A&P Final -5
Thyroid Hormone
increases metabolic rate that increases heat production and utilization of glucose for energy
Growth Effects
stimulates growth of bone and cartilage, increases tissue growth
Hyperthyroidism
autoimmune Grave's disease that results in over secretion of thyroid hormones, elevates BMR, and tissue catabolism
Parathyroid Gland
parathyroid hormone increases CA2+ levels by stimulating osteoclasts to digest bone matrix
Thyroid gland
follicles synthesize thyroglobulin and adds iodine to it
Goiter
results from enlarged thyroid when iodine isn't available
Calcitonin
produced by thyroid gland; lowers blood calcium levels by inhibiting osteoclast activity and releases calcium; regulates CA2+ concentration in blood
Parathyroid gland increases
absorption of Ca2+ from gut and kidneys
Adrenal Cortex
produces steroid hormones (corticosteroids)
Adrenal Cortex 3 zones:
zona glomerulosa, zona fasciculata, zona reticularis
Zona glomerulosa
makes mineralocorticoids (chiefly aldosterone)
Zona fasciculata
makes glucocorticoids (chiefly cortisol)
Zona reticularis
makes gonadcorticoids (androgens)
Androgens
most important; dehydroepiandrosterone that converts to testosterone
Androgen main source in females:
regulates sex drive
Metabolic effects
increases protein synthesis, lipids for energy, and decreasing carbohydrates
Secretion changes/increases by:
starvation, hypoglycemia, low fatty acid levels, stress from exercise, excitement, or trauma, and deep sleep
Growth Hormone levels:
high in children; levels decrease throughout life