Module 14: Endocrine System Flashcards
what two systems are responsible for maintaining homeostasis?
endocrine and nervous
is a mediator molecule secreted from one part of the body that circulates via the body fluids to cells in another part of the body
hormone
where are hormones initially secreted
interstitial fluid, then to the bloodstream
the study of endocrine and hormones is called
endocrinology
molecules can be both ____ and _____
neurotransmitters, hormones
hormone receptors are simply
cellular proteins
increased responsiveness by increasing receptor numbers
up-regulation
decreased responsiveness by decreasing receptor numbers
down-regulation
hormones secreted into the interstitial fluid and then the bloodstream
circulating hormones
hormones secreted into the interstitial fluid that act on neighboring cells
paracrines
hormones secreted into the interstitial fluid that act on the same cell that secreted it
autocrines
what are the three examples of lipid-soluble hormones
steroid hormones
thyroid hormones
nitric oxide (gas)
what are the three examples of water-soluble hormones
amines
peptides & proteins
eicosanoids
what are characteristics of water-soluble hormones?
freely circulate in bloodstream
can’t pass through cell membrane
what are characteristics of lipid-soluble hormones?
mostly carried in blood by transport proteins
can freely diffuse through cell membrane
what are three examples of second messengers?
ca++ ions
cAMP
cGMP
when the hormone output reverses a particular effect it is what homeostatic loop?
negative feedback loop
when the hormone output reinforces the stimulus effect it is what homeostatic loop
positive feedback loop
action of one hormone requires the presence of another
permissive effect
the effects of two hormones acting together is greater than one acting alone
synergistic effect
one hormone opposes the action of another
antagonistic effect
is the major link between the nervous and endocrine systems
hypothalamus
what connects the pituitary gland and the hypothalamus
infundibulum
the anterior pituitary is also referred to as the
adenohypophysis
the posterior lobe is also referred to as
neurohypophysis
how is the anterior pituitary connected to the hypothalamus
blood vessels
how is the posterior pituitary connected to the hypothalamus
nerves
where are the hormones from the posterior pituitary produced
neurosecretory neurons of the hypothalamus
hormones from the hypothalamus that stimulate the release of hormones from the adenohypophysis
releasing hormones
hormones from the hypothalamus that inhibit the release of hormones from the adenohypophysis
inhibiting hormones
hormones from the adenohypophysis that act on other endocrine glands
tropic hormones
what are the seven hormones secreted by the anterior pituitary
hGH, TSH, FSH, LH, PRL, MSH, ACTH
what is the function of hGH
stimulates growth of body cells
what is the function of TSH
stimulates thyroid gland
what is the function of ACTH
stimulates cortex of adrenal gland
what is the function of FSH
ova/sperm development and production
what is the function of LH
maturation of uterine lining, testosterone, production, and ovulation.
what is the function of PRL
lactation of mammary glands
what is the function of MSH
darkens melanocytes
over-production is referred to as
hypersecretion
under-production is referred to as
hyposecretion
is cause by hypo secretion of hGH during childhood. the epiphyseal plates will close before the child achieves a normal height.
Pituitary dwarfism
is caused by hyper secretion of hGH during childhood. patient will be very tall. main cause is tumor of the anterior pituitary gland
Giantism (pituitary)
is a disorder caused by excessive HGH secretion; the problems occur during adulthood after a person is done growing; after epiphyseal plate closure, one ceases to grow linearly
acromegaly
what hormones are produced in the hypothalamus and stored in the posterior pituitary
oxytocin
ADH (vasopressin)
targets smooth muscle in the uterus and breasts. uterine contractions, and in response to sucking from an infant “milk letdown”
oxytocin
causes arterioles to constrict thereby increase BP, and targets collecting ducts in the kidneys and sweat gland for retention of water
ADH (vasopressin)
where are osmoreceptors and what do they do
hypothalamus; monitor blood osmotic pressure
what are the three targets of osmoreceptors
kidneys
sudoriferous (sweat) glands
smooth muscle cells of blood vessels
hypo secretion of ADH
Diabetes Insipidus
insufficient production or secretion of ADH
Neurogenic DI
diminished renal response to the ADH that is produced
Nephrogenic DI
where is the problem in Neurogenic DI
hypothalamus (insufficient production or secretion of ADH)
where is the problem in Nephrogenic DI
kidneys (Diminished renal response to the ADH that is produced)
the tissue connection between the two lobes of the thyroid
isthmus
an enlargement of the thyroid gland
goiter
formerly called cretinism; a low growth rate and mental retardation due to the synergistic relationship between the thyroid hormones and human growth hormones; hypothyroidism in children
Congenital hypthyroidism
hypothyroidism in adults; causes dry brittle hair, dry skin due to decrease perspiration, gain weight easily, diminished intelligence
myxedema
hyperthyroidism. an autoimmune disease that results in product of antibodies against TSH receptors.
Graves disease
what are two symptoms of graves disease
exopthalmos
goiter
what part of the thyroid is T3 & T4 produced
thyroid folllicular cells
what part of the thyroid gland is calcitonin produced
parafollicular cells (c cells)
what does calcitonin do to the blood
inhibits osteoclastic activity therefore decreasing blood calcium and phosphate levels
what part of the parathyroid secretes parathyroid hormones
chief (principal) cells
what does PTH’s action
Increases blood ca+ and Mg by stimulating osteoclastic activity
decreases blood phosphate and calcitriol
what is calcitonin’s action
increases blood phosphate and calcitriol
decreases blood calcium and magnesium
chromaffin cells of the medulla are controlled by
sympathetic preganglionic neurons from the CNS
what are the three functional zones of the adrenal cortex
zona glomerulosa
zona fasciculata
zona reticularis
what is the zona glomerulosa responsible for
produces and secretes the mineralcorticoids (aldosterone)
what is the zone fasciculata responsible for
produces and secretes the glucocorticoids (cortisol)
what is the zona reticularis responsible for
produces and secretes the gonadocorticoids (androgens)
in females androgens are also converted to
estrogens
hypo secretion of cortisol. an autoimmune destruction of the adrenal cortex. results in low BG, low blood Na+, High blood K+, and low BP
Addison’s disease
hyper secretion of cortisol, high BG, poor wound healing, HTN, and redistribution of body fats
Cushing Disease/ Syndrome
is a benign tumor of the chromaffin cells of the adrenal medulla; results from hypersecretion
pheochromocytoma
provide exocrine function of the pancreas
acini cells
provide endocrine function of the pancreas
pancreatic islets, or islets of Langerhans
cells that secrete glucagon
Alpha cells
cells that secrete insulin
Beta cells
cells that secrete somatostatin
Delta ( D cell )
cells that secrete pancreatic polypeptide
F cells
what are the two types of diabetes mellitus
Type 1, Juvenile onset, and insulin dependent
Type 2, Adult onset, and non-insulin dependent
low blood sugar may result in
Insulin Shock
high blood sugar may result in
Diabetic Coma
results from destruction of beta cells. lower than 50% autoimmune. environmental factors thought to be a cause
type 1 diabetes
patients produce less insulin and don’t utilize what they produce appropriately down-regulation of insulin receptors
type 2 diabetes
where a patient doesn’t have any available glucose due to a complete lack of insulin. rely on fatty acid metabolism for their ATP production
ketoacidosis (increase in ketones and acids)
what hormones do the ovaries produce
estrogen
progesterone
inhibin
relaxin
what hormones do the testes produce
testosterone
attached to the top of the third ventricle. epithalamus
pineal gland
what hormone does the pineal gland secrete
melatonin
what is the function of melatonin
circadian rhythms
other related hormones from the thymus gland encourage the maturation of T-lymphocytes
thymosin
anything that causes stress
stressor
heightens responsiveness and helps increase concentration. good stress
eustress
stress that has a negative effect is called, and is always harmful
distress
GAS
general adaptation syndrome (GAS)
what are the three stages of the stress response or GAS
fight-or-flight
resistance reaction
exhaustion
body is trying to quickly activate mechanisms to allow an immediate physical response; alarm reaction
fight-or-flight
also initiated by the hypothalamus, but in this case by secreting the releasing hormones, easily predict the results; coping reaction
resistance reaction
the body’s resources have become so depleted, they can’t maintain a resistance reaction/ response; signs and symptoms, exceed coping mechanism
Exhaustion phase
what are the characteristics of lipid-soluble hormones
diffuse through the cell membrane
bind to a receptor and create and complex
receptor is on the DNA/nucleus
do not require a messenger
