Endocrine 2: Hormones and the Hypothalamus Flashcards Preview

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Flashcards in Endocrine 2: Hormones and the Hypothalamus Deck (59)
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1
Q

the mechanism of thyroxine is a ___feedback loop

A

negative

2
Q

when thyroxine is high in the blood, negative feedback is sent to the brain which stops the production of ___ and therefor stops the production of thyroxine

A

RH

3
Q

when iodine is completely absent from the diet, ___ cannot be made

A

thyroxine

4
Q

what causes a Goiter?

A

iodine not present in the blood so thyroxine cannot be made, so when the pituitary continues to secrete TSH, it builds up and forms the loiter

5
Q

breastfeeding is a ____feedback loop that will result in the continuous secretion of ____ until the baby stops feeding

A

positive; oxytocin

6
Q

where is the hypothalamus located?

A

at the base of the brain, just below the thalamus and above the pituitary

7
Q

the hypothalamus is attached to the pituitary by the __

A

infundibulum

8
Q

the _____ senses any unbalance in the body and secretes hormones into the blood to maintain homeostsatisi

A

hypothalamus

9
Q

there are two groups of ____ cells in the hypothalamus

A

neuroendocrine

10
Q

stimulating and inhibitory hormones are secreted by the ___ pituitary

A

anterior

11
Q

anti-diuretic hormone and oxytocin are secreted by the ___ pituitary

A

posterior

12
Q

the anterior and posterior pituitary secrete hormones in response to

A

signals from the hypothalamus

13
Q

the anterior pituitary is also called the ___

A

Adenhypophysis

14
Q

the posterior pituitary is also called the ___

A

neurohypophysis

15
Q

secretion from the anterior pituitary is controlled by the ___ hormones secreted by the hypothalamus and reach the pituitary through the ____ vessels

A

hypothalamic releasing and inhibitory; portal

16
Q

secretion from the posterior pituitary is controlled by ___ that start in the hypothalamus and terminate in the posterior pituitary

A

nerve signals

17
Q

between the two lobes of the pituitary, there is a small vascular zone called the ___

A

pars intermedia

18
Q

the pars intermedia is almost ___ in humans, but is much more ___ in other animals

A

absent; large/functional

19
Q

t/f the two lobes of the pituitary secrete different hormones and have different functions

A

t

20
Q

the ____ pituitary is vital to fertility and contributes significantly to a variety of critical functions ranging from growth and development to general well being

A

anterior

21
Q

the ___ pituitary is important for the body osmoregulation and breastfeeding

A

posterior

22
Q

the ___ pituitary is often referred to as the master gland bc it controls the activity of most other hormone-secreting glands

A

anterior

23
Q

the posterior pituitary is actually an extension of the ___ of the hypothalamus

A

neurosecretory cells

24
Q

the cell bodies of the neurosecretory cells rest in the __ and their axons can be found in the ___

A

hypothalamus; posterior pituitary

25
Q

does the posterior pituitary make hormones?

A

no!

26
Q

the function of the posterior pituitary is to store and release 2 neurohormones that act on ___ target tissues

A

non-endocrine

27
Q

what are the 2 neurohormones secreted by the posterior pituitary?

A

antidiuretic hormone, oxytocin

28
Q

what is the function of the ADH?

A

acts on kidney to promote water reabsorption

29
Q

what is the function of oxytocin?

A

stimulates smooth muscle contractions in uterine and mammary tissue regulate labor and milk production and letting

30
Q

plasma osmolarity is maintained within a narrow range by employing mechanisms that regulate both ___ and ___

A

water intake and output

31
Q

____ sense changes in plasma osmolarity and changes of ___mOsm/kg induce action

A

hypothalamic osmoreceptors; 2-3

32
Q

the control os plasma osmolarity involves control of the blood water level, which is secrete by the __ hormone

A

antidiuretic

33
Q

control of hormone synthesis in the hypothalamus is at the level of ___

A

gene transcription

34
Q

what is the hormonal response to thirst?

A

hypothalamic osmoreceptors stimulate secretion of ADHand turn on gene machine to increase ADH expression on mRNA in magnocellular neurons

35
Q

ADH hormones are first made as large ___, then are enzymatically processed to produce the ___ and 2 ___

A

preprohormones; mature hormone and 2 byproducts

36
Q

what ae the 2 byproducts of ADH synthesis?

A

neurophysin and glycopeptide

37
Q

the mature form of ADH is transported by ___ to the posterior pituitary along ___ tracks

A

neurosecretory vesicles; microtubule

38
Q

ADH vesicle transport increases when synthesis is ___ and stops when stimulus is __

A

stimulated; removed

39
Q

ADH activates ____receptors, leading to ____mediated activation of __, which will phosphorylate ___and lead to their insertion in the cell membrane

A

V2 GPCR; cAMP; PKA; Aquaporin 2

40
Q

what is the function of inserting AQ2 channels in the cell membrane ?

A

reabsorb water

41
Q

tropic neurohormones are carried from the hypothalamus to the anterior pituitary by ___

A

portal vessels

42
Q

tropic hormones from the hypothalamus act on ___ cells in the anterior pituitary which will then release ___ into a second set of capillaries for distribution through the body

A

endocrine; peptides

43
Q

what are the 5 types of cells that secrete hormones in the anterior pituitary and what are the hormones they secrete? and what % of AP cells are they?

A
  1. somatotropes–> human growth hormone (GH) 30-40%
  2. thyrotropes–>TSH 3-5%
  3. Corticotropes–> adrenocorticotropin hormone (ACTH) 20%
  4. gonadotropes –> gonadotropic hormones (LH, FSH)
  5. lactotropes –> prolactin (PRL) 3-5%
44
Q

with the exception of ____, all anterior pituitary hormones are collectively referred to as tropic hormones bc they turn on/off the function of other hormones

A

GH

45
Q

which AP hormone is not tropic?

A

GH

46
Q

all AP hormones act on ____ receptors except GH

A

GPCR

47
Q

the GH is also called ___ or ____

A

somatotropin hormone; somatotropin

48
Q

GH is a small protein of around ___aa

A

200

49
Q

unlike tropic hormones, GH does not function on a ___, but rather exerts its effects by ___

A

acting directly on all (or almost) tissues of the body

50
Q

GH also acts through an intermediate substance called ___ or ___

A

insulin-like growth factor or somatomedin

51
Q

which of the 2 (GH/IGF) attaches weakly to transporters for a short time and which attaches strongly for a long time?

A

GH weak and short, IGF strong and long

52
Q

IGF-1 is activated by ___ and supports the ___, ___ and ___ of many tissues, ranging from muscle and immune cells to nervous and immune systems

A

GH; bioenergetic prossesses, metabolism, and growth

53
Q

IGF-1 regulates GH through negative feedback loops at the level of the ___, where it activates the release __

A

hypothalamus; growth hormone inhibitory hormone (GHIH)

54
Q

GH binds to GH receptors which undergo___ and then interact with ___ that activate the receptor by the phosphorylation of ___ on GH receptors

A

dimerization; janus kinase (JAK), tyrosine residues

55
Q

the GH JAK complex interacts with the ____- that gets phosphorylated by JAK causing its dimerization and movement into the nucleus where it induces the transcription and production of ___

A

signal transducer and activator of transcription (STAT); IGF-1

56
Q

list some things that may cause abnormalities in GH secretion

A

GH deficiency, GH receptor mutation, IGF deficiency, IGF receptor mutation, TH deficiency, insulin/insulin receptor defects, nutrition deficiency

57
Q

hyper secretion of GH before puberty causes

A

giantism

58
Q

hyper secretion fo GH acter puberty causes

A

acromegaly

59
Q

what is the treatment for hypersecetion of GH?

A

somatostatin analogues (Octreotide)