endocrine Flashcards
Name the various endocrine organs of the human body
- hypothalamus
- pituitary gland
- thyroid gland
- parathyroid gland
- suprarenal gland
- pancreas
- ovary/testi
describe the anatomy of the pituitary gland and its relation to the hypothalamus and the body skull
- its connected to the hypothalamus by the pituitary stalk (infundibulum)
- posterior pituitary is a continuation of the hypothalamus
- anterior pituitary originates from branchial arches.
- sits in the sella turica/ pituitary fossa in the brain
- found in the sphenoid bone
- attaches to optic chiasm
Describe the parts of the pituitary gland
- 2 lobes - anterior (pars anterior/adenohypophysis) and posterior (pars nervosa/ neurohypophysis)
- anterior lobe = larger, glandular and manufactures various hormones
- posterior lobe = continuation of stalk, stores and secretes vasopressin and oxcytocin
describe the histological appearance of the pituitary gland
posterior = light pink staining, contains non-myelinated axons which are neurosecretory cells
anterior = dark pink/ purple staining -
has 3 types of cells = acidiophilic (stains pink), basophilic (stains light purple), chromophobic (doesn’t stain so pale)
what is the resultant visual field deject be due to a pituitary gland enlargement
bitemporal hemianopia
state the classes, secretary products and target organs of acidophil cells
- somatotrophs, secrete GH, main target is condocytes in epiphyseal growth plate
- mammotrophs, secretes prolactin, targets alveolar cells in breast tissue
state the classes, secretary products and target organs of basophil cells
- corticotrophins, secrete ACTH and MSH, targets corticosteriod cells of adrenal cortex
- thyrotrophs, secrete TSH, target follicular epithelial cells of thyroid
- gonadotrophin, secrete FSH and LH, target gonad cells.
describe the arterial supply of pituitary gland
- from branches of the internal carotid artery - the superior hypophyseal artery and the inferior hypophyseal artery
- the superior hypophyseal artery enters into the substance of the hypothalamus before breaking up into capillaries ( the hypophysial portal system). These capillaries then supply the anterior pituitary.
- the inferior hypohysial artery suppled the posterior pituitary.
state the venous drainage of the pituitary gland
through hypophysial veins into the cavernous sinus
state the blood supply of anterior pituitary
the superior hypophysial artery splits into the hypophysial portal system
state the blood supply of the posterior pituitary
inferior hypophysial artery
describe the anatomy of the thyroid gland
2 lobes connected by isthmus
describe the location of the thyroid gland
Located in the neck anterior to the trachea and just inferior to the larynx
- located at vertebral level of C5-T1
- Located between the thyroid cartilage and the 6th tracheal ring
The isthmus lies opposite the 1st to 3rd tracheal rings.
state what strap muscles overlie the thyroid gland
sternothyroid
sternohyoid
Name the two nerves that supply the muscles of the vocal cords
- recurrent laryngeal = runs between trachea and oesophagus
- superior laryngeal = runs along pharynx and internal carotid artery
from which main artery in the neck does the superior thyroid artery arise
ECA
from which artery does the superior thyroid artery arise
subclavian artery
into which vein does the superior thyroid vein drain
IJV
into which vein does the middle thyroid vein drain
IJV
into which vein does the inferior thyroid vein drain
brachiocephalic veins
where do the lymph vessels of the thyroid gland drain
drain into the deep cervical group of lymph nodes
describe the histology o the thyroid gland
- the hormones of the thyroid gland are stored in cavities, surrounded by secretory cells. These make up a follicle.
- within the cavity of the follicle, the hormone is bound to a glycoprotein and is called a colloid.
what type of cell do you see lining the follicles of thyroid gland
squamous follicular cells
what colour does the colloid stain (in a H&E stained slide)
light pink
what do parafillicular/ clear cells secrete
calcitonin
what hormones does the thyroid gland secrete
thyroxine and triiodothyronine
describe the parathyroid glands
lie on the lateral half of the posterior surface of each thyroid lobe, external to the thyroid fibrous capsule.
- most people have 4
- they are separated from the thyroid gland by a thin fibrous capsule
state the location of the parathyroid glands
superior parathyroids are situated at the level of the inferior border of the cricoid cartilage.
inferior parathyroids are usually near the inferior poles of the thyroid, though their position is variable.
state the arterial supply to parathyroid glands
inferior thyroid arteries
state the venous drainage of the parathyroid glands
via the veins draining the thyroid to the IJV
state the two types of cells present in the parathyroid gland
chief cells and oxyphil cells
- chief cells are more numerous and have a darker staining cytoplasm
are suprarenal glands intraperitoneal or retroperioneal
retroperitoneal
state the parts of the suprarenal glands and the origins of these
- outer cortex = originates from mesodermal epithelium
- inner medulla = originates from the neuroectoderm
state the 3 pairs of suprarenal arteries
- superior suprarenal artery from inferior phrenic artery
- middle suprarenal artery from aorta
- inferior suprarenal artery from renal arteries
state which vein the suprarenal vein drains into
on right side = IVC
on left side = left renal vein
what does the medulla secrete
secrete adrenalin and noradrenalin from large ovoid chromatin cells
state the 3 distinct zones of the cortex and what they secrete
outer zona glomerulosa - thin = mineralcorticoid = salt
middle zona fasiculata- thick = glucocorticoid= sugar
inner zona reticularis - immediately adjacent to medulla - sex hormones(androgens) = sex
identify the location and relations of the pancreas
- retroperitoneal
- level of transpyloric plane = L1
- related to kidneys, stomach. gallbladder, liver, duodenum, spleen
state the parts of the pancreas
the uncinate process, head, neck, body and tail
state the blood supply of the pancreas
- gastroduodenal artery
- splenic artery
- superior pancreaticoduodenal artery
- superior mesenteric artery
state the exocrine and endocrine parts of the pancreas
exocrine part = pancreatic acini
endocrine part = islets of langerhans (light staining)
what cell types are found in the islets of langerhans and what do they secrete
alpha cells = glucagon
beta cells = insulin
delta cells = somatostatin
F cells = pancreatic polypeptide
