Functions of the Endocrine system

integrates and controls other systems by growth and metabolism; reproductive organs; stress responses; control of blood chemistry

Endocrine system and nervous system work together to bring....

homeostasis

Characteristics of endocrine glands

usually epithelial glandular tissue; small and widley scattered; may be trune "organ" or may be part of an organ; secretes hormones

Hormones

steorid based or amino acid based molecules; carried via blood; affect target cells by changing proetin systhesis/acitivty

Target cells

contain hormone receptor on cell membrane or in cytoplasm

hypothalamus

master control of endocrine system; links nerevous and endocrine systems

2 regulatory hormones which control the pituitary gland

releasing and inhibiting hormones

releasing hormone

stimulate production/secretion of specific anterior pituitary hormones

inhibitiing hormones

deter production/secretion of specific anterior pituitary hormones

2 hormones stored in posterior pituitary

oxytocin and antidiuretic hormone (ADH)

oxytocin

indicues uterine contractions

anti-diuretic hormone (ADH)

decreased urine production

hypothalamo-hypophyseal portal system

the circulatory connection b/t the hypothalamus and the anterior pituitary

hypothalamo-hypophyseal tract

the nervous connection b/t the hypothalamus and the posterior pituitary

Pituitary Gland

pea-sized gland under the hypothalamus

infundibulum

connects the pituitary gland to the hypothalamus

hypophyseal fossa

sella turica's structure that houses the pituitary gland

2 lobes of pituitary gland

anterior (adenohypophysis) and posterior (neurohypophysis)

Anterior pituitary

glandular epithelia tissue; controlled by hypothalamus

7 hormones secreted by anterior pituitary

growth; thyroid stimulating; adrenocorticotropic; prolactin; follicle stimulating; leutinizing; melanocyte-stimulating hormone

growth hormone (somatrotropin)

stimulates growth; promotes cell division of body cells

thyroid stimulating hormone (thyrotropin)

stimulates thyroid to produce hormone

adrenocorticotropic hormone (corticotropin)

stimulates adrenal glands to produce hormones

prolactin

stimulates milk production in breasts and possible influence in males also

Follicle stimulating hormone

Females - development of follices/secretion of estrogen

Males- maturation of sperm

Leutinizing hormone

Females-ovulation

Males- production of testosterone

Posterior pituitary

nerve tissue continous w/ hypothalamus; stores and release oxytocin and ADH made by hypothalamus

Thyroid

larges endocrine gland; butterfly shaped organd around trachea; inferior to larynx; compsed of follicles (spheres line w/ cuboidal cells)

thyroid hormone

released by cuboidal cells; increases cell metabolism of all cells; needs iodine

calcitonin

released by parafollicular cells b/t follicles; decreases blood calcium level; stimulates bone growth

If defiency of iodine in diet....

thyroid will not be able to make thyroid hormone

thyroid stimulating hormone

causes the thyroid to enlarge which results in an endemic colloid goiter

Parathyroid glands

4 pea sized glands embredded in posterior thyroid

parathryoid hormone (PTH)

increases blood calcium level by stimulating osteoclasts

Adrenal glands

pyramid shaped organs on top of kidneys; regulates stress response; contains outer cortex and inner medulla

Medulla

nervous tissue forms sympathetic nervous system; releases epinephrine and norepinephrine in fight-or-flight response

Outer cortex

zona glomerulosa (outer); zona fasciculata (middle); zona recticularis (inner)

Three major hormones produced by cortex

glucocorticoids, mineralocorticoids; gonadocorticoids

Glucocorticoids

produced by zona fasciculata; regulates long term stress; boosts blood glucose level; increases metabolism of lipids and proteins; anti-inflammatory

Mineralocorticoids

produced by zona glomerulosa;control electrolytes and water balance in body fluids long term

gonadocorticoids

produced by zona reticularis; small amounts of sex hormones

Pancreas

leaf like organ behind stomach and over small intestine; 2+ inches; retroperitoneal

pancreatic acini

secrete digestive enzymes into intestines

pancreatic islets

clusters of mainly alpha and beta type cells

insulin

decreases blood glucos level; acts mainly on skeletal muscle, liver, and adipose cells; produced by beta cells

glucagon

increases blood glucose level; acts on liver cells to release stored glucose; produced by alpha cells

Pineal gland

melatonin

thymus

controls immune system cell development

testes/ovaries

sex hormones

stomach and small intestines

hormones controlling digestion

heart

decreases blood volume