endocrine system Flashcards
what is the biggest difference between the nervous system and the endocrine system?
the nervous system utilizes neurotransmitters to control body functions and the endocrine system utilizes hormones to control body functions
what is the difference between neurotransmitters and hormones when it comes to where their actions are performed?
neurotransmitters perform their action close to the site of release and hormones usually perform their action far from their site of release
what type of structures does the nervous system act upon?
muscle cells (smooth, cardiac, and skeletal), glands, and other neurons
what type of structures does the endocrine system act upon?
virtually all cells of the body
what is the difference between the nervous system and the endocrine system in regards to the time it takes them to act
nervous system-action typically occurs within milliseconds of neurotransmitter release
endocrine system-action can take seconds to days to occur after release of the hormone
in regards to the duration of actions set off by the endocrine system and nervous system, which tend to be longer?
the actions tend to be briefer in duration in the nervous system and longer in duration in the endocrine system
definition of a hormone
a mediator molecule that is released in one part of the body but regulated activity of cells in other parts of the body
can a neurotransmitter also be a hormone?
yes, several of them are including norepinephrine
what is the travel passage of a hormone
most enter the interstitial fluid and then the bloodstream. They travel through the bloodstream to cells throughout the body
what are the functions of hormones?
- help regulate: chemical composition and volume of the internal environment, metabolism and energy balance, contraction of smooth and cardiac muscle fibers, glandular secretions, and some immune system activities
- control growth and development
- regulate operation of reproductive systems
- help establish circadian rhythms
what structures make up the endocrine system?
all endocrine glands and hormone secreting cells (ie: pituitary, thyroid, and adrenal glands)
which organs in the body contain endocrine tissue but are not endocrine glands exclusively
hypothalamus, thymus, pancreas, stomach, skin, heart
what does it mean that the nervous system and endocrine system act as a coordinated supersystem (neuroendocrine system)?
parts of the neurons stimulate or inhibit the release of hormones and hormones can promote or inhibit the release of nerve impulses
which type of gland secrete their products into ducts that carry secretions into body cavities, into the lumen of an organ, or to the outer surface of the body
exocrine glands
which type of glands secrete their hormones into the interstitial fluid surrounding the secretory cells
endocrine glands
which type of glands are sudoriferous glands
exocrine glands
*sudoriferous (sweat)
which type of glands are pituitary glands?
endocrine glands
which type of glands are sebaceous glands
exocrine glands
*(oil)
which tyoe of glands are thyroid glands?
endocrine glands
which type of glands are mucous and digestive?
exocrine glands
which type of glands are parathyroid glands?
endocrine glands
which type of glands are adrenal and pineal?
endocrine glands
what is endocrinology
the study of the science of endocrine glands, function of endocrine glands, diagnosis of endocrine disorders and treatment of endocrine disorders
how does the binding of hormones to receptors work
hormones affect only certain target cells. Only target cells for a given hormone have specific receptors that bind and recognize that hormone. Target cells for a particular hormone are those cells that have the appropriate receptor mlecules (protiens or glycoproteins) that can bind to the hormone.
if a hormone is present in excess, the number of target cell receptors may _____
why?
What is this called?
decrease, in order to decrease the sensitivity of that target cell to a particular hormone. (Down-regulation)
explain up-regulation
when a hormone (or neurotransmiter) is deficient, the number of receptors may increase in order to make a target cell more receptive to a specific hormone
synergistic effects of hormones
the sum of the actions of the 2 hormones is greater than either hormone individually (ie: estrogens and FSH promote the development of oocytes)
antagonistic effects of hormones
one hormone opposes the actions of another (ie: insulin promotes synthesis of glycogen and glucagon which stimulates the breakdown of glycogen)
what structure serves as a major integrating link between the nervous system and the endocrine system?
hypothalamus
T/F, painful, stressful, and emotional experiences cause changes in hypothalamic activity
T
what structure regulates and exerts control over the pituitary gland?
hypothalamus
what are the five types of anterior pituitary cells & the 7 hormones they secrete?
- Corticotrophs - secrete adrenocorticotropic hormone (ACTH) or corticotropin, which stimulates the adrenal cortex to secrete glucocorticoids
- Gonadotrophs - secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH) which act on the gonads by stimulating the secretion of estrogen, progesterone, and testosterone
- Lactotrophs - secrete prolactin (PRL), which initiates milk production
- Somatotrophs - secrete human growth hormone (hGH) or somatotropin, which stimulates tissues to secrete insulin-like growth factors (IGFs) to stimulate body growth and some regulation of metabolism
- Thyrotrophs - secrete thyroid-stimulating hormone (TSH) or thyroptropin; regulating activites of the thyroid gland
hormones that influence another gland are called _____.
tropic hormones or tropins
what is the difference between anterior pituitary glands and posterior pituitary glands in regards to secreting and synthesizing hormones?
- the secretion of anterior pituitary hormones is regulated by releasing hormones and inhibiting hormones that are delivered from the neurosecretory cells of the hypothalamus by a hypophyseal portal system of blood vessels
- the posterior pituitary does not synthesize hormones, but it does store and release two hormones synthesized in the hypothalamus. (oxytocin & antidiuretic hormone ADH, aka vasopressin)
what is the purpose of oxytocin?
to enhance contraction of smooth muscle cells in the wall of the uterus during delivery and stimulate milk ejection from mammary glands in response to the suckling infant after delivery
what is the purpose of antidiuretic hormone (ADH)?
to decrease urine production and increase blood pressure