Chapter 10: Endocrine Flashcards
Likely causes of Hyperpituitarism
benign pituitary adenoma
microdenoma (< 1cm) or macroadenoma (> 1 cm)
Manifestations of a microadenoma (lactotroph)
hyperpituitarism
manifestations of hormone excess
lactotroph = increased prolactin = hypogonadism and infertility
Manifestations of a macroadenoma
hyperpituitarism
headache, visual disturbances (impingement on cranial nerves and optic chiasm [where optic nerves cross])
causes of hypopituitarism
pituitary = congenital defect, surgery/radiation, infection (TB, meningitis), pituitary tumor, pituitary infarction (Sheehan syndrome)
hypothalmic = hypothalmic tumor, infection, infiltrative disorder (histocytosis, sarcoidosis), TBI, Radiation
hypopitiuitarism manifestations
growth hormone deficiency = delayed growth and development
fsh/lh deficiency = impaired reproductive (infertility, amenorrhea, irregular menses, hot flashes)
tsh deficiency = central hypothyroidism
acth deficiency = secondary adrenal insufficiency (cortisol deficiency, not aldosterone)- weakness, nausea, anorexia, hypotension
ADH deficiency = diabetes insipidus – excessive urination.
signs of SIADH
hyponatremia (dilutional), high urine osmolality (concentrated), low urine output, low serum hypo-osmolarity (<270), n/v, confusion, weakness, cramping
signs of DI
hypernatremia, low urine osmolarity, high urine output, serum hyperosmolarity (>320), polydipsia, nocturia
cause of acromegaly or gigantism,
excess GH and IGF-1
often due to an adenoma
cause of dwarfism
growth hormone deficiency d/t tumor, GHRH receptor mutations, pituitary agenesis (no organ development), panhypopituitarism
what is a pheochromocytoma
As a tumor of adrenal medullary tissue, a pheochromocytoma produces symptoms of catecholamine excess. Anxiety, headache, and palpitations are direct effects of catecholamine discharge; weight loss is secondary to one of the metabolic effects of excessive circulating catecholamines. These include an increase in basal metabolic rate and an increase in glycolysis and glycogenolysis, leading to hyperglycemia and glycosuria
causes of goiters
increased intake of foods containing goitrogens (eg, rutabaga, cabbage, turnip, cassava)
A diminished intake of foods containing iodine (eg, fish)
Use of medications associated with goiter (eg, propylthiouracil, methimazole, nitroprusside, sulfonylureas, lithium)
Symptoms of thyroid encroachment on surrounding structures such as respiratory or swallowing difficulties should be elicited.
Because of this patient’s fatigue and depression, the physician should also probe for other symptoms of hypothyroidism.
- A predominant effect of a prolonged excessive growth hormone level is:
A) short stature with obesity.
B) high androgen hormone levels.
C) increased blood glucose levels.
D) insulin-like growth factor (IGF) depletion.
C) increased blood glucose levels.
- The most common cause of hypothyroidism is:
A) goiter.
B) myxedema.
C) thyroidectomy.
D) autoimmune thyroiditis.
D) autoimmune thyroiditis.
- Thyroid hormone deficit , which alters the function of all major organs in the body.
A) decreases metabolism
B) increases protein synthesis
C) causes vitamin deficiencies
D) enhances absorption of glucose
A) decreases metabolism
- The most common cause of thyrotoxicosis is Graves disease, which has the distinguishing characteristic of in addition to a diffuse goiter.
A) muscle fatigue
B) facial myxedema
C) ophthalmopathy
D) decreased cholesterol
C) ophthalmopathy
- The major adrenal cortical hormones are steroids and are synthesized from acetate and:
A) ACTH.
B) albumin.
C) amino acids.
D) cholesterol.
D) cholesterol.
- Primary adrenal insufficiency is manifested by:
A) truncal obesity and edema.
B) hypokalemia and hypervolemia.
C) hyponatremia and hypoglycemia.
D) hypopigmentation and hypertension.
C) hyponatremia and hypoglycemia.
- One of the earliest signs of Cushing syndrome is the loss of variable diurnal secretion of cortisol-releasing hormone (CRH) and:
A) GH.
B) TSH.
C) DHEA.
D) ACTH.
D) ACTH.