Endocrine: Thyroid/Adrenal Systems Flashcards
1
Q
HPA
A
Hypothalmus Pituitary Axis
2
Q
Types of hormones
3
A
- Steroid: receptor in cytoplasm
- Thyroid: receptor in nucleaus
- Peptide: receptor on cell membrane
3
Q
The 4 F’s
A
- Feeding
- Fighting
- Flight
- F-ing
Stress>HPA>Endocrine system> Altered behavior
4
Q
Median Eminence
What hormones
A
- CRH: corticotropin-releasing hormone (releasing)
- TRH: thyrotropin-releasing hormone (releasing)
- SS: somatostatin (Inhibiting)
- DA: dopamine (Inhibiting)
5
Q
Anterior Pituary makes what?
A
ACTH: Adrenocorticotropic hormone
TSH: Thyroid-stimulating hormone
6
Q
Anterior Pituitary
Structures, pathway, hormones
A
- Neurons: Parvicellular (hypothalamus)
- Median eminence: DA, SS, CRH, TRH
- Ant Pituitary: ACTH, TSH
- Systemic circulation
7
Q
Posterior Pituitary makes what?
A
- OT: Oxytocin
- AVP: Arginine Vasopressin (same as ADH)
8
Q
Posterior Pituitary
Structures, pathway, hormones
A
- Neurons: Magnocellular (hypothalmus)
- Magno Produces: OT, AVP
- Stored: in synaptes of Post Pit
9
Q
Neurohormones
Releasing Hormones
A
- Hypothalmic Secretions
- Target Ant Pit
- TRH, CRH
10
Q
Tropic Hormones
A
- Ant pit secretions
- Target endocrine glands
- TSH, ACTH
11
Q
Trophic?
A
Induce growth of the target endocrine gland
i.e. TSH during a goiter
12
Q
Non-tropic Hormones
A
- Endocrine gland secretions
- Targets cells not glands
- i.e. Cortisol, Epi, NO, T3, T4
13
Q
Primary verse Secondary
A
Primary: Dysfuntion of gland itself
Secondary: Dysfuntion elsewhere in the pathway
14
Q
Stimulation and Supression Tests
A
- Stim: determines gland ability to respond to control mechanism
- Supress: Determine if negative feedback is working
15
Q
what is the thyroid glands secretory functional unit?
A
follicle
16
Q
what does the thyroid follicle include?
A
cuboidal cells (follicular cells)
colloid (lumen)
c-cells (parafollicular cells)
17
Q
cuboidal cells function
A
TG synthesis
(I2) iodine
TG: Thyroglubulin
18
Q
colloid cell function
A
TG storage
T4/T3 storage
19
Q
c cells function
Parafollicular or Parathyroid cells
A
calcitonin
lowers calcium in plasma
20
Q
Hyptothamus-Pituitary-Thyroid Axis Regulation
HPTA / Stimulation and Inhibition
A
- Stimulation
* TRH: Thyrotropin Releasing Hormone
* TSH: Tyroid Stimulating Hormone
* TBG: Thyroid Binding Globulin (T3/T4/ bind to this)
* TSI: Thyroid Stimulating Immunoglobulin (Attaches to TSH receptor) - Inhibits
* T4/T3 (Inhibits Ant Pit and Hypothamlus)
* Decrease TBG lvls (liver disease)
21
Q
TSH
A
Thyroid Stimulating Hormone
Precursor: TRH
22
Q
TSI
A
Thyroid-stimulating immunoglobulin
23
Q
TBG
A
Thyroid binding globulin
Binds to T3/T4
24
Q
what are the 8 steps to synthesis of t3/t4
TNOOCEHD
A
1 TG synthesis and transport to lumen
2 Na/I cotransport into membrane
3 oxidation of I by peroxidase
4 organification of I into MIT and DIT on tyrosine on TG by peroxidase
5 coupling of MIT and DIT into t3/t4 by peroxidase
6 endocytosis of TG
7 hydrolysis and entering circ of t3/t4 by proteases
8 deiodination of MIT and DIT, recycle I and tyrosine
Tyrosine precurser for TG sythesis / TG = Thyroglobulin
25
T3 Coupling
MIT+DIT
| DIT+MIT doesn't do anything
26
T4 coupling
DIT+DIT
27
what are the 4 B’s of normal T3 function?
basal metabolic rate
beta adrenergic effects
brain maturation
bone turnover– bone growth
28
what is hashimotos thyroiditis?
levels of T4, TSH, TRH, Goiter?
chronic lymphocytic thyroiditis
(primary HYPOthyroidism)
T4- decrease
TSH- increase
TRH- increase
Goiter? possible
29
what is pituitary hypothyroidism?
levels of T4, TSH, TRH, Goiter?
secondary hypothyroidism
T4- decrease
TSH- decrease
TRH- increase
Goiter? no
30
what is graves disease? BUG EYES
levels of T4, TSH, TRH, Goiter?
TSI autoimmune primary HYPERthyroidism
T4- increase
TSH- decrease
TRH- decrease
Goiter? possible
31
does the thyroid make more t4 or t3?
t4 90%
t3/rt3 10% (made mostly by other tissues deiodinizing)
32
in the circulation are t3/t4 free or bound?
bound 70% to TBG
bound 29% to albumin
33
does birth control increase or decrease TBG?
increase
34
does liver failure increase or decrease TBG?
decrease
35
to have a goiter what do you need?
activation of TSH receptor, by TSH or TSI
36
does t3 or t4 have greater affinity for the THR?
| THR: Thyroid Hormone Replacement
t3
37
when would you have an increased likelihood of fracture? hypo or hyper thyroidism?
BOTH
38
what is a good starting point to test thyroid function?
TSH
39
Is Iodine deficiency hypo or hyper? TSH?
hypo, TSH increase
40
is HPA depression hypo or hyper? TSH?
hypo, TSH decrease
41
is pituitary adenoma hypo or hyper? TSH?
hyper, TSH increase
42
what are the clinical manifestations of thyroid storm?
| DAFT-NV
diarrhea
arrhythmias
fever
tachycardia
nausea
vomit
43
what pts are most likely to have thyroid storm?
graves disease
thyroid tumor
high dose thyroid meds
subclinical hyperthyroidism
| Subclinical: no clinical symptoms of disease yet, but still has disease
44
what are the treatments for thyroid storm?
PTU (inhibit t4/t3)
potassium iodide (wolff-chaikoff effect, too much iodine)
beta blocker (also slow t4-t3 conversion)
45
once thyroid hormones are transported to tissue cells what happens?
bind to hormone receptors that bind DNA and alter gene transcription
46
what are the two functional glands of the adrenal cortex?
cortex (3 layers that surround the medulla)
medulla (functions as modified sympathetic ganglion)
47
what are the 3 layers of the cortex
| G-F-R
glomerulosa
fasciculata
reticularis
48
Primary Regulator: ANGII/⬆K+
Cortex: Zona Glomerulosa
Hormone: Aldosterone
| Mineralcorticoid (salts)
49
Primary Regulatory: ACTH
Cortex: Zona fasciculata
Hormone: Cortisol
| Glucocortisol (regulate sugar)
50
Primary Regulatory: ACTH
Cortex: Zona reticularis
Hormone: Androgens
| DHEA and androstenedione (sex hormones)
51
Primary Regulator: ACTH/Cortisol
Pre-ganglionic SNS (Ach)
| Crommafins
Medulla
Hormone: Epi
| from stress
52
Synthesis of NE and EPI in chromaffin cells
| Adrenal medulla / 10 steps
1. Tyrosine
2. **TH** (Tyrosine Hydroxylase)
3. L-DOPA
3. AADC
4. DA: Dopamine
5. **DBH**: Dopamine B-hydroxylase
6. NE (20%)
7. **PNMT** (80%)
8. EPI
9. Pre-gang sympathtetic Ach releases EPI/NE
| T-T-L-A-D-D-N-P-E-P (bolded answers enchance rxn)
53
17alpha-OH deficient, ACTH? BP? aldosterone? androgen?
ACTH- increase
BP- increase
Aldosterone- increase
androgen- decrease
54
21beta-OH deficient, ACTH? BP? aldosterone? androgen?
ACTH- increase
BP- decrease
Aldosterone- decrease
androgen- increase
55
11beta-OH deficient, ACTH? BP? aldosterone? androgen?
ACTH- increase
BP- increase
Aldosterone- increase
androgen- increase
56
what in cortisol production causes skin pigment changes?
MSH
| Melanocyte-stimulating hormone
57
how much of cortisol is protein bound?
CBG 92% (less available)
albumin 8%(bioavailable)
58
when is cortisol highest in the day
morning
59
what are the critical effects of cortisol? BIG FIB
BIG
increase in BP
increase in Insulin resistance
increase in Glucose
FIB
decrease in Fibroblasts (stretch marks)
decrease in Inflammation and immunity
decrease in Bone formation
BONUS:
impaired learning/mem
60
what things make cortisol anti inflammitory
| CHILL-PW
A
stabilizes lysosomal membranes
decrease capillary permi
decrease WBC migration
decrease lymphocyte prolif
decrease in interleukin, histamine, prostaglandin
61
if you are fasting and have acute stress what are the results?
liberation of all forms of energy: increase EPI/NE
liver- glycogen to glucose
sm- protein breakdown, glycogen to glucose
adipose- fat breakdown
62
if you are overfed and chronically stressed
muscle wasting/ IR/ weight gain: decrease EPI/NE
CNS- increase appetite
liver- increase glycogen synthesis
sm- protein breakdown, decrease glucose uptake
adipose- decrease fat breakdown, TG synthesis, decrease glucose uptake
63
what is cushings syndrome usually caused by
ACTH secreting tumor
adrenocortical hyperplasia
excess cortisol
64
what does cushings disease look like?
| HUMID-BSB
unusual obesity
striae
bone loss
muscle wasting
buffalo hump
diabetes
HTN
Infection Risk
| HUMID-BSB
65
what can increase aldosterone?
**mostly RAAS = ANGII**
increases serum K+
increases ACTH
66
what does aldosterone do to Na and K?
increases Na reabsorption
increases K secretion
67
what is the half life of aldosterone?
20min
68
how do corticoid receptors fx?
hormone binds to receptor in cytosol and sends regulatory proteins that allow the hormone-receptor complex to bind to DNA and alter transcription
69
does aldosterone bind MR or GR?
MR
70
does cortisol bind MR or GR?
MR and GR
71
what is addisons disease caused by?
autoimmune attack on adrenal cortex
decreased cortisol and aldosterone
72
what are the symptoms of addisons disease?
| HIHH-HID
hypoglycemia
increased lymphocytes
hypoNa
Hypotension
hyperK
increase ACTH (increase MSH, why JFK had tan)
decrease vascular response to adrenergics
73
short term stress response
adrenal medulla releases EPI
increase BP, HR, blood sugar, metabolic rate
changes in blood flow to vital organs
dilate bronichioles
74
long term stress response
Adrenal cortex release Aldosterone and Cortisol
Increase in Na and water retention
Increase in blood volme = HTN
Protiens and fat brokedown or converted to glucose
Increased blood sugar
Supression of immune system
