Exam1Lec5ConnectiveTissue Flashcards
What is the connective tissue?
Tissue (cells + fibers) that supports, protects and gives structure to other tissues & organs in the body.
What is connective tissue made of?
4 different types of cells and 3 diff types of fibers
What are the 4 different types of cells (originated from mesenchymal stem cells)?
- Fibroblast >produces collagen fibers (i.e., it is the main cell producing ECM fibers)
- Macrophage = immune cell
- Mast cell = immune cell >produces response to allergic reaction
- Plasma cell = immune cell > produces antibodies
What are the 3 diff types of fibers for connective tissue?
- Collagen (type IV)
- Elastic
- Reticular (type III collagen) > stains w/ silver (metal)
-Produced by reticulocytes
collagen and elastic are both prduced by fibroblasts
Connective tissue is what plus what?
Cells + ECM (fibers + ground substance)
What is the major cellular component of CT? What do they produce?
Fibroblasts, and they produce collagen fibers (i.e., other major component of CT)
But can also produce elastic fibers that do NOT contain any collagen
What synthesiszes collagen?
Fibroblasts (alos osteoblasts and chondroblasts)
rer: synthesis of pre and pro collagen
golgi: packaging/secretion of procoll
ECM: enzymatic processing, self aggregation, cross linking
What characteristcs of fibroblasts do we see under a LM?
stain?
cell shape?
nuclei shape?
Stain = dark purple w/ H-stain > b/c they have rER + ribosomes
Cell = spindle-shaped
Nuclei = flat; cigar-shaped
What are the immune cells of connective tissues?
Macrophages, mast cells, plasma cells
Macrophages
fxn?
stain?
cell shape?
cytoplasm?
nuceli shape?
- Phagocytic > have lysosomes to digest material
- Stain = purple (H-stain)
- Cell = irregular shape
- Cytoplasm = vacuoles appear as “open spaces”
- Nuclei = large, irregularly-shaped
Mast cells
fxn?
location?
stain?
cell shape?
cytoplasm?
nuceli shape?
-
Degranulation > leads to allergic response
-Localized, mild reaction that is site specific
-Hyperallergic > severe immediate reaction that is systemic - 2 locations = mucosa (loose CT = lamina propria) & adult CT (CT proper)
- Stain = purple (H-stain)
- Cell = round/oval shape
- Cytoplasm = many dark purple granules
- Nuclei = lightly-stained round shape
know fxn and lxn
releases heparin, histamikne, proteoglycancs, ECF-A
Is lamina propria of gut and loose connective tissue the same thing?
slide 25
No, lamina propria is the layer where you can find connective tissue
ex: submusosa layer of gut> find dense irreg
Plasma cells
fxn?
stain?
cell shape?
cytoplasm?
nuceli shape?
- B-lymphocytes exposed to Ag > produces Abs
- Stain = purple (H-stain) w/small pale area near nucleus (golgi apparatus)
- Cytoplasm = purple staining d/t lots of rER
- Nuclei = large, eccentric (off-center), cartwheel appearanc
What are the 2 locations of mast cells?
- Mucosal found in loose CT under muscosal epithelium
- adult CT proper
What are the largest of fixed cells of CT?
Mast cells (20-30 microns)
macrophages are NOT fixed, they move around alot
Whar is ECM?
A gelatinous blend of water + ions + collagen + glycoprotein + proteoglycan
Surrounds cells & fibers of CT for support, metabolism + cell communication
What are Glycosaminoglycans (GAGs)?
- Exist as proteins complex w/ polysaccharides
-Keratin sulfate
-Chondroitin sulfate - Fxn = control linkages b/n ECM components
- Make up the major component of PG aggregates
-They attach to PGs which cause PGs to bind the core protein
What are proteoglycans (PGs)?
- Fxn = adhesion of ECM components
- Linker proteins attach to PG aggregates to hyaluronan
-Results in lots of hydration of the EC
major part of ECM, they consist of GAGS
What are glycoproteins?
Glycoproteins = fibronectin & laminin
ECM fxn?
ECM Fxn = regulation of distribution + transport of substances
Ground substance of ECM
GAGs + PGs + glycoproteins
ECM=
ground substance + fibers
For CT classification, what are the 3 categories of CT?
- Embryonic = mesenchyme located in the embryo
- Specialized = cartilage, bone, blood, adipose, hemopoietic and lymphatic
- Adult (CT proper) = loose & dense
-Classified as regular (fibers oriented in same direction) or irregular (fibers oriented in opposite direction)
CT classificationn depends on the cell to ECM ratio, what is the ratio for
Loose (areolar) CT and Dense CT?
- Loose (areolar) CT = cells > ECM (fibers)
- Dense CT = cells < ECM (fibers)
Where is loose (areolar) CT located?
Under epithelium, surrounds bv, nerves, and muscles
Where can you find dense regular CT?
Tendons, ligaments, cornea of eye
transmits physical force and light energy
Where can you find dense irregular CT?
dermis layer of skin, submucosa of GI
Reticular CT vs Elastic CT
Reticular CT: dense irregular CT where reticualr fibers predomiate, seen in lymphatic tissues
Elastic CT: dense irregular CT where elastic fibers made by either fibroblasts (loose CT) or smooth muscle cells (aorts). Seen in large blood vessels and ligaments
Dense irregular CT = elastic CT (b.v.) & reticular CT (lymphoid organ
Specialized connective tissue includes:
adipose tissue, cartilage, bone, blood, and hematopoietic tissue
Connective tissue proper (adult CT) consists of what?
Cells and ECM that includes fibers and ground substances
just asking what is ct
The classification fo CT proper is based on
- Distribution and relative number of cells
- Types of fibers present and their arrangement
- The amount and type of ECM
The major (permanent residents) cell types found in CT are?
- fibroblasts (collagen, elastic, reticular fibers)
- macrophages
- adipose cells
- mesenchymal stem cells.
The wandering (transient) cell population includes: lymphocytes, plasma cells, neutrophils, eosinophils, basophils, monocytes
lymphocytes, plasma, and esonophils are immune cells
The ECM is a complex structural network that does what 3 things?
- Surrounds
- Supports and a metabolic compartment
- Enables communication b/w cells
What holds water for ECM, and is a big part of proteoglycan aggregating?
GAGs
____ can indirectly bind to the hyaluronic acid molecule by means of link protins.
Proteoglycans
this property of hyaluronian and related polysaccharides regulates the distribution and transport of substances w/in the CT.