endocrine system part 1 Flashcards
______ typically receive information from another neuron via neurotransmitters and in turn release neurotransmitters to excite another neuron or an effector cell
Neurons
________receive information in the form of a chemical messenger in the blood which causes the endocrine cell to secrete its own specific hormonal signal into the blood
Endocrine Cells
_________ function as an interface between the nervous system and the endocrine system, directly stimulated by nerve cells but secrete hormones into the blood
Neuroendocrine Cells
Hormones are secreted into the blood and are ____________ in the body
carried to nearly every cell
_______ are chemical messengers secreted by glands into the circulatory system in very low quantities and upon reaching the target cells elicit a response
Hormones
____ secrete substances into ducts which then empty into lumens or onto body surfaces
Exocrine Glands:
________: lack ducts and their products are released into interstitial fluid, diffuse into blood and travel throughout the body
Endocrine Glands
__________ are transported through blood to distant target cells, and are called endocrine hormones
Circulating Hormones
________are released very close to their target cells and diffuse through the interstitial fluid to the target cell without entering the blood
Local Hormones
________local hormones which act on the same cell which secreted them
autocrine:
_______ acts on neighboring cells
paracrine:
______are derived from cholesterol and are thus lipids (ie. fat soluble) and cross the phospholipid bilayer easily
Steroids
______are simple derivatives of amino acids
Examples: thyroid hormones (from thyroid gland), epinephrine and norepinephrine (from adrenal medulla)
Amines
______consist of chains of amino acids (varying lengths), some are glycoproteins
Examples: insulin (pancreas), pituitary hormones, hypothalamic hormones
peptides and proteins
______ are derived from a 20 carbon fatty acid called arachiodonic acid and act as paracrine or autocrine hormones in most tissues of the body
Eicosanoids
_________ promote inflammation and participate in allergic reactions
leukotrienes
***_______ promote inflammation, regulate body temperature, influence blood clot formation
prostaglandins
______ alters or degrades many hormones, especially steroids
The liver
Many peptide hormones are taken up and degraded by the _______
kidney
Fast acting hormones (such as epinephrine) are inactivated by specific ___________ and are then rapidly excreted in the urine
degrading enzymes circulating in the blood
Many of the larger peptide hormones (i.e. insulin) are ____________
degraded within their target cells
_______ receptors in nucleus on genes
Lipid-Soluble Hormones
________ receptors on cell membrane
Water-Soluble Hormones
______target cells of a certain hormone have receptors that bind and recognize that hormone
Only
__________: when a hormone is present in excess, the number of receptors may decrease. Down regulation can sometimes prevent overstimulation of a gland or tissue
Down Regulation
________ when a hormone is deficient, the number of receptors may increase. Up regulation makes a target tissue more sensitive to a hormone
Up Regulation:
_________ to another hormone enhances the response of the target cell to a second hormone, possibly by increasing the numbers of receptor molecules
Previous exposure
______ two or more hormones interact to produce the effect
Synergistic Effect
________ two hormones have the opposite effect on the target cells
Antagonistic Effect
_____ increases glucose conversion to glycogen in the liver
insulin
_____ increases glycogen breakdown into glucose
glucagon
________ is located in the brain, and is the master controller involved in maintaining homeostasis
Hypothalamus
The hypothalamus responds by transmitting signals to other neurons in the CNS and/or by the production of hormones by _________
neurosecretory / neuroendocrine cells
_________ that stimulate the release of a particular anterior pituitary hormone
Releasing Hormones
________ which reduce secretion of the particular hormone
Inhibiting Hormones
___________ is smaller than the anterior portion. It forms from an outgrowth of the developing hypothalamus, and is therefore derived from ectoderm destined to become nervous tissue
Posterior Pituitary Gland
___________ located in the hypothalamus, hormones produced there are transported down the axons to secretory vesicles located in the swollen synaptic end bulbs of the axon found in the posterior pituitary
neurosecretory / neuroendocrine cells
This is an example of a ___________whereby the sensory input is neural, but the output is endocrine (hormone)
neuroendocrine reflex
_________ is a cause of hypersecretion of thyroid hormones (hyperthyroidism) and
Graves’ disease
_________ (protruding eyes)
exophthalmos
congenital hypothyroidism (low secretion) in children can lead to _______
cretinism
hypothyroidism in adults can be due to ___________ which is an autoimmune attack on the thyroid gland itself, leading to decreased secretion of hormone
Hashimoto’s thyroiditis
iodine deficiency can lead to _____
goiter
PTH secretion is stimulated by _________calcium ion levels
low blood
It increases the activity of osteoclasts, and therefore promotes the _________ to release calcium and phosphates ions into the blood
breakdown of bone
milk secretion + ejection = _____
lactation
Nerve cell function depends on calcium ion levels & calcium ions needed for _____
clotting
________ derived from mesoderm; produces steroid hormones
adrenal cortex -
________- the secretory chromaffin cells are enlarged synaptic end bulbs of neurons of sympathetic nervous system – involved in Fight or Flight response
adrenal medulla
secrete the hormones ______ and _______ into blood rather than neurotransmitters at the neuromuscular or neuroglandular junctions
epinephrine, norepinephrine
Mainly________ which acts on the kidneys to stimulate reabsorption of sodium ions into blood
aldosterone
Control of secretion involves the _________ (kidney autoregulation)
renin-angiotensin pathway
_______Due to hypersecretion of aldosterone
Aldosteronism
Excessive sodium and water retention can lead to ____________
increased blood volume and blood pressure
_____________
Targets are the liver and rest of the body especially immune system
Cortisol, Corticosterone, Cortisone
__________ (Primary Adrenocortical Insufficiency)
Hyposecretion of glucocorticoids and aldosterone due to atrophy of adrenal cortex (autoimmune, infection or tumors)
Addison’s Disease
_________ hypersecretion of glucocorticoids due to tumor of anterior pituitary which produces excessive amounts ACTC, symptoms same as below
Cushing’s Disease -
____________ hypersecretion of glucocorticoids due to tumor of adrenal cortex, or long term glucocorticoid use for immune suppression
Cushing’s Syndrome -
_______ Male sex hormones
Androgens -
_______(Dehydroepiandrosterone) secretion is mainly stimulated by ACTH
DHEA
______ or development of facial and body hair
hirsutism
______or masculinization
virilism
The secretory chromaffin cells are enlarged synaptic end bulbs of neurons of sympathetic nervous system Secrete the hormones _______ and _______ (also called adrenalin and noradrenalin) into blood rather than neurotransmitters at the neuromuscular or neuroglandular junctions
epinephrine and norepinephrine
These hormones epinephrine are released very quickly because the adrenal medulla is directly innervated by neurons of the sympathetic nervous system _______
Fight or Flight response
_______ produce ______ hormone which raises blood sugar levels by
alpha cells, glucagon
alpha cells
produce glucagon hormone which raises blood sugar levels by
increasing what 2 things?
glycogenolysis, gluconeogenesis
this hormone (glucagon) acts on the ____
glucogon also enhances release of glucose from cells into the blood
liver
_______ produce insulin which lowers blood sugar levels by acting on various cells of the body
beta cells
Disorders associated with pancreatic islet disfunction include ________
diabetes mellitus
Loss of beta cells leads to high glucose levels or __________, where excess glucose is eliminated in the urine
hyperglycemia
________of diabeetus are excessive urination, excessive thirst and excessive eating
Three symptoms
Beetus- cardiovascular problems including _________ (damage to capillaries) which in turn can lead to ischemia and gangrene resulting in limb amputation
microangiopathy
_________ insulin-dependent diabetes mellitus; appears to be due to an autoimmune response whereby the immune system destroys pancreatic beta cells
type I diabetes mellitus
________ more common than type I; associated with obesity even in children; characterized by insulin resistance and relative insulin deficiency
type II diabetes mellitus
