Ch. 16 PPT Notes Flashcards
(endocrine system) acts with the … to coordinate and integrate the activity of body cells
influences … activities by means of … transported in the blood
nervous system;
metabolic;
hormones
(endocrine system) responses occur more … but tend to … than those of the nervous system
slowly; last longer
(endocrine system) endocrine glands: ... ... ... ... ...
pituitary; thyroid; parathyroid; adrenal; pineal
(endocrine system) some organs produce both … and … products (e.g. … and …)
examples of exocrine products are … and …
hormones; exocrine;
pancreas; gonads;
sweat; saliva
(endocrine system) the hypothalamus has both … and … functions
neural; endocrine
(endocrine system) other tissues and organs that produce hormones include
…
…
cells in the walls of the …, …, …, and …
adipose cells; thymus; small intestine; stomach; kidneys; heart
hormones: long-distance chemical signals that travel in the … or …
…: chemicals that exert effects on the same cells that secrete them
..: locally acting chemicals that affect cells other than those that secrete them
blood; lymph;
autocrines;
paracrines
autocrines and paracrines are … and will not be considered part of the endocrine system
local
(chemistry of hormones)
two main classes:
1. … -based hormones
2. …
amino acid;
steroids
(chemistry of hormones)
two main classes:
1. amino acid-based hormones:
…, …, …, and …
amines;
thyroxine;
peptides;
proteins
(chemistry of hormones) two main classes: 2. steroids: synthesized from ... ... and ... hormones
cholesterol;
gonadal; adrenocortical
(hormone action on target cells) 1. alter … or … by opening or closing …
plasma membrane permeability; membrane potential; ion channels
(hormone action on target cells) 2. stimulate synthesis of … or … molecules
- active or deactivate …
- induce … activity
- stimulate …
proteins; regulatory;
enzyme systems;
secretory activity;
mitosis
(mechanisms of hormone action) two mechanisms, depending on their chemical nature
1. water soluble hormones (all … hormones except …)
cannot … the target cells
act on …
amino acid-based;
thyroid hormone;
enter;
plasma membrane receptors
(mechanisms of hormone action) two mechanisms, depending on their chemical nature
1. water-soluble hormones:
coupled by … to intracellular … that mediate the target cell’s response
G proteins; second messengers;
(mechanisms of hormone action) two mechanisms, depending on their chemical nature
2. lipid-soluble hormones (… and … hormones)
act on … that directly activate …
steroid;
thyroid;
intracellular receptors;
genes
(mechanisms of hormone action) two mechanisms, depending on their chemical nature
2. lipid-soluble hormones:
thyroid hormones are … into the cell and bind to …
transported;
nuclear receptors
(signal pathways: receptor locations)
target cell receptors:
lipophilic signal molecules –> bind to receptors either in … or … –> slower responses related to changes in …
lipophobic/lipophilic signal molecules bind to receptors on the …
cytosol; nucleus; gene activity
plasma membrane
(plasma membrane receptors and second-messenger systems) cAMP signaling mechanism:
- Hormone (…) binds to receptor
- receptor activates …
- the thing that was just activated activates …
first messenger;
G protein;
adenylate cyclase
(plasma membrane receptors and second-messenger systems) cAMP signaling mechanism:
- adenylate cyclase converts … to … (…)
- this activates …
ATP; cAMP; second messenger; protein kinases (this is referring to cAMP)
(plasma membrane receptors and second-messenger systems) cAMP signaling mechanism:
- activated kinases … various proteins, activating some and inactivating others
- cAMP is rapidly degraded by the …
- intracellular enzymatic cascades have a huge … effect
phosphorylate;
enzyme phosphodiesterase;
amplification
(plasma membrane receptors and second-messenger systems) cAMP signaling mechanism:
active protein kinase triggers responses of target cell (activates …, stimulates .., opens .., etc)
enzymes; cellular secretion; ion channel
(plasma membrane receptors and second-messenger systems) PIP2-calcium signaling mechanism:
Used by some … hormones in some tissues
involves a …, which activates … enzyme
amino acid-based;
G protein;
phospholipase C
(plasma membrane receptors and second-messenger systems) PIP2-calcium signaling mechanism:
… splits membrane phospholipid PIP2 into two second messengers: … and …
phospholipase;
diacylglycerol (DAG);
IP3
(plasma membrane receptors and second-messenger systems) PIP2-calcium signaling mechanism:
DAG activates …; IP3 triggers release of …
protein kinases;
Ca2+
(plasma membrane receptors and second-messenger systems) PIP2-calcium signaling mechanism:
calcium alters … or … or binds to the regulatory protein …
enzymes; channels; calmodulin
(intracellular receptors and direct gene activation)
steroid hormones and thyroid hormone:
1. diffuse into their target cells and bind with intracellular receptors
2. … enters the nucleus and (3) binds to a …
4. this prompts … to produce …, which directs …
receptor-hormone complex; specific region of DNA; DNA transcription; mRNA; protein synthesis
(intracellular receptors and direct gene activation)
steroid hormones and thyroid hormone:
the specific DNA sequence that the receptor-hormone complex binds to is called a …
hormone response element
(target cell specificity) target cells must have specific … to which the hormone binds:
ACTH receptors are only found on certain cells of the …
… receptors are found on nearly all cells of the body
receptors;
adrenal cortex;
thyroxin
target cell activation depends on three factors:
- … of the hormone
- relative … on or in the target cell
- … between receptor and hormone
blood levels;
number of receptors;
affinity of binding
(target cell activation) hormones influence the number of their …:
… - target cells form more receptors in response to the hormone
… - target cells lose receptors in response to the hormone
receptors;
up-regulation;
down-regulation
(hormones in the blood) hormones circulate in the blood either free or bound:
… and … are attached to plasma proteins
all others circulate without …
steroids; thyroid hormone;
carriers
(hormones in the blood) the concentration of a circulating hormone in blood reflects:
…
speed of … and … from the body
rate of release;
inactivation; removal
(hormones in the blood) hormones are removed from the blood by:
- …
- …
- …
- …- the time required for a hormones blood level to decrease by half
degrading enzymes;
kidneys;
liver;
half-life
(interaction of hormones at target cells) multiple hormones may interact in several ways:
…: one hormone cannot exert its effects without another hormone being present
…: more than one hormone produces the same effects on a target cell
…: one or more hormones opposes the action of another hormone
permissiveness;
synergism;
antagonism
(control of hormone release) blood levels of hormones:
are controlled by … systems
vary only within a …
negative feedback;
narrow desirable range
(control of hormone release) hormones are synthesized and released in response to: 1. ... stimuli 2. ... stimuli 3. ... stimuli
humoral;
neural;
hormonal
(humoral stimuli) changing blood levels of … and … directly stimulates secretion of hormones
ions; nutrients;
(humoral stimuli) example: Ca2+ in the blood
declining blood ca2+ concentration stimulates the … to secrete … (…)
PTH causes Ca2+ concentrations to … and the stimulus is removed
parathyroid glands;
PTH; parathyroid hormone;
rise
(neural stimuli) … stimulate hormone release
e.g. sympathetic nervous system fibers stimulate the … to secrete …
nerve fibers;
adrenal medulla;
catecholamines
(neural stimuli) … stimulate adrenal medulla cells to secrete catecholamines (… and …)
preganglionic sympathetic fibers;
epinephrine; norepinephrine
(hormonal stimuli) hormones stimulate other endocrine organs to release their hormones:
- hypothalamic hormones stimulate the release of most … hormones
- … hormones stimulate targets to secrete still more hormones
- …: hormones from the final target organs inhibit the release of the anterior pituitary hormones
anterior pituitary;
anterior pituitary;
hypothalamic-pituitary-target endocrine organ feedback loop
(nervous system modulation) the nervous system modifies the … of endocrine glands and their … mechanisms
example: under severe stress, the hypothalamus and the sympathetic nervous system are activated –> as a result, … levels rise
stimulation;
negative feedback;
body glucose
the pituitary gland (…) has two major lobes:
… and …
hypophysis;
posterior pituitary;
anterior pituitary
posterior pituitary: … (glial like supporting cells) and … - more for … of neurohormones (… and …)
pituicytes;
nerve fibers;
storage;
oxytocin; ADH
anterior pituitary:
…
… tissue
adenohypophysis;
glandular
(posterior lobe) a downgrowth of … tissue;
neural connection to the hypothalamus (…)
hypothalamic neural;
hypothalamic-hypophyseal tract
(posterior lobe) nuclei of the hypothalamus synthesize the neurohormones … and …
… are transported to the posterior pituitary
oxytocin; antidiuretic hormone;
neurohormones
(posterior lobe) 1. hypothalamic neurons synthesize oxytocin and ADH
- oxytocin and ADH are transported along the … to the posterior pituitary
- oxytocin and ADH are stored in … in the posterior pituitary
- oxytocin and ADH are released into the blood when …
hypothalamic-hypophyseal tract;
axon terminals;
hypothalamic neurons fire
anterior lobe: originates as an out-pocketing of the ... hypophyseal portal system: ... ... ...
oral mucosa;
primary capillary plexus;
hypophyseal portal veins;
secondary capillary plexus
anterior lobe;
carries … and … hormones to the anterior pituitary to regulate hormone secretion
releasing; inhibiting
anterior lobe:
- when appropriately stimulated, hypothalamic neurons secrete releasing and inhibiting hormones into the …
- hypothalamic hormones travel through the … to the anterior pituitary where they stimulate/inhibit release of hormones from the anterior pituitary
- anterior pituitary hormones are secreted into the …
primary capillary plexus;
portal veins;
secondary capillary plexus
anterior pituitary hormones:
- …
- … or …
- …
- …
- …
- …
growth hormone (GH); thyroid-stimulating hormone (TSH); thyrotropin; adrenocorticotropic hormone (ACTH); follicle-stimulating hormone (FSH); luteinizing hormone (LH); prolactin (PRL)
anterior pituitary hormones:
all are …
all except … activate cyclic AMP second-messenger systems at their targets
proteins;
GH
anterior pituitary hormones:
…, …, .., and … are all tropic hormones (regulate the secretory action of other endocrine glands)
TSH;
ACTH;
FSH;
LH
growth hormone:
produced by …
stimulates most cells, but targets … and …
promotes … synthesis and encourages use of … for fuel
somatotrophs;
bone; skeletal muscle;
protein;
fats
growth hormone:
most effects are mediated indirectly by …
insulin-like growth factors (IGFs)
growth hormone (GH):
GH release is regulated by:
… (…)
… (…/…)
growth hormone-releasing hormone; GHRH;
growth hormone-inhibiting hormone; GHIH; somatostatin
direct action of GH:
stimulates …, …, …, and … to produce insulin-like growth factors
liver; skeletal muscle; bone; cartilage
direct action of GH:
mobilizes …
elevates blood glucose by … and encouraging … (… effect of GH)
fats;
decreasing glucose uptake;
glycogen breakdown;
anti-insulin
homeostatic imbalances of growth hormone:
hypersecretion:
in children results in …
in adults results in …
hyposecretion:
in children results in …
gigantism;
acromegaly;
pituitary dwarfism
hypothalamus secretes … and …, leading to release of growth hormone (which then inhibits … release and stimulates … release and inhibits … synthesis and release)
growth hormone-releasing hormone (GHRH); somatostatin (GHIH);
GHRH;
GHIH;
GH
growth hormone:
indirect actions (growth promoting):
… and other tissues produce … which lead to increased … formation and … growth and increased … synthesis, and cell .. and …
liver; insulin-like growth factors (IGFs); cartilage; skeletal; protein; growth; proliferation;
growth hormone:
direct actions (metabolic, anti-insulin):
increased … breakdown and released
increased blood … and other … effects
fat;
glucose;
anti-insulin
thyroid-stimulating hormone (…):
produced by … of the anterior pituitary
stimulates the normal development and secretory activity of the …
thyrotropin;
thyrotrophs;
thyroid
(thyroid-stimulating hormone-thyrotropin) regulation of TSH release:
stimulated by … (TRH)
inhibited by rising blood levels of … hormones that act on the … and …
thryotropin-releasing hormone;
thyroid;
pituitary; hypothalamus (negative feedback)
adrenocorticotropic hormone- …
secreted by … of the anterior pituitary
stimulates the … to release …
corticotropin;
corticotrophs;
adrenal cortex; corticosteroids
(adrenocorticotropic hormone-corticotropin) regulation of ACTH release:
triggered by by hypothalamic … in a daily rhythm:
level peaks in the …
rising levels of … feed back and block receptors of CRH and ACTH
corticotropin-releasing hormone;
morning;
glucocorticoids
(adrenocorticotropic hormone-corticotropin)
regulation of ACTH release:
internal and external factors such as …, …, and … can alter the release of CRH
fever;
hypoglycemia;
stressors
(gonadotropins)
… hormone and … hormone
secreted by … of the anterior pituitary
follicle-stimulating (FSH);
luteinizing (LH);
gonadotrophs
(gonadotropins)
FSH stimulates … (… or …) production
LH promotes production of …
absent from the blood in … boys and girls
gamete; egg; sperm;
gonadal hormones;
prepubertal
(gonadotropins) regulation of gonadotropin release:
triggered by the … during and after puberty
suppressed by … (feedback), which are produced in response to the gonadotropins, suppress FSH and LH
gonadotropin-releasing hormone (GnRH);
gonadal hormones;
(prolactin-PRL) secreted by … of the anterior pituitary
stimulates … in females
lactotrophs;
milk production
(prolactin-PRL) regulation of PRL release:
primarily controlled by … (…);
blood levels rise toward the …
… stimulates PRH release and promotes continued milk production
prolactin-inhibiting hormone (PIH/dopamine);
end of pregnancy;
suckling
