Endocrine Repro Targets Of The Pituitary

Front 1

When you think about the hypothalamus you should think about the production of _____ and _____

Back 1

releasing and inhibitory hormones

Front 2

Where is the secondary capillary bed in the hypophyseal portal system?

Back 2

anterior pituitary

Front 3

How are hormones released into the capillary bed in the Posterior Pituitary?

Back 3

They are transported from the hypothalamus via EXOPLASMIC transport down the INFUNDIBULAR STALK into the posterior pituitary

Front 4

What makes neuroendocrine cells unique?

Back 4

They are simply neurons but they exocytose NT into the blood

Front 5

T/F
Parafollicular cells are targets of the Anterior Pituitary

Back 5

False
They are not targets of the anterior pituitary

Front 6

The follicular cells must have extensive RER and Golgi to make ______ and the vesicles needed for its release.

Back 6

Thyroglobulin

Front 7

Thyroglobulin contains a lot of?

Back 7

Tyrosine

Front 8

Where does iodination of the tyrosine take place?

Back 8

lumen of the follicle

Front 9

When the mature thyroglobulin is endocytosed into the cell, what breaks apart the mature thyroglobulin?

Back 9

lysosome cleaves the R groups resulting in triiodothyronine and thyroxine

Front 10

How do T3 & T4 get from the follicular cell and into the blood?

Back 10

They diffuse

Front 11

What happens to T4 in the blood?

Back 11

Once in the blood, we see spontaneous de-iodination of T4 resulting in a 14:6 ratio of T4 - T3

Front 12

What type of thyroid hormone is considered the active form?

Back 12

T3

Front 13

What is T4 used for?

Back 13

Feedback Inhibition
◊ Inhibits further release of TRF from the hypothalamus
◊ Inhibits further release of TSH from the anterior pituitary

Front 14

What are the actions of TSH?

Back 14

TSH increases the synthesis of T3 and T4 by:
1. Stimulating iodine uptake from the blood
2. Stimulating thyroglobulin synthesis
3. Stimulating fusion of the lysosomes with endocytotic vesicles

Front 15

What does a lack of iodine in the diet result in?

Back 15

Increase in TRF secretion
Increase in TSH secretion

Front 16

What does low T3 in children lead to?

Back 16

Dwarfism & Cretinism

Front 17

What are the symptoms of Low T3 in adults? (hypothyroidism)

Back 17

Mentally Sluggish
Physically Sluggish
Decreased BMR (tend to have increased weight gain)
Decreased heat production
Heat Tolerance

Front 18

What are the symptoms of High T3 in adults?

Back 18

INCREASE IN BMR**
leading to: increased cardiac output, increased heat production, cold tolerance

Front 19

If you look at the sequence of amino acids in the beta-LPH portin there are the sequences for:

Back 19

Endorphins
Beta-MSH

Front 20

Which two sections of the prohormone must be removed to make the mature form of ACTH?

Back 20

Cryptic peptide
Beta-lipophilic hormone (beta-LPH)

Front 21

Which two sections of the prohormone must be removed to make the mature form of ACTH?

Back 21

Cryptic peptide
Beta-lipophilic hormone (beta-LPH)

Front 22

What is the source for endorphins in the anterior pituitary?

Back 22

When the beta-LPH portion is further broken down after breaking away from the ACTH

Front 23

How is the mature form of GH and Prolactin formed?

Back 23

Snip off the signal protein that caused it to insert into the lumen of the RER

Front 24

How is the mature form of TSH, LH and FSH formed?

Back 24

All involve glycosylation

Front 25

What is the active culprit in producing the effects associated with GH?

Back 25

Somatomedins
(have a structure similar to insulin)

Front 26

What is the cause of Pituitary Dwarfism?

Back 26

Low GH

Front 27

T/F
Pituitary dwarfism can be treated by administering HGH at any stage of life.

Back 27

False
HGH will only be effective if administered before puberty.

*the earlier you start treatment, the more normal the height of the adult
*must start before the long bones fuse

Front 28

What are two major sytems that are affected by HGH?

Back 28

Bone
Muscle

Front 29

How does HGH affect bone?

Back 29

1) stimulates chondroblast activity (elongation in epiphyseal plates)
2) stimulates bone lengthening
3) stimulates bone thickness

Front 30

How does HGH affect muscle?

Back 30

Increases net protein synthesis (non-polypeptide kind of effect because it is a change in gene expression)

Front 31

How does HGH cause an increase in net protein synthesis?

Back 31

1) decreasing protein catabolism (inhibits proteolytic enzymes)-can be activated by secondary messengers
2) increased amino acid uptake-can be activated by secondary messengers
3) increased mRNA (alters gene expression)-the non-polypeptide effect

Front 32

T/F
There is a surge of GH at puberty.

Back 32

False
GH levels stay relatively constant over our life span

Front 33

What does Low GH in adults cause?

Back 33

No big problems

Front 34

What does High GH in adults cause?

Back 34

1)Diabetes-like symptoms
*increased blood glucose
*increased blood free fatty acids
2)Acromegaly

Front 35

What causes GH levels to peak at 2am and bottom out at 2 pm?

Back 35

Diurnal Rhythm

Front 36

Why is the diurnal rhythm helpful for growth?

Back 36

most of the growing of bone and muscle will be done late at night, where there are less demands from the rest of our body.

Front 37

What causes release of GHIH from the hypothalamus?

Back 37

1) Decreased AA and Increased blood glucose
2) Somatomedins (presence of somatomedins causes release of GHIH (somatostatins)

Front 38

What is another term for somatostatins?

Back 38

GHIH

Front 39

What inhibits the release of GHRH from the hypothalamus?

Back 39

HGH

Front 40

Which hormone levels stay fairly constant over the course of days to weeks, but they are increased in the winter and decreased in the summer?

Back 40

T3 levels

Front 41

What provides the negative feedback to the hypothalamus and the thyrotrophs in the anterior pituitary?

Back 41

T4

Front 42

What type of feedback occurs when the primary hormones feed back to inhibit the hypothalamus from releasing more RF?

Back 42

Short loop feedback

Front 43

Which of the following would be expected following ablation of the anterior pituitary?

a)Lose of insulin secretion
b)Loss of glucagon secretion
c)Increased sensitivity to insulin
d)Increased sensitivity to epinephrine
e)Loss of ability to metabolize fat

Back 43

Increased sensitivity to insulin

Front 44

The release of which of the following may be associated with endorphin and enkephalin release?

a)Somatomedin
b)Adrenal corticotrophic hormone
c)Thyroid stimulating hormone
Cortisol
d)Somatostatin

Back 44

Adrenal corticotrophic hormone

Front 45

Which of the following is released in response to elevated blood glucose or low amino acid levels in plasma?

a)Somatomedin
b)Adrenal corticotrophic hormone
c)Thyroid stimulating hormone
d)Cortisol
e)Somatostatin

Back 45

e)Somatostatin

Front 46

Growth Hormone (HGH) in a normal individual

a)Is at highest levels during puberty
b)Is at highest levels at night
c)Promotes closure of epiphyseal plates
d)A and B
e)B and C

Back 46

b)Is at highest levels at night

Front 47

Which of the following stimulates release of somatomedin by the liver?

a)Growth hormone
b)Thyroid hormone
c)Prostaglandins
d)Releasing factors
e)More than one of the above

Back 47

a)Growth Hormone

Front 48

Which of the following is FALSE regarding Growth Hormone?

a)GH increases chondroblast activity
b)GH is stimulated by somatostatin
c)GH enhances protein synthesis
d)GH is stimulated by low plasma glucose levels
e)GH is secreted by the adenohypophysis

Back 48

b) GH is stimulated by somatostatin

THIS IS INCORRECT GH IS STIMULATED BY GHRH

Front 49

Which of the following occurs as plasma aldosterone increases?

a)Urinary output of both Na+ and K+ decreases
b)Urinary output of both Na+ and K+ increases
c)Elevated Na+ and decreased K+ in plasma
d)Decreased Na+ and elevated K+ in plasma
e)Osmotic diuresis

Back 49

c)Elevated Na+ and decreased K+ in plasma