Endocrine System Flashcards
What controls the pituitary gland?
What does it release in order to control it?
- hypothalamus
- releasing and inhibiting hormones.
What is the function of the endocrine system?
has a set of organs that secrete/ produce hormones, aka chemical messengers, into the circulatory system, which transports the hormones to go and affect target organs.
neurotransmitters from nervous system are also chemical messengers
Endocrine hormones are released into the [_____]
blood stream
Exocrine products are sent through [____] to [___]
- ducts
- skin or mucus membrane
products include: sweat, tears, enzymes-ie. digestive enzymes, mucus
____ type of hormones bind to cell membrane receptors on surface of target organs
- amino acids based [polar]
___ type of hormones binds to intracellular receptors
* list examples of these types of hormones
- steroid [non-polar] ie. estrogene, progesterone, testosterone, cortisol, aldoesterone, thyroxine
What hormones are released by the Hypothalamus? (look at image on ipad)
- TRH (thyrotrpoin releasing hormone) –> stimulate TSH release from anterior pituitary
- Dopamine (and estrogen and progesterone released from ovaries)–> inhibit prolactin release from anterior pituitary
- CRH –> stimulate ACTH release from anterior pituitary
- GHRH (GROWTH HORMONE RELEASING HORMONE) –> stimulate GH release from anterior pituitary
- somatostatin –> inhibit GH release from anteiror pituitary
- GnRH (GONADotropin releasing hormone)–> stimulate FSH and LH release from anterior pituitary
- What hormones does the anterior pituitary gland release?
- Where is this structure located?
- What is the general function of these hormones?
- ACTH, TSH, FSH, LH, PRL, GH, MSH (melanocyte stimulating hormone)
- base of the brain
- controls growth and development
ACTH
What secretes this?
stimulates adrenal cortex to secrete corticosteroids (steroid hormones of adrenal cortex) aka glucocorticoids
TSH
What secretes this?
stimulates the thyroid gland to release thyroid hormone (T3 and T4)
FSH
What secretes this?
Gamete production
* Female: stimulates production/development of ova aka eggs (oogenesis) as well as follicle maturation
* Male: spermatogenesis
LH
What secretes this?
Sex hormone production
* females ovaries: estrogen and progesterone; surge triggers ovulation
* males testis: testosterone
Prolactin (PRL)
stimulates milk production in the mammary gland
inhibited by dopamine release from hypothalamus and also estrogen and progesterone release during pregnancy
Growth hormone
stimulates growth (long bones that are still growing @ epiphyseal plate and muscles) and metabolic functions and cell repair
almost all cells have receptors for this
MSH
What secretes this?
causes melaoncytes to make pigement on the skin, hair, and iris
- What hormones does the posterior pituitary gland release?
- Where is this structure located?
- Special note about these posterior pituitary gland hormones?
- ADH/ vasopression and oxytocin
- behind the anterior pituitary
- both these hormones are MADE in the PVN of hypothalamus but are RELEASED in the posterior pituitary
ADH
* what is the other name?
* when is this activated?
What secretes this?
- vasopressin
- causes late DCT and collecting tube to reabsorb water (water retention)–> increases blood volume (and so BP) or decreases dehydration and so less urine produced
- low bp, when sweating alot or high plasma osmolarity ie. high salts, electrolytes
pth
oxytocin
What secretes this?
stimulates
* uterus contraction to induce labor in child birth and after birth allows uterus to go back to normal size and to prevent excessive post-partum blood loss.
* contraction of smooth muscle around mammary glands to stimulate lactation- milk let down- when the child stimulates the nipples
* stimulates brain to allow emotional bonding (ie. after orgasm or mother and child)
secreted by posterior pituitary BUT made in the hypothalamus
- What hormone does the pineal gland secrete?
- Where is the pineal gland located?
- melatonin
- CENTER of the brain B/W THE 2 HEMISPHERES (epithalamus)
Melatonin
What secretes this?
regulates sleep cycles (makes you sleepy); biorhythms
pineal gland (epithalamus) at the center of the brain b/w the 2 hemispheres when it is dark
- What hormones does the thyroid gland release?
- Where is this structure located?
- What is the general function of these hormones?
What stimulates the thyroid gland to release hormones?
- T3, T4, calcitonin
- neck
- regulation of growth, development, and metabolism
TSH
T3
What secretes this?
metabolism, causes cells to use more energy (increases ATP production)
T4
What secretes this?
metabolism and temperature; causes cells to use more energy (increases ATP production)
Calcitonin
What secretes this?
inhibits the release of Ca from bones and stimulates the storage of Ca in bone –> decreases blood Ca
- What is hormone is secreted by the parathyroid gland?
- What cells in parathyroid gland secrete this?
- Where is it located?
- PTH
- chief cells
- 4 glands on the thyroid
PTH
What secretes this?
stimulates
* bone breakdown and release of Ca from bones into the blood from indirect activation of osteoclasts bc PTH binds to osteoblasts only, which then through cell to cell contact activate osteoclast precursor cells into osteoclasts
* Ca reabsorption from kidneys DCT (direct and indirect) and Ca absorption from small intestines (indirect) through PTH aid (BUT NOT REQUIRED) in activation of Vit D in the kidney’s, so Ca can be used to later build bone or be used in other parts of the body bc Ca is needed for cell communication in neurons and in muscle contractions.
* all to increase blood Ca
direct= PTH direct cause; indirect= thru PTH Vit D activation
What hormones are secreted by the thymus?
thymosin
the thymus involutes with age
Thymosin
What secretes this?
stimulates T cell maturation; trains them to recognize actual pathogens and NOT attack self or other environmental factors that would cause autonimmune dz’s and allergic rxn’s, respectively.
- What hormones are secreted by the adrenal glands (cortex and medulla)
- Where are the adrenal glands located?
- What is the general function of the hormones?
- What is another name for adrenal glands and when do they release these hormones?
What stimulates adrenal cortex to make its hormones?
- cortex: steroid hormones- aldoesterone (mineralocorticoid), cortisol (glucocorticoid), a lil bit of testosterone ; medulla: epinephrine and norepinephrine (both are catacholamines)
- above the kidneys
- stimulates fight or flight response through sympathetic NS; regulates HR, BP
- stress glands ; during times of stress
ACTH
Cortisol
What type of steroid is it?
What secretes it?
stress response
* increases blood glucose (liver glycogenolysis, lipolysis, gluconeogenesis-increasing carb metabolism)- to mobilize energy bc stressed
* increases fat breakdown (lipolysis by liver and adipose tissue- increasing fat metabolism)-to mobilize energy bc stressed
* decrease inflammatory immune response to save energy- so is anti-inflammatory
glucocorticoid
adrenal cortex
Aldosterone
What type of steroid is it?
What secretes it?
stimualtes Na reabsorption in the late DCT and collecting tube [ water is reabsorped along with it and also causes K+/H+ secretion ] –> increases blood volume –> inc BP
mineralocorticoid
adrenal cortex
Epinephrine
What broad class is it a part of?
What secretes it?
fight - increase HR and BP (inc BP by constricting blood vessels) and increases muscle strength and metabolism
catecholamine
adrenal medulla
Norepinephrine
What broad class is it a part of?
What secretes it?
flight-DIRECTLY constricts blood vessels –> inc BP
catacholamine
adrenal medulla
What hormones are made by ovaries?
What stimulates those hormones to be made?
- estrogen and progesterone
LH
Estrogen
What stimulates this to be made?
- stimulates egg maturation (in the dominant follicle)
- THICCENS endometrium
- controls secondary sex characteristics
- BUT surge of estrogen inhibits FSH and so inhibits follicular maturation (makes sense bc already have a dominant follicle and dont need another one)
LH
Progesterone
What stimulates this to be made?
- prepares the uterus to receive a fertilized egg by making the endometrium JUICY with spiral arteries and thicc
- maintains pregnancy
- regulates the menstrual cycle
first made by corpus luteum that is the empty follicle left behind after ovulation
LH
What hormone is made in the testis?
What stimulates this to be made?
testosterone (made by testis leydig cells)
LH
Testosterone
Where is this made?
AN ANDROGEN
* regulates sperm production and secondary sex characteristics
* can aromatize to estrogen in testis sertoli cells (that’s why male body builder’s can become more “feminine”) (done alot by females)
* regulates sex drive
* bone and muscle strength
* fat storage
* aggression, competition
* hair growth
* deepening of the voice
Males: mainly testis (Leydig cells)
Females: adrenal cortex and ovarian follicle thecal cells, through LH stimulation
What hormones are secreted by the kidneys?
erythropoietin and renin
Erythropoietin
When is this secreted?
What secretes this?
- stimulates the red bone marrow to start making RBC’s
- when cellular hypoxia (low O2)
kidney’s renal cortex
Renin
What secretes this?
promotes production of angiotensin in the pathway to increase BP
kidney’s
What hormones are secreted by the liver?
angiotensin 2
Angiotensin 2
What secretes this?
vasocontriction of arterioles, aldosterone release from adrenal cortex and ADH release from posterior pituitary to increase BP.
liver
What hormones are released by the pancreas?
What 2 classes of hormones does pancreas release?
- glucagon- alpha cells
- insulin-beta cells
- both cell types are in islets of langerhan.
endocrine AND exocrine (exocrine is digestive enzymes)
Glucagon
What secretes this?
increase blood glucose by liver glycogenolysis (also done by skeletal m.), lipolysis (also done by adipose tissue), and gluconeogenesis
alpha pancreatic cells
Insulin
What secretes this?
decrease blood glucose by cellular uptake of glucose (ie. liver stores glucose as glycogen or lipids)
beta pancreatic cells
What hormone is secreted by the stomach?
gastrin
Gastrin
What secretes this?
response to food; stimulates production of gastric juices
stomach
What hormones are secreted by the intestines?
- secretin
- CCK
Secretin
What secretes this?
repsonse to acidity in small intestines (from chyme from stomach); stimulates basic secretion by liver and pancreas , bile and bicarb, respectively.
intestines
CCK
What secretes this?
production of bile salts (to breakdown lipids into water soluble micelles so lipases from pancreas can actually further break it down) and contracts the gallbladder to release bile into the duodenum of the small intestines
intestines
What hormone is secreted by the heart?
Atrial Natriuretic Peptide (ANP)
ANP
What secretes this?
increases Na excretion and so water excretion , decreases ECF –> dec cblood volume –> dec BP
heart
What is required for thyroid hormone production?
iodine from diet
What stimulates hormone production in
* adrenal cortex?
* adrenal medulla?
- ACTH
- sympathetics from thoracolumbar region.
Which layers of the adrenal cortex are the steroid hormones produced?
- zone glomerulosa - aldosterone
- zona fasiculata - cortisol
- zona reticularis - andorgens (ie. testosterone) and estrogen
Blood pressure regulation
- increase BP- renin to set off RAAS [ includes ADH through reabsorption of water to increase blood volume; aldosterone- through rebsorption of Na and so water to increase blood volume; angiotensin 2]; epi and norepi through vasoconstricting blood vessels and increasing peripheral resistance
- decrease BP- ANP through inc Na excretion, which dec ECF and blood volume
Blood Ca regulation
- increase Ca- PTH causes bone breakdown (resorption of bone) and indirectly and directly Ca reabsorption from kidneys DCT and indirectly Ca absorption from small intestines [ indirectly = through help (though NOT required) in activation of Vit D into calcitrol, which is required for Ca absorbtion of any kind]
- decrease Ca- Calcitonin inhibits the release of Ca from bones and stimulates Ca storage in (compact) bone
Blood Na regulation
- increase Na- aldosterone stimulates Na reabsorption from late DCT and collecting tube of the kidneys
- decrease Na- ANP increases Na excretion from kidney’s
Blood glucose regulation
- increase glucose- glucagon, cortisol
- decrease glucose- insulin
Type 1 vs Type 2 DM
- Type 1: genetic; no insulin production
- Type 2: adult onset (ie. no exercise, overweight); dec response to insulin (insulin resistance)
diabetic sx’s: stocking glove sensory and motor loss and diabetic retinopathy
(primary) HYPERthyroidism
- too much thyroid hormone production due to thyroid gland dysfunctioning –> dec TSH production
- lots of thyroid hormone = increase ATP production and metabolism = weight loss/thin; inc RBC production = always hot (heat intolerance) bc blood is hot; high HR and high BP; easily agitated and irritable
- graves dz= exopthalmos bc high BP behind the eye.
Gigantism
excess growth hormone in children BEFORE epiphyseal plate aka growth plate closed –> huge height.
Homeostasis
- constant stable internal environment regulated mainly through negative feedback
Cushing Disease
ACTH secreting pituitary tumor –> adrenal cortex make too many steroid hormones leading to:
* edema , high BP [ from inc aldosterone]
* more acne, facial hair [ from inc in testosterone]
* belly fat, buffalo hump, and moon facies [from inc in testosterone]
* high blood sugar [ from inc cortisol]
(primary) HYPOthyroidism
- too little thyroid hormone produced bc thyroid gland dysfunctioning –> inc TSH
- less thyroid hormone leads to :
1. foggy thinking, depression , low energy (low energy also from dec ATP production
2. low HR and low BP
3. dec RBC production –> anemia (cold, pale, tired)
4. overweight bc low energy so not exercising and not using stored energy (ie, fats) to make ATP.
Give an example of positive feedback
- childbirth
1. head of baby pushes against the cervix
2. cervix sensory nerves sends info to brain
3. hypothalamus stimulates the posterior pituitary to release oxytoxin
4. oxytocin carried in blood stream to the uterus
5. oxytocin stimulates even more uterine contractions to push bbs head towards the cervix.
another example is blood clotting (wound = blood clot = inc in blood clotting factors)
What gland releases hormones in response to flight or fight or stress?
adrenals
remember: cortex- cortisol, aldosterone, testosterone; medulla: epi and norepi
