Tissue Level of Organization Flashcards
what are Tissues?
- a group of cells with common embryonic origin that function together to carry out a specific function
Includes hard (bone), semisolid (fat - stores triglycerides) & liquid (blood, CSF, Lymph)
List the types of tissues
- Epithelial
- Connective (5 classifications)
- Muscular
- Nervous
Epithelial tissue
covers body surfaces, lines hollow organs, cavities ducts & forms glands
(5 classifications)
What type of tissue connects, supports & binds organs?
Connective tissue
What tissue generates physical force needed to move the body and generate body heat?
Muscular tissue
What tissue type detects changes in the body & responds by generating nerve impulses?
Nervous tissue
All tissue types form from which 3 things?
(Germ layers)
- Endoderm (GI tract, internal organs)
- Mesoderm
- Ectoderm
Epithelial tissues develop from all 3 germ layers
all connective and muscle tissue derive from the what?
mesoderm
the ectoderm creates what tissues?
Nervous tissue and skin
What is a biopsy?
A sample of living tissue taken:
-looking for cancer
-infections
-inflammatory processes
-connective tissue disorders
What are the 5 most common types of cell junctions?
- Tight junctions (linkers)
- Adherens junctions
- Desmosomes
- Hemidesmosomes
- Gap junctions
What type of junctions are common in epithelial tissues of the stomach, bladder, urinary & intestines?
Tight junctions
* prevent passage of substances between cells from leaking into surrouding tissues
* Transmembrane proteins fuse cells together (linkers)
Adherens Junction
- dense layer of proteins called plaque form adhesion belts that encircle the cell (found 1 in epithelial cells)
- resists separation of cells during contractile activities
- cadherins are transmembrane proteins that insert into the plaque
- located inside the cell & attach to both membrane proteins and microfilaments of the cytoskeleton
What are desmosomes?
- Contain plaque and
cadherins that extend into
the intercellular space to
attach adjacent cells - the plaque attaches to intermediate filaments that contain the protein keratin
- prevents epidermal cells from separating under tension & cardiac muscle cells from pulling apart during contraction
cell junction
Hemidesmosomes
cell junction
- Connects epithelial tissue to underlying tissue (fascia)
- anchors CELLS to BASEMENT membrane (NOT cells adjacent to cells)
- contains transmembrane glycoprotein integrin
- Integrins attach to intermediat filaments and the protein lamilin present in the basement membrane
resembles half a desmosome