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)
Where is type IV collagen found? where did it originate? What is the tissue properties like?
Basal lamina
Epithelial cells, muscle cells, schwann cells
Support and filtration of basal lamina
Which collagen type is network forming?
IV
What type of collagen is highly glycosylated and known as reticular fibers?
collagen type III
What do you call defects in collagen synthesis?
collagenopathies
What can lead to Ehlers-Danlos type IV?
What are the symptoms?
faulty transcription or translation of type III collagen
aortic and/or intestinal rupture
What can lead to Ehlers-Danlos type VI? What are the symptoms?
Faulty lysine hydroxylation
augmented skin elasticity, rupture of eyeball
What can lead Ehlers-Danlos Type VII? What are the symptoms?
decrease in procollaen peptidase activity increased articular mobility (ability to move joints) frequent luxation (displacement of joints) ie rubber band joints
What can lead to scurvy? what are the symptoms?
Lack of vitamin C (cofactor for proline hydroxylase)
ulceration of gums, hemorrhages
What can lead to osteogenesis imperfecta? What are the symptoms?
change in one nucleotide in genes for
collagen type I
-Spontaneous fractures, cardiac insufficiency
(blank) are composed of elastin and microfibrils (fribillin).
elastic fibers
(blank) is a family of proteins which provides the scaffolding for the deposition of the elastin core. Mutations in the fibrillin gene results in (blank).
Fibrillin
Marfan syndrome
What is an amorphous material that imparts a high degree of elasticity characteristic of elastic fibers. These fibers may be stretched to 150% of their resting length without breaking. Their elasticity is due to the protein elastin. and their stability is due to the presence of microfibrils.
elastin core
What makes up the entire elastic fiber?
microfibrils and elastin core
what makes up the microfibrils?
fibrillin
What can be organized into groups, networks, or sheets/membranes (allowing for uniform dilation and constriction as in blood vessels.) ?
elastic fibers
Where can elastic fibers be synthesized?
fibroblasts, smooth muscle cells, and chondrocytes
When you see black fibers what can you assume they are?
elastic fibers.
(blank) is a systemic disorder of connective tissue with a high degree of clinical variability. Cardinal manifestations involve the ocular, skeletal, and cardiovascular systems. People are at increased risk for retinal detachment, glaucoma, and early cataract formation. The skeletal system involvement is characterized by bone overgrowth and joint laxity. The extremities are disproportionately long for the size of the trunk (dolichostenomelia). Overgrowth of the ribs can push the sternum in (pectus excavatum) or out (pectus carinatum). Scoliosis is common and can be mild or severe and progressive. The major sources of morbidity and early mortality are related to the cardiovascular system.
marfan syndrome
Stroma of the lymph node stained with silver are what kind of fibers?
reticular fibers
What are the types of fixed (resident) CT cells?
Fibrocytes (Chondrocytes, Osteocytes)
Fibroblasts (Chondroblast, Osteoblast)
Adipose Cells
Mast Cells
Macrophages (Osteoclast)
Pericytes
-stem cells for CT
-role in angiogenesis
& hypercellular obesityWhat are the types of free (transient) cells?
Plasma cells Lymphocytes Neutrophils Eosinophils Basophils Monocytes Macrophages
what are the major producers of fibers and ground substance in connective tissues. Depending on the environment, what other cells can produce fibers and ground substances?
fibroblasts
osteoblasts and chondroblasts
(blank) are euchromatic (i.e. their DNA is constantly being replicated) as are “blast” forms of other cells. They are primarily found in embryonic tissue and sites where formed connective tissue has been traumatized and undergoing repair.
fibroblasts
(blank) are heterochromatic so their nuclei stain very dark. They are capable of maintaining formed connective tissue.
Fibrocytes
Where do you find plasma cells?
scattered throughout connective tissues. Present in greatest number in chronic infammation and where foreign subtances or microorganisms have entered the tissues.
What are plasma cells derived from?
B lymphocytes
What do plasma cells do?
What kind of nucleus do they have?
When they have been activated with antigen, produce and secrete antibodies.
clock face
(blank) are derived from circulating monocytes. They differentiate upon entry into connective tissue.
Macrophages
What are the two varieties of macrophages?
fixed and free
Are macrophages part of the mononuclear phagocytic system (MPS)?
yes
What are these characteristics of?
Phagocytic or Antigen Presenting Cell
Phagocytosis may be immune or non-immune
mediated
macrophages
macrophages, osteoclasts,microganglia, langerhans cells are all part of the (blank)
mps
what does a mast cell look like?
granulated with an eyeball
What does this describe:
They are derived from progenitor cells in the bone marrow.
Possess granules containing histamine, heparin and others considered to be primary mediators
They degranulate with secondary exposure to an allergen
Capable of synthesizing secondary mediators
mast cells
what is the primary response of mast cells?
What is the secondary response?
IgE binding to Fc receptors
Secondary Response
Antigen crosslinks IgE molecules
Granules released (primary mediators)
Secondary mediators released
What do white fat cells look like?
look clear and white with red nucleus along outsides like a ring, unilobular
what does a white fat cell function in?
functions include calorie storage, insulation, protection, hormone production (leptin and adiponectin)
When are the number of fat cells determined?
perinatally (before birth)
Is distribution of white fat cells genetically determined and gender specific?
yes
What are some tumors of white fat cells?
lipomas, liposarcomas
white fat cell distribution is associated with various (blanks) succh as diabetes (males), heart disease (males) and breast cancer (females)
diseases
Where do you find brown fat cells?
around the neck and inter-scapular region
What does this describe:
Multilocular cells with abundant cytoplasm filled with great numbers of lipid droplets and mitochondria; the later responsible for the brown gross appearance
brown fat cells
(blank) have a different unilocular form of brown fat
adults
(blank) fibers are associated with brown fat. White fat only have (blank) associated with ONLY their blood vessels.
nerve
nerve
What Functions in thermogenesis by oxidation of fatty acids. Thermogenins allows for the uncoupling of oxidation from phosphorylation. Heat is made instead (of ATP) which is then transferred to capillaries.
fat cells-brown
where is dense regular connective tissue (type I collagen) found?
areas where tension is exerted in a single direction (tendons, aponeuroses, ligaments)
What are cords attaching muscles to bones?
tendons
What are flat sheets attaching muscles to bones or to other muscles?
aponeuroses
What attach bones together at joints and contain more elastic fibers then do tendons therefore more stretchy?
ligaments
in a vangesen stain, what stains red, with small spaces of white in between which have elongated nuclei?
collegen
Where is dense irregular connective tissue found?
where tension is exerted in many directions. i.e. skin, heart valves,Fibrous pericardium,
Perichondrium (membrane around the surface of cartilage),
Periosteum (membrane around the surface of the bone),
Fibrous capsules of organs and of joints.
where in the skin is dense irregular tissue found?
in the deeper layer of dermis and wall of digestive track. (forms submucosa.)
serves as a cushioning
layer throughout the
body
often associated with
adipose tissue
... What does this describe?loose connective tissue.
what connective tissue is flexible, well vascularized, has little tensil strength and can be found easily in hypodermis and lamina proprea?
loose connective tissue.
what color do elastin fiber apear as in a veroeff slide, and what color does collgen appear?
black
red
In the renal sinus, islands of (blank) are often surrounded by white adipose tissue, which emphasizes the different appearances of the two tissue types.
In brown adipose tissue, the nuclei of adipocytes are (blank). In addition capillaries are very frequent.
brown adipose tissue
are round and located more or less centrally in a cytoplasm
In an umbilical cord, what can you see?
large vessels, mucoid conective tissues (whartons jelly), simple squamos epithelium.
In mesenchymal connective tissue can be found in what?
dental pulp and in a fetal kidney
