Endocrine 1 Flashcards
What are the different types of endocrine pathologies?
- Hyperfunction- too much hormone
- hypofunction- not enough hormone
- tumors/cancer
- often causes hyperfunction
- sometimes cause Bulk disturbance, where the size of the tumor affects the function of the cells that would normally release hormone (causing hypofunction)
- Defective receptor or enzyme (genetic disease)
What kinds of dysfunctions can cause either an elevated or depression of hormone levels?
- failure of feedback systems
- dysfunction of an endocrine gland
- secretory cells are unable to produce, obtain, or convert hormone precursors
- the endocrine gland synthesizes or releases excessive amounts of hormone
- increased hormone degredation or inactivation
- ectopic hormone release
What are the different types of target cell failure?
- Receptor-associated disorders
- decrease in number of receptors
- impaired receptor function (usually autoimmune)
- presence of antibodies against specific receptors (usually autoimmune)
- antibodies that mimic hormone action (ex. graves disease)
- Unusual expression of receptor function
What are the different hyperthyroidisme diseases?
graves disease
hyperfunctioning adenoma (toxic goiter)
TSH cell adenoma
What are the different types of hypothyroidism diseases?
Hashimoto thyroiditis
iodine deficiency
ablation (usually accidental removal when trying to remove parathyroid)
idiopathic
What are the thyroid hormones?
How are they different?
How are they measured?
- T4:T3 ratio is 10:1
- T3 is 3-4x more active than T4
- TSH is measured with the third generation of the TSH assay
- it can distinguish even very slight abnormalities in levels of TSH secretion which is helpful in diagnosis
If TSH is elevated and T3/T4 are elevated, what might be the problem?
- You have too much TSH being produced
- Pituitary adenoma secreting TSH
- Extopic TSH production (ex lung cancer)
If TSH is elevated and T3/T4 is decreased, what problems might you have?
- Thyroid dysfunction:
- Hashimotos thyroiditis- autoantibodies against thyroid proteins
- Iodide deficiency
If you have decreased TSH and elevated T3/T4, what problems might you have?
- Thyroxine production not under the control of TSH
- graves disease
- toxic goiter
- Thyroxine secreting thyroid tumor
If you have decreased TSH and decreased T3/T4, what is probably causing your problems?
- Pituitary dysfuntion
- panhypopituitarism
- null cell adenoma
- sheehan’s syndrome
What are the symptoms of hyperthyroidism?
- anxiety
- irritability
- difficulty sleeping
- fatigue
- rapid or irregular heartbeat
- a fine tremor of hands or fingers
- an increase in perspiration
- sensitivity to heat
- weight loss, despite normal food intake
- brittle hair
- goiter
- light menstreal periods
- frequent bowel movements
What are the treatments for a goiter?
- BB for relief of S&S
- anti-thyroid meds (PTU) which prevent conversion of T4 to T3
- radioactive iodine
- surgery
What are the causes of hypothyroidism?
- Hypothyroidism- causes:
- hashimoto disease
- autoimmune destruction of gland
- causes thyroid inflammation
- lack of iodine
- idiopathic causes like lack of appropriate enzymes required for thyroid hormone production
- hashimoto disease
What are the symptoms of hypothyroidism?
- increased sensitivity to cold
- decreased:
- CO
- baroreceptor function
- HR
- slowed conduction
- fatigue
- constipation
- pale, dry skin
- a puffy face
- hoarse voice
- elevated blood cholesterol
- unexplained weight gain
- muscle aches, tenderness and stiffness
- pain, stiffness or swelling in joints
- muscle weakness
- heavy menstrual periods
- depression
- mental retardation in infants or in utero
How is hypothyroidism treated?
Levothyroxine
iodine if issue is iodine deficiency
How does Hashimoto Thyroiditis work?
- Helper T-cells induce the cytotoxic T cells and antibody secreting B cells to activate autoimmune response
- cytotoxic T cells are mostly responsible for the parenchymal destruction
- B cells secrete antibodies that inhibit the TSH receptor
- Antighyroglobulin and antithyroid peroxidase antibodies do not really contribute to the disease, but are useful serologic markers of the disease
What is Myxedema?
- Almost total lack of thyroid hormone
- increase in chondroitin and hyaluronic acid causing interstitial fluid to increase and cause edema
- Why it happens is not clear
What is cretinism?
- Extreme hypothyroidism in fetal life, infancy or childhood
- can be d/t lack of a thyroid gland
- lack of thyroid hormone
- lack of iodine
- skeletal growth is more stunted than soft tissue
- disproportionate stuntin of growth
- obesity with large tongues
What is pheochromocytoma?
- neoplasm of chromaffin cells (on adrenal gland)
- catecholamine secreting tumors
- secretes mostly NE; 85:15 ratio to epi
- rarely, in 15% of tumors epi excretion predominates
What are the symptoms of pheochromocytoma?
- tachycardia
- palpitations
- excessive sweating
- chest pain
- upper abdominal pain
- severe HA
- shaking of hands
- anxiety
- fright
- HTN etc….
How is pheochromocytoma treated?
- Alpha blockers
- beta blockers
- surgery
What are the different ways cushing syndrome can be caused? What is cushing syndrome?
- Cushing syndrome is hypercorticalism
- Pituitary cushing syndrom-Tumor in pituitary gland releasing too much ACTH which causes the adrenal to release lots of cortisol.
- Adrenal cushing syndrome-Problem with the adrenal gland (either tumor or hyperplasia) causing excessive release of cortisol
- Paraneoplastic cushing syndrome- lung or other non endocrine cancer that releases ACTH, causing the adrenal to release lots of cortisol
- Iatrogenic cushing syndrome- pt taking exogenous steroids. The steroids cause the cushing syndrome while the adrenal gland atrophies
What is the feedback loop for ACTH and glucocorticoid secretion?
- Various stimuli cause the hypothalamus to release CRH which goes to the anterior pituitary
- Anterior pituitary releases ACTH which goes to the adrenal.
- Adrenal cortex releases glucocorticoid
- Glucocorticoid provides negative feedback to anterior pituitary AND hypothalamus
What are the effects of cushing’s syndrome?
- increases blood glucose
- increases protein catabolism causing muscle wasting and weakness
- mobilization of fat from lower body to abdomen, face, trunk, and back
- Other symptoms:
- wt gain
- fatigue
- stretch marks
- thin fragile skin
- slow healing of cuts
- depression
- acne
- irregular menstrual periods
- high blood pressure
What are the treatments for cushing’s syndrome?
- reducing corticosteroid use
- surgery
- radiation therapy
- medical therapy
What is Conn’s disease?
- Primary Aldosteronism (hyperaldosteronism)
- Caused by tumors in the zona glomerulosa that releases aldosterone
- sodium retention HTN
- leads to hypokalemia
- metabolic alkalosis
- increases in ECF and blood volume
What is Addison’s disease?
- Adrenocortical insufficiency
- Caused by primary atrophy or injury to adrenal cortices
- Leads to decreased mineralocorticoid and glucocorticoid hormones
- low aldosterone causes depletion of ECF with decrease in NA, BP, and CO; leading to hyperkalemia and mild acidosis
- low glucocorticoid decreases the ability to maintain BP or ability to mobilize fat and proteins causes decreased metabolic function and decreased ability to respond to stressors
What are the symptoms of Addison’s disease?
- muscle weakness and fatigue
- wt loss and decreased appetite
- darkening of the skin
- low BP, even fainting
- salt craving
- low BS
- N/V/D
- irritability
What are the two types of hyperparathyroidism and what are the symproms?
Treatment?
- Types:
- Primary- usually caused by adenoma or hyperplasia
- Secondary- usually caused by low Ca or high phosphate
- Symptoms
- hypercalcemia
- hypercalciuria
- kidney stones
- heartburn, PUD
- N/V appetite loss
- osteoporosis
- confusion
- muscle weakness
- Treatment
- surgery, but cannot remove all four parathyroid glands permanently
What happens with hypoparathyroidism?
Treatment?
- Osteoclasts become almost totally inactive
- decreases calcium levels
- Tetany, especially in smaller muscles of the larynx
- Treatment: parathyroid hormone and Vitamin D
What hormones can a decreased hypothalamic function affect?
*Dopamine should say decreased PIF (prolactin realease inhibiting factor)
What is diabetes insipidus?
- A disease of the posterior pituitary
- insufficiency of ADH
- polyuria and polydipsia
- partial or total inability to concentrate the urine
- neurogenic
- insufficient amounts of ADH
- Nephrogenic
- inadquate response to ADH
What is SIADH?
- hypersecretion of ADH
- enhanced renal water retention
- hyponatremia
- hypoosmolarity
What can cause hypopituitarism?
- Pituitary infarction
- sheehan syndrome- necrosis due to heavy blood loss in delivery of a baby
- shock
- Panhypopituitarism- usually due to cell destroying tumors
- ACTH deficiency
- TSH deficiency
- FSH and LH deficiency
- GH deficiency
- Others- head trauma, infections, and tumors
What usually causes hyperpituitarism?
How does it manifest?
- commonly due to a benign, slow growing pituitary adenoma
- Manifestations
- HA and fatigue
- visual changes
- hyposecretion of neighboring anterior pituitary hormones
What diseases can hypersecretion of growth hormone cause?
- Acromegaly- if it happens in adulthood
- big facial features
- Gigantism- if it happens in children and adolescents
- actual giant
What causes dwarfism?
- generalized deficiency in childhood
- stunts growth
- body develops appropriately propotional but growth rate is slowed
- inability to go through puberty
- in 1/3 only growth hormone is missing so can develop sexually and reproduce
