Summarizing Regulation of Body Processes
Summary
Water levels in the body are controlled by antidiuretic hormone (ADH), which is produced in the hypothalamus and triggers the reabsorption of water by the kidneys. Underproduction of ADH can cause diabetes insipidus. Aldosterone, a hormone produced by the adrenal cortex of the kidneys, enhances Na+ reabsorption from the extracellular fluids and subsequent water reabsorption by diffusion. The renin-angiotensin-aldosterone system is one way that aldosterone release is controlled.
The reproductive system is controlled by the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are produced by the pituitary gland. Gonadotropin release is controlled by the hypothalamic hormone gonadotropin-releasing hormone (GnRH). FSH stimulates the maturation of sperm cells in males and is inhibited by the hormone inhibin, while LH stimulates the production of the androgen testosterone. FSH stimulates egg maturation in females, while LH stimulates the production of estrogens and progesterone. Estrogens are a group of steroid hormones produced by the ovaries that trigger the development of secondary sex characteristics in females as well as control the maturation of the ova. In females, the pituitary also produces prolactin, which stimulates milk production after childbirth, and oxytocin, which stimulates uterine contraction during childbirth and milk let-down during suckling.
Insulin is produced by the pancreas in response to rising blood glucose levels and allows cells to utilize blood glucose and store excess glucose for later use. Diabetes mellitus is caused by reduced insulin activity and causes high blood glucose levels, or hyperglycemia. Glucagon is released by the pancreas in response to low blood glucose levels and stimulates the breakdown of glycogen into glucose, which can be used by the body. The body’s basal metabolic rate is controlled by the thyroid hormones thyroxine (T4) and triiodothyronine (T3). The anterior pituitary produces thyroid stimulating hormone (TSH), which controls the release of T3 and T4 from the thyroid gland. Iodine is necessary in the production of thyroid hormone, and the lack of iodine can lead to a condition called goiter.
Parathyroid hormone (PTH) is produced by the parathyroid glands in response to low blood Ca2+ levels. The parafollicular cells of the thyroid produce calcitonin, which reduces blood Ca2+ levels. Growth hormone (GH) is produced by the anterior pituitary and controls the growth rate of muscle and bone. GH action is indirectly mediated by insulin-like growth factors (IGFs). Short-term stress causes the hypothalamus to trigger the adrenal medulla to release epinephrine and norepinephrine, which trigger the fight or flight response. Long-term stress causes the hypothalamus to trigger the anterior pituitary to release adrenocorticotropic hormone (ACTH), which causes the release of corticosteroids, glucocorticoids, and mineralocorticoids, from the adrenal cortex.
Glossary
acromegaly
condition caused by overproduction of GH in adults
Addison’s disease
disorder caused by the hyposecretion of corticosteroids
adrenocorticotropic hormone (ACTH)
hormone released by the anterior pituitary, which stimulates the adrenal cortex to release corticosteroids during the long-term stress response
aldosterone
steroid hormone produced by the adrenal cortex that stimulates the reabsorption of Na+ from extracellular fluids and secretion of K+.
androgen
male sex hormone such as testosterone
antidiuretic hormone (ADH)
hormone produced by the hypothalamus and released by the posterior pituitary that increases water reabsorption by the kidneys
calcitonin
hormone produced by the parafollicular cells of the thyroid gland that functions to lower blood Ca2+ levels and promote bone growth
corticosteroid
hormone released by the adrenal cortex in response to long-term stress
cortisol
glucocorticoid produced in response to stress
Cushing’s disease
disorder caused by the hypersecretion of glucocorticoids
diabetes insipidus
disorder caused by underproduction of ADH
diabetes mellitus
disorder caused by low levels of insulin activity
diabetogenic effect
effect of GH that causes blood glucose levels to rise similar to diabetes mellitus
epinephrine
hormone released by the adrenal medulla in response to a short term stress
estrogens
- a group of steroid hormones, including estradiol and several others, that are produced by the ovaries and elicitsecondary sex characteristics in females as well as control the maturation of the ova
follicle-stimulating hormone (FSH)
hormone produced by the anterior pituitary that stimulates gamete production
gigantism
condition caused by overproduction of GH in children
glucagon
hormone produced by the alpha cells of the pancreas in response to low blood sugar; functions to raise blood sugar levels
glucocorticoid
corticosteroid that affects glucose metabolism
gluconeogenesis
synthesis of glucose from amino acids
glucose-sparing effect
effect of GH that causes tissues to use fatty acids instead of glucose as an energy source
glycogenolysis
breakdown of glycogen into glucose
goiter
enlargement of the thyroid gland caused by insufficient dietary iodine levels
gonadotropin
hormone that regulates the gonads, including FSH and LH
growth hormone (GH)
hormone produced by the anterior pituitary that promotes protein synthesis and body growth
growth hormone-inhibiting hormone (GHIH)
hormone produced by the hypothalamus that inhibits growth hormone production, also called somatostatin
growth hormone-releasing hormone (GHRH)
hormone released by the hypothalamus that triggers the release of GH
hyperglycemia
high blood sugar level
hyperthyroidism
overactivity of the thyroid gland
hypoglycemia
low blood sugar level
hypothyroidism
underactivity of the thyroid gland
insulin
hormone produced by the beta cells of the pancreas in response to high blood glucose levels; functions to lower blood glucose levels
insulin-like growth factor (IGF)
growth-promoting protein produced by the liver
mineralocorticoid
corticosteroid that affects ion and water balance
norepinephrine
hormone released by the adrenal medulla in response to a short-term stress hormone production by the gonads
osmoreceptor
receptor in the hypothalamus that monitors the concentration of electrolytes in the blood
oxytocin
hormone released by the posterior pituitary to stimulate uterine contractions during childbirth and milk let-down in the mammary glands
parathyroid hormone (PTH)
hormone produced by the parathyroid glands in response to low blood Ca2+ levels; functions to raise blood Ca2+ levels
pituitary dwarfism
condition caused by underproduction of GH in children
prolactin (PRL)
hormone produced by the anterior pituitary that stimulates milk production
prolactin-inhibiting hormone
hormone produced by the hypothalamus that inhibits the release of prolactin
prolactin-releasing hormone
hormone produced by the hypothalamus that stimulates the release of prolactin
renin
enzyme produced by the juxtaglomerular apparatus of the kidneys that reacts with angiotensinogen to cause the release of aldosterone
thyroglobulin
glycoprotein found in the thyroid that is converted into thyroid hormone
thyroid-stimulating hormone (TSH)
hormone produced by the anterior pituitary that controls the release of T3 and T4 from the thyroid gland
thyroxine (tetraiodothyronine, T4)
thyroid hormone containing 4 iodines that controls the basal metabolic rate
triiodothyronine (T3)
thyroid hormone containing 3 iodines that controls the basal metabolic rate
This lesson is part of:
The Endocrine System