Lecture 7: Connective Tissue, Tandler Flashcards
What are three types of connective tissue?
- Fibrous CT
- Cartilage/bone
- Blood
What are 4 functions of fibrous connective tissue?
- Support (physical and nutritional whereby all blood vessels and lymphatics are lined by fibrou CT)
- Defense: Immune responses
- Repair: Scar formation
- Directs embryonic processes–>tells epithelium what to do, and involved in crystallization of hydroxyapatite
What two molecules comprise hyaluoronic acid?
Glucosamine
Glucuronic acid
What are three components of fibrous CT?
- Fibers
- Cells
- Tissue fluid
What are the three types of fibers that constitute the fiber of fibrous CT?
1) Collagenous fibers
2) Reticular fibers (variant of collagen)
3) Elastic fibers
The fibers of fibrous CT are in a medium called matrix. What comprises this matrix? (3 things)
- Polysaccharide molecules
- Ground substance
- Water
What does the complex 3D structure of fibrous CT contribute to in terms of defense in the cell?
It makes the matrix very viscous, which prevents the diffusion in CT of invaders.
What type of stain is used for fibrous CT to see the ground substance? What molecule does it stain? What color will the cells appear that are stained?
Periodic Acid Stain (PAS stain); it stains carbohydrates, there will be a pinkish background in which the cells are embedded
The ground substance of fibrous CT displays a phenomenon called metachromasia with a metachromatic dye. What is everything but the matrix colored with this dye? What color is the matrix?
Everything but the matrix is is blue, but the matrix is violet
What are the 5 cell types in fibrous CT?
1) Fibroblasts (most abundant)
2. Fat cells (energy storage)
3. Macrophages (phagocytic)
4. Mast cells (release histamine)
5. Lymphocytes (change in plasma cells that produce antibodies)
What is the tissue fluid mixed with for fibrous CT?
Matrix
With loose CT (aka areolar CT), how are the fibers arranged? How much space is between adjacent cells? Where is the tissue found in the body (hint: trick question)?
The fibers are scattered, there is a lot of space in between adjacent cells. This tissue is found all over the body.
With dense CT, how much space is between cells compared to the amount of fibers?
There’s more material (i.e. fibers) between the cells than there is space
How are the fibers arranged for dense irregular fibrous CT?
Scattered-pointing in all directions
Dense regular fibrous CT: where is it located?
In tendons, and to a lesser degree ligaments
How is the cytoplasm of fibroblasts described?
Long but thin
What does the protein formed by fibroblasts ultimately make?
Collagen
What type of cell is the second largest collagen producer?
Bone
Where do you find type 2 collagen? What type of cell makes Type IV collagen? (Also a trick question)
Cartilage; IV made by non-CT cell
How does CT help in tissue repair?
Capillaries and fibroblasts grow into the damaged area, where the fibroblasts produce collagen (making granulation tissue)
All molecules in the matrix are synthesized by what cell type?
Fibroblasts
What body system are fibroblasts related to?
Endocrine system
Name the four functions of fat cells
1) Storage for fuel
2) Insulation
3) Fill crevasses (i.e. swimmers)
4) Cushion (bottom of feet)
When do monocytes become macrophages?
When they leave blood vessels and “crawl” into CT
What are two big roles of of macrophages?
1) phagocytosis
2) Role in immune response
What is prominent physically about macrophages when they are stained?
Lysosomal enzymes
Why are mast cells easy to identify?
There are numerous big secretory granules
What two chemicals are present in mast cells?
Heparin, histamine
What does heparin do?
It is an anti-coagulant: keeps blood fluid and lets red blood cells pass freely through small blood vessels
What is a foreign body giant cell comprised of? What does it do?
100s of macrophages; encompasses large offending material
What does histamine do to blood vessels? What type of condition is this associated with?
Causes vasoconstriction-happens with anaphylactic shock.
What causes B lymphocytes to become plasma cells?
After they contact antigens, after which antibodies must be produced
Why are plasma cells able to be visualized easily with a light microscope?
Nuclei
What cell has a “cartwheel nucleus”?
Lymphocytes
How do T lymphocytes work? What particular immunity are they associated with?
They attack foreign material (such as a heart transplant); they are associated with cellular immunity
What is the most abundant fiber in the body?
Collagenous fiber
Where are collagenous fibers synthesized, and by what?
Synthesized by rER in fibroblasts
What is the function of collagenous fibers?
Provides tensile strength to tissue that increases the strength of bones
What type of collagen is reticular fiber a variant of?
Type 1 collagen
In what system do you find reticular fibers? How do you stain it?
Lymphatic system; stains with silver
Is there periodicity to Reticular fibers? How does it compare to Type 1 collagen?
It has the same periodicity as type 1 collagen, “just finer”
What do elastic fibers do to organs?
Provides elasticity
Where do you mainly find elastic fibers?
1) Skin
2) Large blood vessels
3) Aorta
4) Lungs
What are the two main components of elastic fibers?
1) Microfibrils (initial structures in production of elastic fibers)
2) Amorphous material (this is the main stretching component of elastic fibers)
What are the two unique amino acids found in elastin, which provide the stretch to elastin?
1) desmosine
2) isodesmosine
Why do immature elastic fibers have this name?
They never develop amorphous material
