Endocrine System

what are the four functions of the endocrine system?

regulate development, maintain homeostasis of blood composition, control digestive, control reproductive

similarities between the endocrine and nervous system:

chemicals/receptors, chemical messengers, negative feedback, homeostasis

differences between the endocrine and nervous system

the nervous system is very fast, and uses AP + NT's, the endocrine system is slow, because it uses hormones

autocrine

acts on cells that secrete it

paracrine

acts on nearby cells

hormones

released into bloodstream- act far from secretion site

3 types of stimulation:

hormonal, humoral, and nervous

hormonal

release of hormone in response to another hormone

humoral

release of hormone in response to changes in level of blood

nervous system

release of hormone in response to stimulation by nervous system

negative feedback pathway in the endocrine system:

hypothalamus -> pituitary -> endocrine

3 types of endocrine hormones:

peptides, steroids, monoamines

peptides

hydrophillic, travel freely in blood, bind to extracellular receptors, fast effect, short lived

steroids

hydrophobic, need protein carrier, intracellular receptors, slow effect, long lived

monoamines

exhibit chemical properties of peptide or steroid hormones

synergistic

hormones work together

permissive

1st hormone allows action of 2nd

antagonistic

one hormone causes the opposite effect of another hormone

neurohypophysis

between the hypothalamus and posterior pituitary

adenohypophysis

between the hypothalamus and anterior pituitary

the neurohypophysis release what two hormones?

ADH and oxytocin

ADH effects:

decrease urine production, stimulate thirst, constrict BV

oxytocin effects:

milk release, uterine contraction, emotional bonding

the adenohypophysis release what four hormones?

growth, thyroid, prolactin, and cortisol

the adenohypophysis uses the _______ -______ portal system.

hypothalamus-hypophyseal

growth hormone releasing hormone:

GHRH

growth hormone stimulation hormone:

GH

growth hormone effector hormone:

GH + IGF

what is the effect of growth hormone?

growth of bones + tissues

T or F: GH is most active at a young age and at night!

True

thyroid hormone releasing hormone:

TRH

thyroid hormone stimulation hormone:

TSH

thyroid hormone effector hormone:

T3 + T4 (thyroxine)

the thyroid hormone produces more ______

T4!

but, ______ is more active.

T3!

the thyroid hormone requires ___ for T3 + T4 synthesis!

iodine

the thyroid hormone also produces _________!

calcitonin

calcitonin

reduces blood calcium! by giving it to the bones!

the parathyroid regulates _________ levels!

calcium

the parathyroid hormone __________ blood calcium

increases

the parathyroid gland ___________ blood calcium from _______ being released from the kidneys

increases, calcitriol

cortisol hormone release hormone:

CRH

cortisol hormone stimulation hormone:

ACTH

cortisol hormone effector hormone:

cortisol

cortisol levels _____ during sleep.

rise

cortisol also ________ the immune system, __________blood sugar, _______memory, _______serotonin, _______ BP

weakens, increases, better, decreases, increases

the adrenal cortex is stimulated by (_)

ACTH (cortisol)

there are three regions in the adrenal cortex:

zona glomerulosa, zona fasciculata, zona reticularis

zona glomerulosa:

aldosterone (salt)

zona fasciculata:

cortisol (released in response to stress)

zona reticularis:

androgens (reproduction)

the adrenal medulla is stimulated by?

direct nerve

the adrenal medulla is composed of?

catecholamines (norepinephrine + epinephrine)

prolactin releasing hormone:

PRH

prolactin stimulation hormone:

prolactin

prolactin effector hormone:

breast

effects of prolactin:

milk production

dwarfism

not enough GH

gigantism

too much GH

acromegaly

too much GH in adult

hyperthyroidism (graves)

excessive production of TH, weight loss, high metabolic rate

hypothyroidism

decreased production of TH, weight gain, low metabolic rate

goiter

enlargement of the thyroid gland, due to lack of iodine

hypercorticosteroidism (cushings)

hypersecretion of cortisol, muscle weakness, high BP

hypocorticosteroidism (addisons)

hyposecretion of cortisol, anxiety, fatigue, low BP

pancreatic hormones:

glucagon and insulin

released when blood glucose is high:

insulin

insulin is secreted by __ cells

beta

released when glucose is low

glucagon

glucagon is secreted by cells

alpha

_______ __________ contain clusters of endocrine cells

pancreatic islets

destruction of B cells is known as type _____ diabetes

one

type one diabetes is common in ___________

children

type one diabetes requires _____________ daily

insulin

what type of diabetes is the most common?

type two

MODY is called?

mature onset diabetes of the youth

MODY resembles what type of diabetes?

type two

gestational diabetes is common in whom?

pregnant women

when a person exhibits a decreased blood glucose level it is called?

hypoglycemia

melatonin is secreted by the _________ gland of the __ thalamus.

pineal; epi

melatonin functions to ____________ drowsiness and helps maintain __________ _____________.

increase; circadian rythmn

parathyroid axis and melatonin axis do not require input of the ________________.

hypothalamus

the parathyroid glands directly sense blood levels of ___________.

calcium

in response, they secrete PTH; which activates the activity of ______________

osteoclasts

thymus effector hormone:

thymic hormones

heart effector hormone:

ANP

kidney effector hormone:

erythropoietin

stomach effector hormone:

gastrin

small intestin effector hormone:

secretin and CCK

adipose effector hormone:

leptin

liver effector hormone

IGF1