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