ANATOMY OF THE ENDOCRINE SYSTEM Flashcards
What is an endocrine gland
a gland which secretes hormones directly into the blood
what is the difference between an exocrine and endocrine gland
exocrine secrete into a duct on to external surfaces and endocrine secrete directly into the blood
what are the similarities of the nervous system and the endocrine system
rely on chemical messengers
respond to stimuli
work via feedback loops
maintain homeostasis
differences between the nervous system and endocrine system
endocrine is slow and nervous is fast
hormones via blood and signals via neurons
hormones long lasting and signals short acting
what is a hormone
chemical messengers secreted by a gland that affect target organs
what is the function of the hypothalamus
regulation of metabolic processes and other activities of the autonomic nervous system
synthesises and secretes releasing or inhibitory hormones which then stimulate and inhibit pituitary hormones
-links the nervous to the endocrine system
where does the pituitary gland lie
right below the hypothalamus and sits in the pituitary fossa in the sphenoid bone
what covers the superior surface of the gland
dura matter which allows passage of the infundibulum
what are the three parts of the anterior pituitary gland
pars anterior pars intermedia pars tuberalis (wraps around the piuatry stalk/infundibulum)
what are the two parts of the posterior pituitary gland
pars nervosa
infundibulum
what two hormones does the posterior pituitary gland secrete
ADH-controls blood osmolarity
oxytocin-involved in milk secretion and child birth
what two hypothalamic nuclei are present in the posterior pituitary gland
paraventricular
supraoptic
what is the function of the paraventricular nucleus
oxytocin release
what is the function of the supraoptic nucleus
ADH release
what two arteries supply the pituitary gland
superior and inferior hypophyseal artery off the internal carotid artery
what is the hypothalamohypophyseal portal system
connection between he hypothalamus and the pituitary gland
which blood vessel is mainly in the hypothalamohypophyseal portal system
superior hypophyseal artery
what is the thyrotropin releasing hormone
produced in the hypothalamus and drain into the portal and then simulate the anterior pituitary to release thyroid stimulating hormone
what happens at the medial eminence
this is where the inhibiting or stimulating hormones re released into the portal and to the pituitary gland
which cells secrete the inhibitory or stimulating hormones
hypothalamic neurosecrtory cells
what hormones does the anterior pituitary gland secrete ( REMEMBER - the mnemonic is These Leave From Anterior Pituitary Gland )
Thyroid stimulating hormone TSH Lutenising hormone LH Follicle stimulating hormone FSH Adrenocorticotropic hormone ACTH Prolactin Growth hormone GH
which cells produce GH and prolactin
Acidohil cells
which cells produce TSH, ACTH, LH, FSH
basophil
what are cromophobes
cells which dont stain well
what does the pineal gland produce
melatonin which helps moderate sleep
where does the pineal gland get its blood supply from
vascular branch posterior cerebral artery
what connects the right and left lobe of the thyroid gland
isthmus
what does the thyroid gland produce
triidothyronine T3
thyroxine T4
where does the superior and anterior thyroid gland get its blood supply from
superior thyroid artery from the external carotid artery
where does the inferior and posterior thyroid get its blood supply from
inferior thyroid from the subclavian artery
where does the anterior isthmus get its blood supply from
thyroid ima artery from brachiocephalic trunk
which vein drains the superior thyroid
superior thyroid vein into internal jugular vein
which vein drains the inferior thyroid
inferior thyroid vein into brachiocephalic vein
how many parathyroid glands are there and where do they sit
4 and sit posterior to the thyroid
what hormone do parathyroid glands release and what is the function
release parathyroid hormone which controls the calcium concentrations
what is another name for adrenal glands
suprarenal glands
what are the two regions of the adrenal gland
adrenal cortex and adrenal medulla
what are the three layers of the adrenal cortex
zona glomerulosa outer
zona fasiculata middle
zona reticularis inner
what cells make up the zona glomerulosa and whats the function
mineralocorticoids which maintain salt and water balance
what cells make up zona fasiculata and whats the function
glucocorticoids which maintain glucose balance
what cells make up zona reticularis and whats the function
androgens which are male sex hormones
what cells make up the adrenal medulla and whats the function
catecholamines which produce adrenaline and noradrenaline
what is the adrenal gland supplied by
superior, middle and inferior adrenal artery
where does the adrenal gland drain
the right one drains into the right adrenal vein straight into the vena cava and the left adrenal vein drains into other veins before the vena cava
