Patho: Endocrine Disorders I Lecture 14

  1. Hypofunction disorders
    Typically, due to hyposecretion of hormone May also be due to decline in target tissue responsiveness to hormone
  2. hyperfunction disorders
    • Typically, due to hypersecretion of hormone
    • May also be due to hormone production by ectopic tumor
  3. Hormones
    • are chemical messengers that travel through the bloodstream to exert physiologic effects on specific target cells and tissues.
    • In the healthy state, hormones are released by endocrine glands when their action is needed and inhibited when their effect is attained.
  4. Claasification of Endocrine Disorders
    • Primary Defects – Endocrine gland
    • Secondary Defects – Pituitary Gland
    • Tertiary Defects - Hypothalamus
  5. Endocrine Primary Defects
    • endocrine gland
    • result from intrinsic defects within the hormone-secreting gland
  6. Endocrine Secondary Disorders
    • pituitary gland
    • manufactures and stimulate hypothalamus stimulating hormone
    • abnormal secretion
  7. Endocrine Tertiary disorders
    • hypothalamus
    • the controller
  8. Thyroid Hormones
    • increased metabolim and protein synthesis
    • neccesary for growth and development in children esp for normal growth of CNS
  9. Pituitary and Growth Disorders
    • pituitary tumors
    • hypopituitarism
    • isosexual precocious puberty
  10. pituitary tumors
    • May be primary tumors or secondary (metastatic tumors)
    • May be functional tumors or nonfunctional tumors
    • Benign adenomas account for most of functional tumors
  11. hypopituitarism
    Hormones become deficient in order: GH, FSH & LH, TSH, ACTH
  12. Growth and Growth Hormone disorders
    • Short Stature and Growth Hormone Deficiency in Children - Dwarfism
    • Growth Hormone Deficiency in Adults – Increased CV mortality
    • Tall Stature and Growth Hormone Excess in Children - Gigantism
    • Growth Hormone Excess in Adults - Acromegaly
  13. isosexual precocious puberty
    Often caused by tumors (gonadal, adrenal, hypothalamic, CNS)
  14. Causes of Hypopituitarism
    • Tumors and mass lesions
    • Pituitary surgery or radiation
    • infiltrative lesions and infections
    • pituitary infarctions
  15. tumors and mass lesions
    • cause of hypopituitarism
    • pituitary adenomas, cysts, metastatic cancer, and other legions
  16. infiltrative lesions and infections
    • cause of hypopituitarism
    • hemochromatosis, lymphocytic hypophysitis
  17. pituitary infarction
    • cause of hypopituitarism
    • infarction of the pituitary gland after substantial blood loss during child birth (Sheehan's syndrome)
  18. Growth Hormone (GH)
    • produce by somotropes in the anterior pituitary
    • neccesary for linear bone growth in children
    • stimulate cells to to increase in size and divide more rapidly
    • enhances amino acid transport across cell membranes and increase protein synthesis
    • increases the rate at which cells use fatty acids and decreases the rate at which they use carbs
  19. effects fo GH on cartilage growth
    require insulin like growth factors (somatomedins) which is produced by the liver
  20. GH deficiency in children
    • interferes with linear bone growth resulting in short stature or dwarfism
    • normal intelligence
    • budgy, boarder line obesity
    • delay in puberty
    • typically have microphalis (boys) - small penis
  21. Laron-type dwarfism
    • GH deficiency in children
    • GH levels are normal or elevated but there is a hereditary defect in insulin like growth factors
  22. excess growth hormone in children
    • excess of growth hormone prior to puberty
    • increased linear bone growth or gigantism
    • caused by pituitary adenoma
  23. excess growth hormone in adults
    • results in overgrowth of the cartiligenousparts of the skeleton
    • enlargement of the heart and other organs of the body
    • metabolic disturbances resulting in altered fat metabolism and impaired glucose tolerance
    • effect small bones of the hands, mandible, feet, bones of the skull, etc
  24. Characteristics of GH excess in adults
    • hyperostosis -thoracic vertebrae
    • increased size in hand and feet
    • cardiomegaly
    • abnormal glucose tolerence secondary to insulin resistance
    • peripheral neuropathy
    • degenerative arthritis
  25. acromegaly
    • due to pituitary adenoma that happens later in life
    • increase size in nasal bone, skull bones
    • increased prominance of chin
    • enlargement of organs (cardiomegaly)
  26. Growth Hormone Actions
    • Anterior pituitary, which is below the hypothylamus, secretes the growth hormone
    • results in growth promoting actions or anti insulin effects
  27. growth promoting actions
    • actions of growth hormone
    • increasedprotein synthesis results in
    • 1. increased linear growth
    • 2. increased size and function
    • 3. increased lean muscle mass
  28. anti insulin effects
    • actions of growth hormone
    • 1 Adipose tissue - increase lipolysis, increase FFA use, which decrease in adiposity
    • 2. carb metabolism - decrease glucose use, which increase blood glucose
  29. Causes of short stature
    • variants of normal
    • low birth weight
    • endocrine disorders
    • chronic illness and malnutrition
    • functional endocrine disorders
    • chromosomal disorders
    • skeletal abnormalities
  30. Hypothyroidism
    • absent or underdeveloped thyroid
    • produces decrease in metabolic rate
    • an accumulation of a hydrophilic mucopolysaccharide substance (myxedema) in the connective tissue throughout the body
    • an elevation in serum cholesterol
  31. Types of hypothyroidism
    • congenital hypothyroidism
    • acquired hypothyroidism and myxedema
  32. congenital hypothyroidism
    • Common cause of preventable mental retardation
    • can cause cretadin if not treated within 6 weeks
  33. Acquired Hypothyroidism and Myxedema
    Hashimoto Thyroiditis (autoimmune origin) Myxedematous Coma
  34. Hashimoto Thyroiditis
    • autoimmune origin
    • most common acquired hypothyroidism
    • antibodies manufactured and destroy the thyroid
  35. myxedema
    • excessive nonpidding edema that patients with long-term hypothyroidism
    • tend to demonstrate effects brain swelling functioning
    • often seen in older women
  36. goiter
    enlarged thyroid
  37. hyperthyroidism
    • also called thyrotoxicosis
    • overactivity of the thyroid
  38. types of hyperthyroidism
    • graves disease ( autoimmune origin)
    • thyroid storm
  39. Graves disease
    • antibodies mimic thyroid stimulating hormone which results in the thyroid secreting more hormone
    • causes goiter
  40. Thyroid storm
    • life-threatening
    • happens when there is already hyperthyroidism that is not diagnoses
    • percipitated by infection or diabetic ketoacidosis
    • can be triggered by physical or emotional trauma
  41. manifestations of hypothyroidism
    • decreased BMR
    • decreased sensitivity to catecholamines
    • general features: myxedematous features, deep voice, impaired growth (child)
    • increased blood cholesterol levels
    • decreased cardiac output and bradycardia
    • gain weight
  42. manifestations of hyperthyroidism
    • increased BMR
    • increased sensitivity to catecholamines
    • general features: exophthalmos (in Graves Disease), lid lag, decreased blinking
    • decreased blood cholesterol levels
    • increased cardiac output and tachycardia an palpitations
    • loss weight
  43. Characteristics of hypothyroidism
    • generalized edema; periphera edema
    • slowing hert
    • slowing metabolic rate, slow down peristalsis
    • edema in vocal cords (deep course voice)
    • constipation
  44. Characteristics of hyperthyroidism
    • exophthalmos - bulging eys due to lids moved back on eye
    • goiter
    • tachycardia
    • high output failure (oxygen used up at such increase causing increased heart rate)
    • muscle wasting
  45. Adrenal gland
    • sits on top of the kidneys
    • hormones generated from the cortext of the adrenal gland
  46. ACTH
    stimulates adrenal cortex to produce cortisol
  47. androgens
    adrenal sex hormones
  48. Disorders of adrenal cortical function
    • congenital adrenal hyperplasia
    • adrenal cortical insufficiency
    • glucocorticoid hormone excess
    • incidental adrenal mass
  49. Congenital Adrenal Hyperplasia
    • Also known as Adrenogenital Syndrome
    • Caused by an enzyme defect in the synthesis of cortisol, leading to excessive synthesis of adrenal androgens
    • Most common enzyme deficiencies are 21-hydroxylase deficiency and 11-β-hydroxylase deficiency
    • causes ambiguous genitalia - infusion of enlarged clitoris and infused labia
  50. Adrenal Cortical Insufficiency
    • Primanry
    • Secondary
    • Acute adrenal crisis
  51. Primary Adrenal Cortical Insufficiency
    • also called addison disease
    • chronic metabolic disorder
    • needs lifetime treatment
    • Autoimmune destruction of adrenal cortex is most common cause
    • Characterized by hyponatremia, loss of extracellular fluid, decreased cardiac output, hyperkalemia, and orthostatic hypotension
    • Dehydration, weakness and fatigue are common early symptoms
  52. Secondary Adrenal Cortical Insufficiency
    due to hypopituitarism
  53. Acute Adrenal Crisis
    A life-threatening situation, requiring emergency medical treatment
  54. Glucocorticoid Hormone Excess
    • Hypercortisolism; also known as Cushing Syndrome
    • Major manifestations of Cushing syndrome represent an exaggeration of the many actions of cortisol
    • Derangements of glucose metabolism occur in 75% of persons with Cushing Syndrome; clinically overt diabetes mellitus occurs in about 20% of cases
  55. Forms of cushing syndrome
    • Pituitary form, due to excess ACTH production by a pituitary tumor
    • Adrenal form, caused by benign or malignant adrenal tumor
    • Ectopic form, due to ACTH-secreting tumor (e.g., lung cancer)
  56. Incidental Adrenal Mass
    Primary adrenal carcinoma is rare, but the adrenal gland is a common site of metastasis, particularly of lung cancers (and other cancers)
Card Set
Patho: Endocrine Disorders I Lecture 14
Exam 5