what are paracrines?
cells that secrete a substance that stays local
communicates via electrical impulses and neurotransmitters, neurotransmitters synapses at specfic target cells, relatively local specific effects, quick to react to stimuli 1-10 ms, stops quickly when stimulus stops, adapts quickly to continual stimulation.
communicates via hormones, hormones released into blood stream general distribution throughout body, general widespread effects, slow to react to stimuli seconds to days, may continue to respond long after stimulus stops, adapts slowly to continuous stimuli may respond for days to weeks.
what are classified as neurotransmitters and hormones?
norepinephrine, dopamine, antidiuretic hormone.
what are neuroendocrine cells?
neurons that release their secretions into the extracellulare fluid.
What do neuroendocrine cells release?
Oxytocin and catecholamines ADH
what are the overlaping effects of norepinephrine and glucoagon?
what is ACTH and where does it come from?
Adrenocorticotropic hormone ( corticotropin) anterior pituitary.
What is ADH and where does it come from?
Antidiuretic hormone (vasopressin) prosterior pituitary
What is ANP and where does it come from?
Atrial natriuetic peptide, heart
what is CRH and where does it come from?
corticotropin releasing hormone, hypothalamus
What is DHEA and where does it come from?
Dehydroepiandrosterone, adrenal cortex
What is EPO and where does it come from?
Erythropoietin, Kidney, Liver
What is FSH and where does it come from?
follicle stimulating hormone, anterior pituitary
What is GH and where does it come from?
growth hormone (somatotropin), anterior pituitary
What is GHRH and where does it come from?
growth hormone-releasing hormone, hypothalamus
What is GnRH and where does it come from?
Gonadotropin-releasing hormone, hypothalamus
What is IGF's and where does it come from?
insulin-like growth factors (somatomedins), liver, other tissues
What is LH and where does it come from?
luteinizing hormone, anterior pituitary
What is NE and where does it come from?
Norepinephrine, adrenal medulla
What is OT and where does it come from?
Oxytocin, posterior pituitary
What is PIH and where does it come from?
prolactin-inhibiting hormone(dopamine) hypothalamus
What is PRL and where does is come from?
prolactin, anterior pituitary
What is PTH and where does it come from?
parathyroid hormone(parathormone) parathyroids
What is T3 and where does it come from?
What is T4 and where does it come from?
What is TH and where does it come from?
Thyroid hormone (T3 and T4) thyroid
What is TRH and where does it come from?
Thyrotropin-releasing hormone, hypothalamus
What is TSH and where does it come from?
Thyroid stimulating hormone (thyrotropin) anterior pituitary
Where is the pituitary gland housed?
in the sella turcica of the sphenoid bone.
How much does the pituitary gland grow in pregnacy?
what two structures make up the pituitary gland?
adenohypohysis (anterior 3/4) grows upward from the pharynx and neurohypohysis (posterior)neurohypohyseal bud downgrowth of the brain.
how is the anterior (adenohypohysis) pituitary gland connected to the hypothalamus?
Via complex of vessels called the hypophyseal portal system. vascular connection only no nervous connection.
What allows the pituitay gland to uptake and release hormones?
porous capillaries called fenestrated capillaries
What are the characteristics of the posterior pituitary gland?
has a stalk, mass of neuroglia and nerve fibers, the fibers travel from the hypothalamus down the stalk as a bundle called the hypothalamo-hypopphyseal tract and end in the posterior lobe. stores hormones until neve signal triggers its release.
How many hormones does the hypothalamus produce?
How many hormones does the hypothalamus produce that travel through the anterior pituitary and regulate it and what are they?
six- TRH, CRH, GnRH,GHRH, PIH, Somatostain.
What is TRH from the hypothalamus and what does it do?
Thyrotropin- releasing hormone- promotes FSH and PRL secretion.
What is CRH from the hypothalamus and what does it do?
corticotropin releasing hormone, promotes ACTH secretion
What is GnRH from the hypothalamus and what does it do?
gonadotropin releasing hormone, promotes FSH and LH secretion.
What is PIH from the hypothalamus and what does it do?
Prolactin inhibiting hormone, inhibits PRL secretion
What is GHRH from the hypothalamus and what does it do?
growth hormone releasing hormone, promotes GH secretion
What is Somatostain from the hypothalamus and what does it do?
inhibits GH and TSH secretion.
What is the primary function of the posterior pituitay gland and does it produce hormones?
no it does not produce hormones, it stores and releases OT and ADH
Which portion of the pituitary gland produces hormones and how many and what are the first five?
anterior secretes 6 hormones the first five are trophic.
What are trophic hormones?
they stimulate enocrine cells elsewhere to release their own hormones.
what is the target organ for FSH, what does it do and where is it stored?
(folicle stimulating hormone) ovaries, testes, female growth of ovarian folicles and secretion of estrogen male sperm production. anterior pituitary.
What is the target organ for LH, what does it do and where is it stored?
(lutenzing hormone) ovaries, testes, female ovulation, maintenace of corpus luteum , male testosterone secretion. anterior pituitary
What is the target organ for ACTH, what does it do and where is it stored?
(adrenocorticotropic hormone) adrenal cortex, growth of adrenal cortex secretion of corticosteroids esp cortisol. anterior pituitary
What is the target organ for TSH, what does it do and where is it stored?
(thyroid stimulating hormone) thyroid gland, growth of the thyroid secretion of thyroid hormone. anterior piuitary
What is the target organ for PRL, what does it do and where is it stored?
(prolactin) mammary glands, testes, female milk stimulation, male increased LH sensitivity and testosterone secretion. anterior pituitary
What is the target organ for GH, what does it do and where is it stored?
(growth hormone semattotropin) liver, bone, muscle, fat. somatomedin secrection, widespread tissue growth stimulates liver to produce insulin like growth factors IGF-I II. anterior pituitary.
What is the target organ for ADH, what does it do and where is it stored?
(antidiuretic hormone) kidneys, water retention acts as a brain neurotransmitter, posterior pituitary.
What is the target organ for OI, what does it do and where is it stored?
(oxytocin) uterus, mammary glands, labor contractions, posterior pituitary.
What does GH- IGF do?
affects protein synthesis lipid metabolism, carbohydrate metabolism electrolyte balance bone growth cartilage growth and muscle growth IGF 1 prolongs the action of GH
What is a side effect of a tumor in the pineal gland?
premature onset of puberty in boys
Where is the thymus located?
in the mediastinum of the chest
What is the largest endocrine gland?
Where is the thyroid gland located?
immediatly below the larynx
What thyroid hormone is most active?
Where are the parathyroid glands located?
they are partially embedded in the posterior surface of the thyroid.
What is the purpose of the parathyroid glands?
to secrete PTH in response to hyocalcemia.
What does PTH do?
promotes synthesis of calcitriol which promotes calcium absorption in the intesine inhibits urinary calcium excretion and stimulates osteoclastic activity. *in small doses it can stimulate osteoblastic activity.
What is the adrenal medulla?
modified neurons, chromaffin cells that lack dendrites and axons, innervated by sympathetic preganglionic fibers secrete epineprine(85%) and norepinephrine increases alertness boosts glucose levels by promoting glycogenolysis and gluconeogenesis.inhibits insulin secretion glucose sparing. *no parasympathetic inneravation.
what are catecholamines and what do they do?
epinepherin and noepienepherin. increase heart rate, bloodpressure,increase pulmonary airflow raise the metabolic rate and inhibit urination and digestion.
what are the three areas of the adrenal cortex?
zona glomerulosa zona fasciculata zona reticularis. located on top of the kidneys.
What hormones does the adrenal cortex produce and how many?
steroid hormones known as corticosteroids. 25
Which of the areas of the adrenal cortex secretes mineralocoticoids mainly aldosterone and what does it do?
zona glomerulosa and it promotes sodium retention and potassium excretion by the kidney.
What area of the adrenal cortex secretes glucocorticoids mainly cortisol?
Zona fasciculata and it stimulate fat and protein catabolism, promotes gluconeogenesis has an anti inflammatory effect and lon term secretion suppresses the immune system.
What area of the adrenal cortex androgens estrogens?
zona reticularis. androgen male testosterone not very important in men but in woment 50%comes from here. in both it is resp. for pubic hair and libido.Estrogen is unimportant until menopause. it also promotes adolescent sketatal growth and maintains adult bone mass.