PRE-UNIT STUDY TIPS

1. Endocrine system disorders are relatively straightforward. Once you're familiar with the hormones secreted by each gland and their corresponding functions, you'll find that most hormones correspond to two specific disorders caused by either excessive or insufficient secretion.
2. Many endocrine disorders come with noticeable physical characteristics, such as obesity, extreme thinness, bulging eyes, buffalo hump, or moon face. When practicing, pay attention to key terms like these.

0. Anatomy & Physiology

• orderly function of the endocrine system

  • glands secret hormones

  Here comes the hormones!

  

• Hormones that stimulate secretion of other hormones are called tropic hormones.

  • The pituitary gland: which is intricately connected to the hypothalamus, plays a central role in regulating most of the endocrine glands

    • anterior lobes
    • posterior lobes

    

• diagnose

  • correctly matching the patient’s symptoms with a specific hormone dysfunction and obtaining laboratory confirmation of overproduction or underproduction of a particular hormone or hormones.
  • blood test
  • radioimmunoassay (RIA) / immunometric assay (IMA)
  • 24-hour urine test
  • locate the lesion: CT, MRI, ultrasound
  • malignant or not: biopsy

1. Pituitary Glands Diseases

1.1 Gigantism

• Gigantism describes an abnormal pattern of growth and stature.
• hypersecretion of growth hormone (GH, somatotropin) occurs before puberty
• overgrowth of all body tissue
• signs & symptoms:
  • long bones: ****because epiphyseal closure has not begun
  • Sexual and mental developments are often retarded
• etiology: over secretion of GH
  • Hypogonadism may lead to tall stature, but not gigantism, by delaying puberty and closure of the epiphyses.
• diagnosis:
  • level of GH on lab test
  • age-reference norms for insulin-like growth factor 1 (IGF-1) are the best indicator of endogenous secretion of GH
  • MRI & CT: pituitary lesion
  • bone radio: thickening of the cranium, enlargement of the jaw bone, and elongation of the long bones
• treatment:
  • surgery (transsphenoidal approach) -/+ medication or radiation to the pituitary gland to reduce its size
  • Appropriate gonadal hormones may be needed in children or adolescents exhibiting hypogonadism

1.2 Acromegaly

• chronic metabolic condition of adults caused by hypersecretion of GH by the pituitary gland
• signs & symptoms:
  • after puberty: overgrowth of the bones of the face, hands, and feet
  • 30~40yr
  • jaw grows, causing larger spaces between the teeth
  • joint pain: from osteoarthritis
• etiology: a pituitary tumor or adenoma often is the cause of acromegaly
  • female and male equal frequency
• diagnosis:
  • abnormal thickening of the bones of the face, hands, and feet
  • Levels of GH and IGF-1 are elevated
  • glucose tolerance test: increased glucose levels fail to suppress GH levels
  • CT & MRI
• treatment: reverse or prevent tumor mass effects and reduce the amount of GH secreted
  • surgery (transsphenoidal approach) -/+ medication or radiation

1.3 Hypopituitarism

• deficiency or absence of any of the pituitary hormones, produced by the anterior pituitary lobe
• signs & symptoms: metabolic dysfunction, sexual immaturity, or growth retardation
  • if hormone stimulate other endocrine glands: atrophy of those glands.
    • thyrotropin⬇️ (thyroid-stimulating hormone [TSH]): thyroid gland_hypothyroidism
    • corticotropin⬇️ ****(adrenocorticotropic hormone [ACTH]): salt balance and nutrient metabolism
    • gonadotropin⬇️ : impaired sexual function_sexual development, menstruation, lidido
  • growth retardation in children
  • Headache and blindness: tumor infringement on the optic nerve
• etiology:
  • pituitary tumor or a tumor of the hypothalamus
  • congenital deficiencies
  • damage to the pituitary gland caused by radiation or surgical removal or from ischemia of the gland caused by infarct, tumor, or basilar skull fracture
  • panhypopituitarism: Destruction of the entire anterior lobe_a decline in multiple anterior pituitary hormone secretion
  • common in women
• diagnosis:
  • history of head trauma
  • radiation or surgical
  • Plasma levels of all or some of the pituitary hormones are low
  • Radiographic films of the skull, cranial CT, and MRI scans are used to identify tumors
• treatment:
  • neoplasia: removal of tumor
  • replacement theray with sormonal supplements
    • thyroxine (T4)
    • cortisone
    • sex hormones
    • somatropin hGH)

1.4 Dwarfism

• Radiographic films of the skull, cranial CT, and MRI scans are used to identify tumors
• abnormal underdevelopment of the body in children, attaining an adult height of 4 feet 10 inches or less
• signs & symptoms:
• etiology:
• diagnosis: physical
• treatment:

2. Thyroid Gland Disease

• thyroxine (T4) and triiodothyronine (T3)—and mass lesions of the thyroid.
• TSH from the pituitary gland control the secretion of T4 and T3