Chapter 7,8,9 Flashcards
Which component of the endocrine system produces the body’s major metabolic hormone? and what two hormones?
Thyroid gland (thyroid hormone- stimulates the metabolic rate)
and
(calcitonin- decreases blood calcium levels, stimulates osteoblasts in bone to take Ca+2 from the blood and deposit it in bone matrix) this hormone is antagonistic to parathyroid hormone
found at base of the throat and has 2 lobes and a connecting isthmus
the thyroid hormone
What has four small masses on posterior of the thyroid gland? what hormone does this gland secrete?
parathyroid glands
PTH (Parathyroid hormone-increases blood calcium levels, stimulates osteoclasts to release Ca+2 from bone matrix, stimulates kidneys and intestine to absorb more Ca+2) antagonistic to calcitonin
regulates blood calcium levels
what secretes insulin and glucagon to regulate blood glucose levels and where is it located
the pancreas- located in abdomen, close to stomach
mixed gland and has both endocrine and exocrine functions
alpha cells release glucagon
beta cells release insulin
What is the size of a pea, protected by the sphenoid bone, connected to hypothalamus by —- stalk? Hormone it releases is controlled by hypothalamus. It has 2 functional lobes
anterior pituitary gland- glandular tissue: secretes 6 hormones
posterior pituitary-nervous tissue secretes 2 hormones
How are blood levels of most hormones kept within a narrow range ?
negative feedback: which is a homeostatic mechanism. endocrine gland secretes hormone until it receives a feedback signaling the gland to inhibit hormone secretion
what involves nerve fibers directly stimulating hormone release from an endocrine gland?
neural stimuli,
most endocrine glands respond to hormonal or humoral stimuli
one of the cell mechanisms hormones act through is
(H-R)hormone receptors binding initiates a series of reactions that result in the activation of enzymes and changes in metabolism.
second-messenger system
They are used by protein, peptide, and amine hormones which are water soluble. so must bind to receptor
this results in synthesis of new proteins, used by steroid hormones. they are lipid soluble
direct gene activation
all steroids use gene activation
what releases insulin in response to high blood glucose levels?
produced by beta cells of pancreatic islets
actions: lowers blood sugar level and stimulate the uptake of sugar by body cells, especially liver, adipose, and skeletal muscle cells
what releases glucagon in response to low blood glucose levels produced in pancreatic islets
alpha cells - raises blood sugar level and stimulates the release of stored sugar from liver
glucagon increases blood glucose levels by stimulating the liver to break down stored glycogen into glucose and release that glucose into the blood
the hormone that simulates the contraction of smooth muscle in the uterus is
oxytocin, oxytocin also initiates milk ejection during lactation
what triggers ovulation and ovarian production of estrogens and progesterone in women?
luteinizing hormone, this stimulates testosterone production in men
what promotes maturation of ovarian follicles and stimulates production of eggs and sperm
follicle stimulating hormone, in men it stimulates sperm production
the posterior pituitary stores and releases which hormones?
(oxytocin-stimulates uterine contractions)OT
(antidiuretic hormrone, produced by the hypothalamic neurons- stimulates water retention by the kidneys) ADH
what does the anterior pituitary gland produce and release?
(prolactin-stimulates milk production)PRL
(growth hormone-stimulates growth, especially in bones and muscles) GH
(Thyroid-stimulated hormone - stimulates thyroid gland to secrete thyroid hormone)TSH
(adrenocorticotropic hormone-stimulates the adrenal cortex to secrete glucocorticoids like cortisol) ACTH
(follicle-stimulating hormone-stimulates the production of sperm and eggs) FSH
(luteinizing hormone-stimulates the testes and ovaries) LH
what hormone produced by the placenta loosens pelvic ligaments prior to birth
relaxin
what triggers ovulation of an egg from the ovary and stimulates testosterone production in the testes
(luteinizing hormone-stimulates the testes and ovaries) LH
an anterior pituitary hormone
where are the parathyroid glands located
posterior surface of the thyroid gland, they release parathyroid hormone in response to low blood calcium ion levels
where is the thymus located and what hormone does it secrete for what?
anterior to heart and posterior to the sternum
largest in infants and children
Secretes thymosin-involved with the development of the immune system
ON the the superior surface of each kidney (suprarenal glands)
has 2 regions
Adrenal glands
(adrenal cortex-outer 80-90% of gland)
(adrenal medulla- inner 10-20% of gland, nervous tissue
what secretes nonhormonal substances into ducts that empty onto a membrane surface
exocrine glands, such as salivary glands and sweat glands
what are the gonadotropic hormones
luteinizing hormone and follicle stimulating hormone
what causes acromegaly a condition in which the bones of the face, hands and feet enlarge and widen
hypersecretion of growth hormone in an adult
what is it called when there is hyposecretion of growth hormone, gigantism
Has three layers that secrete different steroid hormones in region of adrenal glands
adrenal cortex
Mineralocorticoids (mainly aldosterone) stimulates Na+ retention and K+ elimination by the kidneys
glucocorticoids (mainly cortisol) stimulates increase in blood sugar level in response to long-term stress
Sex hormones- low levels of androgens and estrogens