1000 Histo Connective Tissue Flashcards
What are the five types of connective tissue?
proper, bone, cartilage, blood, lymph
How can proper connective tissue be further subcategorized?
loose, dense, adipose
What are the 5 functions of connective tissues?
Mechanical support and protection of soft tissues Physiological support Storage of energy in fat Defense against infection repair of injuries
How does CT give physiological support?
a. Serves as pathway for vessels and nerves
b. Tissue fluids of connective tissue act as
diffusion medium for exchange of metabolites between tissues and vessels
If the connective tissue is damaged and unable to facilitate diffusion of fluids what results?
edema (fluid build up in tissues)
What is the composition of connective tissue?
ground substance and fibers (ECM) and cells
What kind of connective tissue has these:
Fibrocytes Fibroblasts Adipose Cells Mast Cells Macrophages Pericytes (Chondrocytes) (Osteocytes)
Fixed (resident) CT
What kind of connective tissue has these: Plasma cells Lymphocytes Neutrophils Eosinophils Basophils Monocytes Macrophages
Free (transient) CT
What is the composition of ground substance?
amorphous gel-like material composed of
GAGs
proteoglycans
glycoproteins
What are GAGs?
Long, inflexible, polysaccharides composed of repeating disaccharide units
If you link a repeating disaccharide unit (GAG) to a protein what do you get?
proteoglycan
Glycoproteins are primarly (blank) molecules of the ECM. What are some examples of these.
cell adhesion
integrins, fibronectins, laminin, entactin,
tenascin, chondronectin and osteonectin
(blank) is the most important nonsulfated GAG.
What is it important for?
Where is it found
hyaluronan
absorb semisolids (jello-like)
Found in the ECM of all CT and in vitreous humor and synovial fluid.
The majority of GAGs are (blank)
sulfated
Gags have a strong (blank) charge and attracts active (blank) causing a heavily hydrated matrix strongly resistant to compression.
negative
cations
Since GAGS are negatively charged they repel each other and create a (blank)
slippery surface
Some Important GAGS:
(blank) are well-represented in catrilage,
keratans and dermatins in (blank)
(blank) is crucial to the functioning of basal laminae, especially in the glomerular filtration membrane of the kidney.
chondriotins
skin
heparan
What consists of a protein core to which sulfated GAGs are covalently bound (shaped like test tube brush). Form thick colloids similiar to gravy, pudding, gelatin or glue.
Proteoglycans
What do proteoglycans do?
trap water, occupy space, link to collagen fibers, cell adhesion, slows the spread of pathogens through tissues.
Why is it important the proteoglycans trap water?
- resist compression
- return to original shape
Why is it important the proteoglycans link to collagen fibers?
What do proteoglycans aid with via cell adhesion?
-to form networks
- in bone combine with calcium hydroxyapatite
and calcium carbonate
Embryonic migration
What are glycoproteins?
cell adhesion molecules of the ECM, fibronection found in ECM, Laminin found in basal lamina of all epithelia, external laminae of muscle cells, adipocytes, shwann cells
What is the function of ground substance?
traps and holds water, anchors, acts as a charge and size barrier, contributes to physical properties of a connective tissues, regulated morphogenesis, facilitates cell migration
What is the importance of a ground substance’s ability to trap water?
- fullness to skin
- protection
- reduces fluid loss
- limits pathogenic
invasion
What is the importance of a ground substances ability to acts as a charge and size barrier?
- regulates access to cells
What is the importance of a ground substances ability to regulate morphogenesis?
- migration recognition
- growth factor activation
What are some general problems that can occur with issues within the ground substance?
Improper nutrient/waste management
Improper tissue development (morphogenesis)
Improper tissue growth (e.g. cartilage growth plate)
Cellular malfunction due to GAG accumulation in lysosomes
What is a good example of a disorder of ground substance?
Hurler’s syndrome
What is a family of diseases caused by accumulation of various GAGs in lysosomes?
mucopolysaccharides (MPS)
What are the three fiber types that are routinely stained for at the light microscope level?
- reticular fibers which are
argyrophilic i.e. stain with
silver - elastic fibers that are best seen stained by special elastic stains (black stain)
- collagen fibers which stain well with eosin (H&E) (red stain)
Why is it difficult to see type 1 collagen fibers in bone?
Because they are embedded in the ground substance
collagen has how many different types?
20
Each collagen type is made of different combinations of (blank)
alpha chains
Varying the alpha chain combinations of collagen dictates the (blank) properties of the different types of collagen fibers.
physical
What are the most common types of collagen?
I,II,III,IV
What is the most common of all collagens?
Where is it found?
Type I
Bone, skin, tendon, dentin, fibrocartilage
What does type I collagen originate? and what are its tissue properties?
oseteoblasts, fibroblasts, odontoblasts, chondroblasts.
Stiff, rope-like resists tension
Type I, II, and III collagen are all (blank) forming.
fibril
Where is Type III collagen (reticular fibers, highly glycosylated) found? Where does it originate? what is its tissue properties?
Forms structural framework of lymphatic tissue, adipose tissue, liver, cardiovascular system, lung, skin
Originates:Fibroblasts, reticular cells, smooth muscle cells and hepatocytes
Tissue Properties:Structural, delicate stroma (framework)