Endocrine Disease Flashcards
What are the three classes of pituitary tumours?
Non-cancerous (rare), secretory (cancerous - hormonal effects), non-secretory (cancerous - mass effects)
State the most common secretory adenoma and explain the symptoms observed.
Lactotroph (Lactotrope adenoma)
- increased lactation => increased production of prolactin (stimulates milk production)
- prevention of ovulation => decrease in LH, no LH available for the LH surge required for ovulation
Name the types of secretory adenomas found in the pituitary.
Lactotroph, gonadotroph, somatotroph, corticotroph, thyrotroph
Define primary, secondary and tertiary cause of disease
Primary - issue with target organ/gland
Secondary - pituitary dysfunction
Tertiary - hypothalamic dysfuntion
Explain Hashimoto’s disease and how it is related to hypothyroidsm.
Hashimoto’s disease is an autoimmune disease in which the body produces autoantibodies against self-thyroid cells. The body amounts an immune response to kill the cells resulting in a decreased thyroid function. Due to the destruction of thyroid cells, T3 and T4 production is decreased an TSH is upregulated but cannot be utilised.
What is the primary cause of hypothyroidism?
Hashimotos disease (iodine deficiency, congential, surgery/radioiodine therapy)
Explain hypothyroidism associated goitre.
Goitre is caused due to iodine deficiency within the body. Due to the lack of iodine, hormones T3 and T4 cannot be synthesised within the thyroid gland. The absence of T3 and T4 stimulates the release of TSH, but it cannot be utilised to increase T3 and T4 levels as no iodine is present. The thyroid gland increases in size to compensate.
What are some symptoms observed in hypothyroidism?
Low metabolic rate, weight gain, sensitivity to cold temperatures, thinning hair, dry skin, goitre, constipation, slow speech + mental responses.
Explain the causes and clinical symptoms related to hyperthyroidism.
Hyperthyroidism is an overactive thyroid gland caused by Grave’s disease. Thyroid stimulating immunoglobulin (TSI) stimulates the overproduction of T4. Increase in T4 results in decreased production of TSH.
Clinical symptoms; increased metabolic rate, weight loss, heat sensitivity, bulging eyes (grave’s disease), increase in thyroid size.
What is Toxic Multinodular Goitre?
Form of goitre
Thyroid hyperplasia
characterised by hyperfunctioning nodules and ability to function independently of TSH stimulation.
NOT ASSOCIATED WITH GRAVE’S DISEASE SYMPTOMS
Compare and contrast hyper- and hypo- thyroidism.
Hyper = overactivity
caused by TSI via stimulation of T4 production, decrease in TSH (grave’s disease).
symptoms = high metabolic rate, heat sensitivity, weight loss, bulging eyes (due to grave’s).
hypo = underactivity
caused by Hashimoto’s or iodine deficiency, decrease in T3 and T4 production, increased production of TSH which cannot be utilised.
symptoms = slow metabolic rate, weight gain, cold sensitivity, thinning hair, slow speech + mental responses, etc.
Define hypercortisolism/hyperadrenalism.
Excess cortisol production, excess cortisol or steroid hormone use
Explain the relationship between Cushing’s disease and hyperadrenalism.
Cushing’s disease results in increased production of ACTH from pituitary. Increase in ACTH results in an increase/overproduction of cortisol in the adrenal gland.
Explain hypoadrenalism.
Caused/known as Addison’s disease
Autoimmune disease results in destruction of hormones made in adrenal gland (cortisol and aldosterone)
Symptoms = lethargy, weight loss, loss of appetite, hyperpigmentation, dehydration, low blood pressure, low Na conc. in blood but high K levels.
Match the common names/causes to medical names
a) hyperadrenalism i) Grave’s Disease
b) hypoadrenalism ii) Hashimoto’s Disease
c) hyperthyroidism iii) Addison’s disease
d) hypothyroidism iv) Cushing’s disease
a + iv
b + iii
c + i
d + ii
Describe treatments for cushing’s disease and their potential side effects.
Cushing disease generally due to tumour (hyper production of cortisol => inc. CRH, ACTH, cortisol)
Treated using enzyme inhibitors which act generally on the cholesterol to cortisol pathway.
Side effects = low testosterone/estrogen levels due to potential blocking of cholesterol to sex steroid hormones. Liver failure + drug-drug interactions
Explain the treatments available for Addison’s disease.
Hypoadrenalism - low ACTH levels
supplement with corticosteroids to replenish levels
(2/3 dose in AM, 1/3 dose in PM)
How should dosage of Addison’s disease change during times of stress?
When body is under stress, adrenal glands increase production cortisol, use up ACTH, therefore dosage should be increased to cater for increased corticosteriod utilisation.
Which drug class is used to treat Conn’s disease (high aldosterone levels) and how does it work?
Aldosterone inhibitors
Inhibits aldosterone action
Results in the loss of Na and H2O and retains K levels
What are some of the potential side effects of the use of aldosterone inhibitors in the treatment of diseases other than Conn’s disease?
Dehydration (low H2O), hyponatremia (low Na), hyperkalemia (high K), breast enlargement
Describe a common treatment for hypothyroidism
Thyroxin supplements.
Given at 50-100 microgram daily
Half life of 1 week, 5-6 weeks to reach steady state
How should dosage of thyroxin supplements be altered for patients with ischemic heart disease?
Dosage should be decreased from 50-100 microgram per day to 25-50 micrograms and slowly increased until thyroid function becomes normal.
What are two potential treatment methods that could be used for hyperthyroidism?
Surgical removal of lesion, medical treatment to block thyroid hormone synthesis.
What is acromegaly and how is it treated?
Acromegaly = over growth of muscles and bones due to over production of Growth Hormone (GH).
Since over production of GH is associated with pituitary lesions, surgery can be used.
GH inhibiting hormones (injections) can also be used to inhibit the action of GH on the body
What is the treatment associated with GH deficiency and what are it’s side-effects?
supplementation with synthetic growth hormone (via injection)
Side effects = joint, muscle and growth pain, high sugar levels and swelling (edema).
Match the pituitary adenoma with their effector hormones.
a) lactotroph i) LH + prolactin
b) gonadotroph ii) GH
c) somatotroph iii) LH and FSH
d) cortocotroph iv) ACTH
e) thyrotroph v) TSH
a + i b + iii c + ii d + iv e + v
