Celine Cercado p.2 Endocrine System

Major functions of the Endocrine system

Major endocrine glands/organs and their functions (separate by region/ body cavity)

hormones produced, their functions and their target organs

Compare and contrast steroid vs. non-steroid hormones and list the hormones for each
category

Homeostatic mechanisms of hormone regulation (negative and positive feedback)

Diseases associated with the endocrine system

Steroid

lipid-soluble, they can pass through cell membranes

carried in blood stream... weakly bound to plasma proteins

are located inside the target cell

nonsteroid

combine with receptors in target cell membrane

hormones called 1st messenger

2nd messengers cause changes in the cell

thyroid

Hypothyroidism

causes low metabolic rate, fatigue, & weight gain the adults

infants: cause cretinism, poor growth & bone formation, abnormal mental development, and sluggish.

hyperthyroidism

causes high metabolic rate, restlessness, overeating in adults

over activity in the thyroid gland

Diabetes Mellitus

Metabolic disease due to lack of insulin or inability of cells to recognize insulin

Parathyroid Hormone

Hypoparathryoidism

Deficiency PTH due to surgical removal/ injury to glands

results in decrease in blood calcium

Hyperparathyroidism

Excess of PTH, due to parathyroid tumor

results in an increase in blood calcium

Type 1 diabetes mellitus

an autoimmune disorder

beta cells are destroyed, so insulin production decrease/ stops

Type 2 diabetes

When insulin is produced but isn't recognized by cells

Pituitary Gland

Release & Inhibits hormones from hypothalamus

Thyroid Gland

Parathyroid Gland

Adrenal Gland

Pancreas

Reproductive glands

Kidneys

Thymus Gland

Helps control calorie intake & helps regulate blood calcium levels & bone growth

Maintain homeostasis

hormones diffuse into the bloodstream to act on specific target cells

2 major types of glands

exocrine

endocrine

Increases blood calcium ion concentration & decrease phosphate ion concentration

enclosed in a layer of of adipose and connective tissue.

secretes hormones as an endocrine gland & digestive juice into digestive tract as an exocrine gland

Ovaries

Produce estrogen & progesterone

Testes

produce testosterone

Placenta

produces estrogen, progesterone, & gonadotropin

secretes erythropoeith for blood cell production

secretes thymosines affect production & differentiation of T lymphocytes

Negative

releases hormones from hypothalamus, controls of anterior pituitary hormones

Nervous system influences certain endocrine glands directly

other glands respond directly to change in internal fluid composition

controls hormone release

gland sensitive to concertraction of substance it regulates

Growth Hormones

Stimulates body cell to grow & reproduce

GHRH increases the amount of GH secreted, GH inhibiting hormone

Speeds the rate at which cells use carbohydrates & fats

prolactin

promotes milk production following the birth of an infant

controlled by releasing (PRF) & inhibiting hormone (PIH) from the hypothalamus

Target: bones, muscle & joints

Target: mammary gland

Thyroid-stimulating

control secretion of hormones of thyroid gland

TRH from hypothalamus stimulates the release of TSH

Blood concentration of thyroid hormones increase

Target: thyroid gland

Adrenocorticotropic

regulated by CRH from hypothalamus

stress can increase release CRH, decreases ACTH secretion

Target: Adrenal Cortex

Follicle- stimulating

females develop egg-contain

males: production of sperm cells

Target: ovaries and testes

Luterinizing

sex hormones: released egg cells in female

Target: Ovaries and testes

Antidiuertic

kidneys to conserve water, reduce amount of water in urine

high level causes vasoconstriction of blood vessels, helps maintain blood pressure

Oxytocin

plays a role in childbirth, by contracting muscle in urine wall, milk-let down

stretching of uterus in latter stages of pregnancy release OT

suckling of infants at breast release OT after birth

Target:: Uterine smooth muscle & mammary gland

Thyroid Gland

Thyroxine (T4)

Increases energy release carbohydrates

protein synthesis accelerating growth

Target: Most tissues

Triiodothyronine (T3)

5 times more potent than thyroxine

Calcitonin

lowers blood concentration by stimulating deposition of calcium & phosphate ions into bones

same as Throxine

Target: Bone

Parathyroid Glands

Parathyroid hormone

increases blood calcium ion concentration & decreases phosphate ion concentration

stimulates bone resorption by osteoclasts, releases calcium into the blood

stimulates kidneys to conserve calcium

Targets: Bone, Kidneys, & intestines

Adrenal Cortex

Aldosterone

helps regulate mineral or electrolyte balance

causes kidneys to conserve sodium ions & thus water & to excrete potassium ions

Cortisol

produced cells of middle layer

promotes fatty acids release adipose tissue, increasing use fatty acids for energy & decrease use glucose

Pancreas

Glucagon

increases blood lever of glucose by stimulating the breakdown of glycogen & conversion of noncarbohydrates into glucose

release glucagon is controlled by negative feedback

low blood glucose level stimulates the secretion of glucagon

Insulin

decrease blood level of glucose by stimulating liver form glycogen

release of insulin's controlled by negative feedback

high blood glucose stimulates release of insulin

coordinates to maintain a relatively stable blood glucose concentration