Term
| What are the three categories of connective tissues? |
|
Definition
1. loose CT
2. dense irregular CT
3. dense regular CT |
|
|
Term
| What are some types of CT cell types? (6) |
|
Definition
1. fibroblasts
2. macrophages
3. mast cells
4. plasma cells
5. adipose cells
6. leukocytes
(they can be indigenous or immigrant cells) |
|
|
Term
| What is the major constituent of connective tissue? minor? |
|
Definition
major = extracellular matrix
minor = cells |
|
|
Term
| What are the two components of extracellular matrix? |
|
Definition
1. protein fiber
2. ground substance |
|
|
Term
| What are the functions of extracellular matrix in connective tissue? (4) |
|
Definition
1. structural support of the tissue (bone, cartilage, tendon, ligament, capsules of organs, "filler" tissue)
2. defense (physical barrier to microorganisms)
3. reservoir for hormones controlling cell growth and differentiation
4. medium for nutrients and metabolic wastes to be exchanged between cells and blood supply |
|
|
Term
| What are the two types of connective tissue fibers? |
|
Definition
| collagen and elastic fibers |
|
|
Term
| What is the most abundant protein in the body at 30% of dry weight? |
|
Definition
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|
Term
| Most collagens are made by ______ but ______collagen is made by epithelial cells |
|
Definition
1. fibroblasts
2. type IV collagen |
|
|
Term
Type I Collagen: what is the main function?
- describe
- where is it found?
- made by? |
|
Definition
Function: resistance to tension
- forms fibrils and is densely packed thick fibers and bundles; it is the MOST abundant collagen
- found in dense and loose CT, skin, tendons, fibrous cartilage, organ capsules, bones, cornea, dentin
- made by fibroblasts and specialized CT cells like osteoblasts, odontoblasts, chondroblasts
*birefringent yellow or red fibers and nonargyrophilic |
|
|
Term
type II collagen: main function
- describe
- where found?
- made by? |
|
Definition
Function: resistance to intermittent pressure
- NO thick fibers or bundles but rather THIN fibrils
- found in hyaline and elastic cartilage and vitreous bodies
- made by chondroblasts
*visible with picro-Sirius stain and polarization microscopy |
|
|
Term
Type III Collage: main function
- describes
- where?
made by? |
|
Definition
Function: structural maintenance in expansible organs
- forms reticular fibers
- found in smooth muscle, arteries, uterus, forms networks around cells in spleen, lymph nodes, bone marrow, kidney, liver, endocrine glands
- made by fibroblasts, smooth muscle cells, reticular cells, schwann cells, hepatocytes
* weak birefringent green fibers and argyrophilic |
|
|
Term
| what does argyrophilic mean? |
|
Definition
|
|
Term
| What is a reticular fiber? |
|
Definition
| loosely packed thin fibrils with uniform diameters |
|
|
Term
| Which collagens are part of the group of collagens that are fibril-associated? |
|
Definition
|
|
Term
| What is a fibril-associated collagen? |
|
Definition
| form short structures that bind collagen fibers to each other and other components of the ECM |
|
|
Term
| Type VII collagen - function |
|
Definition
| forms anchoring fibrils to anchor the skin epidermal basal lamina to connective tissue |
|
|
Term
| Type IV collagen - function/describe |
|
Definition
| Forms a network in the basal lamina |
|
|
Term
| Ehlers-Danlos Type IV disease |
|
Definition
deficiency of type III collagen reticular fibers
- ruptured arteries and intestinal ruptures |
|
|
Term
| Ehlers-Danlos Type VI disease |
|
Definition
| defects in processing type I collagen causing hyperextensible skin (increased elasticity) |
|
|
Term
|
Definition
| collagen I defect leading to brittle bones, abnormal teeth, thin skin, weak tendons, progressive hearing loss |
|
|
Term
|
Definition
| it is made in the cell, processed or cleaved and then secreted in the process of making collagen |
|
|
Term
|
Definition
| this is the second setep in making collagen and involves polymerization in an overlapping pattern |
|
|
Term
| what are the steps of collagen synthesis? |
|
Definition
1. procollagen
2. tropocollagen
3. collagen fibrils with cross striations and 64 nm
4. collagen fibers that are long and wavy (stain pink with eosin and blue green with trichrome
5. collagen bundles |
|
|
Term
Elastic fibers:
1. function
2. where found?
3. made by? |
|
Definition
- thin, branching fibers forming netlike units in CT
1. allows stretch and recoil
2. found in almost all CT and enriched in elastic connective tissue - found in places that need stretching and relaxation such as skin, tendons, the heart, blood vessels, fascia of the anterior abdominal wall
3. fibroblasts and smooth muscle cells |
|
|
Term
| What are the two components of elastic fibers? |
|
Definition
1. microfibrils - elastic scaffold made of fibrillin and associated glycoproteins
2. elastin - non-glycosylated protein forming amorphous deposits |
|
|
Term
| what are the three stages of elastic fiber development? |
|
Definition
1. oxytalan fibers - microfibril arrangement of fibrillin
2. elaunin fibers - elastin protein surrounding oxytalan fibers
3. elastic fibers - central core of elastin surrounded by tubular microfibrils |
|
|
Term
|
Definition
| mutations in fibrillin gene resulting in defects in elastic fibers; tissues such as large arteries with lots of elastic fibers suffer from lack of resistance and patients have ruptured aortas |
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|
Term
| one possible stage at which collagen secretion may be altered in the path state is the form in which it is secreted from its cells of origin. what is the initial form in which it is secreted? |
|
Definition
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|
Term
| What is ground substance? what are its two primary components? |
|
Definition
an amorphous, viscous gel where cells and fibers of connective tissue are suspended;
1. glycosaminoglycans (GAG's)
2. glycoproteins |
|
|
Term
| What is a glycosaminoglycan (GAG)? |
|
Definition
| made of linear, non-branching polysaccharides in ground substance; all except hyaluronic acid are attached to a core protein |
|
|
Term
|
Definition
|
|
Term
| what are some examples of GAG's? (5) |
|
Definition
1. dermatan sulfate
2. chondroitin sulfate
3. heparan sulfate
4. hyaluronic acid
5. keratan sulfate |
|
|
Term
| dermatan sulfate - where found? associated with which collagen? |
|
Definition
| a GAG found in the dermis, tendons, ligaments, and fibrocartilage; associated with type I collagen |
|
|
Term
| chondroitin sulfate: where found? associated with which collagen? |
|
Definition
| found in hyaline and elastic cartilage and associated with type II collagen |
|
|
Term
| heparan sulfate: found where? asssociated with which collagen? |
|
Definition
| found in reticular fibers and basal lamina; associated with type III and IV collagen |
|
|
Term
| hyaluronic acid - found where? what does it bind to? |
|
Definition
| found in cartilage and binds to water |
|
|
Term
| keratan sulfate - found where? |
|
Definition
|
|
Term
| what are the functions of GAG's (2)? |
|
Definition
1. structural - binds proteins fibers of ECM and anchors cells to ECM
2. hydration - Proteoglycans bind cations (sodium) and water |
|
|
Term
|
Definition
| found in ground substance and are made mainly of PROTEIN, attached to a smaller amount of carbs |
|
|
Term
| what are three examples of glycoproteins? |
|
Definition
1. fibronectin
2. chondronectin
3. laminin |
|
|
Term
|
Definition
| important for cell adhesion and migration; glycoprotein |
|
|
Term
|
Definition
| binds chondrocytes to collage; glycoprotein |
|
|
Term
|
Definition
| helps bind epithelia to basal lamina; glycoprotein |
|
|
Term
| What are the indigenous cells of connective tissue? |
|
Definition
1. primitive mesenchymal cell
2. fibroblast or fibrocyte
3. adipose cell |
|
|
Term
Primitive mesenchymal cell:
1. origin
2. appearance
3. function |
|
Definition
1. embryonic mesenchyme; differentiates in the growing embryo and multipotent undifferentiated CT cells decrease until single cells are found next to blood vessels as a stem cell population
2. elongated with pale nucleus, defined nucleolus, ill-defined cytoplasm, inconspicuous
3. divide and produce more indigenous CT cells that differentiate when needed |
|
|
Term
Fibroblast/Fibrocyte:
1. origin
2. appearance
3. function |
|
Definition
Fibrocyte = inactive fibroblast
1. primitive mesenchymal cell
2. spindle shaped with long tapering processes, oval nucleus and one or two defined nuclei, eosinophilic cytoplasm; generally found near collagen bundles
3. make and secrete fibers and ground substance of CT ECM such as collagen, elastin, GAG's and PG's and adhesive glycoproteins |
|
|
Term
| what is the most common connective tissue cell? |
|
Definition
|
|
Term
| role of fibroblast in scar tissue |
|
Definition
| injured tissue fills with empty space that are filled with fibroblasts; signals causes inactive fibrocyte to activate and stimulate the synthetic activities and make protein fibers and ground substance. myofibroblasts are used when filling in smooth muscle; responsible for wound closure |
|
|
Term
adipose cell:
1. origin
2. appearance
3. function |
|
Definition
1. primitive mesenchymal cell
2. spherical, large (120 micrometeres), contains a huge fat droplet with a thin rim of cytoplasm; resembles signet ring
3. stores neutral triglycerides; fatty acids and glucose enter here from the blood and are converted to TAG and remain here for 4 days on average; broken down during fasting; balanced by the autonomic system and hormones |
|
|
Term
|
Definition
| found in newborns and hibernating animals with multiple small fat droplets and lots of mitochondria; rapidly metabolize lipid to make heat |
|
|
Term
|
Definition
| form of obesity due to excessive fat accumulation in tissue cells that become abnormally large |
|
|
Term
|
Definition
| form of obesity due to excessive fat accumulation in tissues cells due to an increase in adipocyte number |
|
|
Term
| what are the immigrant cells of CT? (7) |
|
Definition
1. mast cell
2. polymorphonuclear leukocytes (neutrophils, PMN)
3. monocyte
4. macrophage
5. lymphocyte
6. plasma cell
7. eosinophil |
|
|
Term
Mast cell:
1. origin
2. appearance
3. function |
|
Definition
1. stem cells in bone marrow (hematopoietic origin)
2. oval cytoplasm with neutral granules in H &E stain but purple with thiazine dyes, small central nucleus, condensed chromatin
3. stores and releases chem mediators of inflammation; part of host defense by secreting granules in resposne to local stimuli such as physical trauma, radient energy, chemical agents; |
|
|
Term
| what do the granules of mast cells contain? |
|
Definition
| heparin (anticoagulant), histamine (increases permeability of vascular endothelial cells), proteolytic enzymes |
|
|
Term
Polymorphonuclear leukocyte: neutrophil
1. origin
2. appearance : LM and EM |
|
Definition
1. bone marrow by the blood stream; half of all neutrophils can be found sticking or marginating to capillaries
2. LM: round, 9 micrometers, multilobed nucleus, lots of minute granules that stain with neutral dyes like Wright's stain
EM: large, dense primary granules or lysosomes, smaller, less dense secondary or specific granules |
|
|
Term
| what can a marginated neutrophil do? |
|
Definition
| migrate between endothelial cells (diapedesis) into connective tissue |
|
|
Term
| What is the function of polymorophonuclear cells? |
|
Definition
rapid defense system and phagocytosis; the neutrophil recognizes bacteria coated by a serum complement or IgG and then surrounds it with cytoplasmic extensions that fuse and internalize it in a phagosome.
digested with primary and secondary lysosomes; dead bacteria are incompletely digested and persist as residual bodies; neutrophil cannot make more receptors or more granules and is committed to die |
|
|
Term
monocyte:
1. origin
2. appearance
3. function |
|
Definition
1. bone marrow by the blood
2. kidney-shaped nucleus with lots of cytoplasm, inconspicuous azurophilic granules
3. population of potential macrophages to CT |
|
|
Term
what are the special abilities of monocytes?
(4) |
|
Definition
1. motile
2. responds to chemotactic factors that neutrophils respond to
3. marginates and enters CT more slowly at 1-2 mm per day
4. phagocytosis but only after futher differentiation into a macrophage |
|
|
Term
| select the immigrant connective tissue cell that best fits the description. a young adult male suffers from severe hayfever symptoms. His allergist swabs his nasal secretions and reveals a homogenous population of leukocytes. |
|
Definition
|
|
Term
| most epithelia are supported immediately beneath the basement membrane by which connective tissue type? |
|
Definition
| loose (areolar) connective tissue |
|
|
Term
macrophage:
1. origin
2. appearance
3. functions |
|
Definition
- helps in process of antigen presentation
1. monocytes
2. small, irregular nucleus with nucleolus and extensive cytoplasm with variety of particles and vacuoles
3. a) defense to ingest and kill bacteria and fungi coated wwith IgG or serum b) garbage collection to ingest damaged and sensecent cells, dead bacteria, etc c) store wastes in residual bodies like carbon, tar, etc |
|
|
Term
| what are the special functions of macrophages? |
|
Definition
| mature in CT to give tissue macrophages with distinct morphologies and names depending on where they are; relatives include kupffer cells, langherans, dendritic cells, osteoclasts, Hofbauer cells, microglial cells |
|
|
Term
where are these cells found:
1. Kupffer cells
2. Langerhans cells
3. dendritic cells |
|
Definition
1. liver
2. skin
3. lymph nodes |
|
|
Term
where are these cells found:
1. osteoclasts
2. Hofbauer cells
3. microglial cells |
|
Definition
1/ bone
2. placenta
3. nerve |
|
|
Term
lymphocyte:
1. origin
2. appearance
3. functions |
|
Definition
1. bone marrow or lymphatic nodules in CT
2. LM: 8 micrometers, round nucleus, scanty rim of cytoplasm, nucleus is deformed in tight areas, surface membrane has short, irregular microvilli
EM: clumped chromatin (cartwheel appearance), free cytoplasmic ribosomes
3. immunologic; T and B lymphocytes |
|
|
Term
| Function of T lymphocytes |
|
Definition
| make direct contact with foreign cells, viruses, fungo, and certain bacteria and initiate cell-mediated immune response |
|
|
Term
| Function of B Lymphocytes |
|
Definition
| stimulated by contact with antigen, divide and produce cells that differentiate into plasma cells |
|
|
Term
| what are the special abilities of lymphocytes? |
|
Definition
| they are motile and migrate through endothelium and epithelium carrying receptor sites for antigens on the surface membrane |
|
|
Term
Plasma cell:
1. origin
2. appearance
3. function |
|
Definition
1. B lymphocyte in CT
2. LM: oval basophilic cytoplasm with more cytoplasm than in lymphocytes, round nucleus in eccentric place, clumped chromatin in cartwheel pattern, central nucleolus, golgi is a pale area near the nucleus
EM: abundant RER, juxtanuclear golgi
3. make and secrete large quantities of specific immunoglobulins up to 2000 molecules per second |
|
|
Term
eosinophil:
1. origin
2. appearance
3. function |
|
Definition
1. bone marrow by the bloodstream
2. LM: 9 micrometers in diameter, bi-lobed nucleus, cytoplasm has refractile eosinophilic granules
EM: membrane-bound granules with dense crystalloid amorphous matrix
3. in response to mast cells it participates in responding to allergies and parasitic infections with larger numbers in blood and CT; the matrix of granules have lysosomal enzymes like histaminidase and they phagocytose Ag-Ab complexes |
|
|
Term
| what are the three types of connective tissue proper and examples of each? |
|
Definition
1. loose (areolar) ordinary CT (mesentery)
2. dense irregular CT (skin-dermis)
3. dense regular CT (tendons, ligaments, cornea of eye) |
|
|
Term
| loose (areolar) CT - what is it made of? describe ground substance and cells |
|
Definition
| made of collagen fibrils and elastic fibers that are irregularly arranged; lots of ground substance and many cells |
|
|
Term
loose (areolar) CT:
1. cells
2. ground substance
3. collagen
4. blood vessels
5. mechanical properties
6. location |
|
Definition
1. numerous
2. abundant
3. none, moderate, random
4. numerous
5. flexible and not resistant to stress
6. next to epithelium's lamina propria, around BV's and glands |
|
|
Term
| how are the collagen fibers arranged in dense irregular CT? how are elastic fibers arranged? |
|
Definition
collagen - rough lattice parallel to the skin surface
elastic - random |
|
|
Term
dense irregular CT:
1, cells
2. ground substance
3. collagen
4. blood vessels
5. mechanical properties
6. locations |
|
Definition
1. few
2. small amount
3. non-parallel, predominant
4. few
5. resistant to stress
6. dermis, organ capsules, periosteum, perichondrium
**chiefly collagen |
|
|
Term
| dense regular CT in tendons and ligaments: collagen and elastic fibers? |
|
Definition
collagen - parallel thick fibers with fibroblast nuclei and small blood vessels between fibers
elastic - varying amounts |
|
|
Term
| dense regular CT in cornea of eye: collage and elastic properties |
|
Definition
collagen - precisely arranged sheets of collagen in matrix of GAG's
elastin - none |
|
|
Term
dense regular CT:
1. cells
2. ground substance
3. collagen
4. blood vessles
5. mechanical properties
6. location |
|
Definition
1. few
2. small amount
3. parallel, predominant
4. few
5. resistant to stress
6. tendons, ligaments |
|
|
Term
| what are 5 types of specialized connective tissues? |
|
Definition
1. blood
2. bone
3. cartilage
4. adipose
5. reticular CT |
|
|
Term
|
Definition
tissue rich in plasma and cells
- transport of nutrients, hormones and bicarbonate |
|
|
Term
|
Definition
tissue rich in mineralized osseous tissue
- major structural and supportive CT in the body forming the skeleton |
|
|
Term
| cartilage: made of what kind of CT and what are the three classifications? |
|
Definition
| type of dense irregular CT classified as hyaline, elastic or fibrocartilage |
|
|
Term
|
Definition
rich in adipocytes
- cushioning, thermal insulation, lubrication in the pericardium, energy storage |
|
|
Term
|
Definition
rich in reticular fibers
- form soft skeleton for support lymphoid organs like lymph nodes, bone marrow and spleen |
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