Epithelial Tissues

Question 1

What are the three embryonic layers?

Answer 1

The ectoderm; the mesoderm; and the endoderm

Question 2

What is the Ectoderm?

Answer 2

The outermost of three primary germ cell layers in the very early embryo

Question 3

What is the Endoderm?

Answer 3

The innermost of three germ cell layers in the very early embryo

Question 4

What is the Mesoderm?

Answer 4

The middle of the three primary germ cell layers of the early embryo

Question 5

What are some examples of the tissues that grow out of the Endoderm?

Answer 5

Most of the alimentary canal; the respiratory tract; endocrine glands; urinary bladder and part of the urethra

Question 6

What is a tissue?

Answer 6

a group of cells with common functions

Question 7

What is an organ?

Answer 7

two or more tissues that work together to perform a particular function

Question 8

What are the four categories of tissues?

Answer 8

Epithelial: connective: muscular: nervous

Question 9

What are 6 characteristics of epithelial tissues?

Answer 9

cells are close together;form continous sheets;regenerative;avascular;free or apical surface; rest on a basement membrane

Question 10

What are three traits of simple squamous cells?

Answer 10

flat; one layer; found where diffusion and filtration occur

Question 11

What are three examples of tissues comprised of simple squamous cells

Answer 11

alveoli; capillaries; kidneys

Question 12

What are 3 traits of simple cuboidal cells?

Answer 12

cube like; one layer; spherical nucleus; function in secretion and absorbtion

Question 13

What are 4 traits of simple columnar cells?

Answer 13

column shapped; nucleous near base; may be ciliated; function in secretion and absorbtion

Question 14

What are 4 traits of stratified squamous cells?

Answer 14

top layer flat or squamous; basal layers cuboidal or columnar and growing activly; found in areas that need proection

Question 15

What are some examples of tissues comprised of stratified squamous cells?

Answer 15

skin; vagina; mouth; pharynx; esophagus; anal canal

Question 16

What are 3 traits of stratified cuboidal cells?

Answer 16

Rare; usually only two layers; mostly in the ducts of larger glands

Question 17

Where can stratified cuboidal cells be found in the body?

Answer 17

sweat glands, mammary glands

Question 18

What are 3 traits of Stratified Columnar cells?

Answer 18

rare; usually only two layers; mostly in the ducts of larger glands; only apical layer is columnar

Question 19

Where can stratified columnar cells be found in the body?

Answer 19

portions of the pharynx; the male urethra; the junction between the two other types of epithelia; and the lining of some glandular ducts

Question 20

What are Pseudostratified Columnar cells?

Answer 20

a single layer of cells of differing heights; some cells not reaching the surface; nuclei seen at different levels; may be ciliated and have mucous secreting cells

Question 21

What are the functions of Pseudostratified columnar cells?

Answer 21

secretes substances; particularly mucus; propulsion of mucus by ciliary action

Question 22

What are some of the locations of ciliated Pseudostratified Columnar cells?

Answer 22

the trachea; upper respiratory tract

Question 23

What are some of the locations of non-ciliated Pseudostratified Columnar cells?

Answer 23

sperm carrying ducts and the ducts of other large glands

Question 24

What are some characteristics of transitional epithelium?

Answer 24

basal cells cuboidal or columnar; surface cells dome shaped or squamouslike depending on degree of organ stretch; resembles both stratified squamous and cuboidal

Question 25

Where can transitional epithelium be found in the body?

Answer 25

the lining of the ureters; bladder; and part of the urethra

Question 26

What is the function of transitional epithelium?

Answer 26

to stretch readily; especially useful for the bladder which must stretch to accommodate urine

Question 27

What is a gland?

Answer 27

one or more cells that secrete a particular product

Question 28

What is a secretion?

Answer 28

an aqueous fluid that usually contains proteins but can also contain lipids or steroids

Question 29

What is an endocrine gland?

Answer 29

a gland that produces hormones and secretes directly into the extracellular space

Question 30

What are ductless glands?

Answer 30

endocrine glands

Question 31

What are exocrine glands?

Answer 31

glands that secrete their products onto body surfaces or into body cavities

Question 32

What are some examples of unicellular exocrine glands?

Answer 32

mucous cells and goblet cells

Question 33

Where are most unicellular exocrine glands found?

Answer 33

in the epithelial linings of the intestinal and respiratory tracts

Question 34

What is mucin?

Answer 34

a complex glycoprotein that dissolves in water when secreted

Question 35

What is mucus?

Answer 35

a combination of mucin and water which serves to protect and lubricate surfaces

Question 36

What are the two basic components of multicellular exocrine glands?

Answer 36

the epithelium derived duct and the secretory unit

Question 37

What are the structural classifications of multicellular endocrine glands?

Answer 37

based on the duct type (simple or compound) and their secretory type (alveolar;tubular; or tubuloalveolar)

Question 38

What are simple glands?

Answer 38

glands which have an unbranched duct

Question 39

What are compound glands?

Answer 39

glands which have a branched duct

Question 40

What are tubular glands?

Answer 40

glands whose secretory cells form tubes

Question 41

What are alveolar glands

Answer 41

glands whose secretory cells form small flasklike sacs

Question 42

What is a synonym for alveolar?

Answer 42

acinar

Question 43

What are merocrine glands?

Answer 43

glands which secrete their products by exocytosis as they are produced

Question 44

What are holocrine glands?

Answer 44

glands which accumulate their products within them until they rupture