Exam#6 Chapter 18 Flashcards
-a molecule released in one part of the body that regulates activity in another part of the body
hormone
- secrete their products into ducts that carry the secretions into the body cavities, into the lumen of an organ, or to the outer surface of the body
- sudoriferous (sweat), sebaceous (oil), mucous, and digestive glands
exocrine glands
-secrete their products (hormones) into interstitial fluid surrounding the secretory cells rather than into ducts
endocrine glands
-endocrine and nervous systems both target ______
communication
-neurotransmitters released locally in response to nerve impulses, are molecules in the ______ system
nervous
-hormones delivered to tissues throughout body by blood, are molecules of the ______ system
endocrine
-in the _______ system, the site of action is close to site of release, at synapse, binds to receptors in postsynaptic membrane
nervous
-in the ______ system, the site of action is far from the site of release (usually), binds to receptors on or in target cells
endocrine
-target cells in the _____ system are muscle (smooth,cardiac,/and skeletal) cells, gland cells, other neurons
nervous
-target cells in the ______ system are cells throughout the body
endocrine
-time to onset of action in the _____ system is typically within milliseconds
nervous
-time to onset of action in the ______ system, is seconds to hours or days
endocrine
-duration of action in the _____ system is generally longer, seconds to days
endocrine
-interstitial fluid—>capillaries—>blood stream—>target throughout the body
endocrine
-the endocrine system relies on the _____ system to carry its products, so endocrine glands are highly ______
cardiovascular
vascularized
- helps regulate, extracellular fluid, metabolism, smooth and cardiac muscle, glands, some immune activities
- control growth and development
- regulate operate of reproductive systems
- help establish circadian rhythms
functions of endocrine system
- most endocrine hormones are ______, they pass from the secretory cells that make them into interstitial fluid and then into the blood
- circulate in the blood for minutes to hours, eventually deactivated by the liver
circulating hormones
- act locally on neighboring cells or on the same cell that secreted them without entering the bloodstream
- inactivate quickly
local hormones
-local hormones that act on neighboring cells are called ______
paracrine
-those that act on the same cell that secreted them are called ______
autocrines
-hormones like neurotransmitters influence their target cells by chemically binding to specific protein _______
receptors
-a decrease in home one time, target cell is less sensitive to a hormone
down regulation
-increase in hormone time, target cell more sensitive to a hormone
up regulation
- steroid hormones
- thyroid hormones
- nitric oxide
-are chemical classes of hormones called ______
lipid soluble
-derived from cholesterol, different chemical groups bound to the core allow for different functions
steroid hormones
-iodine plus the amino acid tyrosine, which contains benzene
thyroid hormones
-a gas that functions as a hormone and a NT
nitric oxide(NO)
-most lipid-soluble hormones require ______ to make them water soluble and prevent their excretion
transport proteins
-up to _____% of a hormones molecules are not bound to transport proteins, this ______ diffuses out of capillaries to bind to receptors
10%
free fraction
-lipid soluble means ______, it can go through the non-polar centers of plasma membranes and get inside cells
hydrophobic
-aldosterone, cortisol, androgens (adrenal cortex, calcitriol (kidneys), testosterone (testes), estrogens, progesterone (ovaries)
steroid hormones
-because lipid-soluble hormones can enter the cell, this has access to the ______ machine, leading to protein production
nuclear transcription
- free lipid soluble hormone diffuses into cell
- activated receptor hormone within cytosol complex alters gene expression
- newly formed mRNA directs synthesis of specific proteins on ribosomes
- new proteins alter cells activity
lipid soluble hormones bind to receptors inside target cells
action of lipid soluble hormones
- anime hormones
- peptide and protein hormones
- eicosanoid hormones
are ______ hormones
water soluble
-made by modifying amino acids, but all retain an anime group (-NH3+)
amine hormones
- amino acid polymers, ______ are chains of 3-49, ______ are 50-200
- several have attached carbs, and are _______
peptides
proteins
glycoprotein hormones
- are derived from arachidonic acid, a 20 carbon fatty acid
- two major types are prostaglandins and leukotrienes
eicosanoid hormones
-epinephrine, norepinephrine (adrenal medulla), melatonin (pineal gland), histamine (mast cells in connection tissues), serotonin (platelets in blood)
amines
- water soluble hormones are the ______, binding to cell surface receptors that initiate cellular mechanisms
- the molecule produced by the integral receptor protein is the ______ (here, cAMP)
- activated ______ will phosphorylate targets (adding a P), which in turn trigger reactions with physiological effects
first messenger
second messenger
protein kinases
-_______ is responsible for deactivating cAMP
phosphodiesterase
- binding of hormone (first messenger) to its receptor activates G protein, which activates adenylyl cyclase
- activated adenylyl converts ATP to cAMP (second messenger)
- cAMP serves as a second messenger to activate protein kinases
- activated protein kinases phosphorylate cellular proteins
- millions of phosphorylated proteins cause reactions that produce physiological responses
- phosphodiesterase inactivates cAMP
action of water soluble hormones
-_______ hormones bind to receptors inside target cells
lipid soluble hormones
-_______ hormones bind to receptors embedded in the plasma membranes of target cells
water soluble hormones
-like other systems, hormones can interact to fine-tune the body’s response to ______ demands
environmental
-normal responses to hormones depend on hormone concentrations and the number of ______, but they are also affected by the actions of other hormones
target receptors
-a hormones response is increased by simultaneous or recent exposure to a second hormone
permissive effect
-hormones acting together to create a greater response, potentially by activating similar second messenger systems
synergistic effect
-hormones oppose each other’s effects
antagonistic effect
- signals from the nervous system
- chemical changes in the blood
- other hormones
- most regulation is via ______ system with a few exceptions
- example: childbirth
prompts secretion and release of hormones
negative feedback
-the ______ is the “master gland”, along with the ______, it regulates growth, development, metabolism, and homeostasis
hypothalamus
pituitary
-the pituitary is also called the ______
hypophysis
-the pituitary is attached to the hypothalamus by a stalk called the ______, and has two separate portions the anterior and posterior pituitary
infundibulum
- via the ______ system: hormones made by the ______ cells are carried to a second capillary network surrounding the ______
- 5 ______ hormones GHRH, TRH, CRH, PRH, GnRH
- 2 ______ hormones GHIH, PIH
- _______ hormones produced by the hypothalamus, have endocrine glands as their targets
hypophyseal portal system, neurosecretory cells, anterior pituitary
releasing hormones
inhibiting hormones
tropic hormones
- growth hormone-releasing hormone, also known as somatocrinin (GHRH)
- thyrotropin-releasing hormone (TRH)
- corticotropin-releasing hormone (CRH) or (ACTH) and (MSH)
- prolactin-releasing hormone (PRH)
- gonadotropin-releasing hormone (GnRH), (FSH), (LH)
•these are the releasing hormones of the ________
anterior pituitary
- growth hormone-inhibiting hormone (GHIH), also known as somatostatin
- prolactin-inhibiting hormone (PIH), which is dopamine *(MSH) also inhibits dopamine
•these are inhibiting hormones of the ______
anterior pituitary
- stimulates liver, muscle, cartilage, bone, and other tissues to synthesize and secrete insulin-like growth factors (IGF), which in turn promote growth of body tissues
- acts directly in target cells to enhance lipolysis and decrease glucose uptake
growth hormone
-stimulates synthesis and secretion of thyroid hormones by thyroid gland
thyroid stimulating hormone
- initiates development of oocytes and induces ovarian secretion of estrogens
- in males, stimulates testes to produce sperm
follicle stimulating hormone
- stimulates secretion of estrogens and progesterone, ovulation, and formation if corpus luteum
- stimulates testes to produce testosterone
luteinizing hormone
-together with other hormones, promotes milk production by mammary glands
prolactin
-stimulates secretion of glucocorticoids by adrenal cortex
adrenocorticotropic hormone
-exact role in humans is unknown but may influence brain activity, when present in excess, can cause darkening of skin
melanocyte-stimulating hormone
-_______ secreted by the adrenal cortex suppresses secretion of CRH and ACTH
cortisol (negative feedback)
-secretion of ______ is stimulated by growth hormone-releasing hormone and inhibited by growth hormone inhibiting hormone
growth hormone (negative feedback )
- hypoglycemia
- decreased blood levels of fatty acids
- increased blood levels of amino acids
- sympathetic activity
- deep sleep
- testosterone, estrogens, thyroid hormones, and ghrelin
factors that stimulates growth
- hyperglycemia
- increased blood levels of fatty acids
- decreased blood levels of amino acids
- obesity
- aging
- high blood levels of GH and IGFs
factors that stop growth
- has no tropic hormones, so portal system
- posterior pituitary doesn’t produce anything, it stores and secreted ______ and ______
oxytocin and ADH
- hormones are produced and packaged into vesicles
- travel to axon terminals
- exocytosed when the nerve is stimulated
- travel to targets
hypothalamic control of posterior pituitary
- neurosecretory cells of the hypothalamus secrete ______ in response to uterine distension and stimulation of nipples
- stimulates contractions of smooth muscle cells of uterus during childbirth, stimulates contraction of myoepithelial cells in mammary glands to cause milk ejection
oxytocin
- neurosecretory cells of the hypothalamus secrete ______ in response to elevated blood osmotic pressure, dehydration, loss of blood volume, pain, or stress, inhibitors secretion include low blood osmotic pressure, high blood volume, and alcohol
- conserves body water decreasing urine volume, decreases water loss through perspiration, raises blood pressure by constricting arterioles
antidiuretic hormone (ADH)
- hormone receptors are also ______ that beer to be synthesized, and the body regulates the amount of these receptors that are produced
- the need is based on ______
proteins
sensitivity
- if there is a lot of hormones available, there do not have the be many receptors in order for the target cell to get the message
- high hormone concentrations cause ______, lowering sensitivity
down regulation
-if a hormone is found in low concentrations, production of receptor cells will be ______, increasing sensitivity, in order to not miss out on an important signal
up-regulated
- butterfly-shaped, with right and left lobes connected by an isthmus
- the only gland that stores its product up to a 100 day supply
thyroid gland
- ________ cells in thyroid gland produce thyroxine (T4) and triiodothyrine (T3)
- ________ cells produce calcitonin
follicular cells
parafollicular cells
*think growth and activity •increase metabolic rate •calorigenic effect (make heat) •up-regulate catecholamine receptors (permissive effect ) •promote nervous and skeletal growth
thyroid hormones
- tones down calcium
- inhibits osteoclasts (bone breakdown) and accelerates bone growth
calcitonin
-________ is not active in osteoporosis
calcitonin
- low blood levels of T3 and T4 or low metabolic rate stimulates release of TRH
- TRH carried by portal vein to anterior pituitary, stimulates release of TSH by thyrotrophs
- TSH released into blood stimulates thyroid follicular cells
- T3 and T4 released into blood by follicular cells
- elevated T3 inhibits release of TRH and TSH (negative feedback)
secretions and actions of thyroid
- located behind the thyroid gland
- has 4 glands: left and right superior and left and right inferior
parathyroid gland
- low blood Ca2+ levels stimulate secretion
- high blood Ca2+ levels inhibit secretion
- increases blood Ca2+ and Mg levels and decreases blood HPO42- level, increases bone resorption by osteoclasts, increases Ca2+ reabsorption and HPO42- excretion by kidneys, promotes formation of calcitriol (active form of vitamin D), which increases rate of dietary Ca2+ and Mg2+ absorption
parathyroid hormone (PTH)
-calcitonin and parathyroid hormone regulate blood ______ levels
Ca2+
- high level of Ca2+ in blood stimulates thyroid gland parafollicular cells to release more calcitonin
- calcitonin inhibits osteoclasts decreasing blood Ca2+ level
- low level of Ca2+ in blood stimulates parathyroid gland chief cells to release more PTH
- PTH promotes release of Ca2+ from bone extracellular matrix into blood and slows loss of Ca2+ in urine, increasing blood Ca2+ level
- PTH also stimulates the kidneys to release calcitriol
- calcitriol stimulates increased absorption of Ca2+ from foods, which increases blood Ca2+ level
secretion of calcitonin and PTH
-with respect to regulation of blood Ca2+ level, calcitonin and PTH have ______ effects
antagonistic
-______ glands sit on top of the kidneys
adrenal
- mineralcorticoids (aldosterone)
- glucocorticoids (cortisol)
- androgens
•are hormones of the ______
adrenal cortex
-in the ______, chromaffin cells produce epinephrine and norepinephrine
adrena medulla
- increased blood K+ level angiotensin II stimulate secretion
- increase blood levels of Na+ and water, decrease blood level of K+
- from zona glomerulosa cells
mineralcorticoids (aldosterone)
- ACTH stimulates release, corticotropin-releasing hormone (CRH) promotes ACTH secretion in response to stress and low blood levels of glucocorticoids
- increase protein breakdown (except in liver) stimulates gluconeogenesis and lipolysis, provide resistance to stress, dampen inflammation, depress immune responses
glucocorticoids (cortisol)
- ACTH stimulates secrete
- assist in early growth of axillary and pubic hair on both sexes, in females, contribute to libido and are source of estrogens after menopause
androgens (dehydroepiandrosterone DHEA)
- sympathetic preganglionic neurons release acetylcholine, which stimulates secretion
- enhance effects of sympathetic division of autonomic nervous system (ANS) during stress
- chromaffin cells, source adrenal medulla
epinephrine and norepinephrine
- dehydration Na+ deficiency or hemorrhage (not enough ions)
- decrease in blood volume
- decrease in blood pressure
- juxtaglumerular cells of kidneys
- increased renin
- adrenal cortex
- increased aldosterone
- increased blood volume
aldosterone secretion by renin-angiotensin aldosterone (RAA)
-increased _________ are mineralcorticoids that increase sodium and water and raise blood pressure
aldosterone
-in chronic blood pressure aldosterone is ________
active
-regulate metabolism and resistance to
stress
-simple feedback loop, where the product stops the cycle, controlled by 3 glands: hypothalamus, anterior pituitary, and adrenal cortex
glucocorticoids
-a high level of CRH and a low level of glucocorticoids promote the release of ACTH, which stimulates glucocorticoid secretion by the ________
adrenal cortex
- located between kidneys
- 99% is cells arranged as acini (clusters) that make digestive enzymes (exocrine)
- is both an endocrine and exocrine gland
- had alpha, beta, delta, and F cells
pancreas
-small clusters called ______ perform endocrine functions
pancreatic islets (islets of Langerhans)
-cell type in the pancreatic islets •alpha cells secrete \_\_\_\_\_\_\_ •beta cells secrete \_\_\_\_\_\_\_ •delta cells secrete \_\_\_\_\_\_\_ •F cells secrete \_\_\_\_\_\_\_\_
glucagon
insulin
somatostatin
pancreatic polypeptide
-glycogen turns on when _______ is gone
glucose
-low blood glucose stimulates release of _______, high blood glucose stimulates secretion of _________
glucagon
insulin
•low blood glucose (hypoglycemia) stimulates alpha cells to secrete glucagon
•glucagon acts on liver cells to:
-convert glycogen into glucose
-form glucose from lactic acid and certain amino acids
•glucose released by liver cells raises blood glucose level to normal
•if blood glucose continues to rise, hyperglycemia inhibits release of glucagon
negative feedback of secretion of glucagon
-high blood glucose (hyperglycemia) stimulates beta cells to secrete insulin
-insulin acts on various body cells to:
•accelerate facilitated diffusion of glucose into cells
•speed conversion of glucose into glycogen
•increase uptake of amino acids and increase protein synthesis
•speed synthesis of fatty acids
-blood glucose level falls
-if blood glucose continues to fall, hypoglycemia inhibits release of insulin
negative feedback of secretion of insulin
- decreased blood level of glucose, exercise and mainly protein meals stimulate secretion, somatostatin and insulin inhibit secretion
- raises blood glucose level by accelerating breakdown of glycogen into glucose in liver, converting other nutrients into glucose in liver, and releasing glucose into blood
glucagon
- increased blood level of glucose, acetylcholine, arginine and leucine, glucagon, GIP, GH, and ACTH stimulate secretion, somatostatin inhibits secretion
- lowers blood glucose level by accelerating transport of glucose into cells, converting glucose into glycogen, and decreasing glycogenolysis and gluconeogenesis, increasing lipogenesis and stimulates protein synthesis
insulin
- pancreatic polypeptide inhibits secretion
- inhibits secretion of insulin and glucagon, slows absorption of nutrients from gastrointestinal tract
somatostatin
- meals containing protein, fasting, exercise, and acute hypoglycemia stimulate secretion, somatostatin and elevated blood glucose level inhibit secretion
- inhibits somatostatin secretion, gallbladder contraction, and secretion of pancreatic digestive enzymes
pancreatic polypeptide
-glucagon and insulin suppress the secretion of each other
•ACTH, GH, digestion and absorption of food, ups the secretion of _______
•increased activity of ANS, exercise increases ______
insulin
glucagon
-________ puts glucose in cells
insulin
- small gland attached to the 3rd ventricle of the brain
- secreted melatonin, a sleep cycle regulator
- during the day, low levels secreted rhythmically
- at night, 10 fold increase of blood levels, decline before awakening
pineal gland
- located behind sternum, between the lungs
- thymosin, thymic humoral factor (THY), thymic factor (TF), and thymopoetin promote maturation of T cells
thymus
- skin: vitamin D
- GI: digestion and insulin
- placenta: pregnancy and lactation
- kidneys: renin, RAA system, EPO blood cells
- heart: decreases BP
- adipose tissue: suppresses appetite
hormones by other organs that contain endocrine cells
