endocrine system 2 Flashcards
week 1
the hypothalamus is connected to the pituitary gland by a stalk called the —
infundibulum
the posterior pituitary lobe is composed of — tissue that secretes —
neural; neurohormones
the anterior pituitary lobe is composed of — tissue; called the —
glandular; adenohypophysis
the hypophyseal portal system vascularly connects the — to the —
anterior lobe; hypothalamus
the hypophyseal portal system includes the —, —, and —
primary capillary plexus, hypophyseal portal veins, and secondary capillary plexus
why is the the hypophyseal portal system important?
it allows for efficient hormone signaling and regulation between the hypothalamus and anterior pituitary gland
the hypothalamic-hypophyseal tract is a bundle of nerve fibers that connects the — to the —
hypothalamus; posterior pituitary gland
why is the hypothalamic-hypophyseal tract important?
enables the direct release of oxytocin and ADH (hormones) into the bloodstream to regulate functions like water balance, childbirth, and lactation.
paraventricular neurons produce —
supraoptic neurons produce —
oxytocin; ADH
hormones are stored in —, they are released into the blood when neurons fire
axon terminals
— is released during childbirth and is a strong stimulant of contractions
oxytocin
oxytocin should be associated with — feedback mechanisms
positive
oxytocin acts as a — in the brain
neurotransmitter
oxytocin uses the — second messenger system
PIP2-calcium
when concentration is too high, the —is triggered to secrete —
posterior pituitary; ADH
high concentrations of vasopressin lead to —
vasoconstriction
ADH acts to inhibit urine formation by promoting water reabsorption in the —–, helping to prevent —.
kidneys; dehydration
release of ADH is triggered by —, —, and —
pain; low blood pressure; drugs
release of ADH it is inhibited by — and —
alcohol; diuretics
what are diuretics?
substances or medications that promote the production of urine, helping the body get rid of excess salt and water
All six anterior pituitary hormones are peptides, with all except the — hormone using the cAMP pathway
growth
what do tropic hormones (tropins) regulate?
the secretion of other hormones
what are the 6 hormones of the anterior pituitary?
- Growth Hormone (GH)
- Thyroid-Stimulating Hormone (TSH)
- Adrenocorticotropic Hormone (ACTH)
- Follicle-Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
- Prolactin (PRL)
growth hormone is also called —. It is produced by — cells.
somatotropin; somatotrophic
GH has direct actions on — and indirect actions on —
metabolism; growth-promoting
what three direct actions does GH have on metabolism?
- reduces glucose and metabolism use by cells
- stimulates the liver to release glucose from stored glycogen.
- increases blood fatty acids for energy and supports protein building.
what three direct actions does GH have on growth?
- stimulates the liver, muscles, and bones to produce insulin-like growth factors.
- insulin-like growth factors help cells absorb nutrients for DNA and protein production, supporting cell growth, bone formation, and collagen production.
- growth hormone makes cells grow and divide, especially in bones and muscles.
the release or inhibition of GH is regulated by two hypothalamic hormones, what are they?
growth hormone-releasing hormone (GHRH) and growth hormone-inhibiting hormone (GHIH)
growth hormone-releasing hormone — GH
stimulates
growth hormone-releasing hormone — GH
inhibits
the highest amounts of GH are secreted during —
sleep
GHRH is triggered by low — or — levels
blood GH; glucose
GHIH is triggered by increased levels of — and —
GH, IGF
Release of GH is also stimulated by — – the hunger hormone
ghrelin
thyroid-stimulating hormone (TSH) is a — hormone. It is also called —. It is produced by — cells.
tropic; thyrotropin; thyrotropic
TSH stimulates normal development and secretory activity of the —
thyroid gland
release of TSH is triggered by secretion of thyrotropin-releasing hormone (TRH) from the —
hypothalamus
TSH is inhibited by high levels of — hormones in the blood and — hormone
thyroid; growth hormone-inhibiting
adrenocorticotropic hormone (ACTH) is also called — and is secreted by — cells.
corticotropin; corticotropic.
ACTH stimulates the adrenal cortex to release —
corticosteroids
Follicle-Stimulating Hormone (FSH) + Luteinizing Hormone (LH) are secreted by the — cells of the anterior pituitary
gonadotropic
FSH stimulates the production of — (egg or sperm)
gametes
In females, LH helps to mature egg-containing follicles, triggers ovulation, create and release — + —
estrogen; progesterone
In males, LH stimulates the production of —
testosterone
During and after puberty, FSH and LH are triggered by — from the hypothalamus
gonadotropin-releasing hormone (GnRH)
prolactin (PRL) is secreted by — cells in the — pituitary
prolactin; anterior
what does prolactin stimulate in females?
milk production
regulation of prolactin is primarily controlled by — AKA dopamine
prolactin-inhibiting hormone (PIH)
decreased levels of PIH leads to —
lactation
what’s the reason for breast swelling and tenderness during menstruation?
prolactin levels rise and fall in rhythm with estrogen
blood levels of PRL dramatically — at the end of pregnancy
rise
what is the largest pure endocrine gland in the body?
the thyroid gland
where is the thyroid gland located?
on the trachea, just inferior to the larynx.
what are the four parts of the thyroid gland?
- isthmus
- follicles
- colloid
- parafollicular cells
what hormone do parafollicular cells produce?
calcitonin
thyroid hormone is stored extracellularly in the —
follicle lumen
thyroid hormone is found in two forms, what are they?
thyroxine (T4) and triiodothyronine (T3)
what’s the difference between thyroxine (T4) and triiodothyronine (T3)?
thyroxine (T4) has 4 bound iodine atoms whereas triiodothyronine (T3) has 3 bound iodine atoms
at the tissue level, — must be converted to —
T3; T4
thyroid hormone regulates — and —, while maintaining —
tissue growth; development; blood pressure
calcitonin is produced by the — in response to — Ca2+ levels
parafollicular cells; high
calcitonin is an antagonist to parathyroid hormone (PTH). calcitonin — calcium, while PTH — it.
lowers; raises
what three things happen when calcitonin’s level is elevated?
- osteoclast activity is inhibited
- the release of Ca2+ from bone matrix is prevented
- the uptake of Ca2+ by bone matrix is stimulated
where is the parathyroid gland?
The parathyroid gland is located on the posterior (back) side of the thyroid gland, usually 4 to 8 small, yellow-brown glands.
the parathyroid gland contains — and — cells
oxyphil; parathyroid
parathyroid cells secrete —- hormone
parathyroid hormone (PTH)
PTH is the most important hormone in —
Ca2+ homeostasis
PTH’s target organs are the —, —, and —
skeleton, kidneys, and intestines
what are three functions of the PTH?
- stimulate bone breakdown, releasing calcium into the blood.
- increase calcium reabsorption and phosphate excretion by the kidneys.
- activate vitamin D in the kidneys, boosting calcium absorption in the intestines.
where is the adrenal gland located?
on top of the kidneys
what is the difference between the adrenal cortex and the adrenal medulla?
the adrenal cortex is made of glandular tissue, the adrenal medulla is made of nervous tissue
the adrenal cortex secretes —, the adrenal medulla secretes —
corticosteroids; catecholamines
true or false: steroid hormones are not stored in cells
true
the 3 layers of cortical cells produce different types of corticosteroids.
zona glomerulosa produces —,
zona fasciculata produces —,
zona reticularis produces —.
mineralocorticoids; glucocorticoids; gonadocorticoids
what is the strongest mineralocorticoid?
aldosterone
aldosterone stimulates reabsorption of — by the kidneys, which results in increased blood volume and pressure. it also stimulates elimination of K+ by the kidneys
Na+; K+
Atrial Natriuretic Peptide (ANP) tells the body to — Na+
release
glucocorticoids influence the metabolism of most — and help us to resist —
cells; stressors
glucocorticoids work to keep blood glucose levels relatively —
constant
glucocorticoids maintain blood pressure by increasing the activity of —
vasoconstrictors
what are three glucocorticoid hormones?
Cortisol (Hydrocortisone)
Cortisone
Corticosterone
what is the only glucocorticoid made in significant amounts in humans ?
cortisol
Cortisol is released in response to —
ACTH
ACTH is released in response to —
corticotropin-releasing hormone (CRH)
CRH is released when cortisol levels are —. Increased cortisol levels inhibit both — and —
low; ACTH; CRH
cortisol secretion cycles are governed by our patterns of — and —
eating; physical activity
the — can override cortisol’s inhibition of ACTH and CRH leading to more cortisol secretion
central nervous system
what is Cushing’s disease?
a condition where the body produces too much cortisol, causing symptoms like weight gain, high blood pressure, and muscle weakness.
what is Addison’s disease?
a disorder where the adrenal glands don’t produce enough cortisol, causing symptoms like fatigue, weight loss, low blood pressure, and darkened skin.
— disease is characterized by having a “buffalo hump” of fat on the upper back
Cushings
— disease causes a year-round sun tan
Addisons
cortisol increases levels of —, —, and — in the blood
glucose; fatty acids; amino acids
— is one of cortisol’s key functions, where the body makes more sugar (glucose) from fats and proteins, giving energy to the brain while encouraging other cells to use fat for energy instead of glucose.
gluconeogenesis
cortisol enhances — to elevate — quickly and distribute nutrients to —
vasoconstriction; BP; cells
— are weak androgens (male sex hormones)
gonadocorticoids
two examples of gonadocorticoids?
androstenedione and dehydroepiandrosterone (DHEA)
gonadocorticoids are converted to — and some — in the tissue cells
testosterone; estrogen
what are the three functions of gonadocorticoids?
- Help control the timing of puberty and the development of traits like body hair and voice changes.
- Regulate sex drive in women
- Provide a source of estrogens in postmenopausal women
medullary chromaffin cells synthesize —
catecholamines
what are two examples of catecholamines?
epinephrine and norepinephrine
some effects of catecholamines include — , increased — and —, and
redirecting blood to the —, —, and —
vasoconstriction; heart rate; blood glucose levels ; brain; heart; skeletal muscles
epinephrine mainly boosts —, while norepinephrine focuses more on — blood vessels and — blood pressure.
metabolism; narrowing; increasing
pinealocytes secrete — which is a hormone derived from —
melatonin; serotonin
melotonin may affect what four things?
- the timing of sexual maturity and puberty
- day/night cycles
- the physiological processes that slow rhythmic variations – body temperature, sleep, appetite
- production of antioxidants and detoxification molecules
— contains both exocrine and endocrine cells
the pancreas
acinar cells are — cells that produce the enzyme-rich juice needed for —
exocrine; digestion
pancreatic islets contain — cells
endocrine
— cells produce glucagon
alpha
— cells produce insulin
beta
glucagon is triggered by decreased —, rising — levels, or the — system
blood glucose; amino acid; sympathetic nervous
how does glucagon target the liver to raise blood glucose levels?
- breaks down glycogen to glucose (glycogenolysis)
- synthesizes glucose from lactic acid and other noncarbohydrates (gluconeogenesis)
- releases glucose into the blood
insulin is secreted when — levels increase
blood glucose
how does insulin lower blood glucose levels?
- enhances membrane transport of glucose into fat and muscle cells
- inhibits the breakdown of glycogen to glucose
- inhibits the conversion of amino acids or fats to glucose
Insulin is not needed for glucose uptake by the —, —, or —
liver; kidneys; brain
— produce the same steroid sex hormones as the adrenal cortex – just in lesser amounts
gonads
— produce estrogens and progesterone
ovaries
— helps mature the reproductive organs, triggers secondary sex traits like body hair, and works with progesterone to develop breasts and control changes in the uterus.
estrogen
— produce testosterone
testes
— helps develop and maintain reproductive organs, triggers secondary sex traits like facial hair, and is needed for sperm production.
testosterone
the placenta secretes —, —, and —
estrogens; progesterone; human chorionic gonadotropin (hCG)
adipose tissue secretes —, —, and —
leptin; resistin; adiponectin
what is leptin’s role in the body?
helps control appetite and boosts energy use in the body.
what is resistin’s role in the body?
works against the effects of insulin.
what is adiponectin’s role in the body?
enhances the body’s response to insulin.
the gastrointestinal tract secretes —, —, —, —, and —
gastrin; ghrelin; secretin; cholecystokinin; incretins.
what is gastrin’s role in the body?
triggers the release of stomach acid (HCl).
what is ghrelin’s role in the body?
stimulates hunger and increases food intake.
what is secretin’s role in the body?
help the liver make bile and the pancreas release fluids that neutralize stomach acid.
what is cholecystokinin’s role in the body?
stimulates or triggers the pancreas, gallbladder, and hepatopancreatic sphincter to do their specific jobs:
what is incretin’s role in the body?
boost insulin release and reduce glucagon production
the heart releases —
Atrial Natriuretic Peptide (ANP):
what is Atrial Natriuretic Peptide’s (ANP’s) role in the body?
to decrease concentration of Na+ in the blood and therefore decrease blood pressure and volume
the kidneys secrete —
and —
erythropoietin; renin
what is role of erythropoietin in the body?
it triggers production of red blood cells
what is role of renin in the body?
it initiates the renin-angiotensin-aldosterone mechanism
— is a hormone secreted by — (bone cells) in the skeleton
osteocalcin; osteoblasts
osteocalcin stimulates the pancreas to release more —, improve — handling, and reduce —
insulin; glucose; body fat
what is the thymus?
a large organ in infants, shrinks with age
the thymus produces hormones like —, —, and —, which are important for the development of T-lymphocytes, crucial cells in the immune system.
thymulin; thymopoietins; thymosins
