Week 10: Endocrine Flashcards
acromegaly
results from excess secretion of growth hormone (GH), a rare condition
of bone and soft tissue overgrowth.
manifestations of acromegaly
enlargement of hands and feet, thickening and enlargement of
bony and soft tissue on face and head, sleep apnea, signs of diabetes mellitus,
cardiomegaly, and hypertension.
Hypopituitarism
is rare, and involves a decrease in one or more of the pituitary
hormones
Syndrome of inappropriate antidiuretic hormone (SIADH)
results from abnormal
production or sustained secretion of ADH and is characterized by fluid retention,
serum hypo-osmolality, dilutional hyponatremia, hypochloremia, concentrated urine
in presence of normal or increased intravascular volume, and normal renal function.
Diabetes insipidus (DI)
associated with deficiency of production or secretion of
ADH or decreased renal response to ADH.
Types of DI:
o Central DI (or neurogenic DI) occurs when an organic lesion of the
hypothalamus, infundibular stem, or posterior pituitary interferes with ADH
synthesis, transport, or release.
o Nephrogenic DI occurs when there is adequate ADH, but a decreased kidney
response to ADH. Lithium is a common cause of drug-induced nephrogenic DI.
o Primary (or psychogenic) DI is associated with excessive water intake, caused by
a structural lesion in the thirst centre or by psychological disorders.
goitre
an enlarged thyroid gland. In a person with a goitre, the thyroid cells are
stimulated to grow, which may result in an overactive thyroid (hyperthyroidism) or an
underactive one (hypothyroidism).
The primary sign of thyroid cancer is
the presence of painless, palpable nodule or
nodules in an enlarged thyroid gland.
Hashimoto’s thyroiditis
a chronic autoimmune disease in which thyroid tissue is
replaced by lymphocytes and fibrous tissue. It is the most common cause of goitrous
hypothyroidism.
Hyperthyroidism
thyroid gland hyperactivity with sustained increase in synthesis
and release of thyroid hormones.
Thyrotoxicosis
refers to clinical syndrome of hypermetabolism resulting from excess
circulating levels of T4, T3, or both.
Graves’ disease
an autoimmune disease marked by diffuse thyroid enlargement
and excessive thyroid hormone secretion.
Thyrotoxic crisis,
an acute, rare condition in which all
hyperthyroid manifestations are heightened.
manifestations of thyrotoxic crisis
severe tachycardia, heart failure, shock, hyperthermia,
restlessness, agitation, seizures, abdominal pain, nausea, vomiting, diarrhea, delirium,
and coma.
Hypothyroidism
from insufficient circulating thyroid hormone as a result of
various abnormalities.
Cretinism,
hypothyroidism that develops in infancy, is caused by thyroid hormone
deficiencies during fetal or early neonatal life.
myxedema,
an
accumulation of hydrophilic mucopolysaccharides in dermis and other tissues.
myxedema coma
precipitated by infection, drugs (especially opioids,
tranquilizers, and barbiturates), exposure to cold, and trauma. This condition is
characterized by subnormal temperature, hypotension, and hypoventilation. To
survive, vital functions are supported and IV thyroid hormone replacement
administered.
Hyperparathyroidism
involves increased secretion of parathyroid hormone (PTH).
Manifestations of hyperparathyroidism
include muscle weakness, loss of appetite, constipation, fatigue,
emotional disorders, and shortened attention span.
Hypoparathyroidism
rare, and results from inadequate circulating PTH.
Cushing’s syndrome
a spectrum of clinical abnormalities caused by excessive
corticosteroids, particularly glucocorticoids.
cushings syndrome key signs
centripedal (truncal) or generalized obesity, “moon facies”
(fullness of face), purplish red striae below the skin surface, hirsutism and menstrual
disorders in women, hypertension, and unexplained hypokalemia.
addisons disease
all three classes of adrenal corticosteroids
(glucocorticoids, mineralocorticoids, and androgens) are reduced.
Addisonian crisis is triggered by
stress (e.g., infection, surgery, trauma, hemorrhage,
or psychological distress); sudden withdrawal of corticosteroid hormone replacement
therapy; adrenal surgery; or by sudden pituitary gland destruction.
Hyperaldosteronism
characterized by excessive aldosterone secretion, commonly
caused by small, solitary adrenocortical adenoma (primary hyperaldosteronism [PA]).
Pheochromocytoma
a rare condition characterized by an adrenal medulla tumour
that produces excessive catecholamines (epinephrine, norepinephrine).
If undiagnosed and untreated, pheochromocytoma may lead to
hypertensive
encephalopathy, diabetes mellitus, cardiomyopathy, and death.
Diabetes mellitus (DM)
a multisystem disease related to abnormal insulin
production, impaired insulin utilization, or both.
Type 1 DM results from
progressive destruction of pancreatic β cells owing to an
autoimmune process in susceptible individuals.
In type 2 DM,
the pancreas usually continues to produce some endogenous (self-
made) insulin. However, the insulin that is produced is either insufficient for the
needs of the body and/or is poorly used by the tissues.
Gestational diabetes mellitus
develops during pregnancy and is detected
atanywhere between 24 and 28 weeks of gestation, using a sequential screening
method.
A diagnosis of diabetes is based on one of four methods:
(1) glycated hemoglobin
(A1C), (2) fasting blood glucose (FBG) level, (3) random plasma glucose (RPG)
measurement, or (4) 2-hour plasma glucose (PG) level.
Lipodystrophy
(hypertrophy or atrophy of subcutaneous tissue) may occur if the
same injection sites are used frequently.
Somogyi effect
characterized by wide differences in early-morning (low)
and fasting (high) glucose levels. Usually occurring during the hours of sleep, the
Somogyi effect produces a decline in blood glucose level in response to too much
insulin.
OHAs
work on the three defects of type 2 diabetes:
(1) insulin resistance, (2) decreased
insulin production, and (3) increased hepatic glucose production.
The primary action of the sulphonylureas
increase β-cell insulin production from
the pancreas.
meglitinides
increase insulin production from the pancreas.
But because they are more rapidly absorbed and eliminated, they offer a reduced
potential for hypoglycemia.
α-glucosidase inhibitors, also known as starch blockers,
work by slowing down the
absorption of carbohydrate in the small intestine.
Glycemic index (GI)
term used to describe the rise in blood glucose levels
after a person has consumed carbohydrate-containing food. Foods with a high GI will
cause a sharp rise in blood glucose, whereas those with a low GI steadily increase
blood glucose over a longer period.
Diabetic ketoacidosis (DKA)
an acute metabolic complication of DM occurring
when fats are metabolized in the absence of insulin. It is caused by a profound
deficiency of insulin and is characterized by hyperglycemia, ketosis, metabolic
acidosis, and dehydration. It is most likely to occur in people with type 1 DM.
Hyperosmolar hyperglycemic state (HHS)
a life-threatening syndrome that can
occur in the patient with DM who is able to produce enough insulin to prevent DKA but not enough to prevent severe hyperglycemia, osmotic diuresis, and extracellular
fluid depletion.
Diabetic retinopathy
refers to the process of microvascular damage to the blood
vessels in the retina as a result of chronic hyperglycemia, presence of nephropathy,
and hypertension in patients with DM.
Diabetic nephropathy
a microvascular complication associated with damage to
the small blood vessels that supply the glomeruli of the kidney.
Diabetic neuropathy
nerve damage that occurs because of the metabolic
derangements associated with DM. The two major categories of diabetic neuropathy
affect the peripheral nervous system: sensory neuropathy (which affects the somatic
division) and autonomic neuropathy (which affects the autonomic division).
