Exam 4 (Endocrine/Cardiovascular Systems) Flashcards
Hormones control several major processes
reproduction
growth and development
mobilization of body defenses
maintenance of homeostasis
regulation of metabolism
Endocrinology
study of hormones and endocrine organs
Hormones are amino acid based, which includes
proteins
peptides
amines
Pituitary gland
pea-sized gland that hangs by a stalk from the hypothalamus in the brain, protected by the sella turcica of the sphenoid bone
2 functional lobes: anterior and posterior pituitary
Hypothalamus
produces releasing hormones and inhibiting hormones, makes oxytocin and antidiuretic hormone
Posterior pituitary
does not make the hormones it releases, stores hormones made by the hypothalamus
Oxytocin
stimulates contractions in the uterus during labor, sex, and breastfeeding
ADH
inhibits urine production by promoting water reabsorption by the kidneys
6 anterior pituitary glands
2 hormones affect nonendocrine targets (growth hormone, prolactin)
4 are tropic hormones (follicle-stimulating hormone, luteinizing hormone, thyrotropic hormone, adrenocorticotropic hormone)
Growth Hormone (GH)
major effects are directed to growth of skeletal muscles and long bones
causes fats to be broken down for a source of energy
Prolactin (PRL)
stimulates and maintains milk production following childbirth
Gonadotropic hormones
regulate hormonal activity of the gonads
Thyrotropic hormone (TH)
influences growth and activity of the thyroid gland
Adrenocorticotropic hormone (ACTH)
regulates endocrine activity of the adrenal cortex
Pinal gland
secrets melatonin
Thyroid gland
consists of 2 lobes and a connecting thymus
produces 2 hormones; thyroid hormone and calcitonin
Thyroid hormone
major metabolic hormone
controls rate of oxidation of glucose to supply body heat
2 active iodine-containing hormones: T4 and T3
Calcitonin
decreases blood calcium levels by causing calcium deposition on bone
Parathyroid glands
secrete parathyroid hormone (PTH)
most important regulator of calcium ion (CA2+) homeostasis of the blood
stimulates osteoclasts to remove calcium from bone
stimulates the kidneys and intestine to absorb more calcium
Thymus
largest in infants and children
produces a hormone called thymosin
important in developing the immune system
Adrenal glands
sit on top of the kidneys
2 regions: adrenal cortex, adrenal medulla
adrenal cortex
outer glandular region has 3 layers that produce corticosteroids
mineralocorticoids
glucocorticoids
sex hormones
Adrenal medulla
produces catecholamines (adrenaline, nonadrenaline)
hormones prepare the body to deal with short term stress
mineralocorticoids
regulate mineral content in blood
Glucocorticoids
promote normal cell metabolism
anti-inflammatory properties
Sex hormones (male and female)
androgens (male)
estrogens (female)
Pancreas
mixed gland with both endocrine and exocrine functions
Insulin
released when blood glucoses levels are high
Glucagon
released when blood glucose levels are low
Gonads
produce sex cells and hormones
Other organs that are generally nonendocrine in function that also secrete hormones
stomach, small intestine, kidneys, heart
Placenta
produce hormones that maintain pregnancy
produces human chorionic gonad tropic (hCG) in addition to estrogen and progesterone
Human placental lactogen (hPh)
prepares the breast for lactation
Hormones act by 2 mechanisms
direct gene activation
2nd messenger system
The 3 major categories that stimuli falls into
hormonal
humoral
neural
Hormonal stimuli
endocrine organs are activated by other hormones
Humoral stimuli
changing blood levels of certain ions and nutrients stimulate hormone release
Neural stimuli
nerve fibers stimulate hormonal release
