Exocrine Glands- Sum 6

Question 1

exocrine glands function

Answer 1

1. secrete non-hormonal products
2. secrete enzymes, mucus, lipids
3. secretions released onto epithelial surface directly OR via ducts

most but not all will have ducts

Question 2

endocrine glands

function

Answer 2

1. secrete hormones
2. no ducts - secretions releaed into bloodstream OR intracellular space

Question 3

general structure of glands

Answer 3

1. parenchyma = functional portion
2. stroma = CT cover, dividers, scaffolding

Question 4

parenchyma

Answer 4

secretory units to secrete a product

ducts to transport product out of gland or modify the secretion

Question 5

stroma

Answer 5

collagenous CT- covers gland (external capsule) and divides it into lobes and lobules AND forms pathways (inward)

reticular CT forms internal 3D scaffold to surround and support indiv units

Question 6

general drainage

Answer 6

smallest ducts drain 1 secretory unit > merge into larger ducts

1-2 large ducts drain entire gland

will run in septae/trabeculae b/t lobules

Question 7

duct wall appearance

Answer 7

simple cuboidal or columnar
(largest are stratified cuboidal or columnar)

large circular or oval nuclei

Question 8

ways to classify exocrine glands

Answer 8

1. what it secretes/product
2. how it secretes/mode
3. morphology (# cells, shape and branching pattern)

Question 9

types of secretion products

Answer 9

1. mucous glands - secrete mucus
2. serous glands - enzymes in watery fluid
3. mixed/seromucous glands- cells of mucous and serous , intermed viscosity
4. sebaceous glands- sebum (oily, waxy)

Question 10

mucus components

mucous glands

Answer 10

mucinogen (glycoprotein) = mucin
rich in glycosylated proteins + some carbs

mucous acini = cell clusters each w/ central lumen

so PAS +

Question 11

mucous glands

function

Answer 11

protection (vs pathogens, particles, stomach acids)

lubrication

palatine glands of hard and soft palate

Question 12

serous glands

secretions

Answer 12

-rich in nonglycosylated + poorly glycosylated proteins
-primarily enzymes
-often antibodies

Question 13

serous glands

histology

Answer 13

round nuclei @ basal end or central

perinuclear cytoplasm is basophilic

apical cytoplasm is acidophilic (sec vesicles)

Question 14

mixed/seromucous glands

histology

Answer 14

both serous and mucous cells

serous demilunes are an artefact of formalin fixation

Question 15

serous demilunes

Answer 15

artefacts of formalin fixation
-mucinogens swell during prep > mucous cells in tissue swell and push nuclei to basal end = serous cell b/t 2 swollen mucous cells get squished outwards to periphery

only occur in mixed/seromucous acini

cell junctions still maintain lateral connections

Question 16

sebum

sebaceous glands

Answer 16

rich in lipids + FA’s + wax esters + squalene

Question 17

sebaceous gland

histology

Answer 17

sebum not pick up stain well

nuclei central and round
@hair follicles

Question 18

steroids on sebum

Answer 18

androgens stimulate
estrogens inhibit

Question 19

sebaceous gland histology

Answer 19

not pick up well so faint or non staining

nuclei central, round, euchromatic

look similar to mucous acini but nuclei are different

Question 20

types of secretion modes

Answer 20

1. merocrine (most common)
2. holocrine
3. apocrine

Question 21

merocrine secretion

Answer 21

via exocytosis so least destructive

almost every exocrine gland in the body

Question 22

apocrine secretion

Answer 22

apical end pinches off - moderate destruction
large amounts of complex protein/lipid mixture secreted at once

@mammary glands

apocrine SWEAT glands use merocrine secretion, not the same thing

Question 23

holocrine secretion

Answer 23

via cell disintegration so most destructive

@sebaceous glands only

Question 24

unicellular exocrine glands

classify morphology

Answer 24

goblet cells only
@epithelia lining respiratory and intestinal tracts

Question 25

multicellular exocrine glands

classifying morphology

Answer 25

secretory sheets
-no lumen or ducts

@smaller intraepithelial glands (small patches form indents ‘quasi lumen’ no ducts)

and complex multicellular glands (exocrine so true lumen and ducts)

Question 26

complex multicellular glands

detailed

Answer 26

-organized infolding off main epithelium
-both ducts (nonsecretory, conduit) and secretory units (syn product and secrete into lumen)

nearly every named exocrine gland in body

Question 27

tubular glands

Answer 27

secretory portion is a tube but can be straight, branched, or coiled

Question 28

acinar glands

Answer 28

acinus = any spherical exocrine secretory unit (acini plural) mucous/serous/seromucous/or sebaceous

small central lumen normal BUT if very large then = alveolar glands

solo or branched or adj to others

Question 29

tubuloacinar glands

Answer 29

both tubular and acinar portions

i.e Brunner’s glands @ duodenum

Question 30

myoepithelial cells function

Answer 30

contract entire secretory unit (acinus) to push secretions out and into duct toward luminal epithelium

rapid expression

@mammary glands, sweat glands, salivary glands, iris of eye

Question 31

myoepithelial cells histology

Answer 31

smooth muscle features
-keratin IFs + actin + myosin

connect to secretory cells w/ desmosomes and gap junctions

sit b/t secretory cell and BM

Question 32

exocrine glands

clinical relevance

Answer 32

many cancers originate in exocrine glands (adenomas, adenocarcinomas)

subject to infection, inflammation, injury from
-over/undersecretion and blockage of ducts