Test 3: 11 Hypothal And Pituitary

Front 1

1. What are the parts of the anterior pituitary?

Back 1

a. Pars distalis
b. Pars tuberalis
c. Pars intermedia

Front 2

2. What are the parts of the posterior pituitary?

Back 2

a. Pars nervosa
b. Median eminence
c. Infundibulum

Front 3

5. What connects the hypothalamus to the posterior pituitary?

Back 3

a. Neurons

Front 4

What signals posterior pituitary (what type of neruon?)

Back 4

Magnocellular neurons (SON/PVH)

Front 5

What signals anterior pituitary (what type of neruon?)

Back 5

parvicellular neurons (arcuate/PVH)

Front 6

What regulate secretion, production, and sensitivity of hormones?

Back 6

feedback loops

Front 7

Where can feedback be from?

Back 7

target organ product, pituitary product, or physiological response

Front 8

What does ADH do?

Back 8

changes in osmolality and volume, drugs impact secretion
stimulates aquaporin channels in collecting ducts of kidney
other functions, such as vasoconstrictor
DI and SIAD are associated with dysregulation of ADH secretion

Front 9

what regulates oxytocin

Back 9

neuroendocrine and endocrine regulation of secretion

Front 10

What does oxytocin do

Back 10

Lactation, uterine contractions primary fct.

Front 11

5. What connects the hypothalamus to the posterior pituitary?

Back 11

Neurons

Front 12

6. What connects the hypothalamus with the anterior pituitary?

Back 12

a. Blood (superior hypophyseal artery)

Front 13

7. Is there a heavy connection between lobes of the pituitary?

Back 13

a. No, they don’t even share vascular supply

Front 14

8. Nerves going from the hypothalamus to the Anterior pituitary are known as what?

Back 14

a. Parvicellular hypophyseotropic neuron

Front 15

9. Nerves from hypothalamus to posterior pituitary?

Back 15

Magnicellular

Front 16

10. What does the anterior pituitary release? (6)

Back 16

a. TSH: thyrotrophs
b. FSH: gonadotrophs
c. LH: gonadotrophs
d. Prolactin: lactotrophs (mammotrophs)
e. Growth hormone: somatotrophs
f. ACTH: corticotrophs

Front 17

what does the posterior pituitary secrete? (2)

Back 17

oxytocin, ADH/vasopressin

Front 18

13. What are neurophysins?

Back 18

a. They are attached to hormones released from the posterior pituitary, when attached they are in their inactive form

Front 19

14. What neurophysin is attached to ADH?

Back 19

neurophysin I

Front 20

14. What neurophysin is attached to oxytocin?

Back 20

neurophysin II

Front 21

16. What is the role of ADH?

Back 21

increase water uptake by kidney

Front 22

How does the ADH lead to increased water uptake in the kidney?

Back 22

affects the collecting duct at the V2 receptor
-->increase aquaporin-2 channels for H20 to flow through in the kidney

Front 23

besides water uptake, what else does ADH do? (3 things)

Back 23

Arterial and venous constriction
b. V1a receptor mediated: Gq - PLC
c. 3) Stimulate ACTH release
d. V1b receptors: Gq – PLC
e. 4) Stimulate spermaticord contraction
f. mediated via V1 receptor

Front 24

19. What is a primary trigger for the release of ADH?

Back 24

a. When plasma osmolality moves beyond a certain point, ADH will be released in a linear fashion

Front 25

20. What are things that can affect ADH release? 4

Back 25

a. Rapid change in osmolality
b. Drinking
i. Afferents in oropharynx will send signals back to affect ADH release
c. Pregnancy
i. Lower threshold for triggering of ADH release
d. Aging

Front 26

21. What are 2 clinical problems associated with ADH?

Back 26

a. Diabetes insipdus
b. Syndrome of inappropriate ADH secretion (SIADH)

Front 27

22. What are the 3 forms of diabetes insipisdus?

Back 27

a. Deficiency in ADH: Hypothalamic DI
i. Impinged nerves, damaged nerves, etc. would have to be extensive
b. Renal resistance to ADH: Nephrogenic DI
i. Don’t make the aquaporins even when stimulated to do so
ii. Can be genetic or involved in a metabolic disorder
c. Inappropriate, excessive water drinking: Dipsogenic DI
i. Psychosocial disorder (behavioral)

Front 28

23. In pregnancy, what may cause a lowered amount of ADH?

Back 28

a. Placenta has vasopressinase
i. Breaks down ADH

Front 29

24. SIADH

Back 29

a. Most common cause of euvolemic hyposmolaity
b. Primary cause of hypoosmolality encountered in clinical practice

Front 30

What are the types of SIADH?

Back 30

a. A-D: characterized by plasma ADH in releationship to osmolality

Front 31

Causes of SIADH

Back 31

a. Neoplastic disease: pulmonary/mediastinal and non-chest
b. CNS disorders: tumors; inflammatory diseases; degenerative/demyelinative diseases
c. Pulmonary disease: infection; mechanical/ventilatory
d. Drugs: tricyclics; nicotine; angiotensin converting enz. (-); SSRI; carbamazepine
e. Other: idiopathic; AIDS; senile atrophy

Front 32

27. What stimulates the release of oxytocin? (3)

Back 32

a. Suckling: spinal reflex
b. Estradiol (progesterone withdrawal)
c. Fergusson reflex
i. Fetus pressing down on cervix, responds to this oxytocin helps contract uterus to expel fetus

Front 33

28. Inhibition of oxytocin secretion?

Back 33

a. Opiods
b. Catecholamines

Front 34

29. What mediates the activity of oxytocin?

Back 34

G coupled receptor

Front 35

30. Activities of oxytocin? 5

Back 35

a. Milk ejection
b. Uterine contractions
c. Behavior
d. Ovulation
e. Ejaculation

Front 36

31. How is the anterior pituitary formed? (embryo)

Back 36

a. From Rathke’s pouch from ectoderm

Front 37

32. Why would a developmental problem in the anterior pituitary likely effect more than one anterior pituitary cell type?

Back 37

b. some cells of the anterior pituitary gland share a common lineage, so error at a point during the developmental process may impact one or more cell types, depending on when in the developmental process the problem occurs.

Front 38

33. When is prolactin most active?

Back 38

a. In its monomeric form

Front 39

34. Where does prolactin primarily effect?

Back 39

breast and pituitary

Front 40

35. Functions of prolactin?

Back 40

a. Lactation (milk production)
b. Reproduction
c. Lymphocyte growth factor

Front 41

36. Hypersecretion of prolactin causes?

Back 41

a. Men: inappropriate breast development, infertility (effects spermatogenesis)
b. Women: infertility (stop menstruating), inappropriate milk production

Front 42

37. How do you regulate prolactin secretion?

Back 42

a. Inhibited by dopamine release from hypothalamus (tonic negative)
i. So need to inhibit the dopamine release in order to stimulate prolactin
b. Activated by estrogens

Front 43

38. What are the 2 splice variants of GH?

Back 43

a. 22 kD is primary: growth promoting activity
b. 20 kD, minor, diabetogenic effects (slower metabolic clearance)

Front 44

39. In circulation, how are GH normally found?

Back 44

a. Bound to a protein to extend the half-life
b. Have high and low affinity proteins

Front 45

40. How is GH released?

Back 45

in pulses, this gets nullified a bit by protein binding

Front 46

41. Where are the majority of GH receptors?

Back 46

a. Liver, muscle, adipose

Front 47

42. Hyposecretion of GH causes?

Back 47

a. Dwarfism/short stature

Front 48

43. Hypersecretion of GH causes?

Back 48

adult: acromegaly
child: giantism

Front 49

44. Please describe how GH affects growth (pathway)

Back 49

a. GH bind to liver, increase production of IGF I and IGF II, execute the effect of GH b/c more tissues are sensitive to IGF than GH

Front 50

45. What is another name for IGF I and II?

Back 50

a. Somatomedians

Front 51

List the feedback loop for GH

Back 51

Hypothalmus
--GHRH
---somatotroph
------GH (sends (-) to hypothalamus and (+) to somatostatin inhibitory pathway)
----------IGF-1 (sends (-) to somatotroph and hypothalamus, and (+) to somatostatin inhibitory)

Front 52

47. What stimulates GH?

Back 52

a. Ghrelin (stomach)
b. GHRH
c. Fasting

Front 53

what inhibits GH?

Back 53

a. Somatostatin
b. GH
c. Somatomedins

Front 54

49. What do somatostatins do?

Back 54

a. Inhibit GH, PRL, and TSH from pituitary
b. Inhibits insulin and glucagon from pancreas
c. Inhibits secretions from enteroendocrine cells

Front 55

50. What gene is responsible for the creation of ACTH (adrenocorticotropic hormone)

Back 55

POMC

Front 56

51. Where is there regulation for ACTH secretion?

Back 56

a. Central and peripheral

Front 57

52. Is ACTH released in circadian fashion?

Back 57

Yes

Front 58

53. What effect does ACTH have on the adrenal gland?

Back 58

maintains it

Front 59

hyposecretion of ACTH symptoms?

Back 59

a. Fatigue
b. Weight problems
c. Slowing down of individual

Front 60

Hypersecretion of ACTH is known as?

Back 60

Cushings disease

Front 61

feedback loop for ACTH?

Back 61

hypothalamus
---CRH
-----Corticotroph
--------ACTH
----------Adrenal cortex
-----------Glucocorticoids ((-)to hypothalamus and to corticotrophs)

Front 62

59. What is the structure of TSH?

Back 62

a. TSH is a peptide hormone composed of an alpha and Beta chain
i. The alpha chain is shared with LH, FSH, hCG
ii. Beta chain gives uniqueness to peptide

Front 63

What stimulates ACTH?

Back 63

CRH, sleep/wake transition, stress

Front 64

Feedback loop for TSH

Back 64

hypothalmus
-TRH to thyrotroph
--TSH to thyroid folliclces
----Thyroid hormones (turn off thyrotroph and hypothal, also turn on somatostatin)

Front 65

what stimulates TSH?

Back 65

a. TRH
b. Exposure to cold
c. Leptin

Front 66

what inhibits TSH?

Back 66

a. Thyroid hormone
b. Fasting, somatostatin, Dopamine, cortisol, GH

Front 67

what effect does differential release of GnRH have?

Back 67

selective effects on FSH and LH

Front 68

64. Hyposecretion of GnRH?

Back 68

infertility, problems with puberty

Front 69

64. Hypersecretion of GnRH causes?

Back 69

a. Percouscious puberty

Front 70

Feedback loop for GnRH?

Back 70

Hypothalmus
--GnRH
---Pituitary
----LH/FSH
-----testosterone/estrogen/progesterone (all act to turn off LH/FSH release from pituitary and hypothalamus)