Lab 3 Epithelial Cells

Question 1

apical surface

Answer 1

surface of an epithelial cell facing the lumen or external environment

Question 2

basal surface

Answer 2

surface of an epithelial cell facing the basement membrance

Question 3

basement membrane

Answer 3

formed from the epithelial and underlying connective tissue. composed of non-cellular layers of collagen, glycoproteins and glycans. aids in attachment of the epithelial tissue and as a selective barrier to underlying connective tissue

Question 4

lumen

Answer 4

central cavity or open space within an organ

Question 5

what are the four types of epithelial cells

Answer 5

squamous (flat), cuboidal, columnar, transitional (changes shape from polyhedral to flat)

Question 6

simple epithelium

Answer 6

one layer of epithelial cells, all cells in contact with basement membrane

Question 7

stratified epithelium

Answer 7

two or more layers of epithelial cells

Question 8

pseudostratified epithelium

Answer 8

appears layered due to the cells’ nuclei being distributed at different levels betweeen apical and basal surfaces

Question 9

epidermis

Answer 9

outer layer of skin

Question 10

dermis

Answer 10

between epidermis and subcutaneous later

Question 11

subcutaneous

Answer 11

below dermis

Question 12

stratum basale

Answer 12

deepest epidermal layer

Question 13

stratum corneum

Answer 13

most superficial later of the skin

Question 14

stratum granulosum

Answer 14

three to five layers of keratinocytes superficial to the stratum spinosum

Question 15

stratum spinosum

Answer 15

between stratum granulosum and stratum basale

Question 16

keratinization

Answer 16

keratinocytes synthesize significant amount of protein keratin

Question 17

simple squamous epithelium

Answer 17

single layer of thin flat cells, relatively flat nucleus of each cell bulges at center
thinnest possible barrier to allow for rapid diffusion and filtration, secretion in serous membranes
air sacs in lungs, lining of lumen of blood vessels and lymph vessels, serous membranes of body cavities (mesothelium)

Question 18

simple cuboidal epithelium

Answer 18

single layer of cells cuboidal cells, spherical and centrally located nucleus
absorption and secretion, forms secretory tissue of most glands and small ducts
lining of kidney tubules, thyroid gland follicle, surface of ovary, secretory regions and ducts of most exocrine glands

Question 19

simple columnar epithelium

Answer 19

single layer of cells taller than they are wide, oval shaped nucleus orientated lengthwise in basal region of cell, apical surface may have microvilli or cilia, may contain goblet cells
absorption and secretion, secretions of mucin and movement of mucus or oocyte in ciliated
lining of most gastrointestinal tract, lining of bronchioles and uterine tubes in ciliated

Question 20

pseudostratified columnar epithelium

Answer 20

single layer of cells with varying heights, all cells connect to basement membrane but not all the apical surface. nonciliated has goblet cells, celiated does not
protection, secretions of mucin and movement of mucus in ciliated
lining of larger airways of respiratory tract including nasal cavity, part of pharynx larynx trachea and bronchi, rare-lining of male urethra and epididymis in nonciliated

Question 21

transitional epithelium

Answer 21

epithelial appearance varies, depending on whether tissue is relaxed or distended, relaxed epithelium has cuboidal or polyhedral cells, and the apical cells are large and rounded, whereas distended has flattened cells at the apical surface, some cells are binucleated
accommodates urine volume changes in bladder, ureters, part of urethra
bladder, ureters, part of urethra

Question 22

keratinized stratified squamous epithelium

Answer 22

multiple cell layers; basal cells are cuboidal or polyhedral and alive, whereas apical cells are squamous, lack a nucleus, are filled with keratin, and are dead
protection of underlying tissue from abrasion
epidermis of skin

Question 23

nonkeratinized stratified squamous

Answer 23

multiple cell layers; basal cells are cuboidal or polyhedral, whereas apical cells are squamous; all cells are living; each cell contains nucleus and organelles and lack keratin; superficial cells kept moist
protection of underlying tissue from abrasion
lining of oral cavity, part of pharynx and larynx, esophagus, lining of vagina, and anus

Question 24

stratified cuboidal

Answer 24

two or more layers of cells; cells at apical surface are about as tall as they are wide
protection and secretion
ducts of most exocrine glands and ovarian follicles

Question 25

stratified columnar

Answer 25

two or more layers of cells; cells at apical surface are taller than they are wide
protection and secretion
large ducts of salivary glands; conjunctiva covering the eye; lining of the membranous part of male urethra