Hypofunction and Hyperfunction in the Endocrine System Flashcards
Pituitary Gland (Hypophysis)
Anterior Lobe-adenohypophysis (80% of gland); derived from ectoderm growing up from the oral cavity of the fetus.
Corticotropes are cells that secrete ACTH which stimulates the adrenal glands.
Lactotropes secrete prolactin, which causes milk production in breasts.
Somatotropes secrete growth hormone which go to bone and liver.
Thyrotropes secrete thyroid stimulating hormone.
Gonadotropes secrete FSH (follicle stimulating hormone) and LH (lutenizing hormone), which go to the ovaries and testes.
Posterior Lobe-neurohypophysis; derived from brain and is connected to the hypothalamus by the hypophyseal stalk.
NO HORMONES ARE MADE HERE, THEY ARE ONLY STORED HERE.
Oxytocin; breasts, uterus, effects on bonding and appetite.
Vasopressin (antidiuretic hormone); allows you to hold onto water; kidneys and blood vessels.
Both are made in the hypothalamus and secreted from the pituitary.
Hypopituitarism
The deficiency of one or more pituitary hormones.
Panhypopituitarism is the deficiency of ALL of the pituitary hormones.
Can be caused by tumor, infarction, surgery, radiation, trauma, disease, genetic syndromes.
Example: Craniopharyngioma: benign, one of the most common pituitary tumors in childhood.
Congenital cyst-like tumor that causes symptoms by pressure and by destroying some or all of the hormone producing cells in the pituitary; can also have calcified spaces.
Results in hormone deficiencies; mostly in anterior pituitary, sometimes the posterior.
Treatment: surgery, doesn’t restore hormone function.
Example: Isolated defect of hormone production; diabetes insipidus, vasopressin deficiency.
Patients cannot concentrate their urine and drink water and urinate excessively, they become very dehydrated if no access to water.
This can be due to a gene defect, trauma, or a tumor.
Example: Prolactinoma: benign pituitary tumor of lactotrophs that secretes excess prolactin.
Symptoms: galactorrhea (milk from breast whether male or female), headache, impotence (males), infertility (females)..
Thyroid Gland- Nontoxic goiter
An enlarged thyroid that is not hypo functioning or hyper functioning.
Seen in adolescence, pregnancy, and some cases of viral or autoimmune thyroiditis.
HAVE A GOITER, BUT NORMAL THYROID FUNCTION.
Hypothyroidism
Underproduction of thyroid hormones-may occur with or without a goiter.
Nongoitrous: Congenital lesion, Surgery, Thyroiditis; the thyroid gland is either absent or not enlarged; born without a thyroid gland or is ectopic (at the base of the tongue).
Goitrous: Hashimoto thyroiditis: autoimmune thyroid disease; common in families with other autoimmune diseases and in children and adults with down syndrome.
Pathogenesis is lymphocytic destruction and circulating antibodies to thyroid peroxide and thyroglobulin; pathology is lymphocytic infiltrates, gland destruction, and metaplasia of follicular epithelial cells; #1 cause of hypothyroidism in child or adult, more common in women than in men.
Very long time, the gland is destroyed and there is fibrous tissue.
Viral thyroiditis and Lithium can also cause a goiter.
Symptoms: anemia of chronic disease, bradycardia, constipation, cold intolerance, dry skin, hair loss, edema of extremities, fatigue, heavy or absent periods.
Hyperthyroidism
Overproduction of thyroid hormone.
The most common form is caused by an autoimmune disease known as Graves Disease, causes by antibodies that bind to TSH receptors on the thyroid and stimulate hormone production.
Genetic predisposition and is more common in females and in people with down syndrome.
Pathology: enlarged gland with hyper plastic and hyper vascular appearance.
Usually associated with a goiter or nodule.
Symptoms: jittery, tachycardia, heat intolerance, restlessness, irritability, fatigue from never getting into a deep sleep, diarrhea or frequent stools, diaphoresis (excess sweating), heavy or no periods (most common no)
Long time hyperthyrodic=muscle wasting.
Parathyroid glands
Branchial celft derivatives usually found on the back of the thyroid.
Usually 4-12 glands that secrete parathyroid hormone (PTH) to control calcium metabolism.
Symptoms of disease are all caused by calcium.
Hypoparathyroidism
Caused by decreased PTH secretion that leads to low calcium levels. Symptoms of low calcium levels are seizures, tingling, cramps, and stridor (vibrating noises when breathing), painful muscle spasms.
Causes: surgery (common in children and adults), autoimmune disease, congenital syndrome of absence of parathyroid glands (common in children).
Normal Calcium=5 and is needed for transmitting signals from one cell to the next, decrease the calcium=decrease the signal transmission.
Hyperparathyroidism
Caused by excess PTH production causing high calcium levels.
Symptoms: stones, groans, and abdominal moans; kidney and pancreatic ducts stones, psychiatric illness, abdominal pain, bone pain.
Causes: benign tumors, cancer (adenoma), hyperplasia of the parathyroid glands.
Calcium is pulled out of bones.
Usually adenoma, benign and can be surgically removed.
Muscle atrophy is possible.
Primary is rare in children and not rare in adults.
Congenital Adrenal Hyperplasia (CAH)
Genetic, congenital disease in which a person is missing an enzyme in the adrenal cortex pathway.
Causes cortisol deficiency, so the body produces very high levels of ACTH, which causes the adrenal gland to enlarge and overproduce the hormones that DONT DEPEND ON THE MISSING ENZYMES.
Overproduction of androgens (sex hormones).
Most common form is 21-hydrozylase deficiency, which presents as salt wasting with ambiguous external genitalia in baby girls or salt wasting in baby boys.
Cannot make aldosterone; lose salt and increase potassium.
Adrenal cortex insufficiency: Addison disease
Decreased cortisol production.
Signs and symptoms: hypoglycemia, vomiting, weight loss, shock, low blood pressure low sodium, and high potassium.
LIFE THREATENING AND MUST BE TREATED WITH GLUCOCORTICOIDS IMMEDIATELY.
Hydrocortisone, prednisone, dexamethasone.
Causes: autoimmunity, congenital adrenal hyperplasia, adrenal hemorrhages (trauma or surgery), infection, infarction, oral steroids for a long time period.
Hyperpigmentation due to high ACTH levels-bronzing of skin.
Cushing syndrome
Excess in adrenal cortex hormones; if this comes from the pituitary gland overproducing ACTH, it is called CUSHING DISEASE.
Symptoms mostly due to excess cortisol.
Can be caused by adrenal tumors (cancerous or benign) or by taking large amounts of prednisone, hydrocortisone, dexamethasone (corticosteroids).
Signs and symptoms are an obese trunk with thin arms and legs, moon facies (fat face), purple striae on the abdomen, thinning of the skin, hypertension, a dorsal fat pad (buffalo hump), osteoporosis, gaining weight but not getting taller, facial redness, acne, easy bruising.
Autoimmune adrenalitis (addison disease): increased lymphocytes in adrenal cortex, chronic inflammation and fibrosis in the cortex.
Rarely have cushing syndrome from a tumor.
Can’t keep calcium in bone
Autoimmune polyglandular syndromes (APS)
Endocrine diseases can occur in autoimmune combinations.
A constellation of autoimmune endocrine diseases, often associated with non endocrine autoimmune diseases.
At least 3 different polyglandular syndromes exist.
The result of destruction of endocrine glands by antibodies and lymphocytic damage and result in hypo function or hyper function of endocrine glands.
APS 1
A triad of Addison disease, hypoparathyroidism, and mucocutaneous candidiasis (skin and mucous membrane infection caused by Candida).
Autosomal recessive defect in Chromosome 21 in a gene called AIRE gene (autoimmune regulator); can’t distinguish what is self and what is foreign.
Need to have at least 2 of these.
Usually first onset if infection, then the low PTH, then Addison disease.
Can include other diseases: Hepatitis, Autoimmune thyroid disease, Intestinal malabsorption, vitiligo (loss of skin color in blotches), ovarian/testicular failure.
APS 2
Addison disease plus type 1 diabetes, thyroid disease and/or pernicious anemia.
Thyroid disease can be Hashimoto thyroiditis or Graves disease.
HLA antigens such as DR3 and DR4 are involved.
Not autosomal recessive.
Develops in childhood, adolescence and early adulthood.
APS 3
Type 1 diabetes mellitus plus autoimmune thyroid disease.
HLA gene, more common and milder syndrome.
20% of people with T1D have these.
If you diagnose a patient with one autoimmune disease, screen for others!
