Epithelial Cells

Front 1

change in the normal expression of 1+ CAMs can lead to...

Back 1

... pathologic alteration during tissue differentiation or maturation.

Front 2

Epithelial cells - general characteristics

Back 2

- closely apposed and tightly adherent (cell-to-cell - adhesion molecules)
- functional & morphologic polarity (usually)
- avascular: supplied by blood vessels in the underlying CT

Front 3

3 "sides" of the epithelial cell

Back 3

these sides constitute the polarity of the epithelial cell:
- apical surface: free surface; will face lumen if applicable
- basal surface: attaches to the basement membrane
- lateral surface: typically attaches to the adjacent cell

Front 4

what 2 tissue types have cell-to-cell adhesion molecules?

Back 4

epithelial and muscle

Front 5

classification of epithelial cells is based on 3 things

Back 5

cell shape, number of cell layers, surface specializations
NOTE: histological classification refers only to cell shape and # of layers

Front 6

squamos

Back 6

Flat; width greater than height; Nuclei usually also horizontal to surface

Front 7

cuboidal

Back 7

Width, height, depth about equal

Front 8

columnar

Back 8

Height significantly greater than width

Front 9

simple

Back 9

1 layer

Front 10

stratified

Back 10

multiple layers; classified based on the uppermost layer of cells (closest to lumen)

Front 11

transitional

Back 11

rounded, dome shaped cells in the top layer

Front 12

what is the arrow pointing to?

Back 12

basal lamina = basement membrane

Front 13

simple squamous - functions

Back 13

exchange, lubrication and barrier

Front 14

simple squamous - locations

Back 14

blood vessels & lymphatics (endothelium)
endocardium
body cavities (mesothelium)
Bowman's capsule of renal glomerulus
alveoli (lung)

Front 15

ID the cells indicated by the arrow

Back 15

simple squamous (Bowman's capsule)

Front 16

ID the epithelial cells

Back 16

simple squamous (alveoli)

Front 17

ID the epithelial cells; ID the tissue

Back 17

simple squamous (blood vessel)

Front 18

simple squamous - nuclei

Back 18

elongated and oriented in the direction of the cytoplasm
in blood vessels, the endothelial cells will orient longitudinally in the direction of the blood flow. a cross section of a vessel will also show a cross sectional cut of the nucleus (it will look round rather than cigar-shaped): will appear round and will protrude into the lumen

Front 19

simple cuboidal - functions

Back 19

barrier, conduit
absorption
secretion

Front 20

simple cuboidal - locations

Back 20

small exocrine gland ducts
kidney tubules
thyroid follicles
surface of ovary

Front 21

simple cuboidal - nucleus

Back 21

often oriented vertically in the cell

Front 22

ID the epithelial cells (H&E)

Back 22

simple cuboidal (renal tubules)

Front 23

ID the epithelial cells (H&E)

Back 23

simple cuboidal (salivary gland duct)

Front 24

simple columnar - functions

Back 24

absorption
secretion

Front 25

simple columnar - locations

Back 25

small intestine
colon
stomach lining & gastric glands
gallbladder

Front 26

ID the epithelial cell (H&E)

Back 26

simple columnar (mucosa of duodenum)

Front 27

ID the epithelial cell (H&E)

Back 27

simple columnar (gastric gland)

Front 28

What is this cell (the smaller, dark spot)?

Back 28

small lymphocytes that are moving toward the lumen: present as small, round dark nuclei scattered through this layer. They are scouting for any foreign invaders (immunosurveillance) that might try to breach the barrier and gain entrance into the body. They have heterochromatic nuclei because they have not yet been stimulated. It they encounter an invader, they have the capability to unravel their chromatin (becoming more euchromatic) and begin transcribing the relevant genes needed for a response to the threat.

Front 29

stratified squamous - function

Back 29

barrier, protection

Front 30

stratified squamous - location

Back 30

epidermis, Oral cavity, Esophagus, Vagina, Distal urethra

Front 31

stratified squamous - structure

Back 31

-consist of several distinct layers of cells
-shape and height of the cells vary from layer to layer
-only the shape of the uppermost layer is used to classify the type of epithelium
- may be cornified

Front 32

keratin

Back 32

- key structural material making up the outer layer of skin, hair and nails
- Keratin monomers assemble into bundles to form tough, insoluble intermediate filaments
- water resistant protein that forms a protective barrier against the destructive forces of the environment
- found in straiefied squamous epithelial tissue

Front 33

keratinization of cells

Back 33

-cells which have undergone keratinization have an abundant amt of keratin filaments in their keratinocytes in the cornified layer of their epidermis
-process of keratinization leads to cell death.
-topmost layer of the epidermis is composed of many layers of dead, scalelike cells lacking nuclei that eventually slough off and are lost.

Front 34

stratified squamous epithelial cells in _____________ will NOT have the distinct keratin (cornified) layer

Back 34

moist cavities; eg. the oral cavity
cell DO contain keratin but FEWER keratin intermediate filaments
retain their nuclei

Front 35

ID the epithelial cell (H&E) - be specific

Back 35

tongue: "noncornified" stratified squamous

Front 36

ID the epithelial cell (H&E) - be specific

Back 36

skin: cornified stratified squamous

Front 37

stratified cuboidal - functions

Back 37

barrier
conduit

Front 38

stratified cuboidal - locations

Back 38

-large ducts (sweat, salivary glands)
-junction btw pseudostratified columnar and stratified squamous (urethra, anorectal junction)
- stratification isn't uniform from one place to another.
-As the duct enlarges it becomes more likely that a section will show very clearly stratified epithelium

Front 39

ID the epithelial cell (H&E) - be specific

Back 39

stratified cuboidal - salivary duct

Front 40

stratified columnar - functions

Back 40

protection, conduit, secretion

Front 41

stratified columnar - locations

Back 41

-large ducts of compound glands
- conjunctiva: thin membrane that covers the inner surface of the eyelid and the white part of the eyeball (the sclera)
-transitional zones

Front 42

ID the epithelial cell (H&E) - (ignore the arrows & box)

Back 42

conjunctival mucosa - stratified columnar

Front 43

ID the structure indicated by the 2 arrows

Back 43

goblet cells

Front 44

pseudostratified epithelium

Back 44

- single layer of cells (simple) siting along the basement membrane
- not all cells reach the free surface - look stratified
-gives the impression of multiple cell layers

Front 45

ID the 3 structures ID by the black markers

Back 45

top to bottom: goblet cell, columnar ciliated cell, basal cell

Front 46

pseudostratified epithelium - functions

Back 46

secretion
absorption
conduit

Front 47

pseudostratified epithelium - locations

Back 47

tracheal, large bronchi, ductus deferens, efferent ductules of epididymis

Front 48

ID the epithelial cell (H&E) - be specific

Back 48

tracheal mucosa - ciliated pseudostratified columnar epithelium

Front 49

ID the epithelial cell (H&E) - be specific

Back 49

ductules of epididymis - stereociliated pseudostratified columnar epithelium

Front 50

to classify an epithelium you must always look for...

Back 50

a region of the section showing the simplest, edge-on appearance

Front 51

villus

Back 51

finger like structure that projects into the intestinal lumen.
The structure has a core of connective tissue ensheathed on all sides by epithelium.

Front 52

ID the epithelial cell (H&E); specify what the arrows are pointing to

Back 52

- instestinal villus - simple columnar epithelium
Note how epithelium on the right side (arrow) looks pseudostratified due to angle of section - plane of section

Front 53

transitional epithelium

Back 53

A.k.a. urothelium – lines lower urinary tract
Modifications to allow epithelium distension
stratified epithelium composed of basal and dome-shaped cells
Rounded surface of the apical cells is distinguishing characteristic - contracted
the presence of a few binucleated cells along the surface may help to ID transitional cells

Front 54

characteristic appearance of a transitional upper layer cells - EMPTY bladder

Back 54

appear to be cuboidal with a domed apex

Front 55

characteristic appearance of a transitional upper layer cells - FULL bladder

Back 55

tissue actually compresses and the cells become stretched, and they appear to be flat, irregular, and squamous.

Front 56

ID the epithelial cell; specify what the black lines are labeling; NOTE. the 2 lines on the R label the same cell type

Back 56

transitional epithelium (urinary bladder)
L-> R
Basal cell
Dome-shaped columnar cell
plaques: plaques of aggregated proteins are found on the apical plasma membrane of the columnar cells

Front 57

what 2 cell types make up transitional epithelium?

Back 57

Basal cell: attach to the basal lamina
Dome-shaped columnar cell: extend from basal laminam to the lumen

Front 58

transitional epithelial cells - function

Back 58

barrier
distensible property

Front 59

transitional epithelial cells - location

Back 59

renal pelvis
ureters
bladder
proximal urethra

Front 60

What type of epithelial tissue is this? What distinguishes top tissue from the bottom tissue? What does this mean?

Back 60

- hard to ID transitional epithelium from stratified squamous or cuboidal wo knowing the tissue source
- things to look for:
-- in relaxed bladder: uppermost layer cells will often have a dome-shaped (aka umbrella cells), bulging into bladder lumen
-- presence of a few binucleated cells along the surface may help identify cells as transitional
TOP: contracted bladder
BOTTOM: distended bladder

Front 61

ID the epithelial cell (H&E) and explain how the ID is determined.

Back 61

transitional epithelium:
- dome shaped umbrella cells in upper (luminal) layer positively ID transitional - CONTRACTED
- if this tissue were to distend, upper layer would become squamous

Front 62

ID epithelial tissue (H&E)

Back 62

simple columnar epithelium (gallbladder)

Front 63

ID epithelial tissue (H&E)

Back 63

cornified stratified squamous epithelium (skin)

Front 64

ID epithelial tissue (H&E)
what is the white tissue in the lower right corner?
what is the name for the darkest basophilic band bordering the white region?

Back 64

noncornified stratified squamous epithelium
white tissue = CT
basophilic band = basement membrane

Front 65

types of apical domain modifications

Back 65

cilia, primary cilia (monocilia), microvilli, stereocilia

Front 66

cilia - traits

Back 66

short, fine, hair-like structures
microtubule core
basal bodies anchor them
protrusions of the cell's plasma
motile - move in unison

Front 67

cilia - location

Back 67

Mucociliary clearance in airways
Oviducts: Move ova & fluid toward uterus
Sperm (flagellum)
brain: move CSF

Front 68

basal body

Back 68

modified centriole that gives rise to the cilia
anchors the base of each cilia and allows it to rotate or bend
contains a foot that is always oriented in the drxn of the ciliar stroke

Front 69

ID apical domain modification

Back 69

cilia

Front 70

cilia structure

Back 70

- 9 microtuble doublets ring around periphery of cilia
-- one of which is incomplete and shares portion of wall w the other microtubules
-- doublets linked by nexin
- 2 microtubles at the center of the microtubule
-- radial spokes bind the outer doublets to the inner pair

Front 71

cilial doublets are linked by...

Back 71

nexin

Front 72

what binds the outer doublets to the inner pair in cilia?

Back 72

radial spokes

Front 73

what drives cilia movement

Back 73

dynein motor proteins

Front 74

explain the process by which dynein causes movement in cilia

Back 74

sends “arms” out from each double, and forms temporary cross bridges with the adjacent microtubule.
uses ATP to move along surface of adjacent microtubule
facilitates sliding of the microtubules against each other
dependent on calcium.
as the microtubules slide, the cilium eventually bends as the ends of the microtubules are anchored inside the cell by the basal body

Front 75

ID this structure

Back 75

cilium cross section

Front 76

monocilia

Back 76

aka primary cilia
nonmotile
9+0 arrangment: lack the central pair of microtubules; lack dynein

Front 77

what is a structural difference between monocilial and cilial and what does it result in?

Back 77

monocilia lack motility, the central microtubule doublet, and motor proteins

Front 78

which apical domain modification plays a role in the left hand anatomical arrangement of organs

Back 78

monocilial

Front 79

Nonmotile cilia are present in...

Back 79

many types of mammalian cells
cells lining all part of the kidney
found in sensory organs (eg. retina & nose)

Front 80

monocilia and the kidney

Back 80

monocilia line all parts of the kidney and act as mechanoreceptors containing Ca++ channels
normal dev of thekidney depends on the ability of monocilia to detect fluid flow and initial Ca++ influx

Front 81

cell polarity properties are associated with...

Back 81

the apical (modifications; directed towards the lumen, enclosed cavity or tube), lateral (cell-to-cell junctions) and basal (basement membranes) domains of a cell
depending on cell type, organelles may be positioned more toward 1 side of a cell

Front 82

defects in 2 genes that control development of the kidney monocilia have been linked to...

Back 82

development of polycystic kidney disease in which cysts develop in the kidney, expanding and ultimately destroying the kidney parenchyma, leading to renal failure

Front 83

cilium and rods/cones

Back 83

of the vertebrate retina; possess a primary cilium equipped with an expanded tip called the outer segment, which is specialized for the reception and transduction of light.

Front 84

nodal cilia

Back 84

special 1o cilia; play a role in the L-R anatomic location of internal organs
unlike normal monocilia, CONTAIN motor proteins (dyneins or kinesins): CCW rotational movement
gastrulation: nodal cilia in primitive node generates a leftward flow that is detected by the sensory receptors on the L side of the body --> different signaling mechanisms on the L side of the embryo compared to the right

Front 85

immotile or absent cilia during gastrulation ...?

Back 85

development sensory changes do not occur --> random placement of internal organs

Front 86

ID this structure

Back 86

monocilia; aka nonmotile cilia; aka primary cilia

Front 87

microvilli - overview

Back 87

-present on most epithelial cells
-most numerous and best developed in gastrointestinal & renal epithelial cells
-striated or brushed border appearance
-may contain specific enzymes
-- eg. in the gastrointestinal tract, Es resp for digestion of carbs are found in the microvilli

Front 88

ID this apical modification

Back 88

brush border of intestinal mucosa

Front 89

ID this tissue

Back 89

renal tubule epithelial cells

Front 90

microvilli - structure

Back 90

contain a core of actin filaments
- anchored to villin in tip
- extend downward to apical cytoplasm and anchors to horizontal actin fibers in the terminal web
-- stabilized by spectrin (anchors term web to apical cell membrane)
- actin filaments cross-linked by actin bundling proteins: fascin and fimbin
-- provides support and gives rigidity to microvilli
- myosin I binds actin to plasma membrane of microvilli

Front 91

microvilli - contractile ability

Back 91

-provided by myosin II, tropomysoin, calmodulin (Ca-binding molecule) in terminal web
-cause apex of cell to contract, making the microvilli spread apart, increasing the intermicrovillous space

Front 92

stereocilia - location

Back 92

epididymis, proximal ductus deferens, sensory (hair) cells of the ear

Front 93

stereocilia - overview

Back 93

unusually long, immotile microvilli
structurally similar to microvilli except arise from an apical protrusion and have thick stem portions interconnected by cytoplasmic bridges -> makes them appear branched
ID: aggregate into pointed bundles - look like hairs of a paint brush

Front 94

ID this apical modification

Back 94

stereocilia

Front 95

ID this apical modification

Back 95

stereocilia

Front 96

4 kinds of cell junctions

Back 96

3 types on the lateral surface of the cell:
- occluding junctions
- anchoring junctions
- communicating junctions (gap junctions)
1 basal surface junction:
-hemidesmosomes

Front 97

where junction is found exclusively on the basal surface?

Back 97

hemidesmosomes

Front 98

T/F: cell junctions are restricted to epithelial cells

Back 98

FALSE: cell junctions can be found in all 4 major tissue groups (nervous, muscle, CT and epithelial)?

Front 99

Cell adhesion molecules (CAMS)

Back 99

mechanical stability and structural integrity:
- cell-to-cell & cell-to-ICM adhesion
linked with IC filaments & actin that are part of cellular cytoskeleton
major role in cell proliferation and migration.
All stages of tissue differentiation that occurs during embryonic development is defined by the expression of specific CAMs on the cell surface.

Front 100

changes in the normal expression of 1 or more CAMs can lead to...

Back 100

pathologic alteration during tissue differentiation or maturation

Front 101

4 classifications of CAMs

Back 101

cadherins, intergrins, selections, immunoglobulin superfamily

Front 102

cadherins

Back 102

Ca++ dependent CAMs located mainly in the zonula adherens

Front 103

integrins

Back 103

CAMs that interact w extracellular matrix molecules such as collagen

Front 104

selectins

Back 104

CAMs found on WBCs (leukocytes) and endothelial cells

Front 105

immunoglobulin superfamily (IgSF)

Back 105

glycoproteins w a wide variety of functions incudling cell adhesion, differentiation, angiogenesis (new blood vessel formation), microbial attachment, inflammation, neoplasia (formation of new tissue), and tumor metastasis

Front 106

zonula occludens - function

Back 106

aka tight (occluding) junctions
-located in apical region of the lateral surface of the cell
-prevent the passage of molecules and ions through the space btw cells - ensures that materials must enter the cells to pass through the tissue
-prevent the movement of integral membrane proteins btw the apical and basolateral surfaces of the cell - preserves the polarity of the cell's surfaces
-particularly impo in epithelial cells that serve as a physiologic barrier

Front 107

zonula occluden - structure

Back 107

-contain transmembrane proteins embedded in both plasma membranes that join each other
- junction is formed into a band that goes around entire apical perimeter
-major cell adhesion molecules: claudins & occludins
-CAMS bind actin & regulatory and signaling proteins called PDZ-domain proteins
-tightness of junction depends on # of protein strands

Front 108

what are PDZ-domain proteins?

Back 108

regulatory and signaling proteins involved in the structure and function of PDZ-domain proteins

Front 109

identify this structure

Back 109

zonula occluden

Front 110

tight epithelia

Back 110

-contain tight junctions that prevent water and solute movement
-distal convoluted tubule
-collecting duct part of the kidney

Front 111

leaky epithelia

Back 111

-lack tight junctions or have less complex tight junctions
-tight junctions in kidney proximal tubule have only 2--3 junctional strans -> leaky

Front 112

zona adherens

Back 112

- anchoring junctions btw cells to guard against physical disruption of the barrier
-- E-cadherin binds cells
-- require Ca++
-junction forms a band that completely encircles that apical perimeter of the cell
- req'd by tissues needing a strong attachment: skin, cardiac
-- typically contain numerous anchoring jnxns btw cells
-cell membranes will be separated by regular extracellular space
-cytoplasmic face is linked to the actin cytoskeleton (terminal web)
- 3 types

Front 113

term: zonula, in reference to junctions

Back 113

means that the junction completely encircles the region/face of the cell on which it is attached
- eg. zonula adheren and occluden: band completely encircles the apical perimeter

Front 114

ID the prominent structure

Back 114

zonula adheren; anchoring junction

Front 115

3 types of zonla adherens

Back 115

zonula adherens - belt desmosome
fascia adheren
macula adherens or desmosome

Front 116

demosome

Back 116

aka macula adherens
-impo in epithilial that acts as physical barrier: skin, cardiac
-anchoring jnxn btw cells
- cytoplasmic side of plasma mem: demosomal attachment plaque (disc-shaped dense structure)
--made from demoplakins and plakoglobins
-- anchors intermediate filaments (loop through plaque and extend back into cyto)
-ECM-side of plasma: transmembrane glycoproteins hold adjacent cells together: desmoglein & desmocollin
-- extend through intercell space and bind to glycoprotein on adjacent cell
-- (Ca-dependent) cadherin CAMs

Front 117

intercellular bridges

Back 117

-demosomal attachments btw stratified squamous cells of the skin
- preparation of skin tissue w formalin causes epithelial cells to shrink and pull apart; where demosomes are present, the cells remain in contact
-RESULT: lines between squamous cells = intercellular bridges

Front 118

ID the intercellular structure

Back 118

intercellular bridges = desmosome

Front 119

desmoglein 1

Back 119

Ca-binding transmembrane glycoprotein component of desmosomes in vertebrate epithelial cells

Front 120

pemphigus foliaceus & pemphigus vulgarus

Back 120

autoimmune diseases that target the desmoglein proteins (3 and 1, respectively) causing disruption to the desmosome-keratin filament complex leading to a breakdown in cell adhesion
-symptoms: pustular eruptions w hair loss and crust

Front 121

junctional complex

Back 121

epithelia of most glands and cavitary organs have a characteristic tripartite junctional complex found between adjacent cells where apical margins touch:
- zonula occluden jnxns: water-tight seal around the apex of the columnar epithelial cells
- zonula adjerens jnxns: attaches adjacent cells firmly together
-(often) a number of desmosomes btw zonula adherens
VISUALIZE: terminal bar: dark line near (and parallel to) the apical membrane of the cells

Front 122

ID this structure

Back 122

junctional complex = terminal bar
intestine: terminal bar is just below the brush border

Front 123

ID the structure that encompasses this enter intercellular area

Back 123

junctional complex
ZA: zonula adherens
D1 & D2: desmosomes
TW: terminal web
actin filaments insert into the SA and intermediate filaments (IF) insert into the desmosome

Front 124

hemidesmosomes

Back 124

variant of desmosome
- desmosomal plaque w desmoplakin-like protein
- CAM = integrin class of matrix receptor
provides stable connection between cell and CT (compare cell-to-cell w desmosome)
most common in tissue subject to abrasion and mechanical shearing:
- oral cavity & esophagus
- cornea
- skin

Front 125

gap junctions

Back 125

aka communicating junctions
- grp of transmembrane pores
-- connexins form communicating channels
-- undergo reversible conformational changes that open/close their pore
--- "close" = Ca
- mediate the diffusion of small signaling molecules btw cells
- coordinate activity btw adjacent cells:
-- cardiac m
-- smooth m
-- tubular epithelial c

Front 126

ID the structure indicated

Back 126

communicating jnxn = gap jnxn

Front 127

basement membrane - composition

Back 127

collagen (depending on the cell: type IV, III, VII, XVII), fibronectin, laminins, proteoglycans (esp heparin sulfate)

Front 128

basement membrane - overview

Back 128

anchors the basal surfaces of epithelial cells to the underlying CT
found in epithelial cells, muscle cells, peripheral nerves, and adipose tissue
aka basal lamina

Front 129

basement membrane - functions

Back 129

-anchors epithilieum/endothelium to underlying CT
-filtration
-guide for call adhesion and migration
-regulation and signaling

Front 130

laminins

Back 130

-lg trimeric proteins w a, B, gamma chain
-part of the basement layer
-influence cell differentiation, migration and adhesion

Front 131

fibronectin

Back 131

glycoprotein that exists as a dimer
binds to EXM components, such as collagen, and to grp of membrane spanning receptor proteins called integrins
-binding helps it to play a role in cell adhesion and migration

Front 132

reticulofibers

Back 132

aka reticulin
a type of fiber composed of type III collage

Front 133

ID the various structures (H&E)

Back 133

DC: distal convoluted tubule
PC: proximal convoluted tubule
BB: brush border
basement membrane is hard to visualize

Front 134

visualizing the basement membrane

Back 134

not readily seen in H&E
better visualized w PAS (magenta) and silver stain (black)

Front 135

ID the magenta layer

Back 135

PAS stain; basement membrane
renal tubules

Front 136

ID the black ring

Back 136

silver stain; basement membrane
renal tubules

Front 137

basement membrane - location

Back 137

epithelia
smooth, cardiac, skeletal m cells
adipocytes
neurolemmocytes = Schwann cells

Front 138

2 types of glands

Back 138

exocrine and endocrine

Front 139

exocrine glands

Back 139

secrete via ducts opening to a surface

Front 140

endocrine glands

Back 140

secrete into surrounding blood vessels

Front 141

Starting at the top and working CW, ID the tissue types/structures within the 4 dashed circles

Back 141

Top: exocrine duct
lower R: islet cells (endocrine)
lower L: exocrine cells

Front 142

types of secretion

Back 142

serous & mucinous

Front 143

serous secretion

Back 143

-thin, watery secretion
-glands have pink secretory granules in apical salivary gland
eg. pancreas, parotid salivary gland

Front 144

mucinous secretion

Back 144

thick, viscous secretion
mucin stains light blue
nuclei flattened against basal part of cell

Front 145

mucins

Back 145

-family of high MW, heavily glycosylated proteins produced by epithelial tissues
-mucins' key characteristic is their ability to form gels
-key componeny in most gel-like secretions
-functions: lubrication, cell signaling, chemical barriers
VISUALIZE: PAS stains carbs magenta, including glycoproteins that make up mucin

Front 146

what secretory gland is this (based on secretion types)

Back 146

parotid gland - serous secretion

Front 147

what secretory gland is this (based on secretion types)

Back 147

mandibular salivary gland - mucinous secretion

Front 148

goblet cells

Back 148

-only unicellular gland in the mammalian body
- contain mucin in a protective function
locations: nasal turbinate epithelium, salivary glands, gastric mucosa, colon

Front 149

gland classification based on structure

Back 149

simple vs compound

Front 150

simple gland

Back 150

-gland classification based on structure
-cluster of secretory cells that connect to unbranched duct
simple tubular, coiled tubular, branched tubular, branched acinar

Front 151

compound gland

Back 151

-gland classification based on structure
-branching system of ducts w multiple secretory units
surrounded by CT capsule that sends partitions inside the gland to organize it into large units called lobes
--lobes are further subdivided into lobules
-parenchyma can be divided into aggregates of secretory units: lobes, lobules, acini
-compound tubuloacinar, tubular, acinar

Front 152

ID this structure (H&E)

Back 152

goblet cell

Front 153

ID this structure (PAS)

Back 153

goblet cell

Front 154

tubular gland

Back 154

has a tube-shaped secretory portion;
secretory portion may be straight, branched or coiled;
wall of the tubule are parallel w relatively wide lumens

Front 155

acinar

Back 155

aka alveolar
has a globe-shaped secretory portion w a small lumen
secretory portion may be single or branched

Front 156

ID this structure and tissue type

Back 156

simple tubular
large intestine

Front 157

ID this structure and tissue

Back 157

simple coiled tubular
sweat gland

Front 158

ID this structure and tissue

Back 158

compound tubular
brunners glands, duodenum

Front 159

ID this structure and tissue

Back 159

compound tubuloacinar
tracheal glands

Front 160

gland classification based on secretion

Back 160

eg. exocrine pancreas - merocrine secretion
apocrine gland & mammary gland - apocrine secretion
sebaceous gland - holocrine secretion
paracrine gland - type of hormone function in which hormone synthesized in and released from endocrine cells and binds to its receptor in nearby cells (rather then entering the blood stream), affecting their function

Front 161

merocinre secretion

Back 161

secretory prod is delivered in membrane-bound vesicles to the apical region of the cell where they fuse and release their content by exocytosis
eg. pancreatic acinar cells

Front 162

apocrine secretion

Back 162

secretory prod is released at the apical region of the cell surrounded by a thin layer of cytoplasm surrounded by a protion of the cell membrane
eg. mammary glands, ceruminous glands of the ear canal

Front 163

holocrine secretion

Back 163

secretory product accumulates wi the cell which undergoes apoptosis
both secretory product and remains of the dead cell are discharged into the lumen of the gland

Front 164

paracrine secretion

Back 164

type of hormone function in which hormone synthesized in and released from endocrine cells and binds to its receptor in nearby cells (rather then entering the blood stream), affecting their function