Epithelium and Connective Tissue Flashcards
Metaplasia
any tranformation from one type of cell to another in adult tissues
goblet cell
mucus secreting cells in respiratory and intestinal tract
Dysplasia
changing of cells that leads to disease
desmosome/macula adherens
anchor cells to neighbors by ‘spot welds’
Defensins
cationic proteins that live on skin and kill fungi, bacteria and viruses
Connexons
make up gap junctions
CFTR (cystic fibrosis transmembrane conductance regulator)
allow chlorine and thyocyanate across epithelial cells. If you have problems with this protein, you have cystic fibrosis.
Carcinoma
cancerous epithelial cells. Anti-keratin antibodies are important in diagnosing carcinomas.
brush border
microvilli for absorption
basement membrane
Thin layer of ECM between epithelium and connective tissue
basal lamina
basement membrane (under electron microscopy)
zonula occludens/tight junction
junction of two cells that ensures transport and controls permeability of epithelium
zonula adherens
velcro belt, anchors cells to neighbors, plays role in cytoplasmic mobility
terminal web
apical surface in cells with microvilli. Contracts and opens up microvilli to aid in absorption.
terminal bar
attaches epithelial cells on lateral and apical surfaces.
Serous
benign, pale yellow body juice
Keratin
intermediate filaments, tough, form a network.
Connective tissue is derrived from
mesenchyme
4 types of resident connective tissue cells
adipose, fibroblas, mast cells, macrophage
4 types of transient connective tissue cells
lymphocytes, plasma cells, neutrophils, eosinophils
Resident connective tissue cells are derived from
mesenchymal cells (stem cell)
transient connective tissue cells
hemapoetic stem cells
basics of wound healing
Inflammation- neutrophils
Proliferation-from basal layer and fibroblasts from LCT and macrophages
and maturation— restoration from stem cells
consequences of fibrosis rather than normal healing
fibroblasts turn into myofibroblasts, if you get too many you leave a tissue scar.
Fibrosis occurs when?
PERSISTENT tissue damage, and you get replacement of cells and GS with fiber, so you have a less-functional organ (liver, kidney etc)
Type 1 collagen
most abundant type of collagen, forms bundles, ex. dermis, fibrocartilage, bone, tendons (Strength, but not flexibility) resist stretch, provide tensile strength
Type 3 Collagen
Type of collagen that there are no bundles,
ex. stroma of smooth muscle, loose connective tissue in endocrine glands and liver, etc. reticular fibers
dense connective tissue
Lots of fibers, fewer cells. Irreg will be in deeper dermis, organ capsules, submucosa of the intestine. Reg will be tendons and ligaments
glycosaminoglycans (GAGs)
linear chains of repeating disaccharides, Negatively charged, look like bottle brushes, resist compression
granulation tissue
makes up wound tissue while healing. Mostly fibroblasts and myofibroblasts
ground substance consists of
consists of GAGs, proteoglycans, and glycoproteins) and fluid
function of ground susbstance
where you store electrolytes and water, resist compression, attach and move cells in ECM, form fluid barrier
loose connective tissue
areolar connective tissue, lots of cells, few fibers.
Glycoproteins
globular proteins,short branched carbohydrates, connect cells to ECM via integrin receptors.
Eg. Fibronectin and laminin- found at basement membrane
proteoglycan
GAGs with Hyaluronic acid attached to protein backbone to form proteoglycans
plasma cells
- derived from B lymphocytes - produce antibodies
- short lived (10days); “clock-faced” nucleus
parenchyma
the tissue of an organ that is there for the actual function of the organ; usually makes up bulk of the organ
mast cell
- derived from precursors in bone marrow
- inflammatory response, histamine, long life
macrophage
- derived from monocytes
- sense damage and wound repair
- long lived
lymphocytes
- b lymphocytes froduce plasma cells
- t lymphocytes - helper and cytotoxin cells
- long lived
focal adhesion complex
mechanical linkage to ECM
-actin binds to integin that binds to basement membrane
integins
transmembrane receptors that are the bridges of cell to cell and cell to ECM interactions
what is disrupted in oral squamous carcinoma?
desmosomes
adenocarcinoma
cancer of the glands
transient amplifying cells
Stem cells in epithelium. When signaled to reproduce, they become “transient amplifying cells” usually found in the basal layer. Transient amplifying cells then differentiate into different tissue cells
hemidesmosomes
attach one cell to the extracellular matrix
Typical locations for Simple low/squamous
capillaries and alveoli of lungs
Typical locations for Simple columnar
Stomach and small intestine
Typical location for Psuedostratified columnar epithelium
respiratory tract (respiratory epithelium)
Typical locations for stratified squamous
skin, esophagus, mouth, vagina
Typical locations for Stratified cuboidal
sweat glands, mammary glands, salivary glands
Location for Stratified columnar epithelium
male urethra
barrier epithelia examples
oral muscoa, urinary system, upper respiratory tract, skin, gut
Connexons are made up of 6 __________.
Connexins
transcytosis
transporting across interior of cell
Endothelium
Thin layer of cells lining the blood vessels
Stroma
tissue other than the parenchyma; include blood vessels, nerves, CT, etc.
Mnemonic for the other name of desmosomes (spot welds)
macula adherens: “imMACULAte–without SPOT” (spot welds)
Tropocollagen
subunit of collagen fibrils consisting of three polypeptide strands arranged in a helix
elastic fibers
Straight fibers with core protein (elastin) surrounded by glycoprotein (fibrillin)
integrin
proteins that function mechanically, by attaching the cell cytoskeleton to the extracellular matrix (ECM), and biochemically, by sensing whether adhesion has occurred
