Endo Flashcards

1
Q

Mode of inheritance for 5 alpha reductase

A

autosomal recessive

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2
Q

Mode of inheritance for androgen insensitivity

A

x linked recessive

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3
Q

Findings Kallman syndrome

A

isolated gonadotropin RH def and anosmia (embryo: failure of cells to migrate from olfactory bulb)

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4
Q

Until when to expect spontaneous descent of testes

A

6 mons

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5
Q

How does lugols solution work

A

Wolff chaikoff effect

  • inhibit organification in thyroid gland
  • Effective for 10 days
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6
Q

Half life of thyroid antibodies

A

12 days (hyperthyroidism from antibodies- up to 3 weeks)

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7
Q

Treatment of choice for neonatal hyperthyroid

A

methimazole

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8
Q

Findings in thyroxemia of prematurity

A

Dec TBG- dec T4, T3

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9
Q

Most common cause of congenital hypothyroidism

A

thyroid dysgenesis (agenesis, partial dysgenesis, extopic)

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10
Q

Time to normalize TFT with treatment

A

FT4- 3 days; TSH- 2 weeks

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11
Q

Treatment for hyperinsulinism

A
  1. Diazoxide (KATP antagonist)
  2. Octreotide
  3. Ca channel blocker
  4. Pancreatectomy
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12
Q

Function of Mg in relation of Ca

A
  1. PTH release
  2. Calcitriol synthesis
    - significant at Mg 1.5 mg/dl
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13
Q

Signs of HypoCa secondary to HypoMg

A
  1. Tetany
  2. Seizure
  3. Weakness
  4. Prolonged QT
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14
Q

Biochemical features of Osteopenia of prematurity

A
  1. hypophosphatemia (<3.5mg/dl)
  2. Hyperphosphatsia (>800 IU/L)
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15
Q

Treatment for 21-hydroxylase deficiency

A

mineralocorticoid
glucocorticoid
genital reconstruction

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16
Q

treatment for 11-betahydroxylase

A

glucocorticoid
genital reconstruction

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17
Q

Findings in Vit D Rickets

A

pathologic fracture
rachitic rosary
moth eaten metaphases

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18
Q

Lab findings in infant of diabetic mother

A
  1. Hypoglycemia (fetal hyperinsulinism)
  2. Low Mg
  3. low Ca
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19
Q

Signs of hypoMg

A
  1. seizure
  2. muscle weakness
  3. decreased DTR
  4. irritability
  5. inc QT interval
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20
Q

incidence of infant affected by mat graves

A

1%

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21
Q

Timing of passing maternal Ab

A

2nd half of pregnancy

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22
Q

Intrauterine sx of fetal hyperthyroidism

A
  1. fetal tachy
  2. iugr
  3. hydrops
  4. goiter
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23
Q

Duration of infantile hyperthyroid from maternal thyroid Ab

A

4-6 weeks

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24
Q

Embryology of thyroid

A

4wk- endoderm (pharyngeal floor), four pharyngeal pouch (calcitonin)
8 wk- fetal hypothalamus- TRH but TSH low
10-12 wk- thyroid complete
18-20 wk- thyroid gland func matures, response to TSH, inc T4 only
30 wk- T3 rises
-no fetal inhibition on TSH by T4
- hpt axis func abt 1-2 mos after birth

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25
Q

maternal T4 in cord blood at birth

A

30-50%

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26
Q

Medication of hypothyroid before and during pregnancy (should be done before the 3rd TM)

A

Levothyroxine

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27
Q

Effect for hypothyroid in pregnant women to infant

A
  1. lower IQ
  2. Expressive and nonverbal delays
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28
Q

increase in thyroid hormone in pregnancy

A

20-50%, inc TBG

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29
Q

Timing of TSH surge in neonate

A

30 mins after birth then normal 3-5 days

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30
Q

Stimuli for TSH surge

A

cool extrauterine environment

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31
Q

peak of neonatal T4

A

48 hours after birth

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32
Q

Pitfall of NBS using TSH

A
  1. false pos- ideally 2-4 DOL
  2. fail to detect TBG def and central hypothyroid
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33
Q

Pitfall of NBS using T4

A

miss primary hypothyroidism

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34
Q

What is hypothyroxinemia of prematurity

A

Lower total and FT4 in preterm infant due to:

  1. abrupt discontinuation of maternal thyroid hormone
  2. immature HPT axis (dec or absent inc T4 from TSH surge)
  3. Low TBG
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35
Q

What is sick euthyroid

A

Low T3 and T4 (T3 more affected) due to inhibition of conversion enzyme
- Mortality assoc with low both TSH, T4 and T3

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36
Q

Complications of maternal Graves disease

A
  1. gHTN
  2. Pre ec
  3. IUGR
  4. Preterm birth
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37
Q

Meds affecting TFT

A
  1. phenytoin: dec TBG affinity
  2. dopa: dec TSH
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38
Q

Normal male sexual differentiation

A
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39
Q

Normal Female Differentiation

A
  • No SRY- ovarian granulosa/ theca cells
  • No AMH- mullarian (Cloaca) then into internal female (uterus, fallopian, upper 1/3 vagina), no wolfian
  • No testosteron/DHT- clitoris (genital), labia minora (urethral), labia majora (labioscrotal)
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40
Q

Most common cause of genital ambiguity

A

In 46 XX: CAH

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41
Q

Most common cause of CAH (3)

A

21-hydroxylase deficiency

11 hydroxylase decificency

3B-hydroxysteroid dehydrogenase

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42
Q

Presentation of 21 hydroxylase def

A

salt wasting (hyponatremia, hyperkalemia)

hypoglycemia

hypovolemia

shock

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43
Q

Presents as virilization of the mother and the fetus

A

Aromatase deficiency

  • cannot convert androgren precursor to estrogen
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44
Q

Maternal causes of Androgen excess

A
  • ingestion of androgen or progestin
  • virilizing adrenocortical tumors
  • ovarian tumor
  • luteomas
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45
Q

Presentation of vanishing testes or testicular regression

A
  • Before 8 weeks: phenotypic female
  • 8-10 weeks: ambigious genitalia
  • after 12 weeks: normal male
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46
Q

Presentation of complete androgen insensitivity

A

Female external genitalia with a blind vaginal pouch

Presents with primary amenorrhea

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47
Q

Initial lab test for all ambigious genitalia

A

Routine chromosome analysis

-Should be obtained within the 1st 24 hrs after birth

48
Q

Definition of clitoromegaly

A

clitoral length >9 mm or width > 6mm

49
Q

Interpretation of AMH

A
  • reliable marker of testicular function

  • Low: vanishing testes, XY gonadal dysgenesis
  • Elevated: androgen insensitivity, hypogonadotrophic hypogonadism
50
Q

Hormones of anterior pituitary gland

A
  1. Corticotroph: ACTH
  2. Thyrotroph: TSH
  3. Somototroph: GH
  4. Gonadotroph: LH, FSH
  5. Lactotroph: Prolactin
  • in order of cell differentiation
51
Q

Embryology of Pituitary Gland

A

Adenohypophysis: primitive oropharynx (Rathke pouch

Neurohypophysis: Neural ectoderm

Hypothalamus: Diencephalon

  • Functional: 12 weeks
  • HPA axis: 18-20 weeks
52
Q

Findings of septo-optic dysplasia

A
  1. Optic nerve dysplasia: wandering nystagmus
  2. midline abnormalities (agenesis of corpus callosum, absence of septum pellucidum
  3. Pituitary hypoplasia: GH deficiency most common
  • 2 of the 3 is needed for Dx
53
Q

Findings in Pituitary Stalk Interuption

A
  1. Thins or interupted pituitary stalk
  2. absent or ectopic post pit
  3. small or absent ant pit
  • hypoglycemia
  • Jaundice
  • micropenis
  • short fifth digit
  • unilateral ptosis
  • congenital alopecia
54
Q

CHARGE syndrome

A
  • Autosomal dominant
  • Coloboma
    Heart defect
    Atresia coanal
    Retardation growth
    Genital abnormality
    Ear abnormality with sensorial-neural hearing loss
  • Mutation with CHD7
55
Q

Most affected pit hormone in childhood

A

GH defiency

  • hypoglycemia
  • +/- micropenis
  • does not cause IUGR
  • Postnatal linear growth not affected until 6-9 mos
56
Q

Definition of micropenis

A
  • Term: <2.5 cm
  • 34 weeks: <2 cm
  • 30 weeks: <1.5 cm
57
Q

Test for GH def

A
  • random GH: > 10 ng/ml adequate
  • <5 ng/ml with other of pit defiency findings- GH def
  • Done within 1st 7 days
  • IGF-1 cannot be used for the 1st 15-18 mos
58
Q

Findings ACTH deficiency

A
  • hypoglycemina
  • hyponatremia without hyperkalemia- cortisol req for water excretion
  • cholestasis- def cortisol -> poor bile flow
  • failure to thrive
59
Q

Testing for ACTH def

A

ACTH or CRH stim test: 3-4 weeks

  • Due to placental CRH stim: false normal if done early
60
Q

Findings TSH deficiency/ hypothyroidism

A
  • Asymptomatic

  • Prolonged jaundice
  • Feeding difficulty
  • Constipation
  • Umbilical hernia
  • Macroglossia
  • Hypotonia
  • delayed reflexes
  • Widen ant fontanelle
  • Dry skin
61
Q

Diagnosis of central hypothyroidism

A

Low FT4 (<0.8 ng/dl) with low or normal TSH

Differential: Sick euthyrodism, Dopamine infusion

62
Q

Treatment consideration in TSH deficiency

A
  • assess for adrenal deficiency (inc cortisol clearance with thyroid replacement)
    • should be treat 48-72 hrs prior to thyroid tx
  • with cholestasis: higher doses of levothyrox and hydrocort due to dec absorption
  • Discontinue thyroid tx before 3 y/o not recommended
63
Q

How to administer levothyroxine

A
  • Administer 30 mins before feeds
    • absorption inhibited by food and products with soy, iron, calcium, aluminum
  • Crushed tablet with 1-2 ml breastmilk, formula or water
  • Placed in cheek pad
64
Q

Pathway for insulin release

A
65
Q

Action of insulin

A
  1. inc cell glucose uptake
  2. deposition of glucose as glycogen
  3. lipogenesis
  4. inhibition of breakdown of TG (lipolysis), FA (ketogenesis)
  5. Fetal growth factor
66
Q

Maintenance of glucose in newborn prior to establish feeds

A
  1. glycogenolysis via inc glucagon and epinephrine
  2. Supress insulin (4-48 hrs)
67
Q

True or false

gluconeogenesis and ketogenesis is established after birth

A

False

68
Q

Rationale for hypoglycemia in

  1. LBW and IUGR
  2. IDM/Macrosomia
A
  1. decreased glycogen store and low fat stores
  2. high insulin level, delay glucagon increase

Ideal: with establishment of feeds- normal levels in 48 to 72 hours

69
Q

counter regulatory hormones of insulin

A

glucagon- promote glycogenolysis, formation ketone bodies

GH- promotes lipolysis (inc FFA for skeletal and cardiac muscle)

catecholamines- inhibits insulin release and promotes glucagon release

cortisol- inc gluconeogenesis from nin car source: alanine, lactate, glycerol

70
Q

Outcome for severe/ frequent hypoglycemia

A

worse executive and visual-motor integration

71
Q

Etiology of hypoglycemia after 48 hours

A
  1. Maternal diabetes (most common transient cause)
  2. Hyperinsulinism- most common cause of persistent nonketotic hypoglycemia
    • transient: stress
    • permanent: channelopathies
  3. hypocortisolism- midline defect
  4. GH defieciency- midline defect, signs of panhypopituarism
72
Q

Newborn with persistent hypoglycemia- differential pathway

A
73
Q

Most accepted definition of hyperglycemia

A

Plasma glucose 125 mg/dl

74
Q

consequences of hyperglycemia

A

Immediate:

  • dehydration
  • ketosis
  • DKA
  • poor growth
  • weight loss
  • poor pefusion
  • susceptibility to infection

Long Term: Neurodevelopment

75
Q

rationale for consequence of hyperglycemia

A
  • changes in osmolality and blood flow
  • endothelial injury
  • intracellular acidosis
  • inc oxidative stress
76
Q

Etiology of hyperglycemia

A
  1. critical illness
  2. infection
  3. stress
  4. meds (GIR fluids)
  5. inadeq insulin

Rationale:

inc cytokines, dec glucose utilization, inc gluconeogenesis

77
Q

Most common defect of permanent DM

A

KCNJ11 and ABCC8 gene (encode beta-cell subunits of K-ATP channel)

associated with parental consanguinity

78
Q

Management of hyperglycemia

A
  1. Dec GIR
  2. Correct dehydration
  3. establish eneteral feeds- inc incretin
  4. dec IL infusion- dec gluconeogenesis and insulin resistance
  5. Insulin
79
Q

ketogenic AA

A

Leucine

Alanine

Glutamine

80
Q

What is the mechanism for maternal diabetes teratogenecity

A

High glucose concentration

  • HbA1C- correlate with rate of congenital anomalies
  • timing: 2-8 weeks of gestation
  • Alteration of DNA methylation
  • Inc reactive oxygen species, disordered antioxidant defense
  • Inc apoptosis (from distubrance of Ca homeostasis)
81
Q

Maternal DM and CNS

(most common anomalies)

A

neural tube defect

holoprosenecephaly hydrocephaly

82
Q

Maternal DM and Cardiac

(most common defect)

A

truncus arteriosus

AVSD

heterotaxy

single ventricle

83
Q

Maternal DM and Craniofacial area

(common affected)

A

Oculo-Auriculo-Vertebral disorder

  • involves abnormalities from the 1st and 2nd pharyngeal arch: ears, eye, vertebral column

orofacial cleft

84
Q

Maternal DM and GI

(most common associated)

A

Atresia

Imporforate anus

Ventral wall defect (gastroschisis and omphalocele)

85
Q

Maternal DM and GU

A

Hypospadias

renal agenesis/hypoplasia

bladder extrophy

86
Q

Maternal DM and Musculoskeletal

A

Caudal regression syndrome

(highest odd ratio)

87
Q

Prevention of fetal and maternal complication of DM

A
  1. HbA1C- < 6.5% pregestation, <6% in gestation
  2. Closer monitoring: detail anatomy scan at 18 to 20 weeks
  3. Fetal echo to consider
88
Q

Definition of metabolic bone disease

A

reduction of bone mineralization below expected

Characterized by:

  1. Biochemical:
  • Ca <8.5 mg/dl (inadequate intake)
  • Phos <3.6 mg/dl
  • Alk phos
    • <33 wks: > 900 IU/L plus phos <5.6 mg/dl
    • <30 wks: >500 IU/L
  1. Radiographic
  • reduced bone mineralization on xray: 20-40%
  • Normal: normal bone denisty, normal dense white line
  • Grade 1 loss of dense whie line at metaphysis and thining cortex
  • Grade 2: fraying metaphysis with splaying (metaphyseal widening) and cupping (rachitic changes)
  • Grade 3: fractures
89
Q

Incidence of MBD

A

23% VLBW

55% ELBW

Detected at 10-16 weeks postnatal age

90
Q

Embryology of skeleton

A
  • Begins at 6 weeks
  • Pathway:
    1. craniofacial: cranial neural crest
    2. axial: paraxial mesoderm
    3. Limb: lateral plate mesoderm
  • Differentiate:
    1. chondrocyte: cartilage then turns to bone (carilage frame work done by 8 weeks)
    2. osteoblast: osteoid bone matrix (mineralization majority at 3rd TM)
91
Q

Function of osteoblast and osteoclast

A

Osteoblast:

  • secrete osteoid bone matrix (unmineralized bone matrix) forms organic bone after binding with calcium
  • differntiate in osteocytes: signal and mechanoreceptor regulate osteoblast and osteoclast (oversight the two cells)

Osteoclast: from hematopoetic stem cell, bone resorption

92
Q

timing of skeletal mineralization

A

Majority 3rd trimester

93
Q

Hormones regulating Mineralization

A
  1. Parathyroid
  2. Vitamin D
  3. PTH related peptide
  4. Calcitonin
94
Q

Effects of PTH

A
  • Affected by dec serum Ca level
  • Bone:
    1. inc osteoclast activity: inc calcium in blood (by upregulate RANKL expression)
  • Kidney:
    1. Inc Ca reaborsption in distal tubule (inc TRPV5 transport)
    2. Dec phos reabsorption
    3. Inc active Vit D (1,25 dihydroxy Vit D/ Calcitriol)
95
Q

What is Vit D

A
  • Active: 1, 25 dihydroxyvitamin D (Calcitriol)
  • D2- enteral
  • D3- sunlight exposure
  • Inc Ca absoprtion
96
Q

What is PTH related peptide

A

Inc Ca transfer from placenta

Involved in proper chondrocyte dev endochondral bone formation

Produced by: placenta, parathyroid, muscles

97
Q

What is Calcitonin

A
  • secreted from thyroid and placenta
  • inc calcitriol (Vit D)
  • dec osteoclast activity
98
Q

True or false

Calcium, magnesium and phosphorus is higher in the fetus than the mom

A

true

99
Q

Intake of fetus per day of

  1. Calcium
  2. Phosphorus
A

Calcium: 100-120 mg/kg

Phosphorous: 50-65 mg/kg/day

100
Q

Main source of calcium in the fetus

A

via active transport across the placenta

101
Q

Reason for relative hypercalcemia in the fetus (3)

A
  1. Low PTH
  2. Low Calcitriol
  3. High PTH related peptide
102
Q

Absorption of Ca in the newborn is by

A
  • Initial passive
  • GI matures: active transport via calbindins (Vit-D dependent)
103
Q

Risk factors for metabolic bone disease (prenatal and post natal)

A
  • Prenatal
    1. Uteroplacental deficiency ( preeclampsia, IUGR)
    2. Chorioamnionitis
    3. Maternal Vit D def
    4. Male
  • Postnatal
    1. Prematurity- Ca accretion in 3rd TM
    2. Feeding intolerance
    3. Vit D def
    4. Meds (inc excretion): loop diuretics, steroids, caffeine, NaHCO3
    5. Sepsis
    6. acidosis
    7. renal disease
    8. liver disease
    9. GI
    10. Immobility
104
Q

Monitor sked for MBD

A

Biochemical at 4 weeks: alk phos and phos then every 2 weeks

Can d/c if: Alk phos <500-600, phos >4 on full feeds

Xray for changes if alk phos >800

105
Q

What is normal accepted mean blood pressure in preterm infant

A

2-3 mmHg above the infant post menstrual age

106
Q

What are the cell origin for the adrenal glands

A

Adrenal cortex: coelmic epithelium

Adrenal medulla: neural crest

107
Q
  1. Components of the mature adrenal gland and early counter part and hormone produced
  2. Which early counter part contributes most to the size of the mature adrenal at birth
A

Zona reticularis: fetal zone: androgen

Zona fasiculata: transitional zone: cortisol

Zona glomerulosa: definitive zone: aldosterone

Fetal zone contributes to size at birth

108
Q

Components of the development of the fetal HPA axis

A

Pregnant woman

Placenta

Fetus

Early gestation (less than 30 weeks): mom provides the steroids; placenta provides progrestrone

Late gestation (after 30 weeks): inc 11B-HSD in placenta to inactive maternal cortisone; fetus produce own ACTH and cotisol

109
Q

What is the action of cortisol

A

metab, stress response, immune and inflam response

Results in: Inc BS, Inc glucagon, Inc catecholamine (via inhibit B receptor breakdown)

Deficiency results in: CLD, cardiovacular instability

110
Q

Role of Aldosterone

A

Absorb Na, excrete K

Control BP (inc extracellular fluid volume) via distal collecting tubule

Results in alkalosis (Inc H excretion to balance K absorption)

111
Q

Role of DHEA and androgenic steroids

A

Precurssor to estrogen and androgen

DHEA: reduce inflam inc blood flow, immunity, insulin sensitivity, bone metab;

Encourage fetal cortisol production: additional 11B-HSD2 in the placenta

Produced by the fetal zone whihc disappears by 6-12 mons of age

112
Q

Presentation of adrenal insuffiency

A

Vasopressor resistant hypotension

113
Q

Duration of neonatal graves disease

A

3 to 5 months

self-limited condition resolves with the clearance of the thyroid receptor antibodies.

114
Q

When and what to treat with abnormal TFT

A

Treat ASAP

  1. Hyperthyroid
  • Asymptomatic: methimazole
  • Symptomatic methimazole + propanolol
  1. Hypothyroid
    * Levothyroxine
115
Q

what is the main treatment of choice for diabetes insipidus

A

thiazide diuretic

think of DI- hypernatremia, polyuria with diluted urine

116
Q

Mechanism to achieve normothermia in newborns

A

Nonshivering thermogenesis by oxidation of brown adipose tissue

  • has sympathetic innervation, very rich vascularization, and an increased number of mitochondria
  • located in the interscapular area, axilla, around the great vessels and kidneys