Transcript Nrsg 407 Disorders of the Endocrine Glandsx

Disorders of the
Endocrine Glands
Nrsg 407
Function
• Various glands in body
• Secretes hormones
• Transported
throughout body
Negative feedback
• One hormone controls secretion of another
• Last hormone in the pathway controls secretion
of first hormone
Pituitary gland
• Master gland
• Controls several organs
and hormones
• Works together with
hypothalamus
Pituitary Gland
• Anterior or
Adenohypophysis
contains glandular
tissue
• Posterior or
Neurohypophysis
contains nervous tissue
Anterior Pituitary Hormones
Posterior Pituitary
Posterior pituitary - SIADH
• Lack of ADH [aka Syndrome of
inappropriate ADH] or diabetes
insipidus
• Vasopressin (pitressin)
• Act on renal tubules to promote
reabsorption of water
• Vasopressor effect (raise BP)
Thyroid
• 2 types of cells
• Parafollicular cells –
calcitonin
• Follicular cells –
composed of iodine
atoms
• Thyroxine (T4)
• Triiodothyronine (T3)
Thyroid cont’d
• Regulates body metabolism
• Thermal regulation
• Regulation of physical/mental development
Thyroxine hormone
(T4)
Triiodothyronine (T3)
• Same as T4
• Converted once thyroxine
enters cells
• 1 iodine atom eliminated
by enzymes
• Binds to intracellular
receptors in nucleus
Thyrocalcitonin (Calcitonin)
• Lowers plasma Ca and PO4
• Increases Ca deposits in
bone
• Not as important due to
parathyroid
Negative feedback
mechanism
• Low serum thyroxine  incr
TSH  incr thyroxine 
maintain normal BMR
Hypothyroidism
• Poorly functioning thyroid
(primary disease) OR
• Low secretion of TSH by
pituitary gland (secondary
cause)
• Most common: chronic
autoimmune thyroiditis –
Hashimoto’s disease
Myxedema
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Fatigue
General weakness
Muscle cramps
Dry skin
Bradycardia
Cold intolerance
Hyperthyroid
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Most Common: Graves’ disease (primary)
Oversecretion of thyroid
Increased body metabolism
Tachycardia
Anxiety
Heat intolerance
Adrenal Cortex
Glucocorticoids
(Sugar)
Cortisol
Sex hormones
(Sex)
Androgens
Adrenal Cortex
Mineralcorticoids
(Salt)
Aldosterone
Mechanism of Control
Negative feedback
mechanism
Glucocorticoids and
androgens: Anterior
pituitary  release of
ACTH  stimulates
adrenal  glucocorticoid
and androgen
Mechanism of Control
Mineralcorticoids: RAAS
Hormone: Aldosterone
produced
Promote sodium
reabsorption and
potassium excretion
Hypofunction
• Primary
• Destruction by systemic
infectious disease
• Cancer
• Autoimmune process
• Secondary
• Decrease ACTH or
hypothalamus disease
Hypofunction
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Hypoglycemia
Fatigue
Hypotension
Increased skin pigmentation
Anorexia
Vomiting
diarrhea
Hypofunction
• Chronic primary adrenocortical insufficiency
(Addison’s disease)
• Deficiency of all 3 hormones
• Rare – usually caused by autoimmune
destruction
Acute Adrenocortical
Insufficiency
• Caused when glucocorticoids
abruptly withdrawn
• Provide negative feedback to
pituitary to stop secreting
ACTH
• No ACTH  adrenal stops
secreting endogenous
glucocorticoids
• Adrenal cortex shrinks
(adrenal atrophy)
Symptoms of Adrenal crisis
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Nausea
Vomiting
Lethargy
Confusion
Coma / Shock
Cushing’s Syndrome
• Primary
• Cortisol-secreting
tumors
• Secondary
• Pituitary or
hypothalamus tumor
• ACTH secreting tumor
• Iatrogenic
• Overdosage of
glucocorticoid
Signs/Symptoms
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Hyperglycemia
Protein tissue wasting
Bruising
Osteoporosis
Peptic ulcers
Delayed wound
healing
Signs/Symptoms
• Abnormal fat distribution
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Truncal obesity
Striae
“Buffalo hump”
Moon face
• Acne
• Mood/ personality changes
Signs/Symptoms
• Hypokalemia
• Na and water retention
• Decrease inflammatory
response