Chapter 17 Flashcards
________ are ductless glands that secrete hormones into the bloodstream to aid in homeostasis
Endocrine glands
______ are chemical messengers that initiate a change in a target cell
hormones
_________ have specific receptors for specific hormones
target cells
Similarities of Nervous vs Endocrine
- Both respond to stimuli by releasing a ligand (neurotransmitter, hormone)
- The ligands bind receptors on target cells causing a cellular response
Differences of Nervous vs Endocrine
- NS controls a specific location in the body by way of the neuron while ES releases hormone into the bloodstream thus causing a widespread response throughout body
- NS effect is rapid and short lived while the ES has a long response time and long lasting effect
A function of the endocrine is regulating development, growth, and metabolism. Through cell division and _____ (during growth) and both anabolic and catabolic processes.
differentiation
A function of the endocrine system is maintaining homeostasis of blood composition and volume. Regulation of blood glucose, _____, ions (Na+, K+, etc) as well as the formed elements.
amino acids
A function of the endocrine system is controlling digestive process that influence ______ and movement.
secretory processes
An endocrine function is controlling reproductive activities that affect development, function, and ____.
sexual behaviors.
Endocrine tissue and gland are both composed of _____ tissue that release hormones, supported by a ____ tissue framework.
epithelial tissue
connective
Pituitary, pineal, thyroid, parathyroid, and adrenal glands are all.
endocrine organs
single organ, entirely endocrine in function
endocrine organs
secretory cells housed in small clusters within organ that have some other primary functions
endocrine tissues
hypothalamus, skin, thyums, heart, liver, stomach, pancreas, small intestines, adipose tissue, kidneys and gonads
endocrine tissues
3 steps of hormone synthesis and release
- hormonal stimulation
- humoral stimulation
- nervous system stimulation
the release of hormone in response to another hormone
hormonal stimulation
the release of hormone in response to changes in a level of nutrient or ion in the blood
humoral stimulation
the release of the hormone in response to stimulation by the nervous system.
nervous system stimulation
physiological effects a result of hormone blood concentrations
blood hormone regulation
Two factors that influence blood hormone concentration
hormone synthesis
hormone elimination
amount of time necessary to reduce the hormone concentration within the blood to one half of what had originally been secreted
half life
Hormones are grouped according to ____.
chemical structures
Three general categories of hormones
steroids
biogenic amines
proteins
____ are water soluble and the most common type of hormones
proteins
Hormone elimination can happen in 2 different ways; via enzymatic degradation (liver) and removal from blood through ________
excretion by kidneys or uptake by target cells.
Water-soluable hormones have a ____ half-life.
short (few minutes or less)
____ have the longest half-life.
steroids
_____ (a steroid) can last up to ____ days.
testosterone
12
_____ are lipid-soluble molecules synthesized from cholesterol.
steroids
_____ are water-soluble (except thyroid hormones), modified amino acids also called monoamines.
biogenic amines
estrogen, progesterone, testosterone, corticosteroids (cortisol) and mineralocorticoids (aldosterone)
types of steroids
catecholamine’s (epi and nor-epi), thyroid hormones and melatnonin (pineal)
types of biogenic amines
formed from cholesterol
steroids
derived from amino acid that is modified.
biogenic amines
_____ are signaling molecules that do not circulate within blood.
local hormones
____ are the primary local hormone.
eicosanoids
Three types of ____ are: prostaglandins, thromboxanes, and leukotrienes.
eicosanoids
______ are the most diverse ______, stimulate pain receptors, reduce fever, and increase inflammatory response.
Prostaglandins are the most diverse Eicosandoid
Aspirin, ibuprofen and other NSAIDs block the formation of _____.
prostaglandins
hormone works on the same cell secreted from
autocrine stimulation
hormone works on neighboring cell to secretory cell
paracrine stimulation
What three things can stimulate hormone release?
another hormone
changes in an ion concentration
nervous stimulation
What are the three types of hormones?
steroids
biogenic amines
proteins
What is a local hormone?
One that doesn’t release into the blood but instead works on local cells
Lipid soluble hormones require _____ carrier proteins synthesized by the liver.
water-soluble carrier proteins
Carrier proteins can be ___ or ____.
specific (thyroxine-binding) or
nonselective (albumin)
Lipid soluble hormones
steroids
calcitriol
thyroid hormone (TH)
Water soluble amines
proteins biogenic amines (except TH)
About ___ or lipid soluble hormones that are unbound are able to exit the blood and bind receptors of target organs.
1 - 10%
About ____ lipid soluble hormones are bound, readily available source to maintain homeostasis.
90-99%
_____ hormones do not require carrier proteins.
water-soluble hormones
Lipid soluble hormones are ___, ____ molecules that are lipophilic.
small
nonpolar
Lipid soluble hormones diffuse ____ through plasma membrane.
directly
Lipid soluble hormones bind receptors within the cytosol/nucleus of the cell to form a ______. They then bind sections of DNA called ______, which causes the transcription of a specific mRNA and thus the synthesis of a specific protein. This results in either an alteration in cell structure (growth) or a shift in the cell’s metabolic activities (if the new protein is an _____)
hormone-receptor complex (HRC)
hormone-response elements (HRE)
enzyme
Water soluble hormones are ____ molecules, unable to ____.
polar
unable to cross the plasma membrane.
Water soluble hormones must bind receptors on the plasma membrane to initiate a series of biochemical events within the cell, which is called _____.
signal transduction
The first messenger in _____ is the signalling molecule (hormone) which causes the formation of the second messenger.
signal transduction
The second messenger of signal transduction is a molecule that ____ cellular activity.
modifies
Signal transduction starts with the activation of a ____ protein.
G
REVIEW SLIDE SIGNAL TRANSDUCTION
!
Why does a lipid-soluble hormone need a carrier proteins within the blood?
A lipid soluble hormone is non polar which does not mix with the polar nature of the blood plasma.
Lipid soluble hormones cause what to occur?
the transcription of a specific mRNA and thus the synthesis of a specific protein
A water soluble hormone is considered a ____ messenger.
first
Activated G proteins can then activate what two other plasma proteins?
Adenylate cyclase
phopholipase C
Adenylate cyclase activates cAMP which then activates ___.
protein kinase A
Phospholipase C splits PIP2 into
DAG
IP3
The pituitary gland also called the hypophysis is located ___ to the hypothalamus but is connected by way of the ____.
inferior
infundibulum
The pituitary gland consists of ___ lobes and can be found within the sella turcica.
two
The posterior pituitary gland is also called the ____,
neurohypophysis
Posterior pituitary gland is composed of the ____ and pars nervosa.
infundibulum
The posterior pituitary gland makes up about 1/4 of the pituitary ___.
mass.
Axons extend through the hypothalamo - hypophyseal tract from the hypothalamus to the ______.
pars nervousa.
The posterior pituitary gland has two hypothalamic nuclei; paraventricular and the ____.
supraoptic
Most of the pitutitary mass is called the ____.
adenohypophysis
There are three distinct areas of the anterior pituitary gland _______, ________, _______.
pars distalis
pars tuberalis
pars intermedia
Hormones produced in _____ cells (neuronal cell body clusters) of the hypothlamus: paraventricular nucleus - oxytocin and supraoptic nucleus - ____.
neurosecretory cells
ADH
Hormones are stored in vesicles within the synaptic knobs of the neurons located in the ____. hormones are released into blood when nerve signal is sent from the ____.
posterior pituitary
hypothalamus
____ stimulates contraction of smooth muscles within uterus during delivery and breast during infant nursing.
oxytocin
_____ stimulates kidneys to decrease urine output, thirst centers to increase fluid intake and vasoconstriction if released in high enough doses.
ADH (vasopressin)
_____ hormones stimulate the production and secretion of specific AP hormones.
releasing hormones (RHs)
Releasing Hormones of the AP
thyrotropin TRH prolactin PRH gonadotropin GnRH corticoropic CRH growth hormone GHRH
______ hormones decrease the production and secretion of specific AP hormones.
inhibiting hormones (IHs)
Inhibiting hormones of the AP
prolactin PRL
growth hormone GHIH
* only two that have inhibiting hormones
All AP hormones are _____ hormones (except prolactin). They stimulate other endocrine glands/cells to release their hormones.
tropic
Hormones that stimulate other endocrine glands/cells to release their hormones.
tropic hormones
The hypothalamus can be stimulated by:
age time of day nutrient level stress excerices to release GHRH which causes release of GH from AP
______, Growth hormone primary target, release insulin like growth factors (IGFs).
hepatocytes
IGFs similar to growth hormone but create a greater response due to having a greater _____.
half life 20 hours vs 20 minutes
Increased levels of growth hormone and IGF blood concentrations stimulate the ______ to release GHIH and inhibit the release of GHRH as well as ____ from the AP.
hypothalamus
GH
All body cells have receptors for GH and ____.
IGF.
GH and IGF both activate ______.
second messengers
GH and IGF activating second messengers causes increased protein synthesis, increased cellular division, and or ______.
cell differentiation
Growth hormone causes hepatocytes to stimulate to increase ______.
blood glucose levels.
Adipocytes are stimulated by the growth hormone to increase ____.
lipolysis
What is the hypothalamo-hyphyseal tract?
the axons from the hypothalamus to the pars nervosa of the posterior pituitary
The hormones that are released from the posterior pituitary are synthesized where?
In the supraoptic and paraventricular nuclei of the hypothalamus
Of the 6 hormones released from the anterior pituitary, how many are stimulated to be released due to a releasing hormone from the hypothalamus?
all six
What is a tropic hormone
a hormone that stimulates the release of another hormone
What does IGF stand for? Where are they synthesized? Why are they stronger than growth hormones?
Insulin-like growth factor; in the liver; because they have a longer halft live
Largest endocrine structure in the body?
thyroid gland
The thyroid gland is composed of microscopic structures called _____.
thyroid follicles
Thyroid follicles contain a ___ (protein rich fluid) surrounded by follicular cells.
colloid
______ cells found between follicles of thyroid and release calcitonin.
parafollicular cells
_____ is a hormone that decreases blood calcium levels.
calcitonin
Follicular cells produce a glycoprotein called _____ which is secreted and stored within the colloid.
thyroglobin (TGB)
Within the colloid of a follicular cells thyroglobin (TGB) binds with ____ and forms DIT and MIT which are _______.
iodine
thyroid hormone precursors
When thyroid hormone is needed, DIT and MIT are taken from the colloid by the _____ and with the aid of a _____, form into the active forms of thyroid hormone (T3 and T4) which are then released into the blood stream.
follicular cell
lysosome
Hypothalamic-pituitary-thyroid axis
LIST
Thyroid hormone (TH) ___ protein synthesis, in all cells, especially ____.
increases
neurons
Thyroid hormone (TH) ____ production of Na+/K+ pumps (action of ____ pumps generates heat).
increases
more
_____ is the increase of heat production of the body, as by the thyroid hormone.
calorigenic effect
Thyroid hormone (TH) stimulates hepatocytes (liver cells) to _____ blood glucose levels.
increase
Thyroid hormone (TH) stimulates adipocytes (fat cells) to ____ lipolysis.
increase
Thyroid hormone (TH) increases respiratory rate, ______, and _____.
heart rate and stroke volume
What is thyroglobin?
a glycoprotein made by the follicular cells and stored in the colloid
Once thyroglobin binds iodine it creates _____.
DIT and MIT
T3 and T4 are synthesized by the follicular cell with the aid of what organelle?
lysosome
What is the hypothalamic-pituitary-thyroid axis?
TRH is released by the hypothalamus —-> which stimulates the release of TSH from the anterior pituitary (AP) —-> which stimulates teh release of TH from the thyroid
Thyroid hormone increases protein synthesis in which cells of the body?
all cells especially neurons
Adrenal glands are composed of a ____ and ____.
cortex and medulla
Adrenal medulla releases _______ (_______) in response to sympathetic nervous system.
catecholamine’s (Epinephrine and Norepinephrine)
Adrenal cortex syntesizes more than ____ different lipid-soluble corticosteroids.
25
The adrenal cortex is divided into what three regions?
zona glomerulosa
zona fasciculata
zona reticularis
The outer layer of the adrenal cortex
zona glomerulosa
Zona _____ synthesize mineralocorticoids to help regulate the composition and concentration of ___ in the body.
glomerulosa
ions
In the zona glomerulosa, _____, regulates Na+ and K+ concentrations int he blood/body fluids by regulating their secretions from the kidneys.
aldosterone
The middle layer of the adrenal cortex
zona fasciculata
The zona ____ synthesize glucocorticoids such as cortisol and corticosterone.
fasciculata
The inner most layer of the adrenal cortex
zona reticularis
The zona ____ synthesize gonadocorticoids (sex hormones). Primarily male sex hormones called _____.
reticularis
androgens
Cortisol and corticosterone increase ____ levels in blood in response to ____.
nutrient levels
stress of injury.
Hypothalamus is stimulated by decreased levels of blood cortisol levels thus releasing _____ causing the release of _____ from the pituitary. This causes the release of cortisol and corticosterone (95% cortisol)
CRH (corticotropin releasing hormone)
ACTH (adrenocorticotropic hormone)
_____ and ____ are inhibited by increased levels of cortisol.
CRH
ACTH
Cortisol is ____ soluble, binds receptors within cytosol causing changes in ___ activation.
lipid
gene
Cortisol stimulates _____ to increase blood glucose levels.
hepatocytes (liver cells)
Cortisol stimulates adipocytes to increase ______.
lipolysis
Cortisol causes most cells (muscle, lymphatic, skin, bone) to increase _____ as well as decrease glucose uptake.
protein catabolism
High does of cortisol increase retention of ____ and ____.
Na+ and H20
High doses of cortisol decrease _____.
inflammation
High doses of cortisol suppress the _____.
immune system
High doses of cortisol inhibit ____ repair.
connective tissue
Cortisol causes increased glycogeonlysis and gluconeogenesis and ____ in the liver.
decreased glycogenesis
Cortisol causes increased lipolysis on adipose tissue and decreased ____.
lipogenesis
General adaptation syndrome is also known as the ____.
stress response
____ is the nonspecific response of the body to any demand made upon it.
general adaptation syndrome
General adaptation syndrome stressors can be ___ or _____.
emotional or physical
Anxiety, anger, fear, and excitement are ______ stressors.
emotional
Fever, trauma, hermorrhage, surgery and malnutrition are ____ stressors.
physical
The three stages of general adaptation syndrome stages
the alarm reaction
the stage of resistance
the stage of exhaustion
The alarm reaction is ____ and regulated by the ____ nervous system.
immediate
sympathetic
During the alarm reaction stage of general adaptation syndrome there is a release of ______.
epinephrine and norepinephrine
In the alarm reaction stage of general adaptation syndrome the is increased ____
respiration, blood pressure, etc.
The stage of ____ occurs after a few hours in during general adaptation syndrome.
resistance
In the stage of resistance of general adaptation syndrome once the glycogen stores are depleted, ____ is released.
cortisol
During the stage of resistance of general adaptation syndrome there is an increased level of _____ and protein catabolism
blood glucose levels
The stage of _____ occurs after weeks or months in the general adaptation syndrome.
exhaustion
During the stage of exhaustion of general adaptation syndrome the ____ are depleted, and the body is weaker.
fat
During the stage of exhaustion of the general adaptation syndrome there are increased levels of _____ causing fluid, electrolyte, and pH imbalance.
aldosterone
What type of hormone is released by the zona glomerulosa?
mineralocorticoids (aldosterone)
What type of hormone is released by the zona fasciculata?
glucocorticoids (cortisol)
What type of hormone is released by the zona reticularis?
gonadocorticoids (androgens)
In most cells, of the body, what is the effect of cortisol release?
protein catabolism and less glucose uptake
What are the three stages of the general adaptation syndrome or stress response?
The alarm reaction
The stage of resistance
The stage of exhaustion
The pancreas is considered a ____ gland because it has both endocrine and exocrine functions.
heterocrine gland
The pancreas’s endocrine functions to regulate _____.
blood glucose concentrations
Endocrine cells found in pancreatic islets (islets of Langerhans) account for ____ of the pancreatic volume.
1%
What are the two types of pancreatic islet cells?
alpha cells
beta cells
Alpha cells secrete _____.
glucagon.
Beta cells secrete _____.
insulin
____ is released following food intake.
insulin
______ in beta cells detect an increase in blood glucose levels (normal 70-110 mg/dL)
chemoreceptors
Insulin is a ____ messenger.
first
Insulin stimulates increased _____ in the liver.
glycogenesis (s the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage.)
Insulin stimulates _____, removing fatty acids from blood in adipocytes.
increased lipogenesis
In most cells, insulin increases the uptake of _____, causing an increase in protein anabolism (especially in muscle cells)
amino acids
In most cells, insulin increase in glucose _____ especially in muscle cells and adipocytes. This happens by increasing glucose transport of proteins in the ____.
uptake
plasma membrane
Insulin increases uptake of amino acids, which stimulates _____.
protein anaabolism
Insulin causes increased _____ in the liver and decreased _____ and ______.
Increased glycogenesis
Decreased glycogenolysis
decreased glycogeneogenesis
Insulin causes increased ____ in the adipose connective tissue and decreased lipolysis.
lipogenesis
____ is released in response to low blood glucose levels by alpha cells.
glucagon
Glucagon is a ____ messenger that stimulates cAMP.
first
Glucagon increases glyconeolysis and glyconeogeneis and decreases ____>
glycogenesis
Glucagon increases _____ and decreases lipogenesis in adipocytes.
lipolysis
Pineal gland releases _____ which regulates our circadian rhythms.
melatonin
Parathyroid glands releases _____ which stimulates release of calcium from bones, kidneys to conserve calcium and stimulate release of calcitriol from kidneys which is needed to absorb ____ from our diet.
PTH
calcium
The thymus releases ____ hormones and participates in _______.
thymic
T-lymphocyte maturation
The heart releases ____ hormone
atrial natriuretic
Kidneys release _____.
erythropoietin
Liver releases _____.
angiotensinogen
Adipose tissue releases ____, that regulates food intake by binding neurons within hypothalamus that control appetite (increases).
leptin
Stomach/small intestine: releases _____ to increase stomach activity.
gastrin
Stomach/small intestine: releases ____ to stimulate release of liver and pancreatic secretions.
secretin
Stomach/small intestine: releases ______ which stimulates the release of bile from the gallbladder.
cholecystokinin (CCK)
Adipose tissue releases _____.
leptin
Adipose tissue releases leptin which regulates food intake by binding neurons within hypothlamaus that control ______.
appetite
increases
The endocrine system regulates the development, growth, and ______
metabolism
The endocrine system functions to maintain homeostasis of blood _____.
composition and volume
The endocrine system controls _______.
digestive processes
The endocrine system controls the ______
reproductive activities
