Epithelial Tissue Worksheet

Front 1

Explain the following characteristics of epithelium:
Polarity
Avascular
Apical surface specializations

Back 1

-different sides of the cell have different characteristics and perform different functions
-no blood vessels pass between epithelial cells
-the apical surface often has special features such as microvilli or cilia

Front 2

What are the differences between cilia and microvilli?

Back 2

Cilia are long fingerlike extensions from the apical surface, and have a core of microtubules and exhibit
synchronized movements, allowing the cells to move materials over that surface in the extracellular space.
Microvilli are short extensions off the apical surface, increasing the surface area of the plasma membrane, usually allowing the cells more transport activity across that surface of the cell.

Front 3

What is the difference between an endocrine gland and an exocrine gland?

Back 3

Endocrine glands secrete their products into the extracellular fluid; the products diffuse to nearby blood vessels and are carried away in the bloodstream. Exocrine glands secrete their products directly into ducts, pipes which carry the secretions toward a particular location and onto the epithelial surface at that organ.

Front 4

What is a goblet cell?

Back 4

A goblet cell is a single gland cell interspersed among other epithelial cells in a sheet of epithelial cells. The
goblet cell produces mucous

Front 5

epithelium

Back 5

a layer of tightly adjoining related cells
(sheets of cells)
-physical protection
-control permeability
-provide sensation
-produce specialized secretions
located on body surface, lines all hollow structures in body glands

Front 6

polarity

Back 6

cells tightly linked with neighbors (sided-ness)

Front 7

apical

Back 7

often has special features such as microvilli or cilia
-free or exposed surface

Front 8

basil

Back 8

surface anchored to connective tissue

Front 9

basement membrane

Back 9

attaches to underlying surface (connective tissue layer)

Front 10

microvilli

Back 10

don't move. movement of stuff across cell membrane
small fingerlike projections
-on one surface of an epithelial cell (100s/cell)

Front 11

cilia

Back 11

all beat in same direction
-surface of a cell,
rhythmical movement

Front 12

gap junction

Back 12

proteins extend between cells and form a pore connecting the cytoplasm of one cell with the cytoplasm of the adjacent cell, allowing rapid and direct movement of ions between cells

Front 13

tight junctions

Back 13

The plasma membrane of one cell is directly linked by proteins right against the surface of the adjacent cell, leaving no extracellular space between the cells

Front 14

desmosomes

Back 14

proteins link one cell to another across the extracellular space, but there is space between cells for materials to move. Anchor cells together rather than “fusing” them together

Front 15

lateral interdigitations

Back 15

membranes of adjacent cells form complex, interlinking networks; the cells are not physically linked, but the interlocking membranes hinder the movement of materials in the space between the cells.

Front 16

squamous

Back 16

broad, flat cells

Front 17

cuboidal

Back 17

cube-shaped

Front 18

columnar

Back 18

narrow, taller than wide

Front 19

simple epithelium

Back 19

single layer of cells. one cell thick

Front 20

stratified epithelium

Back 20

multiple cells thick

Front 21

gland

Back 21

cells of epithelial line which are specialized to produce and secrete materials outside the cells

Front 22

exocrine gland

Back 22

secrete through ducts onto the surface of the organ

Front 23

endocrine gland

Back 23

release hormones into surrounding fluid to be picked and carried away by the blood

Front 24

secretory vesicle

Back 24

membrane bound vesicle derived from Golgi apparatus, containing material that is to be released from the cell

Front 25

merocrine

Back 25

product is packing into secretory granules, released from cell by exocytosis
mechanism of glandular secretion

Front 26

holocrine

Back 26

the entire cell bursts, releasing product. cells dies and must be replaced
-mechanism of glandular secretion

Front 27

apocrine

Back 27

apical portion of cell is shed, taking product with it
glandular secretion mechanism

Front 28

unicellular gland

Back 28

single cell glands
-secretory cells embedded among an epithelium

Front 29

multicellular gland

Back 29

large accumulations of secretory cells