Karteikarten
Neuroendocrine
Karten in diesem Stapel (109)
- 1endocrine secretion is what?slow. chemical messenger is made far from the target and must travel through the bloodstream to target organ cells. LONG half life
- 2synaptic secretionalso slow. long half life. nerve cells synthesize and store hormones. diffuses into target cells in vicinity. only on a specific cue is released
- 3endocrine cells gathered together formsendocrine glands. can also form discrete clusters (like islets of langerhans in pancreas)
- 4endocrine cells are also dispersed among other cells in epitheial tissues to form_____diffuse neuroendocrine system (gut and respiratory tracts)
- 53 hallmarks of endocrine gland-no duct system
-heavily vascularized
-fenestrated capillaries - 6pituitary gland is tightly controlled byb?hypothalamus
- 7how does hypothalamus control pituitary gland?inhibiting factors and releasing factors based on signals it gets
- 8where do the inhibiting factors come from?feedback from target organ releasing back to pituitary or hypothalamus
- 9where is the pituitary gland located?depression of the sphenoid bone, stella turcica. protected by bone and dura mater
- 10pituitary gland is connected to the brain by?the pituitary stalk. unprotected by dura mater, vulnerable. can be damaged by head trauma
- 11pituitary gland secretes 2 types of hormones are?hormones acting on non-endocrine tissue (growth hormone)
hormones acting on other endocrine glands called tropic hormones (TSH) - 12two major divisions of the hypophysis?neurohypophysis (neuronal origin)
adenohypophysis (ectodermally derived)
- 133 parts of the adenohypophysis?-pars distalis- main glandular endocrine function
-pars tuberalis- upward extension of distalis
-pars intermedia- embroyonic remnant
- 142 parts of the neurohypophysis?pars nervosa- neural lobe
infundibulum- infundibular process and median eminence - 15what is the median eminencefunnel-like extension of hypothalamus.
hypothalamus is above it - 16what makes up the pituitary stalk?pars tuberalis and infundibular process
- 17common element of infundibulum and pituitary stalk?infundibular process
- 18anterior and posterior landmarks?optic chiasma- anterior
mamillary bodies- posterior - 19—PD- pars distalis is dark due to granules
PN - is lighter because axons don't stain as darkly
PI- intermedia in the middle
PT- upward projection of PD, so also dark
- 20—yeah
- 21Adenohypophysis is derived from?ectoderm
Rathke's pouch
- 22Neurohypophysis is derived from?neuronal origin - diencephalon
- 23benign tumor of proliferating of stem of Rathke's pouch which did not regresscraniopharyngioma
- 24what happens with craniopharyngioma?presses on pituitary gland and optic chiasma and results in vision changes
- 25The hypothalamus is in DIRECT communication with the neurohypohysis via theinfundibulum (median eminence and infundibular process)
- 26the paraventriculr nucleus makes what hormone?oxytocin
- 27the supraoptic nucleus makes what hormone?vasopressin
- 28nuclei have bundled unmyelinated axons going towards ______the neurohypophysis (pars nervosa)
this is the hypothalamoneurohypophysial tract - 29the hypothalamus is in contact with te adenohypophysis via ______pitutary portal vessels
- 30the blood supply to the hypophysis i includes 3 arteries from the carotid artery:1)superior hypophyseal artery
2) inferior hypophyseal artery
3) trabecular artery (connects superior and inferior)
- 31which artery supplies the adenohypophysis?superior hypophyseal artery
- 32superior hypophyseal artery enters at the level of the median eminence or the uppper part of infundibular process to form _____primary capillary plexus
- 33what is the purpose of the primary capillary plexus?collect secretions from the neurons located in the hypothalamohypophysiotropic nuclei and funnel them down into pars distalis where the endocrine cells reside
- 34hypothalamohypophysiotropic nuclei release what?releasing or inhibiting factors only acting on other glands
- 35the capillaries merge together and form the _____portal veins
- 36portal veins go down along parss tubalis down to pars distalis to form _____secondary capillary plexus
- 37primary capillary plexus and secondary capillary plexus are connected byportal veins
(forming the hypothalamohypophysial portal system) - 38what is the goal of the secondary plexus?deliver goods from hypothalamohypophyseiotropic nuclei to the endocrine cells
and collect hormones made by endocrine cells send them to blood stream through the hypophyseal vein - 39blood supply of neurohypophysis?inferior hypophyseal artery and trabecular artery (merges with inferior artery before reaching pars nervosa)
- 40inferior hypophyseal artery gives rise to _____capillary plexus (no name) collects oxytocin and vasopressin
- 41role of pars nervosa vs pars distalisits a storage space, unlike pars distalis where things are being made
- 42—C
- 43Pars distalis is formed by what 3 components?1) cords of epithelial cells
2) minimal supporting connective tissue
3) numerous fenestrated capillaries - 44chromophils vs chromophobes?chromophils- stained cytoplasm
chromophobes- unstained cytoplasm (most likely undifferentiated cells)
- 45What are the Acidophilis and what do they make?Chromophils: stained cytoplasm
S-somatotrophs (GH)
A- acidophils
M- mammotrophs (PRL) - 46Types of Basophils and what they produce?Thyrotrophs (TSH)
Gonadotrophs (FSH & LH)
Corticotrophs (ACTH) - 47What do acidophils look like? Basophils?A- acidophils - reddish
B- basophils (bluish)
C- Chromophobes- round nucleus with space around it
S-fenestrated sinusoids
- 48—yup
- 49—a- reddish orange
b- bluesish purple
c-chromophobes have white space and w nuclei
sinusoids are actual white space
- 50—basophil
- 51—acidophil
- 52How are acidophils and basophils distributed in the pars distalis?somatotrophs (GH) on the sides
thyrotrophs (TSH) and corticotrophs (ACTH) in the middle. and mammotrophs and gonadotrophs are scattered throughout
- 53if there's a compression on the sides of the pars distalis, what happens?stunted growth dwarfism (GH affected)
- 54secretory granules are discharged ininto fenestrated capillaries by ______exocytosis
- 55hormones from the anterior hypophysis are stored in secretory granules and released in a _____ mannerpulsatile/cyclical manner
- 56young immature secretory granules come from what part of the cell?golgi
- 57they become mature when theyfuse together
- 58then they fuse with the plasma membraneto passively diffuse content of the granules in the ______pericapillary space- basement membrane and fenestrated capillary
- 59what organelle fuses with the granules to get rid of them?lysosomes
- 60which cells make up 40-50% of the cell population?somatotrophs (responsible for making growth hormone)
- 61path of GH?somatotrophs → hepatocytes → form IGF 1 → epiphyseal plates of long bones → growth
- 62what controls the release of GH?GHRH
- 63high ____ levels inhibit GH release and therefore GH-IGF-I axis in children with type diabetes 1 and 2high glucose levels
- 64decrease of GH in children results indwarfism
- 65excess of GH in children results i ingigantism
- 66excess of GH in adults leads toacromegaly
- 67Mammotrophs contribute to 15-20% of cell population and secreteprolactin
- 68what inhibits mammotrophs?dopamine
- 69mammotrophs are activated bysuckling
- 70prolactin induces lactation which is (3 things)1) mammogenesis- development of lactating mammary gland
2) lactogenesis- initiation /production of milk
3) galactopoeisis- maitenece of milk production - 71gonadotrophs make up 10% of cell population and produce what?follicle stimulating hormone
leutinizing hormone
- 72Gonadotrophs are controlled by ____gonadotropin-releasing hormone and activin (turns on GRH)
- 73FSH does what in females?induce proliferation in granular cells which make estradiol, activin, and inhibin. when inhibin levels exceed activin it stops the gonadotrophs from releasing FSH.
- 74FSH does what in males?acts on sertoli cells in seminiferous tubules in testes, which make androgen binding proteins which activates inhibin.
- 75What does leutinizing hormone do in women?acts on corpus luteum (mid point of menstral cycle day 15) then makes progesterone. if pregnancy occurs, corpus leutum will remain
- 76what does leutinizing hormone do in males?it acts on leydig cells in testes which make testosterone
- 77what happens when you have low levels of LH and FSH?infertility
- 78Thyrotrophs make up 5% of the cell population and make what hormone?TSH
- 79TSH acts on _____the thyroid gland
- 80The thyroid gland makes what?T3- actively regulates activity of thyrotrophs. feedback loop to inhibit hypothalamus
T4
- 81if hypothyroidism is present due to a pituitary gland problem, what would you expect to see on labs?low TSH
- 82if hypothyroidism is present due to a thyroid gland problem what would you expect to see on labs?low T3 and low T4, and increased TSH
- 83what about hyperthyroidism at the pituitary gland?high TSH, high T3 and T4
- 84what about hyperthyroidism at the thyroid gland level?TSH low and high T3 and T4
- 85Corticotrophs make up 20% of the cells and produce what?ACTH- adrenocortcotropin hormone
- 86when is ACTH being released?every morning, gets you going for the day
- 87where does ACTH act?adrenal gland
- 88what are the 3 zones of the adrenal gland?zona fasiculata- the only one acted on by ACTH and makes cortisol **
zona reticularis, zona aglomerulosa these dont matter - 89what does lack of cortisol do?weak, lethargic, no interest
- 90where is cortisol degraded?in the liver. when it reaches a certain threshold, it acts at the level of the corticotrophs to modulate it
- 91what is the main thing that controls the release of ACTH?cortisol
- 92what happens with too much cortisol?high blood pressure and edema, affects salt and water absorbption
- 93what happens if you put your patients on a glucocortioid long term and then stop it?the patient will crash because the corticotrophs are not used to makin their own cortisol. you should taper it down to give the corticotrophs a chance to ramp up again
- 94—regulated by T3
- 95—Pars intermedia - rudimentary (left over of the inner layer of the Rathke's pouch)
C= colloid (Rathke's cyst) surrounded by cuboidal epithelium
- 96—colloid, rathke's cysts (c)
- 97—g
- 98—g
- 99—pink unmyelinated axons
nuclei are pituicytes
arrows- lipofuscin with age
- 100—c- capillary
u-unmyelinated fibers
arrows- nuclei of pituicytes
- 101pars nervosa under control of which nuclei?paraventricular and supraoptic nuclei
- 102the paraventricular nucleus releases what hormone?oxytocin
- 103target organs of oxytocin?uterus - contraction of the myometrium during labor
mammry gland myoepithelial cell - contraction of myoepithelial cells of lactating mammary alveoli - 104absence or reduction in vasopressin secretion results in what?hypothalamic diabetes insipidus (HDI)
- 105the supraoptic nucleus releases what hormone?vasopressin (ADH)
- 106what is the target of vasopressin (ADH)arterioles- increased blood pressure
collecting tubule- increased water permeability - 107what is the difference between HDI (I (hypothalamic diabetes insipidus vs (nephrogenic diabetes insipidus)HDI - LOW ADH, less water reabsorbed via aquaporins in collecting tubules
NDI- no hormone change, but loss of function mutation of ADH V2 or AQP2
if a patient does not respond to synthetic ADH, then they probably have NDI - 108supraoptic or paraventricular nucleus releases its hormones (oxytocin and vasopressin) traveling along unmyelinated axons viaherring bodies and couple with neurophysin
- 109—stored in herring bodies along unmyelinated axons
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- . B&B 3 Karteikarten am Neuroendocrine, erstellt von hanna haile am 07/11/2021.
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- hanna haile · Nov 2021
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- 8 Nov 2021
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