Studied by 16 people
Endocrine system
The body’s second great controlling system which influences metabolic activities of cells by means of hormones
Pituitary, thyroid, parathyroid, adrenal, and thymus
Endocrine glands
Homeostasis
Maintenance of the internal environment ( balance )
Metabolic regulation
Storage and use of energy substrates
Homeostasis
Metabolic regulation
Responses to external stimuli
Control of growth, reposition and development
Roles of endocrine system
Hormones
Chemical substance released by a group of cells to control the function of other types of cells
affect only specific target cell
affect many different types of cell
types of hormones
hypothalamus
has both neural function and releases hormones
adipose cell, pocket of cell in wall of the small intestine, stomach, kidney, and heart
other tissue and organs that produce hormones
at distance
hormones can exert their effect______ from their site of production
neurohormones
specialized neurons that secrete chemical into the blood rather than synaptic cleft
endocrine signaling
a cell targets a distant cell through the blood stream
paracrine signaling
cell target a nearby cell
autocrine signaling
cell target it self
multiple hormone system
play a key role in regulating almost all body function
blood stream
released into and carried via______ to target tissue
target cell
refers to a cell that contain specific receptors (binding sites) for a particular hormone
proteins and polypeptides
steroid
amino acid tyrosine
what are the three general classes of hormones
proteins and polypeptides
secreted by the anterior and posterior pituitary gland, the pancreas `(insulin and glucagon), the parathyroid gland ( parathyroid hormone), and many others
steroid
secreted by the adrenal cortex ( cortisol and aldosterone ), the ovaries (estrogen and progesterone), the testes (testosterone), and the placenta (estrogen and progesterone)
amino acid tyrosine
secreted by the thyroid (thyroxine and triiodothyronine ) and the adrenal medulla (epinephrine and norepinephrine ). there are no known polysaccharides or nucleic acid hormones
peptide (protein) hormones
they can disolves in water (plasma)
steroid hormones
secretedby gonads, adernal cortex, placenta
derived from cholesterol
usually bound to carrier proteins
amine hormones
derived from aminoc acid tyrosine
they include the thyroid hormones epinephrine and norepinephrine (produced by the adrenal medulla) and dopamine (produced byh the hypothalamus)
nonsteroid hormones
first messenger
mechanism of action:
hormones recepetors interaction (first messenger)
enzyme activation
released of the second messenger
effect on cellular function
steroid
pass through the cytoplasm and enter nucleus where they bind with a receptor ( lock and key model )
receptors
region of tissue, or a molecule in a cell membrane, which responds specifically to a particular neurotransmitter, hormone, antigen, or other substance.
protiens
hormonal receptors are large _______
on the surface of cell membrane ( peptides and catecholamines)
in the cell cytoplasm ( steroid )
in the cell nucleus (thyroid hormones )
receptors location
the rate of secretion
the rate of its removal (metabolic clearance )
two factors control the concentration of a hormones in the blood
metabolic destruction by tissue
excretion by the liver into bile
excretion by the kidney into urine
hormones are cleared by
slow
clearance of protein-bound hormones is ________ than clearance of peptide hormones
negative feedback
positive feedback
blood level of hormones are controlled by feedback mechanisms
prostaglandins
powerful substances found in a wide variety of body tissue
pituitary gland
it is located in the diencephalon
diencephalon
where is pituitary gland locatedn
adenohypophysis
anterior lobe
neurohypophysis
posterior lobe
glandular tissue
what is adenohypophysis made up off
adenohypophysis
synthesize and secrete a number of hormones
neurohypophysis
receive, store and release hormones from the hypothalamus
infundibulum
is the stalk that connects the pituitary to the brain
posterior pituitary
is an extension of the neural tissue
anterior pituitary
is a true endocrine gland of epithelial origin
growth hormone (GH)
prolactin (PRL)
thyroid-stimulating hormone (TSH)
adrenocorticotropic hormones (ACTH)
follicle-stimulating hormone (FSH)
luteinizing hormones (LH)
the six hormones of the anterior pituitary
TSH
stimulates growth of the thyroid gland; also stimulates it to secrete thyroid hormone
ACTH
stimulates growth of the adrenal cortex and stimulates it to secrete glucocorticoids (mainly cortisol)
FSH
initiates growth of ovarian follicle each month in the ovary and stimulates one or more follicles to develop to the stage of maturity and ovulation
stimulates sperm production in the male
LH
acts with FSH to stimulates estrogen secretion and follicle growth to maturity
cause ovulation
GH
stimulates growth by accelerating protein anabolism
accelerates fat catabolism and slows glucose catabolism
PRL
stimulates breast development during pregnancy and secretion of milk the delivery of the baby.
adernal cortex
target tissue of ACTH
thyroid gland
target tissue of TSH
most tissue
target tissue of GH
gonads
target tissue of FSH
gonads
target tissue of LH
mammary glands and other sex accessory organ
target tissue or PRL
releasing and inhibiting hormones
hypothalamus neurons synthesize
ADH: supraoptic nuclei and Oxytocin:paraventricular
hypothalamus neruon cell bodies produced
vasopressin
ADH also known as
ADH and oxytocin
posterior pituitary homones
secretory vesicle and neurophysin
these hormones are synthesized in the neuron cell bodies in hypothalamus and pack in______ with _________
does not synthesize hormones and consists of axon terminal neurons
posterioir pituitary gland
hypothalamic neural tissue
the posterior lobe is a downgrowth of
hypothalamus (hypothalamic- hypophyseal tract )
has a neural connection with the
nervous signal from hypothalamus
secretions of the posterior pituitary are controlled by
ADH
synthesized in the cell bodies of hypothalamic neurons(supraoptic nucleus)
posterior pituitary
where is ADH stored
V1 and V2
what are the two types of receptors for ADH
vasoconstriction
v1 receptors mediate
kidneys
v2 receptors located in the principle cells in distal convoluted tubule and collecting duct in the _____
principle cell
ADH binds to V2 receptors on the _______ of the distal convoluted tubules and collecting ducts
reducing urine output w
what is the most important function of ADH to conserve body waste by____
osmotic pressure
baroreceptor
in carotid artery and aortic arch
stretch receptors
in left atrium
ADH high
when the osmotic pressure is high
ADH low
when the osmotic pressure is low
ADH secretion low
when the blood pressure is high
ADH secretion high
when the blood pressure is low
oxytocin
is synthesized in the cell bodies of hypothalamic neurons (paraventricular nucleus)
posterior pituitary gland
where is oxytocin located
stimulates the pregnant uterus to contract
may initiate labor
cause glandular cell of the breast to release milk to ducts
enhande social bonding
function of oxytocin
hypothalamus
where is the actual production of ADH and ocytocin occurs ?
nervous stimulation
the secretion and release of posterior pituitary hormones is controlled by ?
hypothalamus
controls many body functions related to homeostasis ( temperature, appetite, and thirst )
where is thyroid located
t the base of the neck, just below the Adam's apple
vascular
the thyroid is highly_____
metabolic rate
thyroids hormones profoundly increase the________ if the body
thyroid hormones
the body’s major metabolic hormones
thyroxine 90%
T4
triiodothyronine 10%
T3
accelerate catabolism
increase the body metabolic rate
calcitonin
CT
calcitonin
decrease the blood calcium concentration by inhibiting breakdown of bone, which would release calcium into the blood
follicular cells and parafollicular cell
the thyroid tisse is made up of two type of cells
follicular cell
most of the thyroid tissue consist of the______
thyroid hormones
most of the thyroid tissue consist of the follicular cell, which secret the iodine-containing________
c cell
parafollicular cell is also called
calcitonin
the parafollicular cells secrete hormone
Note 
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