Endocrine System Flashcards
List the endocrine glands
Hypothalamus
Pineal
Pituitary
Thyroid
Parathyroid
Thymus
Adrenal
Pancreas
Gonads
How does the endocrine system send signals?
chemical signaling with the release of hormones
What are hormones?
Chemical messengers that are carried through the bloodstream
Define Circulating hormones
hormones secreted into the extracellular fluid and diffuse into the blood or lymph, where they can be carried throughout the body
Define local hormones
hormones that act upon neighboring cells are the original cell that secreted them
Define a water soluble hormone
hydrophilic, bind to receptors outside of cell wall. ex: amine, peptide and protein hormones
Define lipid soluble hormone
hydrophobic, bind to receptors inside cell wall. Ex: steroids, thyroid hormones, nitric oxide and eicosanoids
What controls hormone release?
the hypothalamus
Define positive feedback loop
mechanism that intensifies a change in the body’s physiological condition in response to a stimulus. EX: oxytocin release during child labor
Define negative feedback loop
the inhibition of further secretion of a hormone in response to adequate levels of that particular hormone. Ex: The stop of glucocorticoid release from adrenal glands once glucocorticoids concentration in the blood rise.
What hormones are released from the hypothalamus?
GHRH
TRH
CRH
PRH
GnRH
GHIH
PIH
What hormones are released from the anterior pituitary?
hGH
TSH
FSH
LH
PRL
ACTH
What hormones are released from the posterior pituitary?
OT
ADH (vasopressin)
What is the hypophyseal portal system?
The release of hormones from the hypothalamus to the anterior pituitary through a network of capillaries. This allows the hormones to transit without entering the bloodstream
What are the thyroid hormones and what do they control?
Thyroxine (T4)- controls metabolism and energy levels
Triiodothyronine (T3)- development of fetus and bone growth
Calcitonin- decreases blood calcium concentrations
What are the parathyroid hormones and what do they control?
PTH- raises calcium levels in the blood
What are the adrenal cortex hormones and what do they control?
aldosterone- regulates concentration of sodium and potassium ions
cortisone- controls metabolism, stress response and reduces inflammation
androgens- affects libido and menstrual cycles
What are the adrenal medulla hormones and what do they control?
epinephrine- increases heart rate and blood flow, converts glycogen to glucose in the liver. helps the body respond to stress
norepinephrine- responds to stress, constricts blood vessels to increase bp
What are the pineal hormones and what do they control?
melatonin- regulates sleep-wake cyles
What makes the pancreas an endocrine gland?
pancreatic islets that release insulin and glucagon
What cells release insulin?
beta cells
What cells release glucagon?
alpha cells
what does insulin do?
lowers blood glucose levels
What does glucagon do?
raises blood glucose
