Biology Endocrine System Flashcards
___ glands synthesize and secrete chemical substances called hormones directly into the circulatory system
endocrine
In contrast, ___ glands, such as the gallbladder, secrete substances transported by ducts
exocrine
The hypothalamic hormones regulate pituitary gland secretions via a ___ feedback loop
negative
Releasing hormones are ___ into the hypophyseal portal system
secreted
In the hypophyseal portal system, blood from the capillary bed in the ___ flows through a portal vein into the anterior pituitary (hypophyseal portal system), where it diverges into a second capillary network
hypothalamus
Releasing hormones can immediately reach the anterior ___ without first entering the circulatory system
pituitary
In the hypothalamus, the vast majority of feedback regulation is negative feedback, in which the product of the ___ inhibits its own production
pathway
The pituitary gland hangs below the ___ and is connected to it by a slender cord known as the infundibulum
hypothalamus
The ___ contains both the hypophyseal portal system and the neurosecretory axons, connecting the hypothalamus to the posterior pituitary gland
infundibulum
The anterior pituitary synthesizes both direct hormones , which directly act on their target organs, and tropic ___, which stimulate other endocrine glands to release hormones
hormones
The hormonal secretions of the anterior pituitary are regulated by hypothalamic hormones called ___/inhibiting hormones or factors
releasing
(Tropic Hormones) Follicle stimulating hormone (FSH): In women FSH causes ___ of ovarian follicles which in turn secrete estrogen
maturation
(Tropic hormones) Luteinizing hormone (LH): In women LH stimulates ___ and maintenance of the corpus luteum
ovulation
(Tropic hormones) adrenocorticotropic hormone (ACTH): ACTH stimulates the adrenal cortex and secrete ___ and is regulated by corticotropin-releasing factor (CRF)
glucocorticoids
(tropic hormones) thyroid-stimulating hormone (TSH):TSH stimulates the ___ gland to synthesize and release thyroid hormones, thyroxine (T) and triiodothyronine (T3)
thyroid
(direct hormones) prolactin: ___ stimulates milk production in female mammary glands
prolactin
(direct hormones) endorphins: These are ___ that have pain-relieving properties
neurotransmitter
(direct hormones) growth hormone (GH, somatotropin): GH promotes bone and muscle growth. GH also promotes protein synthesis and lipid mobilization and ___
catabolism
(direct hormones) melanocyte-stimulating hormone (MSH): MSH is secreted by the intermediate lobe of the ___. In mammals, MSH plays a role in the sun-induced darkening of skin (tanning). When amphibians are in darker environments for long periods of time, mSH is released causing darkening of skin in order to better camouflage with the environment
pituitary
The ___ pituitary (neurohypophysis) does not synthesize hormones
posterior
Instead, the posterior pituitary releases the peptide hormones oxytocin and ___ hormone, which are produced by the ___ cells of the hypothalamus
peptide, neurosecretory
Oxytocin, which is secreted during childbirth, increases the strength and frequency of ___ muscle contractions
uterine
___ secretion is also induced by suckling; oxytocin stimulates milk secretion in the mammary glands
oxytocin
Antidiuretic hormone (ADH) increases water permeability in the ___ duct of the nephron, thereby promoting water reabsorption and increasing blood volume, which subsequently increases blood pressure and decreases blood osmolarity
collecting
ADH is ___ when plasma osmolarity increases, as sensed by osmoreceptors in the hypothalamus, or when blood volume decreases, as sensed by baroreceptors in the circulatory system
secreted
In response to stress, adrenocorticotropic hormone (ACTH), which is produced by the ___ pituitary, stimulates the adrenal cortex to produce more than two dozen different steroid hormones, collectively known as adrenocortical steroids or simply corticosteroids
anterior
___ exert their action by determining which genes are transcribed in the nuclei of their target cells and at what rate
corticosteroids
(corticosteroid) glucocorticoids, such as cortisol and cortisone, are involved in ___ regulation and protein metabolism
glucose
(corticosteroid) Glucocorticoids raise blood glucose levels by promoting protein breakdown and ___ and decreasing protein synthesis
gluconeogenesis
(corticosteroid) glucocorticoids are ___ to the effects of insulin and trigger the release of amino acids from skeletal muscle, as well as lipids from adipose tissue
antagonistic
(corticosteroid) ___ also promote the peripheral use of lipids and have anti-inflammatory effects
glucocorticoids
(corticosteroid) mineralocorticoids, particularly aldosterone, regulate ___ levels of sodium and potassium and, consequently, the total extracellular fluid volume
plasma
(corticosteroid) ___ causes active reabsorption of sodium and passive reabsorption of water in the nephron of the kidney
aldosterone
(corticosteroid) Active reabsorption of sodium and passive reabsorption of water results in an increase in both blood ___ and blood pressure
volume
(corticosteroid) The ___ are stimulated by angiotensin II and inhibited by ANP (atrial natriuretic peptide0
mineralocorticoid
(corticosteroid) The production of angiotensin II is regulated by the lungs and the ___, which are sensitive to blood pressure changes
kidney
(corticosteroid) ___ (male sex hormones) are secreted from the adrenal cortex in small quantities in both men and women
androgens
The adrenal medulla produces ___ (adrenaline) and norepinephrine (noradrenaline), both of which belong to a class of amino acid-derived compounds called catecholamines
epinephrine
___ increases the conversion of glycogen to glucose in liver and muscle tissue, causing an increase in blood glucose levels and an increase in the basal metabolic rate
epinephrine