ENDOCRINE Flashcards

Question

precocious puberty

Answer 1

ESTROGEN/TESTESTERON VS IGF ##Idiopathic precocious puberty is characterized by early-onset, pulsatile GnRH secretion, resulting in increased estrogen production. Estrogens promote bone growth but also epiphyseal plate (ie, growth plate) closure, so without treatment, patients typically have an early growth spurt but a shorter-than-expected adult height. A growth spurt occurs during early puberty primarily due to positive feedback by estrogen on growth hormone (GH) production. GH stimulates insulin-like growth factor 1 (IGF-1) synthesis, which leads to the differentiation and proliferation of chondrocytes in the epiphyseal plate and therefore increased linear growth

Answer 2

1.WIGH LOSS-- FAT LOSS 2.LEPTI PRODUCTION LOSS 3.GNRH REDUCED (BY HYPOTHULMUS) 4.FSH/LH REDUCED 5.ESTROGEN REDUCED ركز مهم كثير انه الاستروجين اخر اشي بنزل مش اول اشي results from loss of pulsatile GnRH release from the hypothalamus and is caused by weight loss, strenuous exercise, systemic illness, or abnormal eating habits. Loss of cyclic gonadotropin release leads to a decrease in LH and FSH secretion from the pituitary, which in turn causes low circulating estrogen levels.

Answer 3

Clinical features of hypopituitarism Etiology Pituitary causes Primary (eg, adenoma) or metastatic mass Infiltration (eg, hemochromatosis, lymphocytic hypophysitis) Hemorrhage (pituitary apoplexy) or infarction (Sheehan syndrome) POST DELIVARY Hypothalamic causes Mass lesions Radiation therapy Infiltration (sarcoidosis) Trauma to skull base Infections (tuberculosis meningitis) Clinical presentation ACTH deficiency (secondary adrenal insufficiency) Postural hypotension, tachycardia, fatigue, weight loss, hypoglycemia, eosinophilia Hypothyroidism (central) Fatigue, cold intolerance, constipation, dry skin, bradycardia, slowed deep-tendon reflexes Gonadotropins Women: amenorrhea, infertility Men: infertility, loss of libido ##Acute pituitary hemorrhage (pituitary apoplexy) is characterized by severe headache, bitemporal hemianopsia (compression of the optic chiasm), and ophthalmoplegia (compression of the oculomotor nerve [CN III]). It usually occurs in a preexisting pituitary adenoma. Pituitary apoplexy is a medical emergency that requires urgent treatment with glucocorticoids to prevent acute adrenal crisis and circulatory collapse.

Answer 4

##Use fructosamine instead ##Hemoglobin A1c (HbA1c) – Basics Formed by irreversible nonenzymatic glycosylation of hemoglobin (N-terminal) Reflects average blood glucose over ~3 months (RBC lifespan) ↑ Glucose or longer RBC exposure → ↑ HbA1c ##When HbA1c is FALSELY LOW ✅ Increased RBC turnover Beta-thalassemia minor ↑ HbA2 Microcytic RBCs → hemolysis ↓ RBC lifespan → falsely low HbA1c Use fructosamine instead ✅ Sickle cell disease / trait ↑ RBC destruction Trait: slight ↓ HbA1c Disease: marked ↓ HbA1c ✅ After treatment of: Iron deficiency Folate deficiency B12 deficiency → rapid release of young RBCs → ↓ HbA1c ##When HbA1c is FALSELY HIGH ✅ Decreased RBC turnover Untreated: Iron deficiency Folate deficiency Vitamin B12 deficiency → older RBCs persist → ↑ HbA1c ✅ Advanced diabetic nephropathy ↓ EPO production ↓ new RBCs → ↑ HbA1c TRUE High HbA1c ##Chronically elevated blood glucose (poor glycemic control) ##Key Alternative Test Fructosamine → reflects glycemia over 2–3 weeks Used when RBC lifespan is altered

Answer 5

confirmed by the Whipple triad: 1.Symptoms consistent with hypoglycemia (eg, tremor, diaphoresis, confusion) 2.Low blood glucose level 3.Relief of hypoglycemic symptoms when the blood glucose level is corrected C-PEPTIDE LEVELS TO KNOW IF ITS ENDO OR EXOGENOUS INSULIN

Answer 6

Features of glucagonoma Clinical presentation 1.Necrolytic migratory erythema IMPORTANTTT Erythematous papules/plaques on face, perineum & extremities Lesions enlarge & coalesce, leaving a central indurated area with peripheral blistering & scaling 2.Diabetes mellitus/hyperglycemia 3.Gastrointestinal symptoms (diarrhea, anorexia, abdominal pain) Diagnosis Markedly elevated glucagon levels ##zinc deficiency can resemble necrolytic migratory erythema Zinc deficiency causes erythematous skin lesions (mainly around body orifices) that are predominantly vesicular and pustular. Other features (TO DEFERENTIATE) include hypogonadism, impaired taste and smell, night blindness, and impaired wound healing.

Answer 7

Pheochromocytoma is a malignancy arising from chromaffin cells of the adrenal medulla that typically presents with episodic headaches, diaphoresis, and hypertension. The adrenal medulla is derived from neural crest cells (multipotent, migratory cells that originate in ectoderm), which also give rise to melanocytes and neural ganglia. IMPORTANT ##NOTE: NORMALLY MEDULLA (Chromaffin cells are modified neuroendocrine cells derived from the neural crest) stimulated by acetylcholine

Answer 8

The anterior pituitary is formed from an out-pouching of the pharyngeal roof and is called Rathke's pouch. The posterior pituitary gland arises from an extension of the hypothalamic neurons. ##Craniopharyngiomas are tumors arising from Rathke's pouch remnants in the anterior pituitary. They characteristically have three components: solid, cystic, and calcified. They present during childhood, usually, with mass effect and visual deficits.

Answer 9

DiGeorge syndrome A 22q11.2 microdeletion results from maldevelopment of the third (inferior parathyroid and thymus) and fourth (superior parathyroid) pharyngeal/branchial pouches. Subsequent parathyroid and thymic hypoplasia results in hypocalcemia and T cell deficiency. Conotruncal cardiac anomalies (eg, interrupted aortic arch, truncus arteriosus) features such as hypertelorism, short palpebral fissures, micrognathia, bifid uvula, and cleft palate.

Answer 10

The thyroid gland is formed from an outpouching (evagination) of the pharyngeal epithelium and subsequently descends to the lower neck anterior to the upper trachea and larynx. The lowest part of the evagination forms the thyroid gland and the remaining portion forms the thyroglossal duct, which extends from the foramen cecum on the dorsal surface of the tongue to the superior border of the thyroid isthmus. IMPORTANT : Due to failure of migration, the thyroid can reside anywhere along the thyroglossal duct's usual path, including the tongue (lingual thyroid). Enlargement of a lingual thyroid can lead to obstructive symptoms (eg, dysphagia, dysphonia, dyspnea), typically during times of heightened thyroid stimulation (eg, puberty, pregnancy). Sometimes, this lingual thyroid is the only thyroid tissue in the body, so hypothyroidism can occur if it is removed.

Answer 11

The superior thyroid artery and vein and external branch of the superior laryngeal nerve course together in a neurovascular triad that originates superior to the thyroid gland and lateral to the thyroid cartilage. The external branch is at risk of injury during thyroidectomy as it courses just deep to the superior thyroid artery. IMPORTANT : The cricothyroid muscle is the only muscle innervated by this nerve. The cricothyroid muscle acts to tense the vocal cords, and denervation injury may cause a low, hoarse voice with limited range of pitch. The internal branch of the superior laryngeal nerve does not innervate any muscles but provides sensory innervation to the laryngeal mucosa above the vocal folds. ##The remaining laryngeal muscles (Aryepiglotticus , Lateral cricoarytenoid ,Posterior cricoarytenoid, Thyroarytenoid) are innervated by the recurrent laryngeal nerves, which also provide sensory innervation to the larynx below the vocal folds. The recurrent laryngeal nerves lie posterior to the thyroid, near the inferior thyroid arteries. These nerves can be injured during thyroidectomy .

ENDOCRINE Flashcards

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