Adrenal and Pancreas Histology

Question 1

What are the two distinct parts (structurally and functionally) of the adrenal glands?

Answer 1

cortex and medulla

Question 2

The cortex is derived from????

Answer 2

mesoderm

Question 3

The medulla is derived from____

Answer 3

neural crest

Question 4

How is the adrenal gland innervated - with parasymethetics of sympathetics?

Answer 4

sympathetic

Question 5

What’s special about how the medulla is innervated?

Answer 5

most fibers end in the medulla as preganglionic sympathetics on medullary cells so that the medullary cells are essentially the postganglionic neurons

Question 6

What are the three layers of the adrenal cortex?

Answer 6

zona glomerulosa
zona fasiculata
zona reticularis

Question 7

Describe the zona glomerulosa. WHat do the cells look like/

Answer 7

It’s the narrow outer zone

cells are in ovoid groups or cords and they are round, with vasophilis nuclei and eosinophilic cytoplasm. abundant smooth ER and sparse lipid content

there is a rich capillary network

Question 8

What hormones are secreted by the zona glomerulosa

Answer 8

the salts

mineralocorticoids: aldosterone and deoxycorticosterone

Question 9

Describe the zona fasciculata?

Answer 9

it’s the broadest and middle zone

cells are arranged in parallel cords radiating towards the medulla.

Question 10

What surround the cords of cells?

Answer 10

longitudinal meshwork of sinusoidal capillaries

Question 11

Describe the cells of the zona fasciculata. what are they called?

Answer 11

spongiocytes (because they look like a sponge)

they are cuboidal or polyhedral with abdunant lipid droplets. abundant smooth ER. the mitochondria have tubular cristae

Question 12

What hormone is produced by the zona fasiculata?

Answer 12

glucocorticoids

cortisol or hydrocortisone

some androgens and estrogens, but very little

Question 13

Describe the structure of the zona reticularis

Answer 13

it’s the innermost zone of the cortex

has irregular cords of cells forming an anastomosing network

Question 14

Describe the cells of the zona reticularis

Answer 14

they are dark again - few lipid droplets

abundant SER (steroid producing)

Question 15

What hormones are produced by the zona reticularis cells?

Answer 15

mainly the sex steroids

also some glucocorticoids and extremely minimal estrogen

Question 16

What are the main cells of the adrenal medulla?

Answer 16

chromaffin cells surrounded by capillaries and venules

Question 17

What are the general characteristics of chromaffin cells?

Answer 17

columnar/ovoid/polyhedral
non-regenerative
prominent golgi and rough ER (less SER because not making steroids)
small secretory granules containing catecholamiens or chromogranins

Question 18

How are chromaffin cells triggered to release either epinephrine or NE?

Answer 18

a preganglionic sympathetic nerve releases ACh on it

so it acts almost like postganglionic sympathetic neuron

Question 19

What is the developmental origin of the chromaffin cells?

Answer 19

neural crest

Question 20

What keeps the chromaffin cells in this axon-less and dendrite-less state?

Answer 20

the glucocorticoids secreted by the zona fasciculata

Question 21

What do we call the few chromaffin cells that are extra-adrenal near the symapthetic chain ganglia or around the aorta? What do they secrete?

Answer 21

paraganglia cells
aortic chromaffin bodies
organs of Zuckerkandl

secrete epinephrine

Question 22

How is blood supplied to the adrenal gland?

Answer 22

via the subcapsular plexus of capillaries

Question 23

What are the 3 sets of capillaries that make up the subcapsular plexus?

Answer 23

1. capsular plexus
2. cortical sinusoidal (fenestrated) vessels
3. medullary fenestrated capillaries

Question 24

The medullary venules unite to form what?

Answer 24

the medullary (central) vein which then goes on to make the suprarenal vein

Question 25

In general, how are cells arranged in the pancreatis islets?

Answer 25

in irregular cords within a spheroidal mass

Question 26

Where in the pancreas are the islets most numerous?

Answer 26

more in the tail than in the head

Question 27

What are the 5 different types of cells in the islets?

Answer 27

``` alpha cells beta cells delta cells pancreatic polypeptide cells gastrin (G) cells ```

Question 28

What percentage of the islet cells are alpha cells?

Answer 28

20%

Question 29

Where in the islet do alpha cells tend to be more numerous?

Answer 29

at the periphery

Question 30

What do the alpha cells produce?

Answer 30

glucagon

Question 31

What percentage of the islet cells are beta cells?

Answer 31

70%

Question 32

Where in the islet are the betas more prominent?

Answer 32

in the center

Question 33

What do the beta cells produce?

Answer 33

insulin

Question 34

What percentage of the islet cells are delta cells?

Answer 34

less than 10%

Question 35

What do the delta cells make?

Answer 35

somatostatin

Question 36

What does somatostatin do as a paracrine effect?

Answer 36

suppresses secretion of insulin and glucagon

Question 37

What does somatostatin do via endocrine effect?

Answer 37

reduces contractions of the alimentary tract and gall bladder smooth muscle

Question 38

What percentage are PP cells?

Answer 38

about 1% - very few

Question 39

What do PP (F) cells make?

Answer 39

pancreatic polypeptide

Question 40

What does pancreatic polypeptide do?

Answer 40

inhibits enzymatic secretion from exocrine pancreas relaxes gall bladder resulting in decreased bile secretion

Question 41

When you stain for glucagon and insulin, what colors are they?

Answer 41

glucagon is brown (so you'd expect more brown at the periphery) and insulin is blue (so you'd expect more blue in the center)