Endocrine lab 1 Flashcards
Where does the cortex of the suprarenal gland develop from?
Mesoderm (primitive mesothelium)
Where does the medulla of the suprarenal gland develop from?
Ectoderm (neural crest- primitive autonomic ganglion tissue)
What type of tissue forms the connective tissue capsule?
Fibrous connective tissue
What tissue lies outside the capsule?
Loose connective tissue containing white fat (unilocular adipose tissue) = single large lipid drop
What is the gross anatomical name for the tissue that lies outside of the capsule?
Perinephric fat
Describe the histology of the glomerulosa
Columnar cells arranged to form arches
Describe the histology of the fasciculata
Fascicles
Neat columns of cells separated by straight blood vessels (radially oriented) (spongiocytes)
Describe the histology of the reticularis
Reticular network
How do cells of the zona glomerulosa stain compared with cells of the zona fasciculata
The cells stain more darkly with small dark granules in their cytoplasm
What is another name for the cells forming the zona fasciculata?
Spongiocytes
What is contained within spongiocytes?
lipid and cholesterol
What is the approximate diameter of blood vessels within the zona fasciculata?
Fenestrated capillaries (RBC diameter is approx. 7um
Describe the zona reticularis organisation
The secretory cells form a three-dimensional network
The medulla is supplied by blood from…
> Capillaries/sinusoids from adrenal cortex
> Arterioles passing from the capsule to the medulla
What do the adrenal medullary neurosecretory cells contain
adrenaline and noradrenaline secretory granules
What is the vulpian reaction?
the development of a green colour to the adrenal medullary neurosecretory cells when a weak solution of ferric chloride is applied to the cells before potassium chloride
What are histological features seen with islets of Langerhans?
The epithelial secretory cells form small groups or islets within the exocrine pancreas
Cytoplasm stains lighter
How are islets of Langerhans formed?
By irregular, anastomosing rows or plates of cells separated by tortuous blood capillaries
Which cell type within the islets of Langerhans stains blue with alcian blue and H staining?
The beta cell (insulin secreting)
Which cell type within the islets of Langerhans stains red with alcian blue and H staining?
The alpha cell (glucagon secreting)
What is the arrangement of cells within the islets of Langerhans?
Beta cells generally more centrally located
Alpha cells generally surround beta core
Describe the blood supply to the islets of Langerhans
An arteriole enters one side of the islet and gives rise to a number of capillary branches passing through the islet -> fenestrated capillaries
Capillaries, now with a high content of endocrine hormones in their blood, pass directly into the exocrine pancreas
What type of blood vessel passes through the islet of Langerhans?
Capillaries or small venules
Describe the relative conc. of hormones within blood entering post-islet exocrine pancreas
The conc. of insulin and glucagon in high
proportions of each will vary with blood glucose content
What is the route of capillaries through the pancreas?
Capillaries pass through the endocrine pancreas and then through the exocrine pancreas
What effect does insulin have on the activity of biomechanisms (excl. uptake of glucose by cells)
increased production of insulin by beta cells in the islets stimulates/upregulates synthesis of exocrine pancreatic digestive enzymes for release into the duodenum via the pancreatic duct
