Ch. 4: Histology- Epithelial Tissue(pg 1-6)

Question 1

the study of tissues

Answer 1

histology

Question 2

4 types of tissues

Answer 2

epithelial, connective, muscle, nervous

Question 3

embryonic tissues from which all tissues and organs of the body develop

Answer 3

primary germ layers

Question 4

the fertilized egg (or ______) undergoes multiple rounds of mitosis

Answer 4

zygote

Question 5

after a zygote has undergone multiple rounds of mitosis it becomes a multicellular ______

Answer 5

blastocyst

Question 6

3 germ layers

Answer 6

ectoderm, mesoderm, endoderm

Question 7

5 cell junctions

Answer 7

1. tight junctions
2. adherens junctions
3. desmosomes
4. hemidesmosomes
5. gap junctions

Question 8

feats of tight junctions

Answer 8

• forms seals b/w cells to prevent leakage of fluid b/w them
• web-like strip of proteins
• associated with epithelia covering a surface of an organ or lining a cavity that opens to the outside
• ex) skin, bladder, intestinal lining

Question 9

feats of adherens junctions

Answer 9

-composed of plaque, anchors to adjacent cells by transmembrane glycoproteins, form belts that encircle each cell, resists separation when tissue is stretched (intestine)

Question 10

feats of desmosomes

Answer 10

composed of plaque and transmembrane proteins linking adjacent cells, increase overall stability of cells, ex) epidermis of skin, intestinal lining, intercalated discs of cardiac muscle cells

Question 11

feats of hemidesmosomes

Answer 11

anchors one kind of tissue to another, ex) connects cell to basement membranes

Question 12

feats of gap junction

Answer 12

communicating junctions that permit electrical or chemical signals to pass from one cell to another, transmembrane proteins call connexons form these fluid filled channels, ex) join some neurons in the CNS (electrical synapses), heart muscle (intercalated discs)

Question 13

major types of epithelial tissue (2)

Answer 13

covering and lining, and glandular

Question 14

general characteristics of epithelial tissue (10)

Answer 14

• closely packed cells
• cells arranged in continuous sheets
• apical and basal surfaces
• cell junctions are plentiful
• it’s avascular (relies on diffusion on nutrients from underlying tissues)
• firmly adheres to basement membrane
• has a nerve supply
• high regenerative ability
• derived from all 3 primary germ layers
• has many funcs.

Question 15

feats of simple squamous epithelium

Answer 15

single layer of flattened cells, adapted for diffusion and filtration, ex) alveoli in lungs, lining of blood vessels

Question 16

feats of simple cuboidal epithelium

Answer 16

1 layer of square shaped cells, adapted for secretion and absorption, ex) pancreas

Question 17

what stain is used for staining cells

Answer 17

hematoxylin- purple (nuclei)
eosin- pink (cytoplasm)

Question 18

non-ciliated simple columnar epithelium feats

Answer 18

nonciliated simple columnar: adapted for secretion and absorption, includes cells with microvilli (increases absoption) and goblet cells (secrete mucus), ex) gastrointestinal tract

Question 19

epithelial lining of blood vessels and the heart

Answer 19

endothelium

Question 20

forms part of the serous membranes where it secretes serous fluid

Answer 20

mesothelium

Question 21

ciliated simple columnar epithelium feats

Answer 21

often have goblet cells, adapted to move fluids or particles along a passage, ex) upper respiratory tract, fallopian tubes and uterus

Question 22

feats of stratified squamous epithelium

Answer 22

adapted for protection, underlying cells may be cuboidal or columnar but top apical layer is squamous, ex) found in outer layer of skin, vagina, and mouth

Question 23

feats of stratified cuboidal epithelium

Answer 23

fairly rare, adapted for protection, top layer of cells are cuboidal, ex) found in male urethra

Question 24

feats of stratified columnar epithelium

Answer 24

underlying cells are cuboidal but top is columnar, adapted for protection and secretion, ex) male urethra, parts of anus and eye

Question 25

feats of pseudostratified columnar epithelium tissue

Answer 25

falsely stratified, nuclei at varying depths, 2 types (ciliated and nonciliated)

Question 26

feats of pseudostratified ciliated columnar epithelium

Answer 26

found in upper resp. tract, cells either secrete mucus or have cilia

Question 27

feats of transitional epithelium

Answer 27

allows expansion of the epithelial lining, variable appearance (from stratified squamous to stratified cuboidal), ex) lines urinary bladder, ureter, and urethra

Question 28

glandular epithelium function in ______ of substances

Answer 28

secretion

Question 29

a highly specialized epithelial cell or group of cells that secretes substances into a duct or surface, or into blood

Answer 29

gland

Question 30

2 types of glands

Answer 30

endocrine, exocrine

Question 31

feats of endocrine glands

Answer 31

secretes into extracellular fluid and then (usually) into blood, ductless, secretions are hormones

Question 32

feats of exocrine glands

Answer 32

secrete substances into a duct or onto the free surface of covering and lining epithelia, ex) mucus, sweat, oil, wax, digestive enzymes

Question 33

structural classification of exocrine glands (2)

Answer 33

unicellular glands (goblet cells), multicellular glands (many specialized cells, most are multicellular)

Question 34

functional classification of exocrine cells (3)

Answer 34

merocrine gland (mero= part or partial),
apocrine gland (apo= off, away),
holocrine gland (holo= entire, whole)

Question 35

what is the functional classification of exocrine glands based on

Answer 35

whether a secretion is a product of a cell or consists of entire or partial glandular cells themselves

Question 36

feats of merocrine, apocrine, and holocrine glands

Answer 36

Merocrine: most common exocrine gland, secretion is formed within cell and exits cell via secretory vesicle. ex) salivary glands, pancreas
Apocrine: secretion accumulates in apical portion of cell and eventually pinches off. ex) mammary glands
Holocrine: cell accumulates the secretion it dies and is discharged as part of the secretion. ex) sebaceous glands

Question 37

disorder of epithelial tissue in older people

Answer 37

Sjogren’s syndrome: autoimmune disease of exocrine glands —> dry eyes, dry mouth