Amanda Gil Period 3 Endocrine System

Major Functions

Homeostatic Mechanisms of Hormone Regulation

Steroid vs Non-steroid Hormones

Major Endocrine Glands/Organs

Diseases

diabetes inspidus: condition resulting from insufficient ADH

pituitary dwarfism: GH deficiency in childhood

gigantism: GH over secretion in childhood

acromegaly: GH over secretion in adulthood

hypothyroidism: under activity of thyroid gland, causes low metabolic rate, fatigue, weight gain in adults, causes cretinism in infants- poor bone growth

hyperthyroidism: overactivity in thyroid gland, causes high metabolic rate, restlessness, overeating, eye protusion, and can lead to the formation of a goiter

hypoparathyroidism: deficiency of PTH due to surgical removal or injury of to glands resulting in a decrease in blood calcium

hyperparathyroidism: excess of PTH, possibly due to parathyroid tumor and results in an increase in blood calcium

Addison disease: hyposecretion of glucorticods and mineralocorticods

Cushing syndrome: hypersecretion of adrenal cortisol hormones

diabetes mellitus: metabolic disease due to lack of insulin and inability of cells to recognize insulin

long term stress: lower resistance to infections/cancers, high BP, astherosclerosis, GI ulcers

causes disturbance in metabolism of carbohydrates, fats, and proteins

high blood glucose harms eyes, heart, kidneys, peripheral nerves

glucose entry into body cells is impaired

symptoms: hyperglycemia, glycosuria, polydipsia, polyphagia, acidosis

Type 1 diabetes mellitus: insulin dependent diabetes mellitus, autoimmune disorder where beta cells are destroyed so insulin production decreases/stops

Type 2 diabetes mellitus: noninsulin dependent diabetes mellitus, insulin is produced but not recognized

hypothalamus

anterior pituitary

posterior pituitary

pineal gland

parathyroid

thyroid

kidneys

pancreas

ovaries

adrenal cortex

stomach mucosa

intestinal mucosa

adipose tissue

adrenal glands

testes

adrenal medulla

gonads

placenta

T3 and T4 hormones control metabolic rate and growth and development ---->most tissues

GnRH hormone is associated with the production and secretion of LH/FSH in the pituitary gland ---> pituitary gland

secretin hormone deals with digestive secretions --->liver, pancreas, stomach

corticosteroid hormone controls key functions in the body, acts as anti-inflammatory, maintains blood sugar levels, BP strength, and regulates salt/water---> liver, adipose, brain, lung

thymus

epinephrine and norepinephrine increases metabolism and heart rate as a response to stress and excersize---> all tissues

thymosins provide immune response ---> t lymphocytes

Leptin hormone controls appetite, secretion proportional to fat stores---> Brain

GH deals with growth and development to all body tissues

LH stimulates ovulation and estrogen/testosterone secretion---> ovaries, testes(leydig cells)

renin regulates BP and aldosterone secretion---> smooth muscles in blood vessels and adrenal cortex

cortisol deals with metabolism and its response to stress and excersize--->all tissues

ACTH stimulates cortisol secretion and controls production of sex hormones and gametes ---> and renal cortex

inhibit inhibits synthesis and release of FSH/LH ---> pituitary gland and hypothalamus

FSH stimulates ovarian follicle growth, estrogen secretion, and sperm/egg production --->ovaries/testes

progesterone maintains pregnancy--->corpus luteum

melatonin stimulates circadian rhythm reproduction---> various tissues

TSH stimulates the production and secretion of thyroid hormones--->thyroid gland

PRL stimulates milk production and lactation --->mammary gland

dopamine creates feeling pleasure, satisfaction and motivation--->adrenal glands, kidneys

oxycotin stimulates contraction of uterus and milk ducts ---> uterine smooth muscles and mammary glands

EPO stimulates blood cell production --->bone marrow

aldosterone regulates salt, water balance and BP ---> primarily kidneys

gastrin promotes acid secretion --->stomach and intestines

calcitonin lowers blood calcium and phosphate---> bone

ADH stimulates water secretion and blood pressure ---> kidney, tubules, arteriole smooth muscles

insulin lowers blood sugar levels and stimulates metabolism of glucose ---> most body tissues but mostly muscles and liver

estrogen promotes development of secondary femal sex characteristics and menstrual cycle ---> reproductive organs

glucagon: elevates blood glucose levels ---> primarily liver

progesterone stimulates the lining of the uterus and prepares breasts for milk production ---> uterus

PTH elevates blood calcium---> bones, kidneys, small intestines

testosterone stimulates male sexual characteristics and maturation---> reproductive organs

negative feedback

positive feedback

steroid: derived from cholesterol

non steroid: produced from amino acids- amines, peptides, proteins, glycoproteins

works with the nervous system to maintain homeostasis

cells, tissues, organs called endocrine glands

endocrine glands secrete hormones into body fluids

hormones diffuse into bloodstream to act on specific target cells some distance away

precise in their actions on specific target cells

communicate with cells using hormones

endocrine glands and their hormones regulate metabolic processes within cells and the body

hormones: estrogen, testosterone, aldosterone, cortisol

hormones: norepinephrine, epinephrine, thyroid, antidiuretic, oxycotin, thyrotropin- releasing hormone, parathyroid, growth, prolactin, FSH, LH, thyroid stimulating

lipid soluble, can pass through cell membranes

carried in bloodstream weakly bound to plasma proteins

protein receptor located inside cell

hormone receptor complex binds with DNA and activates specific genes that direct the synthesis of specific proteins

the new protein can function as an enzyme that transports protein/hormone receptor then carries out the effects of a steroid hormone

combine with receptors in target cell membranes that have a binding and activity site

first messenger hormones

second messenger: chemicals in cell that respond to binding of a hormone and causes changes in a cell

signal transduction is the cascade of biological activity through the cell membrane to the inside, starting with the binding of a hormone

other proteins are activated as they carry out effects of the hormone

release of hormones from hypothalamus controls secretions of interior pituitary and its hormones affects activity of other endocrine glands directly

usually control hormone releases

gland is sensitive to concentration of substances it regulates

hormone level rises, exerts effects and further secretion is inhibited by negative feedback and then hormone secretion decreases

concentration of hormones drops below normal levels and causes inhibition removed and gland secretes move again

hormone levels remain constant and fluctuate within a normal range

target gland stimulates hypothalamus or pituitary to increase hormone release

stimulates secretion of target gland

the release of oxyctocin is controlled through positive feedback