7111 oral tissue EXAM 1

what are the four tissue classifications?

epithelial, connective, muscle, nervous

describe epithelial tissue general structure?

strongly attached sheets of polyhedral cells, little ECM, polar, AVASCULAR

where do we find epithelial tissue?

protective linings (protect: epidermis, absorb: intestinal, secrete: parenchymal)

describe connective tissue general structure?

many cell types, lots of ECM, VASCULAR

where do we find connective tissue?

attaching epithelial tissue (support and protection)

epithelial cells are polar, which end is which?

Apical- face lumen/space

Basal- face connective tissue (basement mem)

epithelial tissue is attached to CT by ___________.

basement membrane (ECM matrix)

what cell attachment anchors epithelial cells to the basement membrane?

hemidesmosomes (cell-ecm)

what are the layers of the epithelium? (from apical to basal)

lamina lucida, densa, and, fibroreticularis

what are significant types of epithelial cells?

• squamous, cuboidal, columnar

• simple or stratified (one or multilayer)

the ECM is made up of a ground substance, what type of molecules make this up?

proteoglycans

what are glycoproteins?

specialized proteoglycans. they are in the ECM ground substance, strong hydrophilic GAG chains

what important thing do glycoproteins in the ECM store?

growth factors

the ECM assists in healing of wounds with ________ and __________.

immune cells and growth factors

name the junctions/cell attachments that are CELL-CELL.

tight , adhesion, desmosomes, gap

name the junctions/cell attachments that are CELL-ECM.

focal, hemidesmosomes

what cell attachments bind to actin filaments?

tight, adhesion, focal

what cell attachments bind to intermediate filaments?

desmosomes, hemidesmosomes

what are the functions of tight junctions?

controls cell-cell signaling pathways = polarization and ions

more strands = impermeable (tighter)

what are the functions of adhesion junctions?

hold cells together, prevent overgrowth (contact inhibition)

cadherins (Ca dependant) on the outside, catinins on the inside

what are the functions of focal junctions?

hold cell-ecm and important for cell signaling

integrins instead of cadherins (cell signaling)

what are the functions of gap junctions?

propagate electrical signals

aqueous pores

what are the functions of desmosomes?

strong cell-cell anchors, protect against shearing

form dense e- plaques

what are the functions of hemidesmosomes?

strong cell-ecm attachment, especially at basement membrane

form dense e- plaques

where to CT cells originate from?

mesenchymal cells

CT is involved in scar formation, what is this process called?

fibrosis

what are the permanent CT cell types?

fibroblasts, adipocytes, macrophages, mast cells

what are the transient CT types?

plasma, lymphocytes, neutrophils, eosinophils

what are the components of the cytoskeleton?

microfilaments

intermediate filaments

microtubules

describe the functions of microfilaments?

thin actin filaments that facilitate contractile force w myosin, also for structure

describe the functions of intermediate filaments?

anchor and structure vimentin/actin filaments, non contractile

describe the functions of microtubules.

large tubulin tracts, facilitate vesicle movement (kinases)

what are fibroblasts?

major CT cell that produces collagen, elastin, and ECM

involved in tissue repair (as cells age, repair slows)

where is the only area in which fibroblasts participate in cell-cell connections?

PDL

how to fibroblasts interact with their environment?

cell-ecm (diff subtypes in the pulp, mucosa, pdl)

what is collagen?

triple helix, most abundant body protein, made by fibroblasts

what collagen types are prominent in dentin, pulp, and cartilage?

dentin: 1+3

pulp: 1+3

cartilage: 2

which collagen type has a chicken wire structure?

4

what are the types of CT?

loose, dense IR, dense REG

describe loose CT.

most abundant CT, mostly cells with little fiber.

offers support and form but not much structure.

describe dense regular CT.

mostly fibers, less cells

fibers fun in one direction (tendons and ligaments)

describe dense irregular CT.

mostly fibers, less cells

fibers in all directions for multidirectional movement

what is embryology?

study of prenatal development

what time period of prenatal development is the preimplantation period?

week 1-2 (fertilization to implantation)

what time period of prenatal development is the embryonic period?

weeks 2-8 (disk formation to gastrulation to folding)

what time period of prenatal development is the fetal period?

weeks 8+

what is a primordium?

the earliest indication of a tissue (each craniofacial structure has a primordium)

what happens during the preimplantation period?

1. diploid zygote formation (from two haploid gametes)

2. zygote cleaves and forms morula, further cleavage leads to blastocyst

3. cells move to form the blastocyst (embryoblast and trophoblast) and trophoblast cells absorb uterine fluid

4. trophoblast implants to uterine wall and bilateral disk formation begins

what generally happens during the embryonic period?

1. bilaminar germ disk formation

2. primative streak formation

3. gastrulation

4. folding (somite and neural tube)

when does patterning occur in development? what genes are involved?

embryonic period, HOX and MSX (involves spatial and temporal events like head/tail establishment)

what is induction?

groups of cells tell competent groups of cells to do something

• ex. differentiation, proliferation, and morphogenesis

cont embryonic period

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