Endocrinology

Question 1

Embryologic derivation of the thyroid

Answer 1

Thyrocytes/follicular cells –> foregut endoderm/foramen cecum
Parafollicular cells –> neural crest/ultimobranchial body

Most common site of ectopic thyroid is the base of the tongue

Incomplete obliteration of the thyroglossal duct can cause cysts along the midline of the anterior neck that moves with swallowing and protrusion of the tongue

Question 2

Products of the adrenal glands

Answer 2

GFR –> Salt, sugar, sex

Zona glomerulosa –> aldosterone (regulated by renin-angiotensin)
Zona fasiculata –> glucocorticoids (cortisol), sex hormones (regulated by ACTH, CRH)
Zona reticularis –> sex hormones (regulated by ACTH, CRH)

Question 3

Embryologic derivation of the pituitary gland

Answer 3

Anterior pituitary –> oral ectoderm/Rathke’s pouch

Posterior pituitary –> neural ectoderm

Question 4

Embryologic derivation of the pancreas

Answer 4

Endoderm

Question 5

Embryologic derivation of the adrenal glands

Answer 5

Adrenal cortex –> mesoderm

Adrenal medulla –> neural crest

Question 6

Embryologic derivation of the parathyroid glands

Answer 6

Mesoderm
Superior glands: 4th pharyngeal pouch
Inferior glands: 3rd pharyngeal pouch

Question 7

Which endocrine hormones use cAMP as a signaling pathway?

Answer 7

FLAT ChAMP

FSH, LH, ACTH, TSH, CRH, hCG, ADH (V2-receptor), MSH, PTH

Question 8

Which endocrine hormones use cGMP as a signaling pathway?

Answer 8

ANP, BNP, NO

Question 9

Which endocrine hormones use IP3 as a signaling pathway?

Answer 9

GOAT HAG

GnRH, oxytocin, ADH (V1-receptors), TRH, histamine (H1-receptors), angiotensin II, gastrin

Question 10

Papillae, cells with clear nuclei and nuclear grooves, psammoma bodies

Answer 10

Papillary carcinoma of the thyroid

“Orphan Annie eyes”

Question 11

Sheets of cells in an amyloid stroma

Answer 11

Medullar carcinoma

Amyloid stroma from calcitonin secretion

Question 12

Kallmann syndrome

Answer 12

Failure of GnRH-secreting neurons to migrate

Delayed puberty, anosmia

Question 13

First signs of puberty

Answer 13

Boys: testicular enlargement
Girls: breast enlargement

Question 14

Neuroblastoma

Answer 14

Most common extracranial childhood cancer
Develops from neuroblasts located in the adrenal medulla
S&S: retroperitoneal mass, HTN, anorexia, weight gain
Dx: increased catecholamines in urine
Histology: small blue cells with N-myc amplification
Can metastasize to epidural space, bone marrow, liver, skin, cerebellar paraneoplastic syndrome