Endocrine System Flashcards
The second controlling system of the body
Endocrine system
First controlling system and the fast-control system
nervous system
Uses chemical messengers (hormones) that are released into the blood. These hormones control several processes including reproduction, growth and development, mobilization of body defenses, maintenance of homeostasis, and regulation of metabolism
Endocrine system
They are ductless. Instead, hormones are secreted directly into capillaries and circulate in the blood throughout the body
Endocrine glands
Produced by specialized cells
hormones
Cells that secrete hormones into extracellular fluids while the blood transfers hormones to target sites
specialized cells
In general they help regulate growth, the use of foods to produce energy, resistance to stress, the pH of body fluid and fluid balance, and reproduction
Endocrine system and its hormones
Simple hormones that are structural variations of the amino acids tyrosine
Amines
This group includes thyroxine from the thyroid gland and epinephrine and norepinephrine from the adrenal medulla
Amines
These hormones are chains of amino acids
proteins
Short chains of amino acid
peptides
Antidiuretic hormone and oxytocin, synthesized by hypothalamus are ____
peptide hormones
The precursor of steroid hormones
cholesterol
include cortisol and aldosterone from the adrenal cortex, estrogen and progesterone from the ovaries, and testosterone from the testes
Steroids
Secreted by endocrine glands when there is a need for them, that is, for their effects on their target organs
hormones
Secretes insulin when the blood glucose is high
pancreas
Th stimulus for secretion of insulin
hyperglycemia
Enables cells to remove glucose from the blood so that it can be used for energy production and enables the liver to store glucose as glycogen
insulin
Information about the effects of the hormone is “fed back” to the gland, which then decrease its secretion of the hormone. The effects of the hormone reverse the stimulus and decrease the secretion of then hormone
hormonal negative feedback mechanism
Hormones of the anterior pituitary gland are secreted in response to ____ secreted by the hypothalamus
releasing hormone (also called releasing factor)
Is secreted in response to growth hormone-releasing hormone (GHRH) from the hypothalamus
Growth hormone
Cells where hormones exert their action, must have specific protein receptors for the hormones to bind
Target cells
The hormone diffuse through the plasma membrane of the target cells and enter the nucleus. Once the hormone is inside the nucleus of the cell, it binds to a specific protein within the nucleus then binds into specific sites on cell’s DNA
This activate genes that will result in the synthesis of new proteins
Direct gene activation
The hormone binds to a membrane receptor and does not enter the cell however; it sets off a series of reactions that activates an enzyme
Then the enzyme catalyzes a reaction that produces a second-messenger molecule (such as cAMP) to oversee additional intracellular changes to promote a specific response
second-messenger system
study of hormones and endocrine organs
endocrinology
called the master endocrine gland since it regulates many body functions
pituitary gland
It is about the size of a pea, which hangs by a stalk from the hypothalamus in tthe brain. It is protected by the sphenoid bone and has two functional lobes
pituitary gland
Functional lobe of pituitary gland that is also known as neurophysis is an extensioon of the nerve tissue f the hypothalamus
Posterior Pituitary Gland (PPG)
Functional lobe of Pituitary gland that is known as adenophysis is a separate gladular tissue
Anterior Pituitary Gland (APG)
Its hormones regulate many body functions. They are in turn regulated by releasing hormones from the hypothalamus
Anterior Pituitary gland
The releasing hormones in APG are secreted into capillaries in the hypothalamus and pass through the ___ veins to another capillary network in the APG
Hypophyseal portal veins
Also called somatotropin and it does indeed promote growth.
Growth hormone (GH)
GH stimulates cells to produce _____, intermediary molecules that bring about the functions o GH
Insulin-like growth factor (IGFs)
Increases the transport of amino acids into cells, and increases the rate of protein synthesis.
Growth hormone
cannot be stored in the body, so when they are available, they must be used in protein synthesis
Amino acids
Excess amino acids are changed into ___ or fat for energy storage
carbohydrates
It ensures that amino acids will be used for whatever protein synthesis is necessary, before the amino acids can be changed into carbohydrates
Growth hormone
It also stimulates cell division in those tissues capable of mitosis, which contribute to the growth of the body during childhood, especially in growth in bones and muscles
Growth hormone
GH is still secreted in adults even of the body is not growing in height since some tissues require new proteins for repair or replacement
true
stimulates the release of fat from adipose tissue and the use of fats for energy production which is important for any time we go for extended periods without eating, no matter what our ages
Growth hormone
Increases the secrteion of GH and is produced during hypoglycemia and during exercise
Growth hormone-releasing hormone (GHRH)
may also be called growth hormone inhibiting hormone (GHIH) and it decreases the secretion of GH. It is produced during hyperglycemia
Somatostatin
also called thyrotropin and its target organ is the thyroid gland. It stimulates the normal growth of the thyroid and the secretion of thyroxine (T4) and triiodothyronine (T3)
Thyroid-stimulating hormone
What stimulates the secretion of Thyroid-stimulating hormone from the hypothalamus
Thyrotropin releasing hormone (TRH)
True or false. When metabolic rate (energy production) decreases, Thyrotropin releasing hormone is produced
true
Stimulates the secretion of cortisol and other hormones by the adrenal cortex
Adrenocorticotropic hormone (ACTH)
SEcretion of Adrenocorticotropic hormone is increased by ____ from the hypothalamus. It is produced in any type of physiological stress situation such as injury
Corticotropin-releasing hormone (CRH)
responsible for lactation. I initiates milk production by the mammary glands
Prolactin
What is involved in the regulation of prolactin secretion
prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH)
What is involved in the regulation of prolactin secretion
prolactin-releasing hormone (PRH) and prolactin-inhibiting hormone (PIH)
The mammry glands must be acted upon first by other hormones such as ___ and ____, which are secreted in large amounts by the placenta during pregnancy.
Estrogen and progesterone
one of the gonadotropic hormones, that is it has effects on gonads: the ovaries and testes
Follicle-stimulating hormone
Within the ovaries are ______ that contain potential ova (egg cells) which it initiates egg development in cycles of approximately 28 days, in which follicle-stimulating hormones stimulate
ovarian follicles
Follicle-stimulating hormone stimulates estrogens by _____
follicle cells
The secretion of FSH is stimulated by hypothalamus, which produces _____. It also regulates Luteinizing hormone
gonadotropin-releasing hormone (GnRH)
FSH secretion is decreased by ____, a hormone produced by the ovaries or testes
inhibin
another gonadotropic hormone. In women, it is responsible in ovulation
Luteinizing hormone (LH)
the release of a mature ovum from an ovarian follicle by Luteinizing hormone
ovulation
Luteinizing hormone stimulates ovarian follicle to develop into ____, which secretes progesterone
corpus luteum
Luteinizing hormone stimulates the _______ of the testes to secretr testosterone
interstitial cells
Luteinizing hormone stimulates the _______ of the testes to secretr testosterone
interstitial cells
Luteinizing hormone is also called as
Interstitial cell-stimulating hormone
Hormonal release of Posterior Pituitary Gland is regulated by what hormones
Oxytocin and Antidiuretic hormone
Oxytocin and antidiuretic hormone are transported to ________ of the posterior pituitary
neurosecretory cells
Posterior pituitary is not strictly an endocrine gland, but does release hormones
true
Hormones from the posterior pituitary are made in the hypothalamus by ______
hypothalamic neurons
Antidiuretic hormone, also called _______, increases the reabsorption of water by kidney tubules, which decreases the amount of urine formed
vasopressin
The water is reabsorbed in the blood, so as urinary output decreases, blood volume increase, which helps maintain normal blood pressure
true
the stimulus of the secretion of antidiuretic hormone
decreased water content of the body or dehydration
In severe hemorrhage, ADH is released in large amounts and will cause vasoconstriction, especially in arterioles. This function gives ADH its other name ______
vasopressin
True or false. Ingestion of alcohol inhibits the secretion of ADH and increases urinary output
true
Stimulates contraction of the uterus at the end of pregnancy and stimulates release of milk from the mammary gland
oxytocin
What stimulates the release of oxytocin
cervix of the uterus is stretched which generates sensory impulses to the hypothalamus
causes strong contractions of the smooth muscles (myometrium) of the uerus to bring about delivery of the baby and the placenta
Oxytocin
One of the few positive feedback mechanism, where the external brake or shutoff of the feedback cycle is the delivery of the baby and the placenta
secretion of oxytocin
release of milk
milk let-down reflex
How many amino acids does ADH and oxytocin have
9 each
Located on the front n=and sides of the trachea just below the larynx
thyroid gland
2 lobes of thyroid gland are connected by a middle piece called
isthmus
structural units of thyroid gland tat produce thyroxine (T4) and triiodothyronine (T3)
thyroid follicles
necessary for the synthesis of T4 and T3
iodine
how many atoms of iodine does thyroxine contains
4
how many atoms of iodine does triiodothyronine contains
3
3rd hormone produced by thyroid gand which is secreted by parafollicular cells
calcitonin
Have the same functions and are the most important day-to-day regulators of metabolic rate even though they are not vital hormones
t4 and t3
decreases the reabsorption of calcium and phosphate from the bones to
the blood, thereby lowering blood levels of these minerals. This function helps
maintain normal blood levels of calcium and phosphate and also helps maintain a stable,
strong bone matrix.
calcitonin
A form of calcitonin obtained from salmon is used to
help treat .
osteoporosis
stimulus for secretion of calcitonin is _______ whish is high blood calcium level
Hypercalcemia
Tiny masses on the posterior of the thyroid
parathyroid gland
functions include secretion of parathyroid hormone (PTH), stimulation of osteoclasts to remove calcium from
bone
parathyroid gland
is an antagonist to calcitonin and is important for the
maintenance of normal blood levels of calcium and phosphate.
parathyroid hormone (PTH)
target organs of PTH
bones, small intestine, kidney
raise the blood calcium level and lower the blood phosphate level
parathyroid hormone
Secretion of parathyroid hormone is stimulated by ______, low blood calcium level, and inhibited by hypercalcemia
hypocalcemia
essential for the process of blood clotting and for normal
activity of neurons and muscle cells
calcium
brief excess of PTH, such as can occur by injection, will
stimulate the formation of more bone matrix, rather than matrix reabsorption.
intermittent
responsible
for making sure that the food that we eat is consumed by the cells of our body. At the same
time, it is also responsible for sourcing out the necessary nutrient of our cells during periods
of physical exertion or when you are in the middle of something or somewhere and you have
no food to eat.
pancreas
located in the upper left quadrant of the abdominal cavity, extending
from the curve of the duodenum to the spleen.it is both an exocrine
(digestive) gland as well as an endocrine gland,
pancreas
hormone-producing cells of the pancreas
islets of Langerhans (pancreatic islets)
Alpha cells of pancreas produce
glucagon
Beta cells of pancreas produce
insulin
stimulates the liver to change glycogen to glucose and to increase the use of fats and excess amino acids for energy production.
glucagon
process of changing glycogen into glucose
glycogenolysis
the conversion of excess amino acids
into simple carbohydrates that may enter the reactions of cell respiration.
gluconeogenesis
raise the blood glucose level and to make all types
of food available for energy production.
glucagon
secretion of glucagon is stimulated by _____, which is a low blood glucose level. Such a state may occur between meals or during physiological stress situations
such as exercise.
hypoglycemia
increases the transport of glucose from the blood into cells by
increasing the permeability of cell membranes to glucose.
insulin
used in cell respiration to produce energy
glucose
liver and skeletal muscles also change glucose to glycogen (______, which means “glycogen production”)
to be stored for later use.
glycogenesis
important in the metabolism of other food types; it enables cells to take in fatty acids and amino acids to use in the synthesis of
lipids and proteins (not energy production). Without it, blood levels of lipids tend
to rise and cells accumulate excess fatty acids.
insulin
deficiency of insulin or in its functioning is called
diabetes mellitus
Secretion of insulin is stimulated by ________ , high level of blood glucose level. This state occurs after eating, especially of meals high in carbohydrates.
hyperglycemia
excess glucose will be stored in the liver and muscles as
glycogen
produce the hormone somatostatin, which is identical to growth hormone-inhibiting hormone
delta cells
acts locally to inhibit the secretion
of insulin and glucagon, and it seems to slow the absorption of the end products of
digestion in the small intestine.
pancreatic somatostatin
Type 1 diabetes mellitus and its onset is usually in childhood (juvenile onset)
insulin-dependent diabetes
Type 2 diabetes mellitus and its onset is usually onset in life (maturity onset)
non-insulin-dependent diabetes
Characterized by destruction of the beta cells of the islets of Langerhans and a complete lack of insulin, Onset is usually abrupt. Insulin y injection is essential to control this diabetes
type 1 diabetes
insulin is produced but cannot exert its effects on cells because of a loss of insulin receptors on cell membranes. Onset is usually gradual and risk factors include family history and being overweight. Control may not require insulin
Type 2 diabetes
very serious potential problem for type 1 diabetes. When glucose cannot be used for energy, the body turns to fats and proteins, which are converted by the liver into ketones
ketoacidosis
responsible for moments when you have the so-called adrenaline rush. Other mechanisms in which regulate include your urinary elimination and inflammatory response.
adrenal glands
Latin for marrow. often implies a deep region within a structure,
medulla
Latin for bark. when used generally, the term cortex refers to the outermost layer of
a structure.
cortex
two adrenal glands are located one on top of each kidney, which gives them
their other name of
suprarenal glands
secrete epinephrine and norepinephrine, which
collectively are called catecholamines and are sympathomimetic.
adrenal medulla
both secreted
in stress situations and help prepare the body for “fight or flight.”
Epinephrine (adrenalin) and Norepinephrine (noradrenalin)
secreted in small amounts, and its most significant function is to cause
vasoconstriction in the skin, viscera, and skeletal muscles (that is, throughout the
body), which raises blood pressure.
Norepinephrine
secreted in larger amounts, increases the heart rate and force of
contraction and stimulates vasoconstriction in skin and viscera and vasodilation in skeletal muscles.
Epinephrine
It also dilates the bronchioles, decreases peristalsis, stimulates the
liver to change glycogen to glucose, increases the use of fats for energy, and increases
the rate of cell respiration
epinephrine
secretes three types of steroid hormones:
adrenal cortex
What are the three steroid hormones that the adrenal cortex secretes
mineralocorticoids, glucocorticoids, sex hormones
the sex hormones, “female” _____ and “male” ______
estrogens - androgens
most abundant of the mineralocorticoids
aldosterone
target organs of aldosterone
kidneys
increases
the reabsorption of sodium and the excretion of potassium by the kidney tubules.
Sodium ions (Na+) are returned to the blood, and potassium ions (K+) are excreted in
urine.
aldosterone
maintains normal blood levels of sodium and
potassium, and contributes to the maintenance of normal blood pH, blood volume,
and blood pressure.
aldosterone
Low blood pressure or blood volume activates the
renin-angiotensin mechanism of the kidney
causes
vasoconstriction and stimulates the secretion of aldosterone by the adrenal cortex.
Aldosterone then increases sodium and water retention by the kidneys to help restore
blood volume and blood pressure to normal.
Angiotensin II
representative of the group of hormones called
glucocorticoids and has an anti-inflammatory effect
cortisol
increases the use of fats and excess amino acids (gluconeogenesis) for energy and
decreases the use of glucose.
cortisol
important because it conserves glucose for use by the brain.
glucosesparing effect
blocks the effects of histamine
and stabilizes lysosomal membranes, preventing excessive tissue destruction.
cortisol
Inflammation, more inflammation in which normal cortisol seems to be the break
positive feedback mechanism
Direct stimulus for cortisol secretion is _____ from the anterior pituitary gland, which in turn is stimulated by corticotropin releasing hormone from the hypothalamus
ACTH
result of hyposecretion of adrenal cortical hormones. Unknown cause
Addison’s disease
result of hypersecretion of adrenal cortex, primarily cortisol
Cushing’s syndrome
located in the pelvic cavity, one on each side of the uterus
ovaries
hormones produced by the ovaries
steroids estrogen and progesterone, and the
protein inhibin
secreted by the follicle cells of the ovary; secretion is stimulated by
FSH from the anterior pituitary gland. promotes the maturation of the ovum
in the ovarian follicle and stimulates the growth of blood vessels in the endometrium
(lining) of the uterus in preparation for a possible fertilized egg.
Estrogen
lower blood levels of cholesterol and triglycerides. For women before the age of menopause this is beneficial in that it decreases the risk of atherosclerosis and coronary artery disease.
estrogen
have non-reproductive functions in both men and
women,
estrogen
When a mature ovarian follicle releases an ovum, the follicle becomes the
corpus luteum and begins to secrete progesterone in addition to estrogen.
progesterone
promotes the storage of glycogen and the further growth of
blood vessels in the endometrium, which thus becomes a potential placenta.
progesterone
secretes both progesterone and estrogen during
pregnancy
placenta
corpus luteum secretes another hormone, which helps
decrease the secretion of FSH by the anterior pituitary gland, and GnRH by the
hypothalamus.
Inhibin
located in the scrotum, a sac of skin between the upper thighs
testes
2 hormones secreted by the testes
testosterone and inhibin
a steroid hormone secreted by the interstitial cells of the
testes; the stimulus for secretion is LH from the anterior pituitary gland.
testosterone
promotes maturation of sperm in the seminiferous tubules of the
testes; this process begins at puberty and continues throughout life. brings about closure of the epiphyses of the long bones.
testosterone
secreted by the sustentacular cells of the testes; the
stimulus for secretion is increased testosterone. The function of inhibin is to decrease
the secretion of FSH by the anterior pituitary gland
inhibin
interaction of inhibin, testosterone, and the anterior pituitary hormones maintains _____ at a
constant rate
spermatogenesis
is a hormone produced by the pineal gland, which is located at the back of
the third ventricle of the brain.
melatonin
also produces melatonin, which seems to indicate that the eyes
and pineal gland work with the biological clock of the hypothalamus.
retina
produces the appetite-suppressing hormone leptin
adipose tissue
produces hormones necessary for the normal functioning of the immune
system
thymus gland
produce hormones that regulate aspects
of digestion and appetite
stomach and duodenum
produce a hormone that stimulates red blood
cell production.
kidney
made by virtually all cells from the phospholipids of their cell
membranes. They differ from other hormones in that they do not circulate in the blood to
target organs, but rather exert their effects locally, where they are produced.
prostaglandins
There are many types of prostaglandins, designated by the letters A through I, as in
PGA, PGB, and so on.
true
inhibits the synthesis of
prostaglandins involved in pain mechanisms and usually relieves the pain.
aspirin
