Physiology Spring L27/28/29 Hypothalamus-Pituitary

Front 1

What are the two hormones created by the posterior pituitary?

Back 1

Oxytocin and ADH

Front 2

what are the 7 hormones created by the anterior pituitary?

Back 2

TSH, FSH, LH, ACTH, MSH, GH, Prolactin

Front 3

What are the 6 hormones released from the hypothalamus?

Back 3

TRH
CRH
GnRH
GHRH
Somatostatin
Dopamine

Front 4

What external stiimuli does the H-P unit integrate?

Back 4

light, temp, emotion

Front 5

what internal stimuli does the H-P unit integrate?

Back 5

water metabolism
reproduction/growth
milk secretion/lactation
growth and secretion of thyroid, adrenal, reproductive glands

Front 6

Where are hormones transferred in the posterior pituitary?

Back 6

these are transfered down axons

Front 7

where are hormones stored in posterior pituitary? how are they released?

Back 7

these are stored in vesicles, and released in a neurocrine manner

Front 8

Where are anterior pituitary hormones transferred?

Back 8

these are sent down axons at the median eminence

Front 9

In the anterior pituitary, what is the release pattern of hormones?

Back 9

hormones are first released in a neurocrine fashion into local circulation (portal vein)-- (these encourage the release or inhibition of pituitary hormones)

then, then hormones reach the anterior pituitary, where they are released in an endocrine fashion

Front 10

What hormones are created in the paraventricular nucleus?

Back 10

oxytocin, adh

Front 11

what hormones are created in the periventricular nucleus?

Back 11

somatostatin

Front 12

what hromones are made in the arcuate nucleus?

Back 12

somatostatin

Front 13

what hormones are made in the supraoptic nucleus?

Back 13

ADH and oxytocin

Front 14

What does somatostatin inhibit the release of?

Back 14

GH and TSH

Front 15

What is the anterior pituitary derived from?

Back 15

primitive foregut

Front 16

what is the posterior pituitary derived from?

Back 16

outgrowth of the brain

Front 17

what kind of tissue makes up the anterior pituitary?

Back 17

endocrine tissues

Front 18

what kind of tissues makes up the posterior pituitary

Back 18

made of nervous tissue

Front 19

What is the greatest population of cells in the anterior pituitary?

Back 19

somatotroph

Front 20

What are the four anterior pituitary hormones that stimulate other glands to grow and secrete hormones?

Back 20

ACTH
TSH
FSH
LH

Front 21

What are the two anterior pituitary hormones that stimulate non-endocrine tissue?

Back 21

GH

prolactin

Front 22

What does TSH do? what secretes it? alternate name?

Back 22

this is secreted by the anterior pituitary.
also called thryotropin

this stimulates the secretion of thyroid hormones from the gland, and helps it grow

Front 23

What does ACTH do? what secretes it?

Back 23

this is secreted by the anterior pituitary

this is adrenocorticotropic hormone- stimulates the release of cortisol and androgens from adrenal cortex

Front 24

what does FSH do? what secretes it?

Back 24

this is secreted by the anterior pituitary

in females- this stimulates growth of follicles for egg development

in men- FSH promotes sperm production

Front 25

What does LH do? what secretes it?

Back 25

this is secreted by the anterior pituitary

in females- causes ovulation, regulates estrogen/progesteron secretion

in males- promotes testo secretion

Front 26

What does GH do? what secretes it?

Back 26

this is secreted by the anterior pituitary

has a role in growth and fuel metabolism

Front 27

What does prolactin do? what secretes it?

Back 27

this is secreted by the anterior pituitary

this enhances breast development, and milk production

also induces production of LH receptors in testes

Front 28

Where are ADH and Oxytocin produced?

Back 28

In HYPOTHALAMIC neuronal cell bodies.
-supraoptic nucleus
- paraventricular nucleus

Front 29

What types of hormones are ADH and Oxytocin?

Back 29

these are both neruopeptides.

and both are nonapeptides (9AA's)

Front 30

What is NP 1/2? which one binds what?

Back 30

NP-1 is a carrier protein used to bind Oxytocin, prevents diffusion out of axons

NP-2 is a carrier protein used to bind ADH, prevents diffusion out of the axon

Front 31

What is the role of ADH?

Back 31

this regulates plasma osmolarity

Front 32

When is ADH secreted?

Back 32

this is secreted in response to an increase in plasma osmolarity

Front 33

What is the method of action of ADH?

Back 33

this is used to reabsorb water from distal tubule/collecting duct.

V2 receptors in the kidney- result in the insertion of aquaproin 2

Front 34

How does ADH affect the vasculature?

Back 34

this acts as a pressor- constracts arteriolar smooth muscle via V1 receptors

Front 35

What things inhibit ADH secretion?

Back 35

decrease in plasma osmolarity

volume expansion

HTN

alcohol

Front 36

What are the 3 lesser effects of oxytocin?

Back 36

released during orgasm

involved in embryonic cardiomyocyte differentiation

releases ANP from heart

Front 37

What causes central or neurogenic diabetes insipidus?

Back 37

this is a defect in ADH release- low levels of ADH.

caused by damage to ADH neurons (in posterior pituitary)

Front 38

What causes nephrogenic diabetes insipidus? what are the lab values like?

Back 38

the posterior pituitary is normal, levels of ADH are high

but the collecting ducts are unresponsive to ADH stimulation (due to receptor defects, V2)

Front 39

What are the causes of congenital hypopituiarism?

Back 39

this is caused be a defect in pituitary release of GH, GnRH, TSH, ACTH

Front 40

what is panhypopituitarism?

Back 40

this is a deficiency of all anterior pituitary hormones

Front 41

what are the first hormones to decrease in Pituitary insufficiency?

Back 41

GH and gonadotropins

Front 42

What are the physical symptoms of pituitary insufficiency?

Back 42

adrenal cortex atrophies

sex cycle stops, secondary sex characteristics decrease

from thyroid loss- cold intolerance, dry skin, mental dullness, bradycarida

Front 43

Where is GH made? what is its form?

Back 43

in the somatotrophs of anterior pituitary.

this is made as a larger preprohormone, in a dominant active 22kDa active form.

stored in cytosolic granules

Front 44

how does gender relate for GH secretion?

Back 44

gh secretion is greater in premenopausal women.

Front 45

when is GH secretion greatest in diurnal rhythm?

Back 45

its is greatest during sleep onsent, then declines through out sleep time

Front 46

What does GH-releasing hormone do? via what mechanism?

Back 46

this acts on somatotrophs to induce transcription, and release of HGH.

it does this via G coupled receptors, with cAMP and PLC

Front 47

What does Somatostatin do to GH release?

Back 47

this inhibits GH release, by blocking the action of GH-RH to own receptor

Front 48

What are the 3 main things the cause negative feed back on GH secretion?

Back 48

GH-Rh

Somatomedins (IGFs)- increases somatostatin release (also suppresses response to GH-RH)

GH- causes hypothalamus to release somatostatin

Front 49

What things stimulate the release of HGH?

Back 49

Decreased plasma glucose

agrinine

sleep, TH, fasting, testo

Front 50

What things inhibit HGH release?

Back 50

somatostatin
increased blood sugar
obesity
being old
somatomedins (IGF)
GH

Front 51

What things does HGH exert a direct effect on?

Back 51

this has a direct effect on intermediary metabolism

Front 52

what does HGH exert an indirect effect on?

Back 52

growth (via IGFs (or somatomedins))

Front 53

What are the Direct effects of HGH?

Back 53

Lipolysis in adipose tissue

decreased glucose utilization in most tissues

Front 54

What are HGH's effects on Lipids?

Back 54

these are direct actions

GH is lipolytic, activates HSL-
also increase FA uptake


HGH is also ketogenic, (when insulin is low- as normal)

Front 55

What are HGH's effects on Protein?

Back 55

HGH is a protein anabolic hormone
increases amino acid uptake and incorporation into protein

muscle wasting can occur due to low GH secretion

Front 56

What are HGH's effects on Carbohydrates? How does this effect insulin levels?

Back 56

HGH- decreased glucose uptake by muscle/liver/adipocyte

AND increases gluconeogenesis

NET effect: increase in glucose, and rise in insulin

Front 57

How does HGH affect insulin resistance?

Back 57

this will INDUCE insulin resistance! by increasing blood sugar and insulin levels

Front 58

How does GH affect PO4? Ca2+? ECF volume?

Back 58

this increase PO4 uptake

increase Ca2+ absorption

and increases the ECF volume, due to angiotensin. also inhibits ANP

Front 59

What carries out the indirect actions of HGH?

Back 59

IGF-1/IGF-2

Front 60

How is IGF transported?

Back 60

it is transported by IGF-binding protein

Front 61

What is the major regulator of IGF levels? what changes this regulators concentration?

Back 61

IGF-BP1 is the major regulator

its production is increased by cortisol/glucagon

and its production is suppressed by insulin

Front 62

How do IGF-BP1 levels, and consequently IGF levels change during fasting?

Back 62

During fasting, with low insulin and high glucagon- IGF-BP1 synthesis is promoted.

This will BIND free IGF's LOWERING their concentration in the blood

Front 63

Which IGF receptor is most similar to the insulin receptor?

Back 63

IGF-1

Front 64

What is the biggest IGF effect on growth?

Back 64

this is an increase in linear growth, action on growth plates of long bones

Front 65

What are the effects of IGF on chondrocytes

Back 65

These increase Linear growth-
due to
amino acid uptake/protein synthesis
RNA/DNA synthesis
collagen/chondrotin
cell size and number

Front 66

How do the gonads affect IGF-1 production?

Back 66

gonadotropins stimulate IGF-1 production

Front 67

In the Protein fed state! What happens to insulin/HGH/IGF levels?

what about protein synthesis and growth?

Back 67

Increases In GH, IGF, and Insulin

GH and insulin modulate the IGF production together

GH facilitates insulin action to promote growth

Front 68

How does insulin affect IGF-1 production?

Back 68

this will increase IGF 1 produciton in the liver

Front 69

In the carbohydrate fed state, what happens to insulin/HGH/IGF levels?

what about protein synthesis and growth?

Back 69

Here GH goes down (due to hyperglycemia)
No change in IGF
Increase in insulin- this promotes storage of energy

No growth or protein synthesis

Front 70

in the fasting state, what happens to Insulin/HGH/IGF levels?

Back 70

Insulin secretion falls

Hypoglycemia induces HGH secretion!!

low IGF production

GH opposes the low insulin levels, to promote catabolism/glucose sparing

ALSO high Glucagon/Cortisol- so high IGF-BP1 levels, lowers IGF levels

Front 71

What happens in GH deficiency before puberty?

Back 71

this causes dwarfism

normal shaped bodies, with normal inteliegence.
ususally due to LOW GH and LOW IGF

Front 72

What produces Laron dwarfs?

Back 72

Normal GH levels,
but defect in expressing GH receptor

NO IGF! No IFG-BP

Front 73

What produces african pigmys?

Back 73

Normal GH levels

No rise in IGF with puberty.

partial GH receptor defect

Front 74

What causes acromegaly?

Back 74

Excess GH AFTER puberty

- increases bone, organ, hand, foot size

usually causes by tumor

Front 75

What causes Gigantism?

Back 75

excess GH before puberty

increases linear growth

Front 76

What are the two clinical test for GH secretion?

Back 76

Insulin tolerance test

Arginine administration