HISTO LAB - CT Flashcards
– responsible for providing and maintaining form
CONNECTIVE TISSUE
-made up mainly of non-living material, extracellular matrix
CONNECTIVE TISSUE
-matrix: physically links cells and tissues, gives mechanical support to the different organs
CONNECTIVE TISSUE
-contains blood vessels and nerves; serves the needs of avascular epithelium
CONNECTIVE TISSUE
CT component
CT Cells originate from —————–
precursor cells in primitive mesenchyme
ct fibers are made up of
proteins and polysaccharides
most abundant protein in the human body
collagen
-key element of all CT, basement membrane, external laminae of muscles and nerve cells
collagen
-synthesizes collagen and reticular fibers
collagen
CT fiber
may be arranged as parallel fibers or discontinuous sheets
-has properties of stretching and elastic recoil
elastin
GS is hydrophobic or hydrophilic
hydrophilic
-form a medium for the passage of molecule throughout supporting tissues
ground substance
-for the exchange of metabolites with the circulatory system
ground substance
-gel-like: serves as lubricant, barrier to invasive microorganism
ground substance
embryonic CT which originates from the mesoderm and neural crest ectoderm
- Mesenchymal CT
Mesenchymal CT originates from?
mesoderm and neural crest ectoderm
fibers of Mesenchymal CT
uniformly distributed sparse collagen fibers (reticular type)
cells of Mesenchymal CT
undifferentiated mesenchymal cells (a homogenous population of cells but may also have stem/progenitor cells)
transient type of tissue
mucoid CT
LOCATION OF MUCOID CT
-location: umbilical cord and fetal organs
-matrix of mucoid ct
jelly-like
-fibers: mucoid ct
delicate network of collagen fibers
-cells:mucoid ct
scattered star-shaped fibroblasts (w/ flattened processes that appear to fuse with neighboring cells)
-ground substance: mucoid ct
soft, very abundant, appears homogenous in fresh state, composed chiefly of hyaluronic acid
-residue: contains granules and fibrillar precipitates when fixed; exhibits staining reactions of mucin
mucoid CT
– most widely distributed CT
- Loose/Areolar CT
CT found in almost every microscopic section of the body
- Loose/Areolar CT
-fills up empty spaces
- Loose/Areolar CT
-serves as packing and anchoring material
- Loose/Areolar CT
-supports epithelium where it encompasses the lamina propia (thick layer beneath the epithelial lining of stomach and intestines)
- Loose/Areolar CT
- flexible, but not very resistant to stress
- richly supplied with blood vessels, lymphatic vessels and nerves
- Loose/Areolar CT
-cells of loose ct:
holds a collection of all types of cells, more abundant than fiber
-ground substance of loose ct:
moderate
-cells: adipocytes which may be isolated, in small groups (loose and dense irregular CT), in large aggregates (fat)
- Adipose CT
-efficient thermal insulators
- Adipose CT
-primary storage site for neutral fats (triglycerides)
- Adipose CT
-key regulators of the body’s overall energy metabolism
- Adipose CT
- shock absorbers
- richly vascularized
- Adipose CT
-cells of adipose ct:
adipocytes which may be isolated, in small groups (loose and dense irregular CT), in large aggregates (fat)
– spherical
- large due to the presence of a single lipid droplet
- nucleus appears flattened, displaced on one side
- surrounded by reticular fibers
*Adipocyte
what fibers surround an adipocyte
reticular
*As the number of adipocytes grow, they are pushed aside these fibers forming the ————- (where other CT cells and blood vessels are located).
fibrous septum
2 Types of Adipose Tissue
– found only in fetus, newborn, hibernating animals
-function: heat production during the first months of postnatal life
- Brown or Multilocular
2 Types of Adipose Tissue
20% of body weight
-function: reserve energy source through homeostatic mobilization & mobilization of triglycerides
- White or Unilocular –
- forms the supportive stroma of lymphoid organs, hematopoietic bone marrow and endocrine glands
- Reticular CT
-fibers of Reticular CT:
reticular fibers (Type III) which anastomose forming a delicated 3D closed-meshed network: lattice fibers
-cells of reticular ct:
reticular cells (modified fibroblasts)
-elements create a cell-lined system that allows passage of lymphocytes and lymph
Reticular CT
- contains most of the components found in loose CT
- but has more fibers and fewer cells
DENSE CONNECTIVE TISSUE
-orientation and arrangement of collagen bundles make it resistant to stress
DENSE CONNECTIVE TISSUE
– densely packed coarse Type I collagen
-fibers and cells oriented into parallel cylinders
- Dense Regular CT
– main functional component of tendons and ligaments
• Dense regular collagenous or fibrous CT
is Dense regular collagenous or fibrous CT vascular or not
AVASCULAR
-cells of dense reg collagenous ct:
fibrocytes (appear stellate when the tendon is cut in cross section, sometimes termed tendinocytes)
– occurs infrequently
Dense elastic CT
-location of dense elastic
yellow ligaments (ligamentum flava) of vertebral column, suspensory ligaments of penis
fibers of dense elastic
-thick elastic fibers with thin collagen fibers + flattened fibroblasts
cells of dense elastic
-fibroblasts branch frequently and fuse with one another
-ground substance of dense elastic:
scanty
-individual fibers are surrounded by a network of reticular fibers
what type of ct
Dense elastic CT
– collagen fibers forming unaligned 3D meshwork
Dense Irregular CT
function of Dense Irregular CT
-function: provide resistance to stress in all directions (because of the haphazard arrangement)
location of Dense Irregular CT
-location: fasciae, reticular region of dermis, periosteum, joint capsules, membrane capsules around kidneys, liver, testes, lymph nodes, heart valves
ground substance of Dense Irregular CT
-ground substance: scanty, located between fibers and cells with some bv
cells of Diffuse Lymphoid CT
-cells: irregularly scattered in a loose manner lymphoid cells
stroma of Diffuse Lymphoid CT
reticular fibers + reticular cells
location of Diffuse Lymphoid CT
inter-nodular, deep cortical, medullary regions of lymph nodes
Peri-arteriolar lymphoid sheath of spleen
Nodular regions of tonsils and Peyer’s patches
CT with closely packed lymphoid cells
Dense lymphoid CT
– compact, circumscribed condensations of lymphocytes
Lymph nodules
– pale central portion of lymph nodules, with large lymphocytes showing mitotic figures;
Germinal center of Flemming/ Secondary nodules
site of active production of lymphocytes (but newly formed cells die locally and are disposed by macrophages)
Germinal center of Flemming/ Secondary nodules