Ch 12 - Endocrine Vocab Flashcards
homeostasis
state of dynamic equilibrium; hormones are acting together to keep body’s internal environment healthy
hormones
secreted by organs to maintain homeostasis; usually work in pairs as a negative feedback system (one raises levels, one depletes); example: calcitonin vs. parathyroid hormone in regulating calcium in the blood
endocrine glands
responsible for sexual maturation, and play a role in the body’s ability to metabolize food and store energy
pituitary gland
small, pea-sized structure attached to lower surface of hypothalamus in the brain; “master gland” that controls all other glands of the body; it is controlled by the hypothalamus, though; divided into two lobes (anterior and posterior)
anterior lobe
front lobe of pituitary that secretes:
- Growth Hormone (GH): promotes growth of body structures;
- Thyroid-Stimulating Hormone (TSH): affects growth/function of thyroid;
- Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH): “gonadotropins” that act on the gonads (ovaries to produce ovum, and testes to produce sperm);
- Prolactin: acts on mammary glands to produce milk;
- Adrenocorticotropic Hormone (ACTH): acts on adrenal glands to secrete glucocorticoids like cortisol
Growth Hormone (GH)
secreted by anterior lobe of pituitary; promotes growth of body structures
Thyroid-Stimulating Hormone (TSH)
secreted by anterior lobe of pituitary; affects growth/function of thyroid
Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
secreted by anterior lobe of pituitary; called “gonadotropins” that act on the gonads (ovaries to produce ovum, and testes to produce sperm)
Prolactin
secreted by anterior lobe of pituitary; acts on mammary glands to produce milk
Adrenocorticotropic Hormone (ACTH)
secreted by anterior lobe of pituitary; acts on adrenal glands to secrete glucocorticoids like cortisol
Name all Endocrine System Organs
- Pituitary Gland
- Parathyroid Glands
- Thyroid Gland
- Adrenal Glands
- Thymus
- Pancreas
- Testes/Ovaries
posterior lobe
rear lobe of pituitary that secretes:
- Oxytocin: acts on uterus to promote contractions during labor and delivery;
- Antidiuretic Hormone (ADH): acts on kidneys to increase absorption of water
pineal gland
or “pineal body”; pinecone-shaped and behind thalamus in brain; produces melatonin which regulates circadian rhythm
Melatonin
hormone produced by the pineal gland that regulates circadian rhythm, or sleep-wake cycle
thyroid gland
one of the largest endocrine glands; highly vascular; requires iodine in the diet to function properly; produces:
- Triiodothyronine (T3) and Thyroxine (T4), which are responsible for growth throughout childhood and regulating body metabolism;
- Calcitonin: regulates calcium and phosphorus in the blood
Parathyroid glands
Lie on posterior surface of thyroid within connective tissue; secrete:
1. Parathormone (PTH): also called parathyroid hormone; helps regulate calcium and phosphorus in the blood
Adrenal glands
two triangular glands located on top of each kidney; outer layer is called Adrenal Cortex; inner part called Adrenal Medulla; secrete:
- Epinephrine: also called adrenaline; copes with stress/trauma; converts glucose for quick energy;
- Aldosterone: regulates and maintains water, sodium and electrolyte balance;
- Cortisol: natural steroid; decreases inflammation
- Androgens: secondary sexual characteristics
Pancreas
long flat organ in upper left quadrant; active role in both digestive system and endocrine system; endocrine portion includes the pancreatic islets (“islets of Langerhans”); beta cells secrete insulin to metabolize carbohydrates into glucose and stimulate cells to take it into blood for energy; alpha cells secrete Glucagon to create glucose in the liver when needed
*Diabetes occurs when pancreatic hormones are not working cooperatively to maintain blood glucose levels.
Diabetes mellitus
Blood glucose levels widely fluctuate, resulting in hyperglycemia (high blood sugar) or hypoglycemia (low blood sugar)
Diabetic ketoacidosis (DKA)
when diabetes symptoms become so severe and blood glucose levels so high, lethargy progresses to loss of consciousness (DKA); “diabetic coma”; patient must be hospitalized for rehydration and insulin therapy
Thymus gland
has two symmetrical lobes in the mediastinum (mid-chest); larger in infants/children and shrinks with age; produces T Lymphocytes for the immune system, which is less active as person ages
Ovaries
reproductive gland of females; produce ovum during menstrual cycle; secretes:
- Estrogen: develops secondary sexual characteristics, plays role in menstrual cycle and in preventing osteoporosis;
- Progesterone: preps uterus for pregnancy and supports developing fetus
Testes
reproductive gland of males; secrete:
1. Testosterone: secondary sexual characteristics; production of sperm
Negative feedback system
Almost all endocrine glands work this way; hormones serve to oppose another substance in the body; counteracts increases/decreases of substance; like a thermostat reacting to regulate house temp.
