PUBH 1145 Lecture Notes - Lecture 12: Vasopressin, Egg Cell, Thyroid
4 Nov 2020
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12 – Diseases & Disorders of the Endocrine System
Endocrine System
- Composed of glands that make hormones
- Hormones control bodily functions
Pituitary Gland
- Small gland located at the base of the brain, connected to the hypothalamus by the infundibulum
- Anterior pituitary
o Follicle-stimulating hormone (FSH)
▪ Stimulate egg and sperm production
o Luteinizing hormone (LH)
▪ Stimulates production of sex-hormones, surge causes ovulation
o Prolactin
▪ Stimulates breast development and milk production
o Adrenocorticotropic hormone (ACTH)
▪ Stimulates the release of adrenal cortex hormones
o Growth hormone (GH)
▪ Increases synthesis of protein and promotes growth of bone and tissue
o Thyroid stimulating hormone (TSH)
▪ Stimulates production of thyroid hormone
- Posterior pituitary
o Vasopressin / Antidiuretic hormone (ADH)
▪ Stimulates water absorption by kidneys
o Oxytocin
▪ Stimulates uterine contractions, milk release, and prostate secretions
- Pituitary regulates many other glands
o Feedback loops : hormone or other chemical levels trigger release or holding of other hormones
Diseases of the Pituitary
- Pituitary dwarfism
o Hyposecretion of GH, results in small stature and delayed / absent sexual development
o Adult height under 4’10”
▪ More typically proportioned than achondroplastic dwarves
o Usually idiopathic, but pituitary trauma / cancer can cause
o Supplement with GH if caught early
- Gigantism
o Hypersecretion of GH
o Longer extremities, thickened features
o Headache, late onset puberty, joint pain, cardiovascular compromise
o Most caused by benign tumors
▪ Surgery or radiation for correction
- Acromegaly
o Hypersecretion of GH in adulthood
o Long bones do not lengthen
▪ Hands, feet, head, and jaw grow
o Caused by benign tumor
- Diabetes insipidus
o Decreased secretion or action of ADH
o Excessive urination, excessive thirst
o Central DI : hyposecretion of ADH
o Nephrogenic DI : damage to tubule inhibits ADH
o Risk factors : head trauma, neurosurgery, pregnancy, medications
o Given synthetic vasopressin
o Supportive care to avoid dehydration, monitor electrolytes
Thyroid
- Gland in the neck with lobes on either side of the trachea
- Thyroid hormone (T3 and T4)
o Regulates body temperature, metabolism, tissue growth and development
o Affects most cells of the body
o Negative feedback loop with pituitary
o Promotes regular function of organ systems
Disorders of the Thyroid Gland
- Hypothyroidism
o Hyposecretion of T4 causes metabolic disturbances
o Weight gain, dry skin, hair loss, swollen extremities, cold sensitivities, mental fatigue, depression
o Risk increases with age, certain medications, or damage to the thyroid gland
- Hasimoto’s thyroiditis
o An autoimmune disease that destroys thyroid tissue
o Painless goiter
- Congenital hypothyroidism
o Failure of thyroid to develop
o Infant lethargy, weight gain even with poor eating habits, small stature, enlarged tongue, distended
abdomen
- Hyperthyroidism
o Enlarged thyroid, nervousness, heat intolerance, rapid irregular heartbeat, weight loss, fatigue,
diarrhea
o Grave’s Disease is most common
▪ Exophthalmos / ophthalmopathy
• Autoimmune disorder, antibodies mimic TSH
o Medication to inhibit thyroid hormones, radiation, surgery
- Simple Goiter
o Enlargement of the thyroid can be caused by iodine deficiency
o Soy, peanut, peaches, spinach, turnips, cabbage, brussels sprouts, seaweed
o Treatment with replacement hormone, iodine supplementation
- Thyroid cancer
o Malignancy of the thyroid
o Hoarse voice, swollen lymph nodes, enlarged thyroid
o Treat with chemo, radiation, surgery, radioactive iodine
Parathyroid Glands
- Four glands on the posterior of thyroid gland
- Parathyroid hormone (PTH)
o Increases calcium concentration in the blood
o Important for muscle contraction and cardiac function
Document Summary
12 diseases & disorders of the endocrine system. Small gland located at the base of the brain, connected to the hypothalamus by the infundibulum. Increases synthesis of protein and promotes growth of bone and tissue: thyroid stimulating hormone (tsh, stimulates production of thyroid hormone. Posterior pituitary: vasopressin / antidiuretic hormone (adh, stimulates water absorption by kidneys, oxytocin, stimulates uterine contractions, milk release, and prostate secretions. Pituitary regulates many other glands: feedback loops : hormone or other chemical levels trigger release or holding of other hormones. Gigantism: hypersecretion of gh, longer extremities, thickened features, headache, late onset puberty, joint pain, cardiovascular compromise, most caused by benign tumors, surgery or radiation for correction. Acromegaly: hypersecretion of gh in adulthood, long bones do not lengthen, hands, feet, head, and jaw grow, caused by benign tumor. Gland in the neck with lobes on either side of the trachea.
