Anterior Pituitary

Front 1

GRH

Back 1

Growth Hormone-Releasing Hormone

Front 2

GHIH, SS

Back 2

Somatostatin; growth hormone inhibiting hormone

Front 3

Dopamine, PIH

Back 3

Prolactin-Inhibiting Hormone

Front 4

TRH + others like VIP

Back 4

Prolactin-Releasing Factors

Front 5

TRH

Back 5

Thyrotropin-Releasing Hormone

Front 6

CRH

Back 6

Corticotropin-Releasing Hormone

Front 7

GnRH

Back 7

Gonadotropin-Releasing Hormone

Front 8

Why not just have Neurohypophysis arrangement?

Back 8

Because there isn't a 1-1 arrangement between tropic factors and Anterior Pituitary hormones.

Front 9

GnRH stimulates/inhibits?

Back 9

stimulates FSH and LH

Front 10

GRH stimulates/inhibits?

Back 10

stimulates Growth Hormone

Front 11

SS stimulates/inhibits?

Back 11

inhibits Growth hormone and TSH

Front 12

TRH stimulates/inhibits?

Back 12

stimulates TSH and Prolactin

Front 13

PRF stimulates/inhibits?

Back 13

stimulates Prolactin

Front 14

PIH stimulates/inhibits?

Back 14

inhibits prolactin

Front 15

CRH stimulates/inhibits?

Back 15

stimulates ACTH

Front 16

Why are irregular menstrual cycles one of the hallmark symptoms of hypothyroidsm?

Back 16

In cases of primary hypothyroidism (not enough thyroid hormone), this will dis-inhibit the hypothalamus (making it more active) which will stimulate TRH, which stimulates TSH release, which stimulates the thyroid to make more hormone and at the same time the TRH will stimulate prolactin release, which will make menstrual cycles irregular, because the hypothalamus uses releasing hormones, it doesn't use the posterior pituitary mechanism.

Front 17

HPT

Back 17

Hypophysiotropic

Front 18

HPT Hormones are all ____ of varying length, which bind to ______

Back 18

HPT hormones are all peptides of varying length, which bind to cell surface receptors becaus they are hydrophilic. Therefore, they do not go into the cell to bind to intracellular receptors. Because they are binding to cell surface receptors, they must use Second Messengers.

Front 19

HPT Hormones act on cell-surface receptors. Precise second messenger mechanisms are obscure, but may involve ___pathways

Back 19

cAMP, IP3, and DAG

Front 20

Most peptides will not get into cells, so they must use a ____ mechanism involving second messengers

Back 20

signal transduction

Front 21

HPT Hormones are short-lived in circulation for what 2 reasons?

Back 21

Degraded
Diluted

Front 22

HPT hormones are degraded by _____

Back 22

general and specific proteases

Front 23

Dopamine, or PIH, is degraded by ____

Back 23

catecholamine oxidation pathways

Front 24

What is pulsatile release?

Back 24

When a hormone is produced in the hypothaamus, it is not coming out all the time/not continuously released, but instead it is released as a pulse. When the pulse is coming out of the hypothalamus to the pituitary, the hormones bind to a receptor so that a receptor can respond to it. If the hormone is present all the time, then the anterior pituitary cells that are responding it will be sesensitized, they stop responding and their response per amount of releasing hormone goes down.

Front 25

Advantages of pulsatile release

Back 25

So the pulsatile release is present t keep the anterior pituitary cells responding at their optimal rate/optimal response. Pulses can also convey information.

Front 26

Explain how pulses are important in treating prostate cancer.

Back 26

Prostate cancer is almost always hormone dependent. Prostate cancer is almost always androgen receptor positive. In the absence of androgen, prostate cancer slows its growth rate. If you remove testosterone from the system, you can slow the growth rate of prostate ancer. One of the ways to do this is to provide a GnRH agonsit over time, a little bit is released all the time -> what this does is it desensitizs the pituitary so that it is not making LH which stimulates testosterone production -> so that its not pulsing (released in pulses) like natural GnRH -> produces a lowering of testosterone with a constant (not pulsing) stimulation of the pituitary.

Front 27

Short-loop feedback control: Inhibitory action of ______ on ____secreting HPT hormone.

Back 27

Inhibitory action of anterior pituitary hormone on hypothalamic neurons secreting HPT hormone.

Front 28

Long-loop feedback control: Inhibitory action of ____ on ____secreting HPT hormone.

Back 28

Inhibitory action of target organ hormone on hypothalamic neurons secreting HPT hormone.

Front 29

Which endocrine system does not use short loop feedback?

Back 29

thyroid

Front 30

Enteroceptive

Back 30

emotions, stress, etc.
CRH (and thereby ACTH) secretion increased in response to "stress"

Front 31

Exteroceptive

Back 31

Outside the individual
Light/Dark rhythms, olfactory signals, signals from our environment.

Front 32

Why is the pineal gland an endocrine gland?

Back 32

It produces a hormone (melatonin)

Front 33

The pineal gland appears to lack direct neural connection with the brain, except via ____

Back 33

superior cervical ganglion

Front 34

Pineal gland producs melatonin, a 'hormone' which may be involved in ____

Back 34

circadian regulation

functions in regulating sleep/wake cycles

Front 35

Melatonin production increases in response to what?

Back 35

darkness, hypoglycemia, sympathetic stimulation

Front 36

What are the three groups of anterior pituitary hormones?

Back 36

1) Corticotropin-related peptides
2) Somatomammotropins
3) Glycoproteins

Front 37

What type(s) of cells are corticotropin-related peptides?

Back 37

corticotrophs

Front 38

What type(s) of cells are somatomammotropins?

Back 38

Somatotrophs, lactotrophs

Front 39

What type(s) of cells are glycoproteins?

Back 39

thyrotrophs, gonadotrophs

Front 40

Corticotrophs produce what hormones?

Back 40

ACTH

Front 41

Somatotrophs produce what hormones?

Back 41

GH

Front 42

Lactotrophs produce what hormones?

Back 42

prolactin

Front 43

Thyrotrophs produce what hormones?

Back 43

TSH

Front 44

Gonadotrophs produce what hormones?

Back 44

LH, FSH

Front 45

What cell types are produced in basophilic cells?

Back 45

corticotrophs, thyrotrophs, gonadotrophs

Front 46

What cell types are produced in acidophilic cells?

Back 46

somatotrophs, lactotrophs

Front 47

ACTH is a fragment of what?

Back 47

POMC

Front 48

POMC

Back 48

Pro-opiomelanocortin

Front 49

POMC can be proteolytically cleaved into what main 3 fragments?

Back 49

N-term Fragment, ACTH, B-LPH

Front 50

What does the N-term fragment play a role in?

Back 50

Involved in lipid metabolism, growth stimulation of the adrenal cortex, or just a structure role

Front 51

What does alpha-MSH play a role in?

Back 51

stimulates melanocytes. In disorders where ACTH is overproduced, you get an interesting pigment in skin folds leading to hyperpigmentation. So MSH does explain disorders due to ACTH overproduction.

Front 52

What two fragments of ACTH have more function in lower animals than higher organisms?

Back 52

alpha-MSH, CLIP. These two fragments may explain disorders due to ACTH overproduction

Front 53

What does B-endorphin play a role in?

Back 53

endorphin= pain relieving peptides/ short proteins produced in the brain and modulate pain reception

Front 54

Why would endorphin structure be a part of POMC?

Back 54

stress, caused by pain, releases ACTH, which has endorphins to reduce pain

Front 55

ACTH stimulates ____

Back 55

adrenal cortex

Front 56

ACTH stimulates adrenal cortex to secrete what 3 things?

Back 56

1) glucocorticoids
2) Mineralocorticoids (like aldosterone)
3) androgenic steroids

Front 57

What stimulates ACTH for secretion?

Back 57

1) CRH from the hypothalamus
2) Stress

Front 58

Stress comes in what three forms?

Back 58

1) Physical (highest stress response)
2) Emotional (lowest efficacy for ACTH/CRH production is emotional stress)
3) Chemical

Front 59

Endogenous cortisol (normal amount) will not blunt stress response, but ____ will suppress

Back 59

Endogenous cortisol will not blunt stress response, but high dose exogenous corticosteroids will suppress.
ex: triamcinolone & prednisone respress the stress response and tune down the immune system and inflammation

Front 60

Name two inhibitors of ACTH

Back 60

Cortisol and ACTH

Front 61

Cortisol inhibits normal secretion of ACTH by what two mechanisms?

Back 61

Fast
Slow

Front 62

How does the fast mechanism or cortisol inhibit normal secretion of ACTH?

Back 62

(non-nuclear) --> sensitive to a change in cortisol as a function of time. A rapid rise in cortisol shuts off ACTH production (gene transcription) very quickly because it is too fast to be transcriptionally active.

Front 63

How does the slow mechanism or cortisol inhibit normal secretion of ACTH?

Back 63

(nuclear) --> cortisol comes into the cell, binds to a receptor, influences gene transcrition --> what we would expect. It is sensitive to concentration of cortisol

Front 64

Growth Hormone (GH) is cleaved from what?

Back 64

pro-GH

Front 65

GH effects are mediated by what two things?

Back 65

1) Insulin-like Growth Factor-I (IGF-I)
2) Insluin-like Growth Factor-II (IGF-II)

These do all the growth promoting effects. These both have structures that look a lot like insulin.

Front 66

Functions of GH?

Back 66

1) Enhances amino acid uptake and mRNA transcription & translation

2) Mobilization of fat (by stimulating lipolysis) leads to protein sparing for growth

3) In excess: decreases carbohydrate utilization by imparing glucose uptake. GH interrupts insulin binding to glucose transporter.

Front 67

What physiologic stimuli secretes GH?

Back 67

sleep, exercise, stress, postprandial hyperaminoacidemia (after a meal, more amino acids in the blood)

Front 68

What pharmacologic stimuli secretes GH?

Back 68

GRH, ACTH, ADH, a-agonists, b-antagonists

a-agonists: stimulate effects of epi/norepinephrine

B-antagonists: binds to B-receptors to control BP and arrhythmias

Front 69

What pathologic stimuli secretes GH?

Back 69

Starvation, renal failure

Starvation: preserves those proteins, promotes utilization of other nutrients like fat and glucose.

Front 70

What physiologic secretions inhibit GH?

Back 70

Postprandial hyperglycemia, Free fatty acids

Front 71

What pharmacologic secretions inhibit GH?

Back 71

Somatostatin (antagonist to GHRH), GH (feedback), cortisol, a-antagonist, B-agonists

a-antagonists: blocks the effects of epi/norepinephrine at a-receptors

B-agonists: suppress growth to some degree

Front 72

What Pathologic secretions inhibit GH?

Back 72

Obesity, hypo-and hyper-thyroidism

Front 73

How does hypothyroidism inhibit GH?

Back 73

If you are hypothyroid, you'll produce a lot of PRH, which to some degree reduces GH release

Front 74

How does hyperthyroidism inhibit GH?

Back 74

If you are hyperthyroid, you are burning a lot of nutrients, and you have extra thyroid hormone.

Front 75

Prolactin is cleaved from what?

Back 75

pro-hormone

Front 76

Functions of PRL

Back 76

1) Stimulates postpartum lactation
2) Stimulates breast development in concert with E2 and P during pregnancy
3)Excess PRL feedback- inhibits gonadotropin release, producing hypogonadism, or in womn it is amenorrhea.

Front 77

Why doesn't a woman produce milk during pregnancy?

Back 77

Because estrogen suppresses lactation.

PRL increases during pregnancy but its lactogenic effect is suppressed by estrogen; when estrogen falls after parturition, PRL initiates lactation.

Front 78

What physiologic stimuli secretes PRL?

Back 78

Pregnancy, nipple stimulation, nursing

Front 79

What pharmacologic stimuli secretes PRL?

Back 79

TRH, estrogen, dopamine antagonists

Front 80

What pathologic stimuli secretes PRL?

Back 80

Prolactinomas, lesions of pituitary stalk, liver/kidney disease; hypothyroidsm

Front 81

How does hypothyroidism secrete PRL?

Back 81

If you are hypothyroid, little thyroid hormone is being released, which means that this will be a stimulus for TRH release. And since TH also stimulates prolactin, extra prolactin will be produced.

Front 82

How do dopamine antagonists stimulate secretion of PRL?

Back 82

If you antagonize dopamine receptors, then you will have more prolactin release.

Dopamine is the prolactin inhibitory hormone (PIH). So if you antagonize the receptor effects of dopamine, you will increase prolactin release -> secreting more PRL

Front 83

What pharmacologic secretions inhibit PRL?

Back 83

dopamine (PIH) & Dopamine agonists

Front 84

Give an example of a dopamine agonist

Back 84

bromocriptine

It is useful therapeutically. Bromocriptine was historically used to suppress production/lactation in women who gave birth to stillborns (dead at birth) in the immediate postpartum (after childbirth) period. In this circumstance, it could be stressful for women to produce milk w/out needing to breastfeed.

Front 85

What pathology inhibits PRL?

Back 85

pituitary removal or destruction

Front 86

TSH (thyroid stimulating hormone) is also called?

Back 86

thyrotropin

Front 87

Thyrotropin is a small protein with what two subunits?

Back 87

alpha
beta

Front 88

alpha is similar to what other kind of hormone?

Back 88

similar to other glycoprotein hormones (LH, FSH, HCG

Front 89

beta is ____ in each of these hormones, so confers biologic specificity

Back 89

different

Front 90

So alpha and beta subunits are secreted together but ____

Back 90

not covalently bound

Front 91

Functions of TSH

Back 91

1) Stimulates iodide uptake into thyroid gland
2) stimulates synthesis & release from storage of T4 and T3 (acts via adenylyl cyclase/cAMP)
3) induces increase in thyroid gland size

Front 92

How do you get goiter?

Back 92

If you do not have a lot of iodine in your diet, T4 levels go down. When this happens, TRH goes up. Increases TSH release. Thyroid gland increaes in size -> Goiter

Front 93

What physiologic stimuli secrete TSH?

Back 93

Temperature (low temperatures tend to increase TSH)

insulin-induced hypoglycemia

Front 94

What pharmacologic stimuli secretes TSH?

Back 94

1) TRH (the ability of T3 to regulate the sensitivity of TRH)

2) reduced thyroid hormones (TSH increases because of a lowering of the thyroid hormones T3 and T4)

3) estrogens

Front 95

What pathologic stimuli secretes TSH?

Back 95

TSH-secreting tumors

Front 96

If pregnancy is unknown, why can it look like hyperthyroidism in women?

Back 96

Women tend to have slightly higher TSH levels than men. In pregnancy, the levels of estrogen rise, and so there will be more synthesis of TSH and high T3 and T4. If pregnancy is unknown, it can look like hyperthyroidism.

Front 97

What are the pharmacologic inhibitors of TSH?

Back 97

1) increased T3 &/or T4
2) somatostatin, dopamine (and dopamine agonists), glucocorticoids, growth hormone all negatively interact

Front 98

What are the pathologic inhibitors of TSH?

Back 98

acute or chronic disease, tumors of anterior pituitary or hypothalamus

Front 99

increase TSH, ____T3/T4

Back 99

decrease

Front 100

decrease TSH, ____T3/T4

Back 100

increase