Dermis, Hypodermis, Connective tissue Flashcards
name the 3 most common ct cells
fibroblasts
adipocytes
mast cell
describe fibroblasts
secrete collagen and other elements of EC<
divide to make more
describe adipocytes
store fat
describe mast cells
macrophages and lymphocytes (cells with immune functions)
is the matrix only produced by fibroblasts
nNo
IT CAN BE PRODUCED BY RELATED cell types like chondroblasts in cartilage and osteoblasts in bone
are fibroblasts in all ct
HECK NO
describe ground substance of ct
depends on the type of connective tissue
describe fibers in ct
principal fiber type = collagen
can be others like elastic fibers
describe what collagen fibers do
confers tensile strength with flexibility
describe what elastic fibers do
confer resiliency
what is the most abundant protein in body
collagen
describe ground substance of ordinary ct
water stabilized by glycosaminoglycans, proteoglycans and glycoproteins
describe ground substance of bone
ground substance includes minerals
describe ground substance of blood
ground substance is fluid (plasma)
what is a sheath
fibroblasts - makes fibers and ecm
name and describe the components of amorphous ground substance
structural glycoproteins - 90% protein and 10% sugars
proteoglycans - 50/50 sugar proteins
GAGs
name the GAGs
chondroitin sulfate
dermatan sulfate
heparan sulfate
keratan sulfate
and core proteins (recall composition)
name a structural glycoprotein
fibronectin
name the collagen fibers found in ct and where they are found
type 1 - dermis, tendon
type 2 - hyaline cartilage
type 3 - reticular fiber
type 4 - BM
type 5 - fetal tissues
name the non collagen fibers found in ct and where they are found
elastin - elastic cartilage, arteries
gives elastic properties of cartilage
name the areas that collagen fibers are made in (like what they have to travel through)
nucleus
RER
golgi
extracellular space
describe what happens in nucleus (how collagen fibers are made)
2 copies alpha 1 gene
1 copy alpha 2 gene
forms 3 peptides which come out and goes to RER
describe what happens in RER (how collagen fibers are made)
synthesis and clipping of SP (preprocollagen)
hydroxylation of lysine and proline residues - sticks H on ends, then can exchange for sugar
attachment of glucosyl and galastosyl to hydroxylysyl residues
assembly of procollagen molecules - forms triple helix
describe what happens in golgi (how collagen fibers are made)
packaging and secretion out of cell
describe what happens in extracellular space (how collagen fibers are made)
procollagen peptidases aggregation
it becomes tropocollagen and then aggregated and forms microfibrils and then collagen fibrils and then bundles
describe how procollagen becomes tropocollagen (in extracellular space)
peptidase cleaves peptide bonds and chops off ends of triple helix
the ends must be free - now becomes tropocollagen
what is tropocollagen
building blocks of collagen
280nm in length
specific start and stop
describe how tropocollagen becomes microfibrils (and on)
tropocollagen self aggregates in a regulated fashion (depends on sugar residues) and becomes myofibrils
myofibrils bind with each other and form collagen fibrils
how do collagen fibrils form collagen fibers
self assemble to be collagen fibers and can bundle to become collagen bundle - usually has sheath around bundle
does collagen have a pattern
yeee e
its because of the way the components align - makes a regular repeating patterns which produces a lacunar region and overlapping region
describe lacunar region and overlapping region of collgen
lacunar = space, looks light
overlapping region = dark
what is the periodicity of collagen due to
stepwise overlapping of tropocollagen
name other ct cells and what their functions are - 4
lymphocyte - immunoglobulins (humoral defense)
mast cell - heparin and histamine (anti clotting, inflammation)
plasma cell - phagocytosis (cellular defense)
macrophages
what are cartilage and bone
specialized forms of ct which produce ecm with firm consistency
what does the matrix of cartilage allow for
allows tissue to support mechanical stress without distortion
provides support to adjacent soft tissues
what cells are found in cartilage
chondrocytes
where are chondrocytes in cartilage
within spaces called lacunae or chondroplasts
define lacunae
space in cartilage
usually small
space has isogenic group (cells - chondrocytes)
what is articular cartilage
found at end (head) of bones
special
name the 3 main types of cartilage and where to find them
hyaline - trachea (rings of hyaline with muscle in back)
elastic - ears, nose, larynx
fibrocartilage - intervertebral discs
describe the ground substance of ecm of cartilage - specifics
proteoglycans - keratan sulfate and chondroitin sulfate
hyaluronic acid
various glycoproteins - chondronectin
what fibers are found in hyaline cartilage
collagen type 2
what fibers are found in elastic cartilage
elastic fibers
what fibers are found in fibrocartilage
collagen type 1
T OR F: cartilage continues to grow for all your life
false silly head
cartilage stops growing in mature cartilage
there is no chondrogenic layerr
what is perichondrium
most apical layer
wraps around cartilage - ct sheath
name the layers of the perichondrium
fibrous layer
chondrogenic layer
describe fibrous layer of perichondrium - gen
more fibers less cells
dense irregular ct
collagen type 1
describe fibrous layer of perichondrium - detailed like about cell types
fibrocytes (blasts produced fibers but now they are trapped, so cytes, used to be blasts but older cartilage so no more
describe chondrogenic layer of perichondrium - gen
flat cells
chondroblasts - active cells make ecm, fibers and amorphous ground substance
makes collagen type 2
describe chondrogenic layer of perichondrium - detailed like about cell types
makes all ecm - chondroblasts
can divide and stay in chondrogenic layer or differentiate to chondrocytes (no longer active)
describe appositional growth of cartilage
chondroblasts in chondrogenic layer make ecm and chondrocytes and pushes stuff down
gets thicker and displace - moving away from top
growth of chondrogenic layer is important to make cartilage grow
describe interstitial growth of cartilage
chondrocytes get stuck in spaces = chondroplasts
inside chondroplast = interstitial growth - divide within
chondrocytes still dividing
describe chondroplast - cells
8 cells trapped in lacuna - all 8 cells came from same cell (= isogenic group)
what is similar between hyaline and elastic cartilage
very similar
perichondrium - fibrous layer and chondrogenic layer
cells trapped in ecm, not active, becomes part of cartilage, chondroplasts with chondrocytes stuck in lacunae
what is different between hyaline and elastic cartilage
elastic cartilage HAS ELASTIC FIBERS
chondroblasts of cartilage make another of fiber - elastic fibers
elastic fibers made by chondrogenic layer
what do elastic fibers do for elastic cartilage
gives elasticity
able to move elastic cartilage around because of these fibers
