Definition Flashcards
Endocrine system
Cooperate with the nervous system to maintain homeostasis by regulating body activities. This is accomplished by endocrine hormones that affect various processes throughout the body, such as growth, metabolism, and secretions from other organs.
Is composed of the ductless glands, and other structures that secrete hormones into the bloodstream.
The endocrine system, and the nervous system cooperate to maintain homeostasis.
Endocrine glands
Are ductless glands, which secrete hormones, special chemical substances, into the blood that are carried to another part of the body, where they exert specific physiologic effects.
endocrine glands (for example, the thyroid and pituitary glands) are ductless, so they secrete their hormones into the bloodstream
Endocrine glands are ductless and produce and secrete hormones into the blood or lymph nodes.
Respond to hormones produced by the pituitary gland, it is named the “master gland.”
Hormones
The chemical secretions of endocrine glands.
Special chemical substance
Hormones are either proteins or steroids. Most hormones in the human body are proteins with the exception of the sex hormones, and those from the adrenal cortex, which are steroids, (a special group of lipids.)
Chemical substances produced in an organ that initiate or regulate the activity of another organ are called hormones
Gland
Is an organ that has specialized cells that secrete or excrete substances that are not related to the glands ordinary metabolism.
Glands are classified as either exocrine or endocrine glands.
Exocrine glands
Have ducts that enable them to empty secretions onto an external or an internal body surface.
A sweet gland is an example of an exocrine gland.
Exocrine gland has duct
Exocrine glands, such as sweat glands, are simple glands that have adapt that enables them to empty secretions onto a body surface
Dysfunctions in hormone production
Fall into two categories:
Either a deficiency or an excess in secretion
Deficiency is called hyposecretion
Excess secretion is called hypersecretion
Target organ
The organ or structure toward which the effects of a hormone are primarily directed, is called__________.
If a hormone has a specific affect on the thyroid gland, then the thyroid is the target organ.
If a hormone has a specific affect on the ovaries than the ovaries is the target.
The target cell concept
Explains how only certain cells of specific organs are affected by a specific hormone.
The hormone recognizes the target tissue through receptors (the site that interacts with the hormone ), so the hormones act only on cells that have receptors specific for that hormone. The shape of the receptor determines which hormone can react with it.
Parathyroid
Each parathyroid gland, embedded in the posterior surface of the thyroid, is about the size of a grain of rice.
Thyroid gland
Located at the front of the neck, its hormones are essential to normal body growth in infancy and childhood
Regulates the parathyroid glands by negative feedback
Parathyroid glands,m secrete parathyroid hormone PTH or parathormone (para, is used here to mean near or beside). PTH increases the blood calcium level, and its production and release is regulated by a negative feedback mechanism.
Steroids
Is a hormone
A special group of lipids
Sex hormones, and other steroids can be taken orally
Proteins
Is a hormone
Proteins are quickly in activated in the digestive tract, so, if there is a deficiency, these hormones are administered by injection.
7 Major glands of the endocrine system
Pituitary gland, adrenal gland, gonads, pineal gland, thyroid, parathyroid gland, pancreas
Pituitary gland or hypophysis
The master gland
Also called pituitary, hypophysis cerebri, or simply hypophysis, or nickname “the master gland”
The master gland of the endocrine system, and is located at the base of the brain.
A small, round structure, about 1 cm (or half inch) in diameter that is attached by a stalk at the base of the brain; also called hypophysis.
The anterior pituitary is composed of glandular tissue
The posterior pituitary is composed of nervous tissue
Supplies hormones that act directly on cells or stimulate other glands that govern numerous vital processes.
Adrenal glands or suprarenal glands
One lies above each other of the two kidneys; also called the suprarenal glands.
Releases adrenaline in response to the sympathetic nervous system in stressful situations
Gonads
Ovaries and testes: glands that provide ova and sperm, respectively
Pineal gland
Shaped like a pinecone and is attached to the posterior part of the brain; also called the pineal body
Thyroid
Consist of bilateral lobes that are connected by a narrow strip of thyroid tissue and located at the front of the neck; also called the thyroid gland.
Parathyroid glands
Embedded in the posterior surface of the thyroid; the name implies that they are located “near or beside” the thyroid
Pancreas
An elongated structure that has digestive functions as well as endocrine functions; the islets of Langerhans are microscopic cluster of cells responsible for the endocrine work of the pancreas.
Hypo/physis
Hypophysis
Was so named because it grows under (beneath) the cerebrum
Posterior pituitary lobe
Posterior lobe of the pituitary
Is controlled by nervous stimulation by the hypothalamus and releases two hormones.
Is called the neurohypophysis
The hormones of the neurohypophysis are stored in the axon endings and are released when a nerve impulse travels down the axon.
Anterior pituitary lobe
Is controlled by hypothalamic, hormones brought by the bloodstream and secretes many hormones
hypothalamus
This lobe contains ends of neurons, the cell bodies of which are located in the hypothalamus, a portion of the lower part of the brain.
Regulates the adenohypophysis, the anterior lobe, by replacing regulatory and inhibitory hormones.
Anterior lobe of the pituitary
Releases the greater number of hormones.
Is called adenohypophysis. This lobe is the glandular part of it the hypophysis. The release of the hormones from the adenohypophysis is controlled by regulating hormones produced by the hypothalamus.
Produces many hormones, several of which act on other endocrine glands, causing them also to secrete hormones.
Pituitary hormones
ADH : antidiuretic hormone
STH : somatotropic hormone
MSH : melanocyte-stimulating hormone
The breasts
The uterus
The two hormones produced by the posterior lobe of the pituitary act directly on the specific cells of the kidneys
Adenohypophysis
Is controlled by hormones brought by the bloodstream
Releases several hormones that regulate a large range of body activities.
neurohypophysis
Is controlled by nervous stimulation
Luteinizing hormone LH
In males is also called interstitial cell— stimulating hormone ICSH (interstitial in the name, refers to certain cells of the testes)
Endocrine tissue
Additional endocrine tissue is located in various body cells, the gastrointestinal tract, placenta, kidney, and the skin.
ADH and oxytin
These are the names or abbreviations of the two hormones that are stored in the neurohypophysis and released into the bloodstream after nervous stimulation by the hypothalamus.
STH
MSH
TSH
PRL
LH
FSH
ACTH
The abbreviations of the seven horror moans of the adenohypophysis
Hypothalamus
Controls the neurohypophysis, the posterior lobe, by direct, nervous stimulation
Synthesizes to hormones that are stored in the neurohypophysis. Antidiuretic hormone and oxytocin are synthesized in the hypothalamus and transported to the neurohypophysis for storage. On stimulation by the hypothalamus, the neurohypophysis releases them into the bloodstream.
Antidiuretic hormone, ADH
Affects the volume of urine excreted.
Disorders of the posterior lobe of the pituitary are usually related to a deficiency or excess of ADH, which is the antidiuretic hormone.
pituitary dysfunction can result in hyposecretion or hypersecretion of the pituitary hormones.
Diuretic
Means increasing urine excretion or the amount of urine. It also means an agent that promotes a urine excretion.
Some common caffeinated drinks, (tea, coffee, soda) and even water can act as diuretics. Physicians also prescribe diuretic drugs to rid the body of excess fluid in patients with edema.
Diuretics increase urination.
Diuretic=more urination
Antidiuretic hormone (ADH)
=less urine excretion
Absence of ADH = much urine excretion
Antidiuretic
Pertaining to the suppression of urine excretion
Hormone acts against a diuretic. it acts in the kidneys to reabsorb water from the urine, producing concentrated urine.
Absence of this hormone produces diuresis, passage of large amounts of dilute urine.
Antidiuretic hormone causes a decrease in the amount of water lost in urination.
Oxytocin
Is a pituitary hormone that stimulates uterine contractions and milk ejection
The pituitary hormone, oxytocin, is released in large quantities just before a female gives birth. It causes uterine contractions, thus inducing childbirth. It also acts on the mammary glands to stimulate the release of milk.
Oxytocin’s =Uterus: uterine contraction
before childbirth
functions =Mammary glands: expulsion
of milk after childbirth
Regulatory and inhibitory hormones stimulate, or inhibit the adenohypophysis
Hypothalamic regulatory and inhibitory hormones act on the adenohypophysis to either stimulate or inhibit the secretion of its hormones. When the adenohypophysis, secretes hormones, they travel through the bloodstream and bring about changes in other organs, often another endocrine gland. Note that the control from the hypothalamus to the adenohypophysis is hormonal, whereas the control of the neurohypophysis—as mentioned earlier— is through nervous stimulation.
Tropic
Stimulate
Pituitary secrete TSH
Which causes the glandular cells of the thyroid to produce thyroid hormones
TSH
Thyroid stimulating hormone and is also called thyrotropin
Thyroid gland
The Glenn located at the front of the neck that is stimulated by TSH
The major functions of the thyroid gland are regulation of body metabolism, normal growth & development, and the storage of calcium in bone tissue. It accomplishes these functions by secretion of three hormones: thyroxine, triiodothyronine, and thyrocalcitonin.
Eu/thyroid
Euthyroid
Normal functioning of the thyroid
Good or normal/thyroid
Means a normally functioning thyroid
Thyroxine abbreviated T4(small 4)
The majority of the hormones secreted by the thyroid gland is thyroxine, abbreviated T4, which is tetraiodothyronine, because the molecule contains four atoms of iodine in its chemical structure
triiodothyronine
Another hormone produced by the thyroid gland, but in far lower quantities is triiodothyronine which is abbreviated T3 (small3) . Both of these hormones are synthesized by the thyroid using iodine. If there is a deficiency of iodine in the diet, the thyroid will not be able to produce sufficient T3 and T4 for metabolism.
Thyrocalcitonin (TCT, also called calcitonin)
A third hormone produced by the thyroid gland is thyrocalcitonin. This hormone is involved in the homeostasis of the blood calcium level. TCT is a hormone produced by the thyroid.
Thyroid gland produces
T3=triiodothyronine
T4=tetraiodothyronine
Thyrocalcitonin
Two important pituitary hormones, have the gonads as target organs
Gonadotropic hormones, stimulate the ovaries of the female, and the testes of a male
Follicle-stimulating hormone FSH and luteinizing hormone. LH are produced by the adenohypophysis.
gonadotropin
FSH & LH are gonadotropin
A hormone that stimulates the gonads
gonad/al
gonadal
gonads/pertaining to
Means pertaining to the gonads
Gonadotropic
Is an adjective that means stimulating the gonads. The first gonadal, tropic hormone, FSH, stimulates the ovaries to secrete estrogen and acts on the follicle (as its name implies.) FSH stimulates production of sperm in the testes of males.
Luteinizing hormone, LH
LH is often called interstitial cell-stimulating hormone ICSH in male individuals, because it promotes the growth of the interstitial cells of the testes and the secretion of testosterone.
Stimulates, ovulation, and production of progesterone in the female ovary.
Ovaries LH=Testes Ovaries FSH=(CSH) Testes
Puberty
The period of life at which reproduction becomes possible. It is recognized by maturation of the genitals and appearance of secondary sex characteristics. the onset of puberty is triggered by the hypothalamus and the arterial pituitary. FSH and LH act on the testes and ovaries.
Male sex hormones
Are collectively called androgens, and testosterone is the most abundant
Main hormones secreted by the ovaries and testes
Are estrogen and testosterone
Progesterone
Is another important female hormone produced mainly by the ovaries (and by the placenta during pregnancy) and in minute amounts by the adrenal cortex
Estrogen
Ovaries produce estrogen (largely responsible for female sexual characteristics) and progesterone (also produced by the placenta) which maintains pregnancy.
Secondary female and male sexual
The changes that occur at puberty are brought about by the hypothalamus and the anterior pituitary. Changes in the secretions of FSH and LH bring about changes in the ovaries and testes and the hormones they produce.
Females at puberty
Starts at the pituitary gland ====
FSH and LH ===
ovum matures in ovary ===
production of estrogen and progesterone===
Sexual desire
Growth and distribution of body hair
Breast development
Feminine body features
Ovulation
Menstruation
Males at puberty
Pituitary gland===
FSH and ICSH ===
Sperm and testosterone production of testes
Sexual desire
Growth and distribution of body hair
Deepening of the voice
Masculine body features
Development of sex organs
Muscle building
Testosterone
Is an androgens
Is the most potent androgen and is produced in large quantities by the testes, making that produced by the adrenal glands significant in most cases
Testes produce testosterone, which is responsible for male sexual characteristics.
Androgenic
Means producing masculine characteristics or masculinization. In women, the masculinization effect of androgen secretion may become evident after menopause.
Growth hormone GH
Is also called somatotropic hormone STH or somatotropin.
Somato/tropic hormone
Somatotropic
body/stimulating
Somatotropin
Somato/tropin
This hormone increases the rate of growth and maintains size. Once growth is attained. It is called GH or somatotropin.
Is the hormone that which stimulates body growth
body/that which stimulates
Melanocyte-stimulating hormone MSH
From the pituitary stimulates melanocytes distributed throughout the epidermidis. MSH promotes pigmentation and controls the amount of melanin produced by melanocytes.
Melanin
Implies the color black
-Is a black or dark brown pigment that occurs naturally in the hair, skin, and parts of the eye.
Melanocyte
Sell that produces melanin
Adrenal gland
Each adrenal gland has two parts, a cortex and a medulla, and each part has its own functions
The cortex and medulla of the adrenal gland are stimulated by different means, and they secrete different hormones.
The hypothalamus influences both portions, but the medulla receives, direct nervous stimulation. The cortex is stimulated by adrenocorticotropin, also called adrenocorticotropic hormone ACTH, which is brought by the circulating blood.
Cortex
The outer cortex makes up the bulk of the gland,
Important hormones produced by the adrenal cortex
Mineralocorticoids (main one is aldosterone)
Glucocorticoids main ones are cortisol and cortisone
Androgens, estrogens
Medulla
The inner portion of the gland
Important hormones produced by adrenal medulla
Epinephrine norepinephrine
Mineralocorticoids, glucocorticoids, androgens, and estrogens are secreted by the
Adrenal cortex
Mineralocorticoids, help maintain water balance in the body. As the name implies, glucocorticoids increase
Blood glucose, but they also inhibit inflammation.
Glucocorticoids
Increase blood glucose, but they also inhibit inflammation
Cortisone
Is used to relieve pain and inflammation in topical preparation’s and is also injected in the joints.
Androgens
Have masculinizing effects
Estrogens
Have feminine eyes in effects
Adrenal medulla, secretes two hormones
Is an example of direct, nervous stimulation.
epinephrine, which stimulates the heart, and norepinephrine , which causes construction of blood vessels
Secretes epinephrine and norepinephrine in response to stimulation by sympathetic nerves
epinephrine
Is also called adrenaline, which you have probably heard before, so this may help you remember that these two hormones are sometimes called the fight or flight or moans, because they prepare the body for strenuous activity
Prolactin PRL is also called lactogenic hormone
The most important hormone that stimulates milk production
Because it causes production of milk by the mammary glands. PRL has no known function in males.
Mammary glands
The milk producing glands of the female
Are lactiferous glands in the female breast that are the target organs of oxytocin and PRL. Many problems associated with the breast are not a result of hormones. However, hormones may be related to breast disorders, for example, inappropriate lactation (nipple discharge.)
The memory glands secrete, a cloud of fluid called colostrum during the first few days, after a female gives birth.
Changes in the memory glands, prepare the breast of a pregnant, female for lactogenesis, the production of milk
Are the two glands of the female breast that secrete milk. The female breasts are accessory organs of the reproductive system.
The breasts are located anterior to the chest muscles and each breast contains 15 to 20 lobes of the glandular tissue that radiate around the nipple.
Breasts
Are mammary glands and function as part of both the endocrine and reproductive systems
areola
The circular pigmented area of skin surrounding the nipple
lobule
Means small lobe. The lobes are separated by connective and adipose (fatty) tissue.
adipose tissue
The amount of adipose tissue determines the size of the breasts but not the amount of milk that can be produced
Lactogenic
Means inducing the secretion of milk. lact(o) means milk
Lactogenesis
The production of milk
Colostrum
The mammary glands secrete a cloudy fluid called colostrum during the first few days after a female gives birth. Because of both high antibody and protein contact, colostrum serves adequately as food for the infant until milk production begins 2 to 3 days after birth.
Lactiferous duct
Each breast lobule is drained by its own lactiferous duct, which has a dilated portion called a sinus that serves as a reservoir for milk.
nipple
Located near the center of the breast, contains the opening for the milk ducts.
Lactation
Is the secretion or ejecting of milk. Milk ejection is a normal reflex in a lactating woman and is elicited by tactile stimulation of the nipple (such as nursing by the infant). impulses from the nipple to the hypothalamus stimulate the release of oxytocin by the pituitary gland, which brings about contractions that inject the milk from the breast. If a lactating mother stops nursing, milk production usually ceases within a few days.
Intermammary
Means situated between the breasts
Retromammary
Means behind the breast
Interrelationships of hypothalamus, neurohypophysis, and breast
Suckling by the infant stimulates nerve endings at the nipple. Impulses are carried to the hypothalamus, which causes the neurohypophysis to secrete oxytocin into the bloodstream. The oxytocin is carried to the breast, where it causes milk to be expressed into the ducts. Milk begins to flow within 30 seconds to 1 minute after a baby begins to suckle.
Suckling stimulus — release of oxytocin into bloodstream—hypophysis— perception by brain
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Major hormones, and target organs of the master gland (pituitary)
HORMONE
Neurohypophysis
Antidiuretic hormone ADH
Oxytocin
TARGET ORGAN OR A GLAND ACTION
kidney cells/conserve water
Uterus during pregnancy/uterine contractions; mammary glands of lactating female/release of milk
HORMONE
ADENOHYPOPHYSIS
adrenocorticotropin ACTH
TARGET ORGAN OR GLAND ACTIONS
adrenal cortex (mineralocorticoids, glucocorticoids, androgens, and estrogens); see table 12.1 on page 558.
HORMONE
FOLLICLE, STIMULATING HORMONE FSH
Ovarian follicles (estrogen) ova; testes/sperm
LUTEINIZING HORMONE LH
Ovaries (progesterone); testes (testosterone)
MELANOCYTE-STIMULATING HORMONE MSH
melanocytes in epidermis; pigmentation
PROLACTIN PRL
mammary glands; production of milk
SOMATOTROPIN (GROWTH HORMONE GH)
body cells; growth or maintenance of size
THYROTROPIN
thyroid gland (triiodothyronine T3, thyroxine T4, and thyrocalcitonin TCT; body metabolism and growth