endo-all Flashcards
0
Q
Mechanism of cortisol
A
Glucocorticoid receptor
1
Q
Degradation enzyme of catecholamine that predominates in neuronal mitochondria
A
MAO
2
Q
Biochemical diagnosis of pheochromocytoma
A
Catecholamine excess
Urinary fractionated metaphrenine or plasma free metaphrenine will predict size and location of tumor
3
Q
In the absence of cortisol, GR stays I. Cytoplasm bound to molecular chaperone such as
A
Heat-shock protein 90
Cyclophilin
4
Q
Regulation of aldosterone secretion
A
RAAS
5
Q
Stimulators of aldosterone
A
Angiotensin II = increase STAR and cyp11b2 (potent vasoconstrictor)
Extracellular K
Acute elevated ACTH
6
Q
Reaction 2 in modification of FC to cortisol
A
Pregnenolone to progesterone by 3B-HSD or
Pregnenolone to 17-OH-pregnenolone by CYP17 (hydroxylase func)
7
Q
Results from continuous administration of aldosterone in 2-3days
A
Aldosterone escape
8
Q
Synthesis of epinephrine
A
- Transport of tyrosine into chromaffin cells cytoplasm
- Hydroxylation of tyrosine into DOPA
- DOPA to dopamine
- Transport of dopamine into chromaffin granules (secretory vesicles)
- Dopa to norepi within chromaffin granules as chromogranins
- Norepi diffuses out of granule thru facilitated diffusion
- Methylation of norepi to epi
- Transport of epi back into granules
9
Q
Imaging of choice in pheochromocytoma if there is metastasis, previous operation or for familial, multiple pheochromocytoma
A
MIBG - 1st choice, gets into cell but not metabolized in cell
PET scan - metabolized further in cell
10
Q
Complex of N/NE with ATP, Ca and proteins inside the granules.
A
Chromogranins
11
Q
Renin is produced by
A
Juxta glomerular cell
12
Q
Tissue distribution and potency agonist:
B2 receptor
A
Liver
Epi>norepi
13
Q
Zona glomerulosa is primarily regulated by
A
RAS
Extracellular K
ANP
14
Q
Largest and most Steroidogenic zone in adrenal Cortex
A
Zona fasciculata
15
Q
ACTH binds to what receptor in zona fasciculata
A
Melanocortin-2 receptor
16
Q
Metabolism of catecholamine
A
Draw!
17
Q
Steroidogenic pathways in zona glomerulosa
A
Pregnenolone to progesterone (3B-HSD) to 11-doc (cyp21b) to corticosterone to 18-OH-corticosterone to aldosterone (cyp11B2)
18
Q
Rate-limiting enzyme in Steroidogenesis
A
Cyp11A1
19
Q
Inhibitors of aldosterone
A
ANP (directly inhibits aldosterone production / indirectly inhibits renin release)
Chronic elevated ACTH
20
Q
Mechanism of action of catecholamine
A
Exerted thru adrenergic receptor
21
Q
Congenital adrenal hyperplasia usually due to
A
Cyp21
22
Q
Zona glomerulosa is secondarily regulated by
A
ACTH
23
Q
Important in biogenesis on secretory vesicles and organization of components within vesicles
A
Chromogranins
24
DHEAS/DHEA: has high affinity binding to albumin
DHEAS
25
Tissue distribution and potency agonist:
| B3 receptor
Adipose tissue
| Norepi>epi
26
How is blood collection done in diagnosis of pheochromocytoma?
Supine for 20min
Overnight fast
No nicotine, alcohol within 12hrs
Avoid acetaminophen, TCA and phrnoxybenzamine
27
Conn's disease results in
```
K depletion
Na retention
Ms weakness
Hypertension
Polyuria
```
28
Reduces osmotic burden of storing individual molecule of epi with chromaffin granules
Chromogranins
29
Metabolic action of chronically elevated cortisol in healthy individuals
Increase cortisol
Increase insulin/glucagon ratio
Decrease epi and norepi
30
Reaction 4 in modification of FC to corticosterone
17-Oh-progesterone to 11-deoxycorticosterone by cyp21B
31
What happens when there is Hypervolemia
Hypervolemia means high Na level, this will inhibit the renin release which will lower aldosterone secretion resulting back to normovolemia
32
Reaction5 in modification of FC to corticosterone
11-deoxycorticosterone to corticosterone by cyp11B1
33
Degradation enzyme of catecholamine that is predominant
COMT
34
Primary hyperaldosteronism
| Usually due to aldosterone- secreting tumor
Conn's syndrome
35
Reaction 3 in modification of FC to cortisol
Progesterone to 17-OH-progesterone by cyp17(hydroxylase) or
| 17-OH-pregnenolone (^5) to 17-OH-progesterone(^4) by 3B-HSD
36
Unique features of zona glomerulosa
1. Absence of cyp17
| 2. Presence of cyp11b2 (aldosterone synthase)
37
In pheochromocytoma, lability of Bp is caused by
Episodic catecholamine release
Impaired Symphathetic reflex
Unrecognized chronic volume expansion
38
Chronic effect of ACTH
1. Increase transportation of genes encoding Steroidogenic enzyme and coenzyme
2. Increase LDL and HDL receptor
39
Secretion of noepi and epi is regulated by
Descending sympa signals in response to stress.
Hypothalamus and brain stem send a chemical signal as ACTH to bind to nicotinic receptor in chromaffin cells which increases acty of tyrosine hydroxylase and B-hydroxylase in which stimulates exocytosis of granules
40
Imaging of choice in pheochromocytoma preferred for extra adrenal, pregnant, children and those allergic to contrast.
MRI
41
Tissue distribution and potency agonist:
| a2 receptor
Adrenergic pre synaptic terminals
| Norepi=epi
42
Zona glomerulosa has low affinity binding to transport proteins
True
43
Presence of this enzyme converts cortisol to cortisone (inactivates)
11B-HSD2
44
Steroidogenic pathway in zona reticularis
Pregnenolone to 17-OH-pregnenolone (CYP17) to DHEA (CYP17 -lyase) to DHEAS (SULT2A1) or
DHEA to aldrostenedione (3B-HSD)
45
DHEAS/DHEA: low affinity binding to protein
DHEA
46
Degradation enzyme of catecholamine that predominates as methylation of Norepi/epi in non-neuronal tissue
COMT
47
Reaction 4 in modification of FC to cortisol
17-OH-progesterone to 11-deoxycortisol by CYP21B
48
In pheochromocytoma, hypertension is mainly due to
Increased peripheral resistance
49
Tissue distribution and potency agonist:
| B1 receptor
Heart
| Epi=norepi
50
Increase ACTH due to any enzyme block decreasing cortisol synthesis.
May cause masculinization of female fetus or incomplete masculinization of male fetus
Congenital adrenal hyperplasia
51
Cortisone is converted back to cortisol in liver, skin and other tissues by
11B-HSD1
52
1st reaction in Steroidogenic pathway
Free cholesterol transported in inner mitochondria thru STAR protein, and converted into pregnenolone by CYP11A1
53
Cortisol serves as negative feedback thru
1. Inhibition of pomc gen expression at corticotropes.
| 2. Inhibition of pro-CRH gene expression at hypothalamus
54
Clinical features of pheochromocytoma
```
Sweating
Hypertension
Headaches
Anxiety/fear
Forceful heartbeat with or without tachycardia
Flushing
Fatigue
Tremors
```
55
Renin is release in response to
Low bp
| Low Na delivery to macula densa
56
Zona reticularis begins to appear after birth at..
5 year old
57
Physiologic action of aldosterone in kidney
Increase NA reabsorption
| Increase K and H secretion
58
Zona glomerulosa almost all inactivated by
Liver (conjugated to glucoronide)
59
Acute effect of ACTH
1. Rapid transport of cholesterol to OMM
2. Increase STAR protein gene expression
3. Resulting to increase pregnenolone activity
60
2 primary degradation enzymes of catecholamine
1. Monoamine oxidase MAO
| 2. Catechol-O-methyltransferae COMT
61
Tissue distribution and potency agonist:
| a1 receptor
Adrenergic post synaptic nerve terminals
| Norepi=epi
62
Pheochromocytoma is majorly bilateral/ unilateral?
90% unilateral and sporadic
63
Chromaffin cell tumor that produce, store, metabolize and secrete catecholamine (in excess).
Causing irregular secretion of epi and norepi leading to attacks of raised bp, palpitations, and headache.
Pheochromocytoma
64
Imaging of choice for pheochromocytoma
CT scan
65
Regulation of cortisol production
Thru Hypothalmus-ant. Pituitary-adrenal axis
66
Reaction 5 in modification of FC to cortisol
11- deoxycortisol to cortisol by cyp11B1
67
Metabolic action of cortisol in response to stress
Increase cortisol
Decrease insulin/glucagon ratio
Increase epi and norepi from sympathoadrenal output
68
Adrenal androgens (DHEAS) appear in circulation at
6 year old
69
Mechanism of action of zona glomerulosa
Intracellular mineralocorticoid receptor
70
Regulation of menstrual cycle when there is high freq GnRH pulses
LH production
71
Normal internal genitalia but incomplete masculinized external genitalia - ambiguous genitalia. Mistaken for females at birth
5a reductase deficiency
72
Primary defect of PCOS
Inappropriate signals between HP axis and ovary
73
Loophole in male repro axis..
Intratesticular T level should be >100x more than circulating T level to maintain normal spermatogenesis
74
Short stature, webbed neck, low se tears, shield-shaped chest, short 4th metacarpals and sexual infantilism
Turner syndrome
75
Androgen negative feedback effect on FSH and LH ..more on
LH
76
Primary isolated gonadotropin deficiency due to inability of GnRH neurons to migrate to medico basal hypothalamus from nasal placode. With undescended testes (CRYPTORCHIDISM) and microphallus. Asso with anosmia
Kallmann syndrome
77
Most common cause of congenital hypogonadism
Gonadal dysgenesis or Turner syndrome
78
Genetic disorder in men with extra X chromosome.
| Phenotypically male but with small testis and decreased germ cell
Klinefelter syndrome
79
Due to decreased DHT formation
5a reductase deficiency
80
Functional connections are established between GnRH neurons and portal system by
16wks AOG
81
Testosterone and DHT synthesis
Aldrostenedione to testosterone (17B-HSD) to DHT (5a-reductase)
82
Seminiferous tubular dysgenesis
Klinefelter syndrome
83
isoform of 5a-reductase:
Found in male urogenital tract, skin, hair follicles and Liver
For masculinization of ext genitalia in utero
Type 2
84
isoform of 5a-reductase:
| Expression starts at puberty
Type 1
85
Regulation of development of external genitalia in female
Absence of DHT
86
GnRH neurons have been demonstrated in the feral hypothalamus by
9wks gestation
87
In adult male, LH is secreted in pluses approx every
2 hrs
88
Female repro cell which expresses LH receptor
Theca cells
89
60% of androgen is bound to
sex hormone binding globulin SHBG
90
Regulation of menstrual cycle when there is low freq GnRH pulses
FSH production
91
Chronically a ovulation women with high androgen, estrogen, and LH levels
PCOS
92
Regulation of development of internal genitalia in male
Wolffian duct-Testosterone and presence of MIS
93
Results from hereditary defect of X chromosome gene controlling androgen receptor expression
Phenotypically female but male internal genitalia
Male pseudo hermaphroditism
Androgen insensitivity syndrome
94
Characterized by a striking increase in amplitude of LH pulses with a lesser change in frequency
Puberty
95
Female repro cell which produces androgen (primarily androstenedione)
Theca cells
96
Granulosa cells expresses what enzymes
17b-HSD, cyp19
97
Theca cells expresses what enzyme
Cyp11a1, 3b-HSD, cyp17
98
Regulation of Sertoli cell function
Stimulated by both testosterone and FSH
Expresses FSH receptor
FSH stimulates synthesis of inhibin
99
Characterized by low amplitude GnRH secretionas mirrored by LH secretion
Childhood period
100
Regulation of development of internal genitalia in female
Mullerian duct - absence of MIS
101
Leydig cell produces estrogen peripherally. Effects...
Bone maturation
Insulin sensitivity
Improves lipoprotein profile (increase HDL)
102
Exogenous T level increases circulating T only
True
103
Regulation of development of external genitalia in male
Presence of DHT
104
isoform of 5a-reductase:
| Found in skin - contributes to sebaceous gland activity and acne formation
Type 1
105
Female repro cell which expresses FSH receptor
Granulosa cells
106
Diagnosis of PCOS requires 2 out of 3 of
1. Amenorrhea
2. Evidence of excess androgen secretion (acne, hirsutism)
3. Polycystic ovaries by ultrasound
107
Hormonal Rhythm with a 24hr cycle
Circadian rhythm
108
Type of secretory transport that involved release of neurohormone from axonal endings and regulation of nearby cell by diffusion
Neurocrine
109
Sites of impairment in dwarfism
Reduced GH secretion
Decreased IGF production
Deficient IGF action
110
Zone of adrenal cortex composed of straight cords of large cells with foamy cytoplasm which is filled with droplets representing stored cholesterol ester
Zona fasciculata
111
Pineal gland secretes what hormone?
Melatonin
112
ADH are synthesized as preprohormones:
Preprovasophysin - co secreted peptide - neurophysin I
| Preprooxyphyxin - cosecreted peptide - neurophysin II
113
In embryology of hypothalamus. Division where the cells makes up almost all the adenohypophysis
Pars digitalis
114
Type of DI wherein there is normal ADH production but abnormal renal ADH response
Nephrogenic DI
115
Nursing stimulates PRL production and hence asso with decreased fertility during phase of nursing
Excess PRL in male results in testosterone deficiency and impotence
116
Eicosanoids
Prostaglandins
Leukotrienes
Thromboxanes
Prostacyclin
117
GH induce placenta to produce ___ .
| By increasing maternal blood glucose and FA level! this increases the availability the nutrients for fetus.
Somatomammotropin
118
Steroid hormones are administered orally
Yes
119
Iodothyronines circulate the blood bound or unbound
Bound to serum binding proteins
120
Steroid hormone categories
1. Progestins - progesterone
2. Mineralocorticoids - aldosterone, 11-deoxycorticosterone
3. Glucocorticoids - cortisol, corticosterone
4. Androgens - testosterone, dihydrotestosterone
5. Estrogen - estradiol-17B, estriol, secosteroid (vitD active metabolite)
121
Blood supply of testis
Testicular artery (from branches of internal spermatic artery)
122
Funnel shaped swelling superior to the infundibulum
Median eminence
123
Hypothalamic nuclei that func as:
| Focal point of info processing
Dorsomedial nucleus
124
Iodothyronine have intracellular receptors
True
125
Hormonal rhythm with a 1/2 to 2 hr cycle
Pulsatile rhythm
126
Proteins or peptide hormones are administered orally
False
127
2 types of bv carrying blood from adrenal cortex to medulla
Medullary arterioles - provide high O2 and nutrient to chromaffin cells
Cortical sinusoids - into which cortical cells secrete steroid hormone
128
Pineal gland also contains other bio active peptides such as
TRH, GnRH, somatostatin, norepi
129
Component of pituitary gland composed mainly of neural cells and the site of release of neuro hormones.
Posterior pituitary or neuro hypophysis
130
Hyperprolactinemia is asso with amenorrhea and infertility.
Can have gynecomastia and galactorrhea.
May have visual disturbance (bite,portal hemianopsia) and decreased libido
True
131
Venous drainage of adrenal gland
R adrenal v - post aspect of IVC
| L adrenal v - L renal v - IVC
132
Parafollicular cells are usually located where in the lobe?
Upper 2/3 of lobes
133
Age of gestation where rathke's pouch arise
5th wk
134
Hypothalamic nuclei that func as:
Regulation of appetite
GNHR, GnRH, dopamine, somatostatin
Arcuate nucleus
135
In DI, they are unable to concentrate the urine normally, resulting in large volume of urine excreted.
True
136
```
Tropic hormone secreted of:
Corticotrope
Thyrotrope
Gonadotrope
Somatorope
Lactotrope
```
Tropic hormone secreted of:
Corticotrope - adenocorticotropic hormone ACTH
Thyrotrope - thyroid stimulating hormone TSH
Gonadotrope - follicle-stimulating hormone FSH and leutinizing hormone LH
Somatorope - GH
Lactotrope - prolactin
137
Secretion of ACTH is pulsatile
True
138
Venous drainage of thyroid gland
Superior thyroid vein
Middle thyroid vein
Inferior thyroid vein
139
GH excess that occurs after puberty or after closure of epiphyses
Acromegaly
140
Hypothalamic nuclei that func as:
Magnocellular PVN: ADH, oxytocin
Parvicellular PVN: TRH, CRH, VIP
Paraventricular nucleus
141
PRL inhibitors
Dopamine agonist (bromocriptine)
Somatostatin
TSH
GH
142
4 cell types of adenohypophysis
Basophils:
Gonadotropes FSH, LH
Corticotropes ACTH
Thyrotropes TSH
Acidophils:
Lactotropes Prolactin
Somatotropes GH
143
GH excess that occurs before puberty
Gigantism
144
GH is a ___ aa peptide
191 aa
145
Metabolic actions of GH on lipids
Lipolytic
| Keratogenic after long term admin'n
146
Hypothalamus is a dorsal/ventral derivative of neural tube.
Ventral
147
Hormone that increases during pregnancy, promoting development of breast
PRL
148
Proteins /peptide hormones are stored in
Membrane-bound granules
149
Half life of oxytocin
3-5 min
150
Hypothalamus develops from lateral wall of diencephalon thru ventral extension to a groove in about __wk of gestation
5 1/2 wks
151
Type of secretory transport where in some peptides/amines secreted directly into the gut (ie somatostatin, GASTRIN, secretin, subs P)
Solinocrine
152
Weight of adrenal gland
8-10 gm
153
Nucleus of Mammillary region of hypothalamus
Posterior nucleus
154
Smaller,dendritic and well granulated cells of pancreas
Delta cell
155
Hormone that Stimulates breast myoepithelial cell to contracts thereby ejecting the milk that has been stored in breast
Oxytocin
156
Catecholamine are polar/non polar
Polar
157
SIADH is common in what disease
PTB, pulmonary Ca
158
In suppression test, the administration Of suppressor is to test the..
Autonomy of hormonal secretion
159
Venous drainage of hypothalamus
Majority of hypothalamus - ant.cerebral and basal vein
Dorsal portion - internal cerebral vein
Both reaching the great vein of Galen (rosenthal)
160
Sertoli cells forms these junctions with all stages of sperm cell, allowing sperm cells to be guided towards the lumen
Adherens-type junction
| Gap junction
161
Endocrine hormones that do not have their own personal glands
Gastrin, secretin, cholecystokinin - by GI wall
Erythropoietin - kidney
Prostaglandin
162
LH in female stimulates ___ produces what hormone
Follicle Ovulation and maturation into corpus luteum
| Produces estrogen and progesterone
163
Which is larger? Right or left lobe of thyroid gland?
Right lobe. 2x larger
164
Zona reticularis begins to appear after birth at
5 y/o
165
Aldosterone in zona glomerulosa is regulated primarily by
Renin-angiotensin system
| Extracellular K and ANP
166
Aldosterone in zona glomerulosa is regulated secondarily by
ACTH
167
In embryology of hypothalamus. Division where the cells facing away from infundibulum.
Pars digitalis
168
Regulation of development of external genitalia in the presence of DHT
Male geniality is formed (penis, scrotum,prostate)
169
In stimulation test, the administration of specific stimulators to test the ..
Hormonal secretory reserve to the gland p
170
Hormones that secretes in an Ultradian rhythm
FSH
LH
Testosterone
171
FSH in female stimulates ___ produces what hormone.
Follicular growth
| Produces estradiol
172
Two principal hormones of follicular cells
Thyroxine T4
| Triiodothyronine T3
173
GH is stimulated during deep, slow-wave sleep (stages 3 and 4).
Sleep wake patterns
Pulsatile secretion
174
Metabolic actions of GH on IGF
Stimulates IGF production
Stimulates growth
Mitogenic
175
Exocrine function of Sertoli cells
Production of fluid to move immobile sperm put of testis towards epididymis
Production of androgen-binding protein (ABP)
Determination of release of spermatozoa from seminiferous tubules
176
Hormone that stimulates contraction of uterine myometrium
Oxytocin
177
TRH is inhibited by
Stress
178
Required for homeostasis of all cells
Influence cell differentiation growth and metab
Considered as a major metabolic hormone because they target virtually every tissue
T3 and T4
179
Seat of the soul
Pineal gland
180
In embryology of hypothalamus. Division which is the lower expansion of infundibular process. And becomes the posterior pituitary.
Pars nervosa
181
Steroid hormones are derived form
Cyclopentanoperhydrophenanthrine (CPPP) ring
182
The cells in adrenal cortex develops into
Steroidogenic cells (GC, MC, androgens)
183
Medullary arterioles and cortical sinusoids fuse into ___ of vessels that drains into suprarenal vein and into IVC
Medullary plexus
184
Importance of endocrine system
Allows normal growth and development of organism
Maintains internal homeostasis
Regulated the onset of reproductive maturity at puberty and the func of the repro system in adults
185
A cells of pancreas produces what hormone
Glucagon
186
Which extends higher and lower in the neck? Right or left lobe of thyroid gland?
Right lobe
187
Site of release of ADH and oxytocin
Neurohypophysis
188
The mass of islets of langerhans in pancreas differs with age. Is it greater in adult?
Greater in fetus and young
189
Cell pop in thyroid parenchyma
Follicular cells
Parafollicular C cells
Epithelial cells
190
Gf resistant due to genetic defect in the receptor (total absence of IGF response)
Laron dwarfs
191
PRL is stimulated by
Nursing or breast stimulation which promotes onset and maintenance of milk production
192
Iodothyronine is derived from what aa
Tyrosine
193
Neuroendocrine reflex stimulating the regulation of oxytocin
During labor, Stretching of vagina and cervix
194
LH in male stimulates ___ produced by ___ cell
Testosterone stimulation by leydig cells
195
Catecholamine are have short/long half life
Short half life (1-2min)
196
Age of gestation where pars nervosa arise.
8th wk.
197
The outer part of adrenal glands
Adrenal cortex (90%)
198
Iodothyronines can be administered orally
True
199
Organs which secrete subs in response to stimuli
Glands
200
Type of DI wherein there is destruction of pituitary or hypothalamus resulting to:
High urine volume and low urine osmolality
High plasma osmolality and low ADH levels
Neurogenic DI
201
Cell in peri tubular compartment that produces testosterone
Interstitial cells of leydig
202
Bld supply of hypothalamus
```
Terminal branches of circle of Willis:
Internal carotid artery
Ant.cerebral artery
Post. Cerebral artery
Ant. Comm. artery
Post. Comm. artery
Basilar artery
```
203
Catecholamine are stored in
Membrane soluble granules
204
2 types of neuron in hypothalamus
Magnocellular (large) neuron
| Parvicellular (small) neuron
205
Columnar and caller cells of pancreas with granules
A cells
206
Precursor of Eicosanoids
Arachidonic acid
207
Nucleus of Tuberal region of hypothalamus
Arcuate nucleus
Dorsomedial nucleus
Ventromedial nucleus
208
Half life of ACTH
10 min
209
Polyhedral cells of pancreas arranged in tubes around capillary
B cells
210
Largest single organ specialized for hormone production
Thyroid gland
211
ADH and oxytocin are similar in structures but only differs in only 2 aa.
ADH - Phenylephrine (phe)
| Oxytocin - isoleucine (ile)
212
Hyper or hypo secretion of a hormone due to tumor or disease of an endocrine gland itself.
Primary hypo or hyper function
213
Important in early vasodilators shock
Antidiuretic hormone
214
Neuron of hypothalamus with neuro peptides and biogenic amines
Parvicellular
215
Stimulation test is useful in diagnosing hypofunction/hyperfunction
Hypofunction
| For detecting impaired secretory reserve
216
Regulation of secretion of ADH is inhibited by
Alcohol
Cortisol
Atrial natriuretic peptide ANP
217
Pp cells of pancreas produces what hormone
Pancreatic polypeptide
218
Proteins or peptide hormones has short/ long half life
Short half life
219
PRL stimuli
Stress and sleep
220
Largest and most Steroidogenic zone of adrenal cortex
Zona fasciculata
221
Catecholamines are synthesized by
Adrenal medulla
| Neurons
222
Sertoli and sperm cells are located in what Component of testicular lobule
Intra tubular compartment
223
In embryology of hypothalamus. Division which is composed of thin layer of cells which wrap around the infundibular stalk
Pars tuberalis
224
```
Target endocrine gland of:
Corticotrope
Thyrotrope
Gonadotrope
Somatorope
Lactotrope
```
Target endocrine gland of:
Corticotrope - zona fasciculata and reticularis of adrenal cortex
Thyrotrope - thyroid epith
Gonadotrope - ovary (theca&granulosa); testis (leydig&sertoli)
Somatorope - liver
Lactotrope - none (not part of endocrine axis)
225
Steroid hormones are polar/non polar
Nonpolar - not readily soluble in blood thus curculates bound to transport proteins
226
Adrenal androgen (DHEAS) appear in circulation at what age
6 y/o
227
Hyper or hypo secretion of a hormone produced by excessive or deficient stimulation from its tropic hormone or its physiologic stimulators: no disease of gland per se.
Secondary hyper or hypofunction
228
Most abundant cell type in pancreas
Beta cells
229
Type of glands which secretes salts, water, immunoglobulin and enzymes conveyed to a major lumen via a duct
Exocrine gland
230
Most abundant circulating hormone in young male adult (negligible to female)
Androgen
231
Domain in follicular cell that faces the follicle lumen (colloid) with micro villi and pseudopods
Apical domain
232
Iodothyronines have short or long half life
Long half life
233
Neural crest-derived cells of adrenal ,medulla asso with sympathetic ganglia
Chromaffin cells
234
GnRH is released in pulsatile secretion
True
235
Nurse cell
Sertoli cells
236
Blood supply of pituitary gland
Internal carotid arteries branches:
Superior hypophysial arteries
Middle and inf hypophysial arteries - supplies pituitary stalk and post pituitary
237
Bld supply of thyroid gland
Superior thyroid arteries
Inferior thyroid arteries
Thyroid ima arteries
238
Pineal gland secretes melatonin in response to
Hypoglycemia and darkness
239
Axonal swelling in neuro hypophysis due to storage of secretory granules.
Herring bodies
240
Protein bound fraction of hormone are physiologically inactive fraction
Free or unbound fraction of hormone are physiologically active fraction
241
Steroid hormone is synthesized by
Adrenal cortex
Ovaries
Testes
Placenta
242
In embryology of hypothalamus, the rathke's pouch may persist and becomes
Craniopharyngioma
243
Catecholamine circulates in the blood in unbound/bound form
Both
244
Major difference in between male and female repro tract:
Testosterone exerts neg feedback on secretion of pituitary FSH and LH
Estrogen exerts neg and pos feedback
Major difference in between male and female repro tract:
M: activity does not show rhythm
F: activity based on monthly menstrual cycle or length of pregnancy
245
Contributes to __% active androgen in males for axillary and pubic hair growth and libido
50%
246
Inability to initiate postpartum lactation
PRL deficiency
247
GHRH has a diurnal pattern
Peak - early morning
| Valley - day
248
In embryology of hypothalamus. Division where the cells on the side of the rathke's punch facing the infundibulum.
Lost in adult.
Pars intermedia
249
Target cell of ADH
Cells lining Distal renal tubule
| Principal cells of collecting duct
250
Eicosanoids are short lived compound formed from
Polyunsaturated fatty acids
251
Parafollicular cells produces what hormone
Calcitonin
| Which plays minimal role in Ca metab
252
Regions of hypothalamus
Chiasmatic (preoptic region)
Tuberal region
Mammillary region
253
In gigantism, it may be due to pituitary tumor which may compress the anterior pituitary
In acromegaly, Appositional growth occurs instead of lengthening of long bones.
"Acro" means end/extremity
"Megaly" means enlargement
254
Hypertension, hypokalemic alkalosis are found in excess/deficient ACTH
Excess ACTH (Cushing's disease)
255
The outer cortex of ovary is composed of densely cellular stroma, and within resides ovarian follicles which is covered by
Tunica albuginea
| Ovarian surface epith cells
256
Functional unit of ovary
Ovarian follicle
257
Type of secretory transport that secretes hormones to regulate its cell of origin thru membrane receptor
Autocrine
258
Regulation of development of external genitalia in the absence of DHT
female genitalia is formed (labia majora,minora, clitoris, lower 2/3 of vagina)
259
Milk let down
Oxytocin
260
Endocrine axis
```
Hypothalamus
Releasing hormone
Endocrine cell type
Tropic hormone
Peripheral endocrine gland (adrenal,thyroid, gonads, liver)
Peripheral hormone
Physiologic response
```
261
Type of secretory transport which is the production of an intracellular hormone that binds to an intracellular receptor without leaving the cell
Intracrine
262
Infundibulum + pars tuberalis
Pituitary stalk
263
Proteins/peptide hormones are polar/nonpolar
Polar
264
Hypothalamic nuclei that func as:
| Thermoregulation (heating center)
Posterior hypothalamus
265
Steroid hormones have intracellular receptors
True
266
ACTH has a diurnal pattern
Peak - early morning
| Valley - late afternoon
267
Hormones that have intracellular Receptors
Steroid hormones and Iodothyronines
268
Hypothalamic nuclei that func as:
Thermoregulation (cooling center)
Regulation of thirst
Anterior hypothalamus
269
Regulation of secretion of ADH is released in response to
Cellular dehydration
1. Increase ECF osmolality
2. Decrease blood vol and pressure
3. Na, sucrose, mannitol
4. Drugs: barbiturates, nicotine, opiates
5. Nausea (protective effect)
270
Hormone that maintains the normal osmolarity of body fluids and blood vol
Antidiuretic hormone
271
Effects of SYndrome of inappropriate secretion of ADH
High urine osmolality
Hyponatremia
Low serum osmolality
272
Type of neurocrine wherein the msgr is carried to local or distant site of action via ECF or blood
Nonsynaptic neurocrine
273
Proteins or peptides are synthesized as
Prehormones or preprohormones
274
Catecholamine are derived from what aa
Tyrosine
275
```
Primary hypothalamic regulator of:
Corticotrope
Thyrotrope
Gonadotrope
Somatorope
Lactotrope
```
```
Primary hypothalamic regulator of:
Corticotrope - corticotropin-RH
Thyrotrope - thyrotropin-RH
Gonadotrophs - Gonadotropin-RH
Somatorope - Growth hormone-RH
Lactotrope - dopamine and prolactin-RH
```
276
Hypothalamic nuclei that func as:
| Somatostatin
Periventricular nucleus
277
Inhibin in males is produced by what cell and cause decrease/increase FSH or LH
Inhibin in males is produced by Sertoli cells which decreases FSH
278
GH is under dual control by hypothalmus. It is stimulated and inhibited by..
Stimulation by GHRH
| Inhibition by somatostatin
279
Biochemical classification of hormones
Proteins and peptides
Catecholamines
Steroid hormones
Iodothyronines (aa derivatives)
280
Chemical msgr/signals secreted into the blood stream to act on distant tissues
Hormones
281
Neural down growth
Infundibulum
282
Weight of pituitary gland (hypophysis)
400-800 mg
283
Metabolic actions of GH on proteins
Increase tissue aa uptake
Increase incorporation into proteins
Decrease urea production
Produces positive Nitrogen balance
284
Normal GH level but lack normal rise in IGF during puberty
| Partial IGF response
African pigmy
285
Half life of ADH
15-20 min
286
Stress also triggers CRH release
True
287
Hormone that Stimulates development of breast duct system, breast fat deposition and breast stroma
Estrogen
288
TRH has a diurnal pattern.
Peak - overnight
| Valley - dinner time
289
Weight of thyroid gland
15-25 gm
290
Hypothalamus originates from
Embryonic basal plate
291
Endocrine function of Sertoli cells
Expression of androgen receptor and FSH-receptor
Production of mullerium-inhibiting subs (MIS)
Aromatic action of testosterone to estradiol-17B
Produce inhibin (keeps FSH level within specific range)
292
Hypotension, hyperkalemic acidosis are found in excess/deficient ACTH
Deficient ACTH (Addison's disease)
293
If PRL suppress GnRH release
Lactational amenorrhea
294
Domain in follicular cell that faces extracellular matrix (blood) which contains (+) TSH and NIS
Basal domain
295
Iodothyronines are stored in
Follicle (part of thyroglobulin)
296
FSH in male stimulates ___ produced by ___ cell
Facilitates spermatogenesis
| Produced by Sertoli cells
297
Major difference in between male and female repro tract:
m: gametes contiguous with repro tract
F: gamers not contiguous with repro tract
Major difference in between male and female repro tract:
m: gametic reserve replenished throughout life
F: finite gametic reserve, exhausted by menopause
298
Adrenal medulla synthesize
Catecholamine:
Epi (80%)
Norepi (20%)
299
Supportive function of Sertoli cells
Maintaining, breaking and reforming multiple junctions with developing sperm
Maintaining blood-testis Barrier
Phagocytosis
Transfer of nutrients and other subs from blood to developing sperm cells
Expression of paracrine factors and receptors for sperm-derived paracrine factors
300
Leydig cells synthesize and stores
Cholesterol as cholesterol esters
301
Hormone that keeps FSH level within specific range.
Inhibin
302
Proteins or peptide hormones have cell membrane receptors (2nd msgr)
True
303
TSH is heterodimer. What subunit is common to TSH, FSH and LH
Alpha-Glycoprotein subunit
304
PRL is a ___ aa peptide
199 aa
305
Hormone that Stimulates development of breast glandular tissue, the secretory structure of the breast
Progesterone
306
Sertoli cells contains major secretory products such as
Protease and protease inhibitors.
307
Type of gland that are ductless to which it secretes hormones directly into the circulation.
Endocrine gland
308
Primary endocrine cell of testis
Leydig cells
309
There is no cortisol/androgen synthesis if this particular enzyme is..
Absence of CYP17
310
Neuron of hypothalamus with arginine vasopressine and oxytocin
Magnocellular
311
This enzyme catalyzes the last 3 reactions from DOC to form aldosterone
Presence of CYP11B2 (aldosterone synthase)
312
Catecholamine have cell membrane receptors
True
313
Stage of ovarian follicle growth where that start of ovarian hormone production
Growing antral (tertiary) follicle
314
Cell bodies producing ADH and oxytocin located in what nucleus
Supra optic (SON) and paraventricular nucleus (PVN)
315
Effect of ADH
Decrease urine flow
Increased urine osmolality
Increased mesangial cell contraction - decrease GFR
Inhibits renin release
316
Iodothyronines are polar or nonpolar
Polar
317
```
Peripheral hormone involved in negative feedback of:
Corticotrope
Thyrotrope
Gonadotrope
Somatorope
Lactotrope
```
Peripheral hormone involved in negative feedback of:
Corticotrope - cortisol
Thyrotrope - T3
Gonadotrope - estrogen, progesterone, testosterone, inhibin
Somatorope - IGF-1
Lactotrope - none
318
Delta cells of pancreas produces
Somatostatin
319
B cells produces what hormone
Insulin
320
Nucleus of Chiasmatic region of hypothalamus
Suprachiasmatic
Supra optic
Paraventricular nucleus
Anterior nucleus
321
Isthmus crosses the trachea between rings"
Tracheal rings I and II
322
PRL is under tonic inhibitory control by hypothalamus by
Dopamine
323
Hormone that Stimulates milk secretion into the alveoli in pregnancy and nursing
PRL
324
Normal gametogenesis and development and physiology of male and female repro tract are absolutely dependent on gonadal endocrine func
True
325
GH deficiency
Dwarfism
326
GnRH is a ___ aa peptide
10aa
327
Incrd Skin pigmentation may occur in Addison's disease if
The disease is not of pituitary origin
328
Component of testicular lobule composed of seminiferous tubules
Intratubular compartment
329
Classes of hormones based on structure: glycoproteins
FSH
LH
TSH
HCG
330
The inner part of adrenal glands
Adrenal medulla (10%)
331
Hypothalamic nuclei that func as:
Hunger center
MCH, anorexins
Lateral hypothalamus
332
GH excess
Gigantism and acromegaly
333
Regulates salt and volume homeostasis
Zona glomerulosa
| Aldosterone
334
GH indirectly induce liver to produce
Somatomedin
335
Proteins/peptide hormones circulate the blood in bound/unbound form
Unbound
336
what are the dopamine agonist drugs that cause shrinkage of prolactinomas?
Bromocriptine
Cabergoline
"BRO, you call ur TITS a CAB"
337
ACTH is a ___ aa peptide
39 aa
338
Type of neurocrine wherein the msgr traverses a structure synaptic space
Synaptic neurocrine
339
Suppression test is useful in diagnosing hypofunction/hyperfunction
Hyperfunction
| Hyperfunctioning gland is not operating under normal control mechanism
340
Type of secretory transport that involves secretion of hormone from endocrine cell, its diffusion into capillaries and regulation of distant cells
Hemocrine/ endocrine
341
Cell in thyroid parenchyma where it could be the origin of subset of papillary thyroid Ca
Epithelial cells
342
Inhibin in females is produced by what cell and cause decrease/increase FSH or LH
Inhibin in females is produced by corpus luteum and causes decrease in FSH and LH
343
Beta cells of pancreas are found in
Body
Tail
Anterior portion of head
344
Steroid hormones are stored in
Endocrine gland
345
Deficiency in ADH production
Diabetes insipidus
346
The last 3 reactions from DOC to aldosterone
11-hydroxylation: DOC to corticosterone
18-hydroxylation: corticosterone to 18-hydrocorticosterone
18-oxidation: 18-hydrocorticosterone to aldosterone
347
ANS modulates islet hormone secretion. What stimulation increases insulin, glucagon and PP?
Cholinergic and beta-adrenergic stimulation
348
Blood supply of adrenal gland
Inf suprarenal artery (from renal artery)
Middle suprarenal artery (from aorta)
Superior suprarenal artery (form inf phrenic artery)
349
Hyperprolactinemia is secondary to post/ant pituitary tumor
Anterior pituitary
350
```
Receptor of:
Corticotrope
Thyrotrope
Gonadotrope
Somatorope
Lactotrope
```
```
Receptor of:
Corticotrope - melanicortin-2 receptor MC2R
Thyrotrope - TSH receptor
Gonadotrope - FSH and LH receptor
Somatorope - GH receptor
Lactotrope - prolactin receptor
```
351
Hypothalamic nuclei that func as:
| Regulator of circadian rhythm and pineal function.
Suprachiasmatic nucleus
352
Metabolic actions of GH on carbohydrates
Increase blood glucose
Des peripheral insulin sensitivity
Increase hepatic output of glucose
Admin'n results in increased serum insulin levels
353
Component of testicular lobule that represents true epithelial cells of seminiferous epith and surrounds the sperm cells
Peritubular compartment
354
Components of testicular lobule
Intra lobular compartment
| Peritubular compartments
355
A cells of pancreas are found in
Body
| Tail
356
Catecholamine
Norepi, epi, dopamine
357
Type of DI common in compulsive water drinkers
Psychogenic DI
358
Hypothalamic nuclei that func as:
ADH: osmoregulatioh
Oxytocin: regulation of uterine contraction and milk ejection
Supraoptic nucleus
359
Major difference in between male and female repro tract:
Testis reside outside abdominal cavity
Ovaries reside within abdominal cavity
Major difference in between male and female repro tract:
M: Continuous release of gametes from gonads
F: release of gametes occurs once a month
360
Basic roles of gonadal hormone in male
Support of spermatogenesis
Maintenance of male repro tract and semen production
Maintenance of secondary sex characteristics
Maintenance of libido
361
Dwarfism occurs after or before puberty
Before puberty
362
F or PP cells of pancreas are found in
Post or ventral part of head
363
TSH stimulate the proliferation of Tg synthesizing cuboidal cells of thyroid follicles. Thus an excess TSH will cause enlarged thyroid or..
Goiter
364
Causes of retarded growth in children
```
GH deficiency
Thyroid deficiency
Insulin deficiency
Malnutrition / under nutrition
Physical growth retardation
Constitutional delay
Chronic disease
Genetic disorders charac by short stature
Cortisol excess
```
365
Major difference in between male and female repro tract:
Testosterone always the primary gonadal steroid
Estrogen is the primary steroid in first half of cycle, progesterone in 2nd half
Major difference in between male and female repro tract:
M: repro system does not prepare for NB
F: prepare for NB with breast development and milk production
366
Hormonal rhythm with periodicity <24 hr
Ultradian rhythm
367
Hyperprolactinemia may occur with excess TRH production stimulates PRL secretion in addition to TSH secretion
True
368
Hypothalamic nuclei that func as:
Satiety center
GHRH, somatostatin
Ventromedial nucleus
369
Component of pituitary gland composed mainly of epithelial cells with 5cell types excreting 6 hormones.
Anterior pituitary or adenohypophysis
370
Hypothalamus is composed of gray/white matter
Gray mater
371
Type of secretory transport that release hormone into ECF and its regulation of surrounding cells by diffusion
Paracrine
372
Functional unit of thyroid gland
Follicular cells
373
Hypothalamic nuclei that func as:
| Few GnRH neurons
Preoptic nucleus
374
Circulating ab in graves disease
TRAbs
375
Metabolic effects of T3
1. Lipolysis- FA + glycerol
2. expression of lipogenic enzymes
3. cholesterol catabolism into BA
4. Rapid removal of LDL from plasma
5. Carbohydrate and protein catabolism
376
T3/4: Produced only in thyroid gland
T4
377
During first trimester, ___ is at its highest conc and can stimulate thyroid cells to produce new thyroid hormones.
B-HCG
378
Most frequent cause thyrotoxicosis in iodine-sufficient countries
Graves disease
379
Indication for radioactive iodine treatment
Female planning a pregnancy in the future
Pts with increase ping surgical risk
Pts previously operated or externally irradiated neck
Pts with CI to ATD
380
In some pts with HAshimoto's thyroiditis, they may stay hypothyroid because of inability to escape this effect
Wolff-chaikoff effect
381
TSH level and T4 level of:
| True hyperthyroidism
Low TSH
| High T4
382
Thyroid hormone is critical for normal bone Growth and development
T3 regulates sk maturation at growth plate.
T3 participates in osteoblasts differentiation and proliferation and chondrocytes maturation loading to bone ossification.
383
Patients undergoing surgery (thyroidectomy) should be rendered
Euthyroid
384
RAI therapy or RAI ablation:
| Low dose
RAI therapy
385
Major extrathyroidal T4 conversion site for production of T3
Liver
| Some occurs in liver and other tissue
386
Half life of t3
One day
387
Myxedema is due to
Accumulation of hyaluronic acid which alter the composition of the subs of the dermis and other tissue
388
PTU / MMI:
| More binding to albumin
PTU
389
Half life of t4
7 days
390
Severe hypothyroidism in infancy with irreversible mental and grocery retardation
Cretinism
391
Iodine intake not more than
1100 ug/d
392
Indications for thyroidectomy
```
Planning for pregnancy (<4-6 mos)
Thyroid malignancy
Large goiter (>80gms)
Low RAIU
Coexisting hyperparathyroidism
```
393
Thyroxine therapy must be considered in subj (age) if TSH is ___ and/or TPO ab is (present/absent)
<65 yrs old if TSH >10mU/L and/or TPO ab is present
394
During pregnancy, there is an increased Renal iodine clearance, therefore..
Increased 24-hr RAIU
395
Hallmark of classic HAshimoto's disease
Goiter
396
TSH level, T3 or t4 level in subclinical hypothyroidism
High TSH
| Normal t4 and t3
397
3-8x more potent
T3
398
During pregnancy, there is an decreased plasma iodine and placental iodine transport to the fetus, therefore..
In deficient women, decreased T4, increases TSH then leads to goiter formation
399
Treatment of choice in HAshimoto's disease and /or large goiter
Levothyroxine
400
Mechanism of action of ATDs
Inhibition of organification (iodine binding to Tg)
Inhibition of coupling of Iodothyronines
Inhibition of T4 to T 3 conversion (PTU)
Possible immunosuppressive effects (MMI)
401
Potential complication of thyroidectomy
Hypoparathyroidism
Hypothyroidism
Vocal cord paralysis
402
AOG when fetus is completely dependent on maternal thyroid hormones
First 3 mos
403
Pathologic feature of HAshimoto's thyroiditis
Presence of both mononuclear cells and thyroid follicle destruction
404
During pregnancy, there is an increased serum TBG, therefore..
Increased total T3 and T4
405
T3 is derived from 2 processes
1. 80% of circulating T3 comes from deiodination of T4 on peripheral cells
2. 20% comes directly from thyroid secretion.
406
PTU / MMI:
| Lower conc in breast milk
PTU
407
T4 is converted to T3 by
5-deiodination of outer ring of T4
408
Main ag in graves disease
TSHR
409
Life threatening clinical condi in pts with long standing severe untreated hypothyroidism
Myxedema coma
410
ATD that is used in all patients
MMI
| Except those in 1st tri in pregnancy, treatment for thyroid storm
411
Little or no placental transfer
TSH
412
PTU / MMI:
| With peculiar toxicity - aplastic cutis embryopathy
MMI
413
Excess iodine
Wolff chaikoff effect
| Jodbasedow phenomenon
414
Conditions that increase TBG
```
Pregnancy
Infectious/chronic active hepatitis
HIV infection
Biliary cirrhosis
Acute intermittent porphyria
Genetic factors
```
415
TSH level and free T4 level of:
| Secondary or central hypothyroidism
Low TSH
| Low T4
416
Most common cause of hyperthyroidism
Graves disease
417
TPO uses ___ as the oxidant to activate I- to hypoiodate the iodination species
H2O2
418
PTU / MMI:
| Less placental passage
PTU
419
Thyroid hormone stimulates mitochondrial activity in most tissue
T3 increases basal metabolic rate, body heat production and O2 consumption.
420
PTU / MMI:
| Blocks thyroid hormone production and secretion
Both
421
RAIU level in thyrotoxicosis
Decreased
422
Mechanism of action do radioactive iodine
Destroys the thyroid and stops the excess production of hormone
423
First line therapy for hyperthyroidism or graves disease
Radioactive iodine
424
During pregnancy, there is an increased O2 consumption, therefore..
Increased BMR
425
During pregnancy, there is an increased plasma type 3 deiodinase, therefore..
Accelerates rates of t3 and T4 degradation and production.
426
Thyroid hormones that appear in fetal serum
TSH
| T4
427
TSH level and RAIU level of:
TSH-secreting pituitary tumor
TH hormone resistance
Elevated or normal TSH
428
Dietary iodine reaches the circulation as
Iodide anion
429
DIT plus DIT
Tetraiodithyronine or T4
430
RAI is used by elderly and cardiac pts
True.
431
```
TSH level and RAIU level of:
Graves disease
Toxic multinodular goiter
Toxic adenoma
Gestational hyperthyroidism
```
Low TSH
| High RAIU
432
Iodination of tyrosyl residues then forms monoiodotyrosine and diiodotyrosine which are then coupled to form either T3 or T4. Both reactions are catalyzes by
Thyroperoxidase
433
It functions as iodide concentrating mechanism that enables iodide to enter the thyroid for hormone biosynthesis
NIS
434
TSH level and T4 level of:
| Sick euthyroid syndrome
Low TSH
| Low T4
435
There is transient low TSH during 1st trimester due to increased thyroid hormone production.
True
436
Thyroid hyperfunction induced by excess iodine ingestion in pts with various thyroid disorder (grave's disease)
Jod-basedow phenomenon
437
Normal circulating concentration of t3
60-180 ng/dl
438
Lab diagnosis for thyrotoxicosis and hyperthyroidism
Suppressed TSH <0.1 mU/L
Elevated T4
RAIU
439
Major regulator of mitochondrial activity
T3
440
Decrease or increase TBG effects on total serum T3 and T4 level and free T3 and T4.
Decrease or increase TBG will decrease/increase total serum T3 and T4 level.
While free T3 and T4 remain unchanged
441
PTU / MMI:
| Blocks peripheral conversion of T4 to T3
Porpylthiouracil
442
Pregnancy must be postponed for at least ____ after RAI therapy
6 mos
443
Anti thyroid drugs
Methimazole
Propylthiouracil
Carbimazole
Thiamazole
444
TSH level and T4 level of:
| Graves disease
Low TSH
| High T4
445
Graves disease is a syndrome characterized by
Hyperthyroidism
Ophthalmopathy
Dermopathy
Pretibial myxedema
446
Thyroid hormone is a major regulator of mitochondria activity
T3 induces early transcription and increases TFA expression.
T3 stimulates O2 consumption.
447
In cases wherein TSH <10mU/L and/or TPO ab is absent, thyroxine therapy still might be warranted in individual with high background for
Cv risk, pregnancy and infertility
448
Reserved for disorders that results from sustained overproduction of hormone by the thyroid gland itself
Hyperthyroidism
449
Indispensable component of thyroid hormone comprising 65% of T4 and 58% of T3's weight.
Iodine
450
DIT plus MIT
Triiodothyronine T3
451
Treatment of choice for recurrent hyperthyroidism after ATD therapy
RAI
452
During pregnancy, there is an increased plasma volume, therefore..
Increased T3 and T4 pool size
453
T3/T4 which is biologically active responsible for the majority of thyroid hormone effects
T3
454
Increased thyroid hormone requirements during pregnancy
Increase free TH binding to TBG - marked fall in serum free T4 - if no compensatory increase in thyroid secretion leads to hypo.
Transplacental transfer of T4 - placental degradation of T4 - if no compensatory increase in thyroid secretion leads to hypo.
455
Signs and symptoms in hypothyroidism
```
Constipation
Puffy eyes
Muscle weakness
Weigh loss gain
Bradycardia
Cold intolerance
Dry, patchy skin
Heavy period
```
```
Hairloss
Tiredness
Forgetfulness
Depression
Elevated cholesterol
```
```
Goiter
Hoarseness
Infertility
Irritability
Dry/sore throat
Dysphagia
```
456
AOG when fetal pituitary gland differentiates
10-12 wks
457
Pro hormone for T3
T4
458
Iodide must be first ___ to be able to iodinate tyro sly residues of Tg
Oxidized
459
Most common cause of thyrotoxicosis
Thyroiditis
460
Most common case of hypothyroidism in areas wherein dietary iodine is sufficient
HAshimoto's thyroiditis
461
To liberate t3 and t4, Tg is resorted into follicular cells in the form of ___ which fuse with lysosomes to form phagolysosome
colloid droplets
462
Thyroid hormone influences cv hemodynamics by
```
Increase HR and decrease systemic vascular resistance thus increase CO = improve cardiac performance
Elevate blood volume
Local vasodilators
Decrease diastolic blood pressure
Cardiac chronotropy and inotropy
```
463
T3/4: 80% are from peripheral conversion
T3
464
T3/4: only free hormones are active
T4
465
Excess iodine with transient shut down of thyroid hormone production (normally).
When increasing doses of iodide inhibit organification and hormonogenesis of thyroid hormone.
Wolff chaikoff effect
466
TSH level, T3 or t4 level in subclinical hyperthyroidism
Low TSH
Normal t4 and t3
Asymptomatic
467
Required daily intake of iodine in 7-12y/o.
120 ug/d
468
Environmental triggers of graves disease
Stress
Tobacco use
Infection
Iodine exposure
469
Normal disposition of T4
41% is converter to T3
38% is converter to rT3
21% is metabolized via other pathways (conjugation on liver and excretion in bile)
470
RAI therapy or RAI ablation:
| With intention to destroy all thyroid remnant and metastasis in well diff Ca
RAI ablation
471
Required daily intake of iodine in teenager and adults
150 ug/d
472
Primary secretory product of thyroid gland
T4
473
RAI has no effect on fertility, no increased incidence of congenital malformation and no increased risk of cancer
True
474
T4 is biologically inactive in target tissues
True. Until converted to T3
475
AOG when fetal thyroid begins to conc iodine and synthesize Iodothyronines
10-12wks
476
Signs and symptoms of hyperthyroidism
```
Freq bowel movement
Bulging eyes
Sudden paralysis
Weigh loss / gain
Tachycardia
Heat intolerance
Warm, moist palm
Light period
```
Increase sweating
Insomnia
Nervousness, tremors
```
Goiter
Hoarseness
Infertility
Irritability
Dry/sore throat
Dysphagia
```
477
What would be given in immediate preop period in thyroidectomy
Potassium iodide
To diminish vascularity to suppress the thyroid hormone production becoz patients undergoing surgery should be rendered euthyroid.
478
Iodide trapping by the aid of
NIS
479
Placental transfer without difficulty
Iodide
Thionamides
Thyroid ab
TRH
480
Biosynthesis of T3 and T4
1. Dietary iodide ingestion by follicular cells
2. Active transport and uptake of iodide into colloid by thyroid gland
3. Oxidation of I and iodinatiob of Tg tyrosine residues
4. Coupling of Iodotyrosine residues (MIT & DIT) to form T3 and T4
5. Proteolytic of Tg with release of T3 and t4 into circulation
481
Thyroid secretes approximately how many grams of thyroxine daily
70-90 ug/d
482
TSH level and T4 level of:
T3 thyrotoxicosis
Sub clinical hyperthyroidism
Low TSH
| Normal T4
483
Rare disorder of chronic sclerosing thyroiditis
Riedel's thyroiditis
484
Normal circulating concentration of t4
4.5-11 ug/dl
485
Thyroperoxidase Catalyzes oxidation steps involved in:
I- activation
Iodination of Tg tyrosyl residues
Coupling of iodotyrosyl residues
486
Required daily intake of iodine in pregnant and lactating women
25o ug/d
487
Decreased thyroid hormone concentration may lead to alteration of ___. May develop impairment of attention, slowed motor function, and poor memory
cognitive function.
488
Dermopathy in graves disease
```
Plummer's nail
Hyperpigmentation
Hyperhidrosis
Alopecia
Acropachy (triad of digital clubbing, soft tissue swelling of hands and feet and periosteal new bone formation)
```
489
Drugs that increase TBG
```
Oral contraceptives
Methadone
Clofibrate
5-fluorouracil
Heroin
Tamoxifen
```
490
PTU / MMI:
| Long half life
MMI
491
Refers to classic physiologic manifestations if excessive quantities of the thyroid hormones
Thyrotoxicosis
492
Lab diagnosis to differentiate thyrotoxicosis and hyperthyroidism
RAIU
493
During 1st tri in pregnancy, there is an increased HCG, therefore
Increased free T4 and T3
| Decreased basal TSH
494
Thyroid hormone influences the female repro system
Hypothyroidism may be asso with menstrual disorder, infertility, risk of miscarriage and other complications of pregnancy.
495
RAI therapy or RAI ablation:
| To destroy some thyroid tissue in graves disease or toxic nodules.
RAI therapy
496
Total daily production rate of t3
15-30 ug/d
497
RAI is contraindicated during
Lactation and pregnancy
498
More than 99% of circulating T3 and t4 is bound to plasma protein Carrier proteins which are
TBG 75%
Transthyretin TTR / thyroxine-binding prealbumin TBPA 10-15%
Albumin 7%
HDL 3%
499
Drugs that decrease serum t3 and t4 by decreasing binding
Antiseizure medications
| Salicylates
500
Required daily intake of iodine in 0-7y/o.
90 ug/d
501
Graves disease is an autoimmune disease with a strong familial disposition more common in male/female.
Female
502
Atrial fibrillation is characteristically manifested in what thyroid disorder
Graves disease
503
Self limited anti-inflammatory disorder of thyroid and the most common cause of pain from thyroid origin
Subacute thyroiditis
504
```
TSH level and RAIU level of:
Iodine induced hyperthyroidism
Amiodarone- induced hyperthyroidism
Struma ovarii
Metastatic thyroid Ca
Thyroiditis
```
Low TSH
| Low RAIU
505
Drugs that decrease serum t3 and t4 by decreasing TBG conc
```
Glucocorticoids
Androgens
L-asparaginase
Mefenamic acid
Furosemide
```
506
Some placental transfer
T3
| T4
507
Iodide active transport by thyroid Is mediated by this membrane protein
Sodium-iodide symporter or NIS
508
Primary stimulating signal of PTH
Low circulating Ca level
509
Hormones and minerals found in bones
```
PTH
Vit D
Calcitonin
Calcium
Phosphorus
```
510
Inhibits bone resorption
Calcitonin
| As decreases Ca and Pi
511
PTH receptor that is abundant in bones (osteoblasts) and kidneys (prox and distal convoluted tubules)
PTH1R
512
Circulating forms of calcium
Ionized - 50%
Protein-bound - 40%
Complexed with anion - 10%
513
Major regulator of calcium and phosphorus metabolism
PTH
514
Calcitonin is produce by what cell
Parafollicular C cell
515
Calcitonin release is stimulated by
Vit D
| Ingestion of food due to GASTRIN
516
Effect of PTH to phosphate and Ca level
Increase Ca
| Decrease phosphate
517
Low Ca stimulates renal 1a-hydroxylase thru increased PTH
High Ca inhibits 1a-hydroxylase thru CaSR in proximal tubule
518
Hypoparathyroidism is due to PTH and vitD deficiency. It has high/low Ca and high/low Pi.
Low Ca and high Pi
519
The most important effect of PTH is to increase/decrease plasma calcium level
Increase plasma calcium level
520
PTH decrease /increase plasma phosphate
Decrease plasma phosphate
521
As in chronic renal disease with high Pi and low Ca due to high PTH and low vit D
Renal osteodystrophy
522
Vit D3
Cholecalciferol
523
Calcitonin excess does not produce hypocalcemia (MTC).
| Calcitonin deficiency does not produce hypercalcemia (post total thyroidectomy for thyroid Ca )
Calcitonin plays a very minimal or negligible physiologic role in Ca and phosphate homeostasis
524
PTH receptor that does not bind to PTHrP
PTH2R
525
Very active vit D preparation
Calcitriol
526
Percentage of active vit d that circulates as free steroid
0.4%.
| Other binds to DBP from liver
527
What kind of receptor is vit D receptor
Nuclear receptor
528
PTH stimulation
```
Phosphodieasterase inhibitors
Epinephrine
Dopamine
Histamine
Lithium
Thiazides diuretics
```
529
High Mg level inhibits PTH
True
530
Useful histo chemical marker for MEdullary thyroid Ca
Calcitonin
531
Calcitonin is regulated by
CaSR and high Ca level
532
PTH inhibition
A-adrenergic agonists
Prostaglandins
Aluminum
Chromogranin
533
Normal calcitonin plasma level
10-20pg/mL
Any increase In plasma Ca by 1mg/dl will result to 2-10fold acute rise in calcitonin
534
Low circulating Ca level is sensed by principal cells thru
Ca-sensing receptor (CaSR)
535
VitD deficiency leads to defective bone mineralization in adults
Osteomalacia
536
Major stimulus of calcitonin
Hypercalcemia
537
Larger, mitochondria-rich, eosinophilic cell type of parathyroid gland
Oxyphil cell
538
PTH decrease plasma phosphate by
Inhibiting renal tubular phosphate reabsorption
539
Rate limiting enzyme in vit d synthesis
1a-hydroxylase (CYP1a)
540
Vit D synthesis
7-dehydrocholesterol -(skin UV light)- cholecalciferol - (liver vitD 25-hydroxylase)- 25hydroxycholecalciferol -(kidney 1a-hydroxylase)- 1,25dihydroxyvitamin D
541
Effect of vitD to phosphate and Ca level
Increase Ca
| Increase phosphate
542
Hyperparathyroidism is an excessive production of PTH that is usually due to single adenoma. It has high/low Ca and high/low Pi.
High Ca and low Pi
543
Bone cell type for production of matrix
Osteoblast
544
Predominant parenchymal cell type and a primary endocrine cell of parathyroid gland
Chief/principal cell
545
Facilitates absorption of Ca in duodenum and jejunum
Vit d
546
Ergocalciferol, secosteroid produced in plants. Enters the liver for hydroxylation via portal circulation and chylomicrons
Vit D2
547
PTH receptor that activates adenylyl cyclase and PLC
PTH1R
548
VitD deficiency leads to secondary increase in PTH
Osteoporosis
549
Parathyroid cell type that secretes PTH
Chief cell
550
Calcitonin is expressed in
Osteoclast (inhibits bone resorption)
| Nephrons (inhibits Ca and Pi reabsorption)
551
Effect of calcitonin to phosphate and Ca level
Decrease Ca and decrease phosphate
552
Rare familial disorder charac by tissue resistance to PTH.
Pseudo hypoparathyroidism
553
Pty receptor that bonds both PTH and PTHrP
PTH1R
554
Inhibitors of calcitonin
Low vit D
| Somatostatin
555
Bone is not affected in hypoparathyroidism
True
556
PTH receptors
PTH1R (hPTH/PTHrP)
PTH2R
CPTH
557
Mechanism of action of PTH in kidneys
Stimulates Ca reabsorption
Inhibits Pi reabsorption
Stimulates conversion to 1,25 dihydroxy vitamin D
558
High Ca and low Pi in hyperparathyroidism is due to
Bone demineralization
High GI Ca absorption
High renal Ca reabsorption
559
There is high PTH secretion, low Ca and congenital defects of skeleton.
Pseudo hyperparathyroidism
560
The most important effect of PTH is to increase plasma Ca level by
Stimulate bone resorption
Increase renal tubular reabsorption
Stimulate renal 1,25 dihydroxy- D synthesis
561
VitD deficiency leads to defective bone mineralization in children
Rickets
562
Mg and Ca in vit D deficiency
Low mg and Ca
563
Bone cell type for resorption of matrix
Osteoclasts
564
The low Ca and high Pi in hypoparathyroidism is due to
Impaired GI Ca absorption
Decreased renal reabsorption
Decreased bone Ca mobilization
565
Results in bone deformities due to increase bone resorption ff by increase bone formation.
It has high alkaline phosphatase, osteocalcin and urinary hydroxyproline.
It produces pain, bone deformation and bone weakness.
Paget's disease
566
Bone remodeling is regulated by
PTH
567
PTH receptor that reacts with the carboxylate terminal rather than amino terminal of PTH
CPTH
568
Primary target of PTH
Bone
| Kidneys
569
PTH receptor that is found in brain, placenta and pancreas
PTH2R
570
Secosteroid (class of steroid with 1 open cholesterol ring)
Vit D3
571
Calcitonin is primarily inactivated in what organ
Kidney
572
Insulin receptor has a and B subunit. Which subunit spans the cell membrane.
Beta subunit
573
Insulin receptor has a and B subunit. Which subunit contains hormone binding site?
Alpha subunit
574
Somatostatin has 2 forms
Somatostatin-14
| Somatostatin-28
575
Insulin receptor has a and B subunit. Which subunit is external to cell membrane?
Alpha subunit
576
IRS phosphorylation leads to activation of..
Protein kinase B (PKB) dependent pathway
| Resulting to metabolic effects of insulin.
577
Insulin mechanism of action
Insulin binds to IR
Initiates series of phosphorylation reaction and gene expression
Glut-4 transports glucose from outside to inside
Glycogen, lipid and protein synthesis
578
Termination of Insulin/IR signaling
1. Insulin down- regulates own receptor by receptor-mediated endocytosis and degradation pathways
2. Inactivation of IRS protein by serine/threonine protein kinase
3. Activation of "suppressor cytokines signaling" SOCS which reduces acty levels of IR and IRS proteins.
579
Biphasic phase of insulin that involves release of newly formed insulin.
2nd or late phase
580
Insulin is catabolic/anabolic
Catabolic
581
Insulin is catabolic/anabolic
Anabolic
582
Biphasic phase of insulin that is short lived and prompt.
1st (early phase )
583
Regulation of insulin
```
Glucose enters Bcells by glut-2
Glucose to G6P by glucokinase
Send signals to increase ATP/ADP ratio
Closes K channel
Depolarize
Opens Ca channel
CA entry
Stimulates insulin secretory granule
Release insulin thru exocytosis
```
584
Secreted in equinolar amts as insulin.
| Measured in the blood to quantify endogenous insulin production
C-peptide
585
Insulin receptor has a and B subunit. Which subunit contains tyrosine kinase on cyto solid surface?
Beta subunit
586
Importance of somatostatin is not clearly established but..
It can inhibit insulin and glucagon secretion thru paracrine mechanisms depending in what the body needs
587
Major stimulus of glucagon
Low blood glucose
588
Pancreatic polypeptide is stimulated by
Various GIT hormone
| Vagal stimulation
589
Determines net flow of hepatic metabolic pathway
Insulin/glucagon ratio
590
Primary target organ of glucagon effect
Liver
591
Insulin action
```
Promotes protein synthesis
Inhibits protein degradation
Ptromotes TGL synthesis
Inhibits lipolysis
Has effects on satiety
```
592
Glucose sensor of B cells
Glucokinase
593
Somatostatin is also found in
Hypothalamus and GIT
594
Primary site of degradation of glucagon
Liver
| 80% in single pass
595
Stimulates glucagon secretion
```
Low blood glucose
High aa (arginine, alanine)
```
Sympa NS stimulation (B2 adrenergic)
Stress
Exercise
596
Peak of first or early phase
5 min
597
Insulin is stored in secretory granules in Zn-bound crystals. It is released by exocytosis of granule contents ff by endocytosis. It has 2 biphasic release
1st (early phase)
| 2nd (late phase)
598
Primary stimulus and regulator of insulin
Glucose
599
Glucagon circulates in bound/ unbound form
Unbound form
| Thus has short half life of 6min
600
Duration of 2nd phase
10 min - 1 hr
601
Insulin is degraded by what enzyme found in liver, kidney and other tissue
Insulinase
602
Biphasic phase of insulin that is responsible to peak insulin secretion after meal
First or early phase
603
Entry kg glucose into B-cells is facilitated by
Glut-2 transporter
604
Action of insulin
*Glucose uptake (by GLUT-4 availability in ms and fats)
*Glucose use
Glycogenesis
*Glycolysis
Decrease glycogenolysis
```
Specific in liver
FA synthesis and VLDL
decrease gluconeogenesis
Decrease x
Decrease urea cycle activity
```
Specific in ms
Aa uptake
Protein synthesis
Decrease proteolysis
Specific in adipose tissue
Production of a-glycerol phosphate
Esterification of fats
Decrease lipolysis
605
Glucose is phosphorylated into G6P by what enzyme
Glucokinase
606
Half life of insulin
5-8min
607
Glucagon is a primary counter regulatory hormone by
Increase bld glucose thru hepatic glucose output
Increase glucose production thru (increase glycogenolysis, gluconeogenesis, and decrease glycolysis, glycogenesis and inhibits FFA synthesis from glucose)
608
Insulin + receptor results to cross phosphorylation of B subunits leading to recruitment of adaptor proteins such as..
IRS (insulin-receptor substrates)
SHC protein
APS protein
609
Biphasic phase of insulin that involves release of preformed insulin.
First or early phase
610
Inhibits glucagon secretion
Somatostatin
Insulin
High blog glucose
611
Primary counter regulatory hormone of insulin
Glucagon
612
Biphasic phase of insulin that is slower onset and maintained for considerable periods
2nd or late phase
613
Insulin is responsible for maintaining the upper limit of blood glucose and FFA by
Promoting glucose uptake and utilization by muscle and adipose tissue
Increase glycogen storage in liver and ms
Decrease glucose output by liver
