Unit 4: Tissue level of Organization Flashcards
define histology
the study of tissue
define tissue
a group of cells working together to perform a function
define extracellular matrix (ECM)
non living part that are materials located between cells. Cells secreted it into the tissue and can be proteins, minerals, carbs, glycoproteins, water and gases.
define cell junction
points where membrane of adjacent cells meet
define polarity
superior and inferior regions of cells are different with respect to structure and function
define apical surface
superior region, the “exposed” surface. Can be exposed to outside of the body or to the hollow cavity of an organ. It faces away from the basement membrane. Can have cilia or microvilli
define basal surface
Inferior region; its “attached” surface. attached to basement membrane by hemidesmosome junction
define basement membrane
ECM layer between epithelial tissue and connective tissue. Duties include anchors, supports, and regulates exchange of material
define avascular
does not have blood supply, but obtains nutrient from connective tissue below it
define innervation(innervated)
Has a nerve supply
define squamous
a flat, scale like cell
define secretion (with respect to a gland)
send solutes out of cell
define cuboidal
a box like cells with a. round nucleus that tends to be in the center
define columnar
Tall rectangular cell that has a long, oval nucleus that usually hands by the basal surfce
define simple
sing layer of cell
define stratified
more than one layer of cell
define endothelium
inner lining of vessels and heart that reduce friction
define mesothelium
lining of ventral body cavity
define goblet cells
mucus secreting cells
define keratin (keratinized
Having keratin, a tough protein that provides strength, in apical layer. Dry apical layer because the protein dehydrates the tissue.
define gland
a structure that makes or secrets a product
define mesenchyme
embryonic tissue
define ground substance
a fluid, gel like, or almost solid substance made of nutrients, glycoproteins(bind cells to ground substance) and large polymers called GAGS (which regulate water balance)
define hyaluronic acid
a type of glycosaminoglycans (GAGs)
define chondroitin sulfate
Another type of glycosaminoglycans (GAGs)
define muscle fibers
Long fibrous cells
define intercalated disc
Thick areas of cell membrane that have gap junctions between adjacent cells
Compare and contract the structure and function of 3 types of cells junctions: tight junction, desmosomes (and hemidesmosomes,) and gap junctions: list where each type occurs in the body
Tight junction: no space between cells to prevent leakage and located where leaks are to be prevented like lining of digestive organs
Describe the 2 parts of a tissue: cells and extracellular matrix
Cells are the living parts. ECM is the non living part that is between the cells. Cells secret materials in the ECM.
Compare and contract the structure and function of 3 types of cells junctions: tight junction, desmosomes (and hemidesmosomes,) and gap junctions: list where each type occurs in the body
Tight junction: no space between cells to prevent leakage and located where leaks are to be prevented like lining of digestive organs
Desmosomes: ticken area of membranes (called plaque) that holds cell together. plate attaches to microfilaments or intermediate filaments. They prevent separation of cells and holds cells tougher as a sheet. Found in epidermis and cardiac muscles
Hemi desomomes” happy desmosome and is used to attach cell to basement membrane
Gap junction : channels that hold cell together that is used for chemical communication. found in muscles cells and nerve cells
What is the 6 functions of epithelial tissue
- separates tissues/structure and forms boundaries between them
- absorption and secretion
- filtration
- decking stimuli
- projection
- reduces friction
list 4 locations of epithelial tissue
- external body covering (skin)
- Covering outside of organ
- lining the inside of hollow orange
- glands
describe in detail the 6 characteristics of epithelial tissue
- cells are tightly packed with little ECM
- Cells junction hold cells together as sheets
- CT is always bellow the eptitheal tissue for support, nourishiment, and strength
- has polarity with apical to the exposed surface and basal to the attached surface
- avascular (no blood supply) and innervated (has nerve supply)
- fast regeneration rate
How are epithelial tissue named?
by number of tissue layer : simple (one) stratified (more than one) pseudo stratified (one layer but looks like more) and by shape squamous (flat, scale like) cuboidal (boxy like cell with rounded centered nucleus) and columnar (tall rectangular cell with long oval nucleus at basal surface
What is the function, location, and struck characteristically of simple squamous
one layer of squamous shaped cells that are thin and fragile. It allows materials to pass through, reduces friction and secretes serous fluids. Found innings, inner lining of vessels and heart, lining of ventral body cavity , and kidney tubules
what is the function location and structural characteristics of simple cuboidal
one layer of cuboidal cells that are rounded and can have cilia or microvilli. It is used for secretions, absorption, and to move extracellular substances across the membrane. Found ion kidney tubules, thyroid gland, bronchioles inland, and ducts of glands like salivary.
