Chapter 37: Endocrine Flashcards
adenylate cyclase
an enzyme that catalyzes the conversion of ATP to cyclic AMP
adrenal cortex
Has 3 zones: zona glomerulosa, fasiculata, reticularis
outer portion of adrenal glands that produces corticosteroids
adrenal gland
Pyramid shaped glands on top of kidney
Has 2 regions
Adrenal cortex (outer)
Adrenal medulla (inner)
adrenal medulla
Inner part of adrenal glands
produces epinephrine and norepinephrine
adrenocorticotropic hormone (ACTH)
hormone released by the anterior pituitary, which stimulates the adrenal cortex to release corticosteroids
aldosterone
hormone produced by the adrenal cortex that stimulates the reabsorption of Na+
alpha cell
endocrine cell of the pancreatic islets that produces the hormone glucagon
amino acid-derived hormone
hormone derived from amino acids
Water soluble
androgen
male sex hormone such as testosterone
anterior pituitary
portion of the pituitary gland that produces six hormones; also called adenohypophysis
antidiuretic hormone (ADH)
hormone produced by the hypothalamus
released by the posterior pituitary
increases water reabsorption
atrial natriuretic peptide (ANP)
hormone produced by the heart to reduce blood volume, pressure, and Na+ concentration
Increases salt secretion in urine
beta cell
endocrine cell of the pancreatic islets that produces the hormone insulin
calcitonin
hormone produced by the parafollicular cells of the thyroid gland that functions to lower blood Ca2+ levels and promote bone growth
colloid
fluid inside the thyroid gland
corticosteroid
hormone released by the adrenal cortex in response to long-term stress
cortisol
glucocorticoid produced in response to stress
down-regulation
fewer receptors means a smaller response
endocrine gland
gland that secretes hormones into the surrounding interstitial fluid, which then diffuse into blood and are carried to various organs and tissues within the body
epinephrine
hormone released by the adrenal medulla in response to a short term stress
erythropoietin (EPO)
Peptide hormone produced by the kidneys when oxygen in blood is low
stimulates RBC production
estrogens
Female hormone
elicit secondary sex characteristics
Produced by follicular cells
control the maturation of the ova
first messenger
the hormone that binds to a plasma membrane hormone receptor to trigger a signal transduction pathway
follicle-stimulating hormone (FSH)
hormone produced by the anterior pituitary that stimulates gamete production
G-protein
a membrane protein activated by the hormone first messenger to activate formation of cyclic AMP
glucagon
hormone produced by the alpha cells of the pancreas in response to low blood sugar; functions to raise blood sugar levels
glucocorticoid
corticosteroid that affects glucose metabolism
gluconeogenesis
synthesis of glucose from amino acids
glycogenolysis
breakdown of glycogen into glucose
goiter
enlargement of the thyroid gland caused by insufficient dietary iodine levels
gonadotropin
hormone that regulates the gonads, including FSH and LH
growth hormone (GH)
hormone produced by the anterior pituitary that promotes protein synthesis and body growth
growth hormone-inhibiting hormone (GHIH)
hormone produced by the hypothalamus that inhibits growth hormone production, also called somatostatin
growth hormone-releasing hormone (GHRH)
hormone released by the hypothalamus that triggers the release of GH
hormonal stimuli
release of a hormone in response to another hormone
hormone receptor
the cellular protein that binds to a hormone
humoral stimuli
control of hormone release in response to changes in blood
hyperglycemia
high blood sugar level
hyperthyroidism
overactivity of the thyroid gland
hypoglycemia
low blood sugar level
hypophyseal portal system
system of blood vessels that carries hormones from the hypothalamus to the anterior pituitary
insulin
hormone produced by the beta cells of the pancreas in response to high blood glucose levels; functions to lower blood glucose levels
insulin-like growth factor (IGF)
growth-promoting protein produced by the liver
intracellular hormone receptor
a hormone receptor in the cytoplasm or nucleus of a cell
islets of Langerhans (pancreatic islets)
endocrine cells of the pancreas
isthmus
tissue mass that connects the two lobes of the thyroid gland
leptin
hormone produced by adipose tissue promotes satiety and reduces hunger
lipid-derived hormone
hormone derived mostly from cholesterol
Fat soluble, not water soluble
mineralocorticoid
corticosteroid that affects ion and water balance
neural stimuli
stimulation of endocrine glands by the nervous system
norepinephrine
hormone released by the adrenal medulla in response to a short-term stress hormone production by the gonads
oxytocin
hormone released by the posterior pituitary to stimulate uterine contractions during childbirth and milk in mammary glands
pancreas
located behind stomach Regulates blood sugar level &digestion rate Exocrine and endocrine gland Alpha cells: produces glucagon Beta cells: produces insulin
parafollicular cell
thyroid cell that produces the hormone calcitonin
parathyroid gland
Located on posterior of thyroid gland
Secretes parathyroid hormone
- regulates blood calcium levels
parathyroid hormone (PTH)
hormone produced by the parathyroid glands in response to low blood Ca2+ levels; functions to raise blood Ca2+ levels
peptide hormone
hormone composed of a polypeptide chain
Stored inn vessicles
Water soluble
Released via exocytosis
phosphodiesterase (PDE)
enzyme that deactivates cAMP, stopping hormone activity
pituitary gland
endocrine gland located at the base of the brain composed of an anterior and posterior region; also called hypophysis
pituitary stalk
(also, infundibulum) stalk that connects the pituitary gland to the hypothalamus
plasma membrane hormone receptor
a hormone receptor on the surface of the plasma membrane of a cell
posterior pituitary
extension of the brain that releases hormones produced by the hypothalamus; along with the infundibulum, it is also referred to as the neurohypophysis
prolactin (PRL)
hormone produced by the anterior pituitary that stimulates milk production
prolactin-inhibiting hormone
hormone produced by the hypothalamus that inhibits the release of prolactin
prolactin-releasing hormone
hormone produced by the hypothalamus that stimulates the release of prolactin
renin
enzyme produced by kidneys that causes release of aldosterone
Important for blood pressure
thymus
Deep in the thorax
Large in children small in adults
Produces thymosins: develop and mature the immune response
thyroglobulin
glycoprotein found in the thyroid that is converted into thyroid hormone
thyroid gland (general)
located in anterior neck, near throat
Produces thyroid hormones thyroxine and triiodothyronine
Largest pure endocrine gland
2 lateral lobes connected by isthmus
thyroid-stimulating hormone (TSH)
hormone produced by the anterior pituitary that controls the release of T3 and T4 from the thyroid gland
thyroxine (tetraiodothyronine, T4)
thyroid hormone containing 4 iodines that controls the basal metabolic rate
triiodothyronine (T3)
thyroid hormone containing 3 iodines that controls the basal metabolic rate
up-regulation
more receptors means a larger response
Types of hormones
Peptides
Amines
Steroids
Negative feedback
Stimulus: body temp rising
Sensing: nerve cells and skin
Controlling: sweating activated in brain
Effector: sweat glands
Central dogma
DNA to DNA (replication, DNA Polymerase)
DNA to RNA (transcription, RNA Polymerase)
RNA to protein (translation, ribosome)
Steroids
Main class
Derived from cholesterol
Lipid soluble
dissolve through membranes
Amine hormones
Derived from amino acids
Water soluble
Hypothalamic-pituitary axis
Connection between nervous and endocrine sys
Major regulator of most hormones
Pituitary gland
Located at base of the brain
Connected to hypothalamus by pituitary stalk
Anterior pituitary
Regulated by hormones produced in hypothalamus
Posterior pituitary
Hormones produced in hypothalamus are transported down axons and are released from this gland
adenohypophysis
anterior pituitary name
Can release/inhibit hormones from hypothalamus
Makes and secretes 7 diff hormones:
TSH, ACTH, FSH, LH, GH, PRL, MSH
Hypophyseal portal system
Delivers hormones to anterior pituitary
Can promote or stop release of hormones to AP
Neurohypophysis
posterior pituitary name
Releases 2 hormones
ADH: anti diuretic hormone
Oxytocin: uterine contractions and milk
thyroid gland (structure)
Composed of spherical follicles surround colloid
Follicle cells: produce t3 t4 and thyroglobulin
Parafollicular cells: produce calcitonin
Pineal gland
Part of epithalamus
Produces melatonin (induces drowsiness)
Sets biological clock
Testes
Male gonads Secretes androgens Sperm maturation happens here Steroid hormone: testosterone - produced in interstitial cells
Ovaries
Female gonads
Produces estrogen and progestins
Progestins
Female hormone
Produced by corpus luteum
Prepares uterus for implantation
Prepares mammary glands for secretion
Heart
Atria contain endocrine cells
Produces atrial natriuretic peptide hormone
GI Tract
Cells in here secrete hormones that promote
Digestion, hunger, and satiety
Calcitrol
Produced by the kidneys
Steroid hormone in form of Vitamin D
Stimulates calcium & phosphate absorption from small intestine
Adipose
Fat cells
Produce leptin
Types of stimulation glands
Hormonal
Humoral
Neural