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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor= {{YD}} (Reviewed by  {{YD}})
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Embryology
|MainCategory=Embryology
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|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Endocrine
|SubCategory=Endocrine
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
|MainCategory=Embryology
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|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Endocrine
|SubCategory=Endocrine
|Prompt=A 5 year old boy is brought by his mother to the physician's office for excessive urination. The mother also notes that her child is always complaining he has a dry mouth and is drinking water all the time. Upon further questioning, the physician notes that several members of the patient's extended family have a similar condition. Appropriate work-up is initiated. The patient is found to be normoglycemic and has high-normal levels of plasma osmolality. Water restriction test is performed and shows an increase in urine osmolality to 1000 mOsmol/kg upon administration of antidiuretic hormone (ADH). Which of the following structures is derived from the same embyological origin as that responsible for the patient's condition?
|Prompt=A 5-year-old boy is brought by his mother to the physician's office for excessive urination. The mother also notes that her child is always complaining he has a dry mouth and is drinking water all the time. Upon further questioning, the physician notes that several members of the patient's extended family have a similar condition. Initial work-up of the patient demonstrates that the patient is normoglycemic and has high-normal levels of plasma osmolality. Water restriction test is performed. It shows an elevated urine osmolality that reaches 1000 mOsm/kg upon administration of antidiuretic hormone (ADH). Which of the following structures is derived from the same embryological origin as that responsible for the patient's condition?
|Explanation=Central diabete insipidus may be familial is in the differential diagnosis of a very young patient presenting with polydipsia and polyuria. It is caused by the destruction of neurons of the supraoptic nucleus in the hypothalamus. As a result, ADH will not be produced by the hypothalamus and it will not be available for storage in the posterior pituitary.  Water restriction test is an appropriate test to differentiate central vs. nephrogenic diabetes insipidus. In contrast to nephrogenic diabetes insipidus where ADH receptors are dysfunctional, the administration of ADH in central diabetes insipidus will cause remarkable elevation of urine osmolality, usually to more than 800 mOsm/kg.
|Explanation=[[Central diabetes insipidus]] (CDI) is a heterogeneous disease characterized by [[arginine vasopressin]] ([[AVP]]) deficiency. The hallmark features of CDI are [[polyuria]] and [[polydypsia]]. CDI is caused by the destruction of neurons of the supraoptic nuclei in the hypothalamus by inflammatory, autoimmune, and vascular causes. Also, compressing lesions, such as [[germinoma]], [[craniopharyngioma]], and [[Langerhans-cell histiocytosis]] are common etiologies. Other causes of CDI include trauma or iatrogenic causes, such as surgery. CDI may also be familial; it may be caused by a genetic disease that may be inherited by X-linked recessive or autosomal dominant pattern. Nonetheless, approximately half of cases of CDI among children are idiopathic.
 
Both, the hypothalamus and the posterior pituitary are derived from the neuroectoderm.


Educational Objective:
Physiologically, AVP is produced in the [[hypothalamus]].  AVP is then transported and stored in the [[posterior pituitary gland]] (neurohypophysis). In CDI, AVP will not be produced by the hypothalamus, thus it will not be available for storage in the posterior pituitary. [[Water restriction test]] is an appropriate test to differentiate central vs. nephrogenic diabetes insipidus (NDI). In contrast to NDI, where AVP receptors in the kidneys are dysfunctional, the administration of AVP analog (DDAVP) in CDI will cause remarkable elevation in [[urine osmolality]], usually to more than 800 mOsm/kg. Of note, most cases of DI are mixed.
Central diabetes insipidus is caused by the destruction of supraoptic nuclei of the hypothalamus, which is derived from the neuroectoderm. Retina is also derived from neuroectoderm.


The hypothalamus, the posterior pituitary, and the retina are all embryologically derived from the same origin, the [[neuroectoderm]].
|AnswerA=Retina
|AnswerA=Retina
|AnswerAExp=Retina is derived from neuroectoderm
|AnswerAExp=[[Retina]] is derived from [[neuroectoderm]].
|AnswerB=Dorsal root ganglia
|AnswerB=Dorsal root ganglia
|AnswerBExp=Dorsal root ganglia are derived from the neural crest
|AnswerBExp=[[Dorsal root ganglia]] are derived from the [[neural crest]].
|AnswerC=Schwann cells
|AnswerC=Schwann cells
|AnswerCExp=Schwann cells are derived from the neural crest.
|AnswerCExp=[[Schwann cell]]s are derived from the [[neural crest]].
|AnswerD=Parafollicular cells of the thyroid
|AnswerD=Parafollicular cells of the thyroid
|AnswerDExp=Parafollicular cells of the thyroid are derived from the neural crest.
|AnswerDExp=Parafollicular cells of the [[thyroid]] are derived from the [[neural crest]].
|AnswerE=Follicular cells of the thyroid
|AnswerE=Follicular cells of the thyroid
|AnswerEExp=Follicular cells of the thyroid are derived from the endoderm
|AnswerEExp=Follicular cells of the thyroid are derived from the [[endoderm]].
|EducationalObjectives=Central diabetes insipidus (CDI) is caused by the destruction of supraoptic nuclei of the hypothalamus, which are derived from the neuroectoderm. Retina is also derived from neuroectoderm.
|References=Maghnie M, Cosi G, Genovese E, et al. Central diabetes insipidus in children and young adults. N Engl J Med. 2000;343(14):998-1007.<br>First Aid 2014 page 553
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=retina, neuroectoderm, embryological, origin, derived, central, diabetes, insipidus, polyuria, polydipsia, water, restriction, test, ADH, antidiuretic, hormone, hypothalamus, posterior, pituitary
|WBRKeyword=Retina, Neuroectoderm, AVP, Arginine vasopressin, Posterior pituitary, Diabetes insipidus, Posterior pituitary gland, Water restriction test, Central diabetes insipidus, Embryological, Origin, Central, Diabetes, Insipidus, Polyuria, Polydipsia, Water, Restriction, ADH, Antidiuretic, Hormone, Hypothalamus, Posterior, Pituitary
|Approved=No
|Approved=Yes
}}
}}

Latest revision as of 01:30, 28 October 2020
Author [[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Embryology
Sub Category SubCategory::Endocrine
Prompt [[Prompt::A 5-year-old boy is brought by his mother to the physician's office for excessive urination. The mother also notes that her child is always complaining he has a dry mouth and is drinking water all the time. Upon further questioning, the physician notes that several members of the patient's extended family have a similar condition. Initial work-up of the patient demonstrates that the patient is normoglycemic and has high-normal levels of plasma osmolality. Water restriction test is performed. It shows an elevated urine osmolality that reaches 1000 mOsm/kg upon administration of antidiuretic hormone (ADH). Which of the following structures is derived from the same embryological origin as that responsible for the patient's condition?]]
Answer A AnswerA::Retina
Answer A Explanation [[AnswerAExp::Retina is derived from neuroectoderm.]]
Answer B AnswerB::Dorsal root ganglia
Answer B Explanation [[AnswerBExp::Dorsal root ganglia are derived from the neural crest.]]
Answer C AnswerC::Schwann cells
Answer C Explanation [[AnswerCExp::Schwann cells are derived from the neural crest.]]
Answer D AnswerD::Parafollicular cells of the thyroid
Answer D Explanation [[AnswerDExp::Parafollicular cells of the thyroid are derived from the neural crest.]]
Answer E AnswerE::Follicular cells of the thyroid
Answer E Explanation [[AnswerEExp::Follicular cells of the thyroid are derived from the endoderm.]]
Right Answer RightAnswer::A
Explanation [[Explanation::Central diabetes insipidus (CDI) is a heterogeneous disease characterized by arginine vasopressin (AVP) deficiency. The hallmark features of CDI are polyuria and polydypsia. CDI is caused by the destruction of neurons of the supraoptic nuclei in the hypothalamus by inflammatory, autoimmune, and vascular causes. Also, compressing lesions, such as germinoma, craniopharyngioma, and Langerhans-cell histiocytosis are common etiologies. Other causes of CDI include trauma or iatrogenic causes, such as surgery. CDI may also be familial; it may be caused by a genetic disease that may be inherited by X-linked recessive or autosomal dominant pattern. Nonetheless, approximately half of cases of CDI among children are idiopathic.

Physiologically, AVP is produced in the hypothalamus. AVP is then transported and stored in the posterior pituitary gland (neurohypophysis). In CDI, AVP will not be produced by the hypothalamus, thus it will not be available for storage in the posterior pituitary. Water restriction test is an appropriate test to differentiate central vs. nephrogenic diabetes insipidus (NDI). In contrast to NDI, where AVP receptors in the kidneys are dysfunctional, the administration of AVP analog (DDAVP) in CDI will cause remarkable elevation in urine osmolality, usually to more than 800 mOsm/kg. Of note, most cases of DI are mixed.

The hypothalamus, the posterior pituitary, and the retina are all embryologically derived from the same origin, the neuroectoderm.
Educational Objective: Central diabetes insipidus (CDI) is caused by the destruction of supraoptic nuclei of the hypothalamus, which are derived from the neuroectoderm. Retina is also derived from neuroectoderm.
References: Maghnie M, Cosi G, Genovese E, et al. Central diabetes insipidus in children and young adults. N Engl J Med. 2000;343(14):998-1007.
First Aid 2014 page 553]]

Approved Approved::Yes
Keyword WBRKeyword::Retina, WBRKeyword::Neuroectoderm, WBRKeyword::AVP, WBRKeyword::Arginine vasopressin, WBRKeyword::Posterior pituitary, WBRKeyword::Diabetes insipidus, WBRKeyword::Posterior pituitary gland, WBRKeyword::Water restriction test, WBRKeyword::Central diabetes insipidus, WBRKeyword::Embryological, WBRKeyword::Origin, WBRKeyword::Central, WBRKeyword::Diabetes, WBRKeyword::Insipidus, WBRKeyword::Polyuria, WBRKeyword::Polydipsia, WBRKeyword::Water, WBRKeyword::Restriction, WBRKeyword::ADH, WBRKeyword::Antidiuretic, WBRKeyword::Hormone, WBRKeyword::Hypothalamus, WBRKeyword::Posterior, WBRKeyword::Pituitary
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