonic connective tissue that differentiates into cells that become fibroblasts, chondrocytes,, adipocytes and ostecytes
what can mesenchyme invade and migrate through
Extracellular matrix to create important transportation
where is mesenchymal common
in the walls of cappillaries outside the endothelium known as pericutes
what is loose arerolar
loosley packed fibres seperateded by abundant ground substances
what does areolar refer to
small fluid filled spaces in tissuew
what does loose mean
mainly the fibres of extracellualr matrix are arranged loosely
what is an example of loose areolar connective tissue
mesentery stroma of many organs
what is also found in loose areolar connective tissue
elastic fibres and fibroblast nuclei
what is dense connecitve tissue
densley packed bundles of collagen fibres
what is the portions of fibres to ground substances in dense connective
less ground substances more fibres
what are the two types of dense connective tissue
dense regular and dense irregular
what is irregular
the fibresbundles go in many different directions
what is an example of dense irregular connective tissue
dermis of the skin
what is dense regular connective tissue
bundles run in a regular arrangement of collagne bundles and fibroblasts are paralleled to one another
what is an example of dense regular connective tissue
tendon
what is adipose tissue
a type of connective tissue that stores the fat
how much ground substance are in the adipose tissue
little
where is adipose tissue moslty found
just beneath the skin
what is the function of adipose tissue
help shape the body while deposits int he form of pads to act as shock absorbers
elsewhere it fills up the spaces between tissues and helps to keep tissues in position
what is brown fat / multicoular
many small fat droplets
have alot of mitchochondria
where is brown fat moslty found
in the fetus / neonate
what happens to brown fat when it is oxidized
large amount of heat is generated
what is white fat
contains one large fat droptlet
what happens when whtie fat is oxidesed
ATP is produced
what is collagen syntehsised in
fibroblasts
what is collagen formed by
polypeptide chains
what is collagen fibres
are inelastic most common form has tensile strength (also flexible)
What are three specialised types of connective tissue in adults?
adipose , reticular and elastic
what can pro collagen not do
self assemble
how does procaollagne assmble
fibroblasts release procollagen molecules and theyw ill be transformed into collagen molecules and will assemble into a fibril outside the fibroblast
what is each collagen fibril made of
self assembling strands (3 strandes together)
what is this arrnagement of polypeptide chains called
triple helix arrangement
what do Type I Fibril make
skin bone dentin tendon and ligament
where is type II fibril found
cartilage , interveterbal disc and vitreous body
what is type III fibrils
skin blood vessels and internal organs
Type IV sheet like network
basal laminae
what is a reticualr fibre made of
type III collagen
what foes reticular fibres form
support netowkr in many organs
what do retciuarl fibres do for the liver lymph nodes and sleepn
form supporting scaffolding
what happens during healing for the reticular fibres
syntehsied by fibroblasts and are later replcaced by type I collagen
why are reticular fibres not present in HE
very thin but if they are stained with silver salts they turn black
what is elastic fibres made of
proien elastin and the microfibril fibrillin
what does elastic fibres form
random coils
what does cross links between elastin molecules cause
elastic array of fibres
where is elastic fibres found
blood vessels, lungs, mesentry
what is the funtion of elastic fibres
provide elasticity to tissue
what is linear polysacchardised formed by
charactersitic repeating dissacchride units
what forms proteoglycans
polysacchardies being bount to a protien core
GAGs help to gove
turgor and determine the diffusion of the substance through ECM
what is examples of glycosaminolgycans
keratin sulfate herpain sulfae and hyaluronic acid
what is proteoglycans
composed of core protiens which are covanlety attached
what can sulfated GAGS be
be various numbers or combinations
where are proteoglycans syntehised
RER
where do protelgycans mature
golgi + secreted by exocytsisc
what is the phillic of proteocyglcians
hydrophillic due to presence of hydroxyl carboxyl and sulphate groups
what is the function of protelgycans
trap water
what can structual glycoprotiens do
bind molecules ont he surface of cells (integrins) as well as extracellular matrix components
what do glycoporitens elastblish
strutucal conintuity between the cytoskeletona dn the extracellular matrix
what are exmaples of glycoportiens
fibronectin laminin chondronectin and osteonectin
what is fibrnectin
also binds ECM to EMC
what is laminin
found in basal lamina
what is chondronectin
found in caritlage
what is osteonectin
found in bone
