Following a long history of facial and hand changes, Bill Brown was diagnosed with a somatropic adenoma. Adenoma refers to:
bone cartilage enlargement;
an endocrine tumour;
abnormally high levels of Growth Hormone;
A 22-year-old male is admitted to the intensive care unit with a closed head injury sustained in a motorcycle accident. The injury has caused severe damage to the posterior pituitary. Which of the following complications should be anticipated?
Dehydration from polyuria
Insufficient thyroid hormone production during pregnancy and childhood can result in:
cretinism
To adapt to high hormone concentrations, many target cells have the capacity for:
downregulation
Removal of the posterior pituitary would cause a decrease in the release of which hormone?
Antidiuretic hormone (ADH)
Antidiuretic hormone (ADH)
follicle-stimulating hormone;
Signs and symptoms of hypothyroidism are:
bradycardia, myxoedema and weight gain;
Bill was found to have abnormally high levels of Growth Hormone. An increase in growth hormone in adulthood results in:
acromegaly.
Diagnosis of Cushing’s disease includes:
striae, hyperglycemia, osteoporosis;
Insulin is primarily regulated by:
serum glucose levels;
Management of diabetes mellitus involves measuring glycated (glycosylated) haemoglobin (haemoglobin A1c) levels. The purpose of this test is to:
monitor long-term serum glucose control;
Gabriel is likely to have an enlarged thyroid gland is known as goitre. In which thyroid states would goitre be found?
Hypothyroidism, Hyperthyroidism and Chronic iodine deficiency
A 54-year-old patient with pulmonary tuberculosis (lung infection) is evaluated for syndrome of inappropriate ADH secretion (SIADH). Which of the following electrolyte imbalances would be expected in this patient?
Hyponatraemia
Gabriel developed severe tachycardia, agitation and nausea. The nursing staff were concerned he had developed cardiac failure because:
hyperthyroidism is associated with increased metabolic rate, an increased cardiac output and possible atrial fibrillation which can lead to congestive heart failure.
An example for tertiary endocrine dysfunction is:
a tumour in the hypothalamus
Endocrine functions are
homeostasis, stress response, growth and development and sexual maturation.
Hormones are released
in response to an alteration in the cellular environment, to maintain a regulated level of certain substances or other hormones.
Regulation of hormones is mainly through
negative feedback.
Low levels of hormones cause
an increase in receptors on the cell known as up regulation.
High levels of hormones cause
a decrease in receptors on the cells known as down regulation.
Hormone receptors are located
in the plasma membrane or inside the target cell.
Protein based (water soluble) hormones
cannot cross the barrier require a messenger to cross.
Steroid based (lipid soluble) hormones
easily diffuse across the membrane
Endocrine dysfunction
Primary
Secondary
Tertiary
Primary endocrine dysfunction
malfunction of the gland producing the hormone
Secondary endocrine dysfunction
normal gland
abnormally releasing or stimulating gland (usually pituitary gland)
Tertiary endocrine dysfunction
problem with the hypothalamus and pituitary axis
usually caused by a tumor.
Anterior pituitary gland releases
growth hormone (GH)
thyroid stimulating hormone (TSH)
adrenocorticotropic hormone (ACTH)
follicle stimulating hormone (FSH)
luteinising hormone (LH)
Prolactin
Posterior pituitary gland releases
anti diuretic hormone (ADH)
Oxytocin
SIADH
syndrome of inappropriate antidiuretic hormone secretion.
increase secretion of ADH
causes increased renal water retension, hyponatraemia and hypo-osmolality.
Alterations if pituitary function include
diabetes insipidus
Diabetes insipidus
insufficent ADH
polyuria and polydypsia
partial or total inability to concentrate the urine
Pituitary tumors
Primary - adenoma
Secondary - metastatic lesions
functional - secrete pituitary hormones
nonfunctional - do not secrete hormones.
Decrease growth hormone causes
dwarfism
Increased growth hormone causes
gigantism
Somatotropin
used for treatment of GH deficiency
Somatostatin
used for treatment of excessive GH inhibits release of GH from hypothalamus
Excessive growth hormone in adults can cause
acromegaly
Type 1 diabetes mellitus is
destruction of insulin producing beta cells therefore no insulin produced.
Type 2 diabetes mellitus is
cellular resistance, insulin produced but target tissues are not responsive.
Gestational diabetes
diabetes during pregnancy due to hormonal changes associated with pregnancy
Metformin is used for
type 2 diabetes mellitus. It decreases glucose production, decreases glucose absorption in the gut and increases receptor sensitivity for insulin.
Thyroid produces
calcitonin - inhibits osteoclast activity reducing calcium within the blood.
Parathyroid produces
parathyroid hormone - increases osteoblast activity to increase calcium within the blood.
The hypothalamis is the coordinating center of the brain for
the endocrine, behavioural and autonomic nervous system function
Primary defects in the endocrine function originate in
the target gland responsible for producing the hormone.
Hypofunction of the pituitary gland results in
short stature
An overactive thyroid gland results in
a higher metabolism.
What hormone is central to the maintenance of body metabolism, growth and development in children?
Thyroid hormone.
What hormone has multiple roles including anti-insulin effects, the length of linear bones and the rate of cell division.
Growth hormone.
When hormones act locally on cells other than those that produced the hormone, the action is called
paracrine.
When a hormone acts on the cell that produced it
autocrine
Goitre is
a visible increase in size of the thyroid gland and can be caused by either hyperthyroidism or hypothyroidism.