hypothalamus and pituitary gland

master regulator of the brain and body

hypothalamus

deals with the central brain circuitry and motivation as well as pituitary/systemic that deals with hormones

hypothalamus

-in suffix =

peptide hormones

is kind of extension of hypothalamus, Kind of hanging a little below brain

pituitary

Very long, Originate in hypothalamus and extend all the way down to capillary beds

posterior pituitary

Originate in hypothalamus, Reach about halfway down to the median eminence, Then goes to anterior pituitary gland

anterior pituitary

hypothalamus releases hormones down the portal system in the median eminence which binds to pituitary target cells which then release the hormone into the pituitary blood stream

anterior pituitary

PRL = —, anterior pituitary cell type

prolactin

GH =—, anterior pituitary cell type

growth hormone

ACTH =—-, anterior pituitary cell type

adrenocorticotropin

TSH =—-, anterior pituitary cell type

thyroid stimulating hormone

LH =—-, anterior pituitary cell type

luteinizing hormone

FSH =—, anterior pituitary cell type

follicle stimulating hormone

Secreted via gonadotrophs that are scattered throughout the anterior pituitary

luteinizing hormone and follicle stimulating hormone

CRH, product Includes ACTH & β-endorphin, anterior pituitary cell

corticotrophs

TRH, product = Thyroid-Stimulating Hormone (TSH)

thryotrophs

GnRH, produces LH and FSH, anterior pituitary cell

gonadotroph

GHRH, produces growth hormone, anterior pituitary cell

somatotrophs

dopamine, produces prolactin (which is normally turned off), anterior pituitary cell

lactotrophs

hypothalamic neuron release hormone into the pituitary blood stream

posterior pituitary

Made in the Hypothalamus and Released in the Posterior Pituitary

oxytocin and vasopressin

targets: Uterus, Mammary Myoepithelial Cells, action: Uterine Contraction, Milk Ejection (increases smooth muscle contraction of uterine and breast tissue)

oxytocin

targets: V1R: Smooth Muscle Cells, V2R: Kidney Collecting Ducts, action: Vasoconstriction, Increased Water Retention

vasopressin

stretch of cervix and breastfeeding done by oxytocin are examples of what

mechanical stimulus

mechanical stimulus releases

hormones

oxytocin increases cellular —- levels, considered the second messenger, important we have these levels up

calcium

increase in calcium levels activates—- which then activates——, leading to muscle relaxation/contraction

calmodulin, myosin light chain kinase

take inactive proteins and shuttle them into an active state through phosphorylation

kinase

feeling secure, privacy, dim lighting, people you know, touch, comfortable environment, relaxation

increase oxytocin release

feeling frightened, feeling watched, bright lights, strangers, questions, uncomfortable environment, thinking

inhibits oxytocin release

low BP causes decreased baroreceptor stimulation in the vasculature which then stimulates the hypothalamus to act, hypothalamus releases vasopressin into bloodstream to increase pressure and return to homeostasis

baroreceptor reflex

dehydration is an increase in sodium in extracellular fluid which stimulates osmoreceptors in hypothalamus, those release vasopressin into the bloodstream and increases thirst

hypothalamic response to dehydration

water channels in the kidney that retain water, antidiuretic hormone, retain the water to dilute the extracellular fluid with too much sodium, vasopressin targets this when dehydration occurs

aquaporins

coordinated effects of vasopressin include

baroreceptors and osmoreceptors

receptors in blood vessels, increased vasculature resistance

baroreceptors

receptors in kidneys, increase in blood volume

osmoreceptors