Endocrine Flashcards
I week following a total thyroidectomy, a 32-year-old female notes marked numbness and tingling in
her feet and hands. On examination, both Trousseau’s and Chvostek’s signs are positive.
Select which biochemical abnormality is MOST LIKELY to be associated with her problem.
Select one:
a.Increased phosphate metabolism
b. Increased calcium reabsorption from the gut
C.Decreased plasma phosphate
d. Decreased plasma calcium
D
Trousseau’s and Chvostek’s: hypocalcemia
15-month-old Ethiopian child presents with bow legs and “rachitic rosary” on palpation of his ribs. ,
clinical diagnosis of vitamin D deficiency is made.
Select which of the following biochemical abnormalities would be expected in this child.
Select one:
a. Decreased serum magnesium
b. Elevated serum phosphate
C.Elevated serum parathyroid hormone
d. Elevated serum calcium
C
less vitamin D = less Ca2+ = stimulates PTH
- vitamin D increases Ca2+ and PO4- absorption so B and D are out
Select which of the following statements is MOST CORRECT for Hashimoto’s (autoimmune) thyroiditis.
Select one:
a. Hashimoto’s (autoimmune) thyroiditis causes hypothyroidism requiring thyroxine treatment.
b. Hashimoto’s (autoimmune) thyroiditis is associated with suppressed levels of TSH.
c. Hashimoto’s (autoimmune) thyroiditis commonly presents as a grossly enlarged gland with no clinical symptoms.
d. Hashimoto’s (autoimmune) thyroiditis is most common in men between the
ages of 20 and 30 years.
A
b/ hashimotos is primary hypothyroidism where autoimmune cells attack T3 and T4 causing low levels, but TSH is still intact/high
Select which of the following combination of signs is MORE LIKELY to be seen in a female patient with
Cushing’s disease.
Select one:
a. Acanthosis nigricans, buffalo hump, cataracts, necrobiosis lipoidica, sweet-smelling breath
b. Buffalo hump, cataracts, pretibial myxoedema, necrobiosis lipoidica, thin skin with bruises
c. Acne, cataracts, hirsutism, spade-shaped hands, vitiligo
d. Acne, buffalo hump, hirsutism, proximal myopathy, thin skin with bruises
D
Necrobiosis lipoidica (NL) is a rare, chronic, and idiopathic granulomatous disease of collagen degeneration. It has an associated risk of ulceration and is classically associated with diabetes mellitus,
Acanthosis nigricans: A skin condition characterised by dark, velvety patches in body folds and creases.
Acanthosis nigricans typically occurs in people who are obese or have diabetes. More rarely, it can be a warning sign of a cancerous tumour in an internal organ, such as the stomach or liver.
Dark, velvety patches of skin often appear in the armpits, groin and neck.
What is the most common non-functioning pituitary adenoma?
Space occupying benign tumour, causing bilateral hemianopia due to compression of optic chiasm–peripheral vision lost
What is the most common functioning pituitary adenoma?
Secreting PRL –> males–erectile dysfunction, loss of libido, gynaecomastia
Females: galactorrhoea, amenorrhea, infertility, osteopenia
What is gigantism/acromegaly? What is the cause and what are the common symptoms?
Excess GH–> due to GH secreting pituitary adenoma. Acromegaly: Excessive growth and bone thickening in ADULTS (after fusion of bones) rather than lengthening; Spade-like hands, large facial features, prognathism(Extended chin; Underbite. Prognathism is an extension or bulging out (protrusion) of the lower jaw (mandible). It occurs when the teeth are not properly aligned due to the shape of the face bones. Prognathism is a descriptive term for a jaw (upper or lower) that protrudes forward beyond the plane of the face_
Gigantism: excessive bone lengthening and growth (before fusion of bones) in CHILDREN
What are the causes of Cushings’ disease? What are some characteristic symptoms to look out for
Excess cortisol production:
1. Primary: Cortisol secreting tumour of the adrenal glands
2. Secondary: (2nd most common) benign tumour of pituitary secreting ACTH
3. (Most common) due to pharmacological agents
Moon face, Buffalo hump, central obesity, hriutisym, thinning skin and easy bruising, hypertension, striae, osteoporosis, immunosuppression
What is diabetes insipidus
Insufficient ADH action (neuropathic or nephropathic). Symptoms of polyuria and polydipsia
Which is true about the hypothalamic-pituitary-organ axis?
a. The sole function of the hypothalamus is to regulate secretion of pituitary hormones
b. Short-loop feedback is contained within the CNS
c. Pituitary hormones do not feedback upon hypothalamic secretion
d. Prolactin is responsible for milk letdown
e. FSH and LH are stimulated by CRH
B
A. Hypothalamus also controls ANS, temperature regulation, water balance, food intake and energy balance, emotions and behaviour
C. This is short-loop feedback
D. Oxytocin – milk letdown; prolactin – milk production
E. FSH and LH stimulated by GnRH, ACTH stimulated by CRH
Which of the following best describes the embryological development of the pituitary?
A. The anterior pituitary arises from the mesoderm
B. The anterior pituitary arises from the neuroectoderm
C. The posterior pituitary arises from the neuroendoderm
D. The pituitary stalk arises from Rathke’s pouch
E. The pituitary stalk arises from the neuroectoderm
E
Anterior pituitary arises from the Rathke’s pouch (dorsal ectoderm); posterior pituitary and pituitary stalk arise from the neuroectoderm of the hypothalamus and 3rd ventricle
A 36yo woman presents with gradual onset of headaches and bitemporal hemianopia. Assuming she has a functioning pituitary tumour, which of the following is she most likely to have as well?
Postural hypotension
Increased frequency of voiding
Spade-like hands
Amenorrhoea
Central obesity
D
Most common form of functioning pituitary tumour is prolactinoma, a prolactin secreting tumour. Common symptoms for women include galactorrhoea, amenorrhoea, infertility and osteopenia.
Fill in the blanks
Enzyme involved in thyroid synthesis: XXX
Secretion: XXX –> XXX –> TX, XX
T4 is also deiodinated to T3 in the periphery
Main action: ? (3)
Pathology:
Primary vs secondary, hyper vs hypo
Grave’s (Primary XX, X pathogenesis?)
Hashimoto’s (XX hypothyroid, X pathogenesis?)
+ pharm
Enzyme involved in thyroid synthesis: TPO
Secretion: TRH 🡪 TSH 🡪 T4, T3
T4 is also deiodinated to T3 in the periphery
Main action: increase basal metabolic rate, O2 consumption and heat production
Pathology:
Primary vs secondary, hyper vs hypo
Grave’s (Primary hyperthyroid, TSAbs)
Hashimoto’s (Primary hypothyroid, anti-TPO)
+ pharm
The first-line pharmacological treatment for Grave’s disease is:
Carbimazole
Propylthiouracil
Propranolol
Radioactive iodine
Thyroidectomy
Carbimazole.
It is less hepatotoxic than PTU. Although: in first trimester pregnancy/breast feeding: PTU preferential
Both carbimazole and PTU inhibit TPO and hinders iodination and thyroid hormone synthesis
A patient has taken radioactive iodine. Which will be a factor in determining hyperthyroidism?
A. Decreased uptake
B. Increased uptake
C. Increased serum Ca
D. Decreased serum Ca
B
Increased uptake indicates high follicular activity
