Hyposecretion of Anterior Pituitary Hormones Flashcards
What is the difference between primary, secondary and tertiary endocrine gland disease?
Primary – problem with the endocrine gland/hormone released
Secondary – problem with the pituitary gland/hormone released
Tertiary – problem with the hypothalamus
What is the term given to decreased secretion of all anterior pituitary hormones?
Panhypopituitarism
Broadly speaking, what can panhypopituitarism be caused by?
Congenital defects (rare) Gene mutations (more rare)
In what order does loss of secretion occur?
Usually develops in adults with progressive loss of pituitary secretion Gonadotrophins GH Thyrotrophin Corticotrophin Prolactin
What are three main types of panhypopituitarism?
Simmond’s Disease
Sheehan’s Syndrome
Pituitary Apoplexy
Describe the onset of Simmond’s disease and state some of its causes and symptoms.
Insidious (slow) onset Can be caused by: Infiltrative diseases Craniopharyngioma Cranial injury Pituitary adenomas Following surgery Symptoms: (mainly due to loss of adrenal, gonadal and thyroid function) Impotence Loss of libido Hypotension Tirednesss Secondary amenorrhoea or oligomenorrhoea Loss of body hair Waxy skin
State the cause of Sheehan’s syndrome and describe its onset.
This is specific to WOMEN
It is caused by vasoconstrictor spasm of hypophysial arteries as a result of post-partum haemorrhage
This spasm causes pituitary infarction
This develops very RAPIDLY
What is pituitary apoplexy? Describe its onset.
This is similar to Sheehan’s syndrome but isn’t specific to women
It is caused by intra-pituitary infarction or haemorrhage This also has a RAPID presentation
Why is a single measurement of most hypothalamic hormones not useful?
Most hypothalamic hormones tend to be released in pulses
What type of test do you do to test if someone is producing a hormone?
Stimulation/provocation test
How are the releasing hormones administered in these tests?
Intravenous
What is the name given to the secondary endocrine gland failure that results from a lack of corticotrophin release from the pituitary?
Hypoadrenocorticalism
What are the effects of a lack of somatotrophin in children and in adults?
Children – stunted growth (pituitary dwarfism)
Adults – loss of GH effects are uncertain
State some other causes of short stature.
Genetic
Malnutrition
Emotional deprivation
Endocrine disorders
State some genetic and acquired causes of GH deficiency in children.
Genetic:
Deficiency of hypothalamic GHRH
Mutations of GH gene
Developmental abnormalities (e.g. aplasia or hypoplasia of the pituitary gland)
Acquired:
Tumours of the hypothalamus and pituitary
Other intracranial tumours nearby (e.g. optic nerve glioma)
Irradiation
Head injury
Infection or inflammation
Severe psychosocial deprivation