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what connects the hypothalamus to the pituitary

infundibulum

the pituitary controls the hormone release of which organs and glands

thyroid, adrenal, gonads, and liver

what are the two sections of the pituitary

adenohypophysis (anterior) and neurohypophysis (posterior)

how are pituitary hormones produced

by neurons in the hypothalamus

what is a portal system

when two capillary beds are interconnected

explain the process of anterior pituitary hormone production and secretion

-hormones (from hypothalamus) bind to receptors in the anterior pituitary

-they signal to either stimulate or inhibit the secretion of pituitary hormones

-pituitary hormones are released into the portal vessels

-the hormones travel from the portal vessels into general circulation

what is the process for posterior pituitary hormone production and secretion

-hypothalamic neurons send their axons into the posterior pituitary

-pituitary releases hormones into capillary beds

-hormones travel from capillary beds into general circulation

what hormones are produced by the anterior pituitary

-adenocorticotropic hormone

-thyroid stimulating hormone

-growth hormone

-prolactin (milk production)

-luteinizing hormone

-follicle stimulating hormone

-melanocyte stimulating hormone

what hormones are released from the posterior pituitary

-anti-diuretic hormone

-oxytocin

what does TSH stimulate the release of

thryroxine (T4) and triiodothyronine (T3)

what stimulates the release of TSH

thyrotropin releasing hormone (TRH)

where is ADH

the kidneys

what does ADH do

-increases water retention in the kidneys resulting in lower volumes of urin

-increases thirst

what stimulus triggers the release of ADH

-an increase in blood osmolarity (solutes in the blood)

or

-decrease in blood pressure

what does ethyl alcohol do

-inhibits release of ADH

-causes diuresis (lots of peeing)

-decreased water retention

what does oxytocin do

-causes contraction of myoepithelial cells for milk ejection during nursing

-causes uterine myometrial contractions during labor

what can cause the release of oxytocin

mechanical stimulation of the vagina, cervix, or uterus (which would induce a fetal ejection reflex)

what is the purpose of synthetic oxytocin

used to induce labor and reduce postpartum bleeding following the delivery of the placenta

what does prolactin do

-stimulates mammary gland development and milk production

-inhibits ovulation and shortens luteal phase in ovarian cycle

what inhibits prolactin

dopamine

what does estrogen do in terms of prolactin

it stimulates prolactin secretion and synthesis in the pituitary

what happens during pregnancy in terms of prolactin

is it released more and more during pregnancy and hits it max levels at term

what is the stimulus of prolactin most potent

during nursing

is blood glucose relatively constant

yes

what is the range for blood glucose

60-120 mg/dL

when does insulin rise

in response to food intake (after eating a meal)

do glucagon levels remain relatively stable

yes

what is glucagon

-counteracts the actions of insulin

-stimulates glucose production to increase blood glucose levels

what is the source of blood glucose after a meal

carbohydrates for 2-3 hours after the meal

what does glucagon stimulate between meals

glycogenolysis in the liver

what is glycogenolysis

breakdown of glycogen into glucose for quick energy

what happens when hepatic (liver) glycogen is low

glucagon and cortisol stimulate gluconeogenesis

what is gluconeogenesis

the creation of new glucose

what is the order of the postabsorptive state

1.carbs are source for blood glucose 2-3 hours after meal

2.glycogenesis occurs between meals (glycogen in liver breaks down into glucose)

3.when hepatic glucose is low gluconeogenesis occurs