5: Epithelia And Glands

Front 1

basement membrane

Back 1

layer which separates epithelium from underlying connective tissue and blood vessels

Front 2

zonula occludens

Back 2

a zone that surrounds the entire apical perimeter of adjacent epithelial cells; prevents movement of substances from the lumen to the intercellular space; formed be occludins, claudins, and actin

Front 3

fascia occludens

Back 3

ribbon-like fusion of the transmembrane proteins on adjacent endothelial cells lining capillaries; analogous to zonula occludens of epithelia

Front 4

zonula adherens

Back 4

the zone that surrounds the entire perimeter of epithelial cells, just basal to the zonula occludens; mediated by E-cadherin, vinculin, alpha-actinin and actin

Front 5

fascia adherens

Back 5

a ribbon-like adhesion zone present in intercalated discs in cardiac muscle; analagous to zonula adherens

Front 6

E-cadherin

Back 6

a transmembrane glycoprotein present in zonula adherens and fascia adherens

Front 7

macula adherens (desmosome)

Back 7

a small, discrete, disk-shaped adhesive site; contains dense plaque of desmoplakins and keratin filaments (intermediate filament)

Front 8

gap junction (nexus)

Back 8

adhesion between cells that couples them metabolically and electrically; made of six subunits of connexin

Front 9

basal lamina

Back 9

extracellular supportive structure of epithelium that contains collagen IV, laminin, entactin, and heparin sulfate; composed of lamina lucida/rara and lamina densa

Front 10

lamina rara/lucida

Back 10

layer of basal lamina that lies closer to the epithelial cells

Front 11

lamina densa

Back 11

layer of basal lamina that lies between the lamina rara/lucida and the reticular lamina; composed of collagen IV, glycoproteins and GAGs

Front 12

basement membrane

Back 12

term encompassing the basal lamina and the underlying reticular lamina

Front 13

hemidesmosome

Back 13

specialized junctions that resemble one-half of a desmosome; mediate adhesion of epithelial cells to the underlying ECM via cytoplasmic plaque, integrins, and collagen VII

Front 14

basal plasma membrane infoldings

Back 14

deep invaginations of plasma membrane of ion-transporting epithelia; compartmentalize mitochondria; bring ion pumps closer to energy supply

Front 15

microvilli

Back 15

fingerlike projections of epithelia (1micron) that extend into the lumen; composed of 30 actin filaments in core

Front 16

stereocilia

Back 16

long microvilli that are located in epididymus and vas deferens

Front 17

cilia

Back 17

actively motile processes extending from epithelia which propel substances along their surface; contain an axoneme

Front 18

axoneme

Back 18

arrangement of nine doublet microtubules uniformly spaced around two central microtubules; composed of dynein arms, radial spokes, central sheath, and nexin; arises from basal body during ciliogenesis

Front 19

dynein arms

Back 19

chains of dynein ATPase that are present on one member of each microtubule doublet of axoneme; interact with adjacent doublets

Front 20

radial spokes

Back 20

part of axoneme which extends from each of nine microtubule doublets towards the central sheath

Front 21

central sheath

Back 21

membrane that surrounds the two central microtubules in axoneme; regulates ciliary beat

Front 22

nexin

Back 22

an elastic protein of axoneme that connects adjacent doublet microtubules and helps maintain the shape of the cilium

Front 23

basal body

Back 23

a cylindrical structure located at the base of each cilium; consists of nine triplet microtubules arranged radially like a pinwheel; less complex than centriole

Front 24

parenchyma

Back 24

functional portion of secretory and ductal epithelial cells of a gland

Front 25

exocrine glands

Back 25

glands that secrete into a duct or onto a surface

Front 26

endocrine glands

Back 26

glands that secrete into the bloodstream

Front 27

paracrine glands

Back 27

glands that secrete into the local extracellular space

Front 28

mucus

Back 28

a viscous material secreted by glands that protects or lubricates cell surfaces

Front 29

serous secretions

Back 29

gland secretions that are watery and often rich in enzymes

Front 30

merocrine secretion

Back 30

secretion via exocytosis

Front 31

apocrine secretion

Back 31

secretion involving release of part of the apical cytoplasm with the contents

Front 32

holocrine secretion

Back 32

secretion involving release of the entire secretory cell

Front 33

immotile cilia syndrome

Back 33

a genetic defect that causes an abnormal ciliary beat or the absence of a beat; lack of dynein arms; associated with recurrent lower respiratory tract infections, reduced fertility in women, sterility in men

Front 34

carcinoma

Back 34

malignant tumors that arise from surface epithelia

Front 35

adenocarcinomas

Back 35

malignant tumors that arise from glands

Front 36

bullous pemphigoid

Back 36

an autoimmune disease in which antibodies against hemidesmosomes are produced; causes chronic blisters of the skin