Endocrine System: General Overview Flashcards
Growth hormone-releasing hormone
Hypothalamus: Increases the release of growth hormone
Growth hormone-inhibiting hormone
Hypothalamus: Decreases the release of growth hormone
Gonadotropin-releasing hormone
Hypothalamus: Increases the release of luteinizing hormone and follicle-stimulating hormone
Thyrotrophin-releasing hormone
Hypothalamus: Increases the release of thyroid-stimulating hormone
Corticotropin-releasing hormone
Hypothalamus: Increases the release of adrenocorticotropic hormone
Prolactin-releasing hormone
Hypothalamus: Stimulates release of prolactin
Prolactin-inhibitory factor; dopamine
Hypothalamus: Decreases the release of prolactin
Growth hormone
Pituitary: Promotes growth and development; increases the rate of protein synthesis
Follicle-stimulating hormone
Pituitary: Promotes follicular development and the creation of estrogen in females; promotes spermatogenesis in males
Luteinizing hormone
Pituitary: Promotes ovulation along with estrogen/progesterone synthesis from the corpus luteum in females; promotes testosterone synthesis in males
Thyroid-stimulating hormone
Pituitary: Increases the synthesis of thyroid hormones T3 and T4
Adrenocorticotropic hormone
Pituitary: Increases cortisol synthesis (adrenal steroids)
Prolactin
Pituitary: Allows for process of laction
Oxytocin
Pituitary: Increase contraction of uterine muscles; promotes release of milk from mammary glands
Regulation of Secretion: Nerve impulses from the hypothalamus; stretching of cervix; nipple stimulation
Antidiuretic hormone
Pituitary: Increases water reabsorption; conserves water; increases blood pressure through stimulating contraction of muscles in small arteries
Regulation of Secretion: Decreased water content
Androgen
Adrenal Cortex: Increases masculinization; promotes growth of pubic hair in males and females
Regulation of Secretion: Influenced by release of GnRH and Luteinizing hormone (LH)
Aldosterone (mineralocorticoid)
Adrenal Cortex: Increases reabsorption of sodium ions by the kidneys to the blood; increase excretion of potassium ions by the kidney into the urine
Regulation of Secretion: Low blood sodium level; high blood potassium
Cortisol (glucocorticoid)
Adrenal Cortex: Influences metabolism of food molecules; anti-inflammatory effect in large amounts
Regulation of Secretion: Adrenocorticotropic hormone
Epinephrine
Adrenal Medulla: Increases HR and force on contraction; increases energy production; vasodilation in skeletal muscle
Regulation of Secretion: Sympathetic impulses from the hypothalamus in stress situations
Norepinephrine
Adrenal Medulla: Vasoconstriction in skin, viscera, and skeletal muscles
Regulation of Secretion: Sympathetic impulses from the hypothalamus in stress situations
Estrogen, progesterone
Ovaries: Involved in regulation of the female reproductive system and female sexual characteristics
Regulation of Secretion: Cyclical rise and fall of hormone levels
Glucagon
Pancreas: Increases blood glucose by stimulating the conversion of glycogen to glucose
Regulation of Secretion: Hypoglycemia
Insulin
Pancreas: Decreases blood glucose and increases the storage of fat, protein, and carbohydrates
Regulation of Secretion: Hyperglycemia
Parathormone
Parathyroid: Increase blood calcium
Regulation of Secretion: Hypocalcemia
Testosterone
Testes: Involved in the process of spermatogenesis and male sexual characteristics
Regulation of Secretion: Influenced by pituitary release of LH
Thyroxine (T4), and Triiodothyronine (T3)
Thyroid: Involved with normal development; increases cellular level metabolism
Regulation of Secretion: Thyroid-stimulating hormone
Calcitonin
Thyroid: Increases calcium storage in bone; decreases blood calcium levels
Regulation of Secretion: Hypercalcemia
Hypofunction of Adrenal Cortex (decreased production of cortisol and aldosterone)
S&Sx: Hypotension, weakness, anorexia, weight loss, altered pigmentation, metabolic dysfunction and electrolyte imbalances
Addison’s Disease
Hyperfunction of Adrenal Gland (increased cortisol production), Pituitary gland produces excessive adrenocorticotropic hormone (ACTH)
S&Sx: evolves over years, persistent hyperglycemia, growth failure, truncal obesity, purple abdominal striae, “moon shaped face”, “buffalo hump” posteriorly at the base of the neck, weakness, acne, hypertension, and male gynecomastia. Mental changes include depression, poor concentration, and memory loss
Cushing’s Syndrome
Most common cause of Hypothyroidism
Hashimoto’s thyroiditis
Most common cause of Hyperthyroidism
Grave’s Disease
S&Sx of Hypothyroidism
Fatigue Forgetfulness Dry skin Dry hair Brittle nails Constipation Weight gain Muscle cramps Depression Decreased menstrual flow Swelling in the front of the neck (goiter)
S&Sx of Hyperthyroidism
Feeling hot Sweating Problems falling asleep Racing thoughts Difficulty focusing on one task Forgetfulness Change in bowel habits, where bowels are looser Elevated heart rate and palpitations Anxiety, nervousness, or irritability Weight loss Menstrual problems Fatigue
Autoimmune disease that stimulates the thyroid gland to become overactive
Common in women over age of 20, but affects men and any age group.
S&Sx: Hyperthyroid presentation. Classic signs include- Goiter, heat intolerance, nervousness, weight loss, tremor, and palpitations
Grave’s Disease
S&Sx of Hypoparathyroidism
Decreased bone resorption
Hypocalcemia
Elevated serum phosphate levels
Shortened 4th & 5th metacarpals (pseudohypoparathyroidism)
Compromised breathing due to muscle spasms
Cardiac arrhythmias and potential heart failure
Increased neuromuscular activity (tetany)
S&Sx of Hyperparathyroidism
Increased bone resorption
Hypercalcemia
Decreased serum phosphate levels
Osteitis fibrosa, subperiosteal resorption, arthritis, bone deformity
Nephrocalcinosis, renal hypertension, and renal damage
Gout
Decreased neuromuscular irritability
S&Sx of Hyperglycemia
Blood glucose >180-200 mgl/dl
Increased thirst and frequent urination
Ketoacidosis
S&Sx of Ketoacidosis
Dyspnea Fruity breath odor Dry mouth Nausea Vomiting Confusion Loss of consciousness
S&Sx of Hypoglycemia
Blood glucose
Cause by destruction of islets of Langerhans cells secondary to possible autoimmune or viral causative factor
Onset: usually less than 25 years of age, abrupt onset
5-10% of cases
Insulin production: very little or none
Ketoacidosis can occur
Treatment includes insulin injection, exercises, and diet
resistance at insulin receptor sites usually secondary to obesity; ethnic prevalence
Onset: Usually older than 45 years of age, gradual onset
90-95% of cases
Insulin production: variable
Ketoacidosis will rarely occur
Treatment includes weight loss, oral insulin, exercise, and diet
Adult onset Male hypogonadism
Decreased libido erectile dysfunction Infertility Decreased cognitive skills Mood changes Sleep disturbances
Prepubescent onset Male hypogonadism
Sparse body hair
Underdevelopment of skeletal muscles
Long arms and legs secondary to delay in the closure of epiphyseal growth plates
Prepubescent onset Female hypogonadism
gonadal dysgenesis Short stature Failure to progress through puberty Primary amenorrhea Premature gonadal failure
Adult onset Female hypogonadism
Secondary amenorrhea is the primary symptom
