5.4: hypothalamus & pituitary gland

hypothalamus: part of diencephalon, homeostatic control center

-neuroendocrine origin: has both ___ & ___ functions

-secretes hormones that regulate ___ __

neural, endocrine, pituitary gland

pituitary gland contains ___ and ___ lobes

anterior, posterior

hypothalamus: _____ cells: modify neurons that release hormones (rather than neurotransmitters)

-connected to anterior pituitary gland via: ______

-connected to posterior pituitary gland via: ____

neurosecretory, hypophyseal portal system, hypophyseal tract

anterior pituitary:

-made of: ___

-secrete 6 hormones

-regulated by: ____

glandular tissue, hypothalamic hormones

posterior pituitary types:

stimulatory:

-thyrotropin-releasing hormone (TRH)

-cortico-releasing hormone (CRH)

-gonadotropin-releasing hormone (GRH)

-growth hormone-releasing hormone (GHRH)

inhibitory:

-prolactin inhibiting hormone (PIH)

-growth hormone-inhibiting hormone (GHIH)

.

hypophyseal portal system

-contains 2 adjacent capillary beds

-____ cells release hormones into primary capillary bed

-hormones travel to anterior pituitary through: ____

-anterior pituitary releases hormones into: _____

neurosecretory, hypophyseal portal veins, secondary capillary bed

anterior pituitary hormones

-growth hormone

-prolactin

-gonadotropins

→follicle-stimulating hormone (FSH)

→luteinizing hormone (LH)

-adrenocorticotropic hormone (ACTH)

-thyroid stimulating hormone (TSH)

.

growth hormones

-important for tissue growth as it stimulates: ____

-primarily targets bone & skeletal muscle

-induces ___ secretion from liver

protein synthesis, hypertrophy, mitosis

glucose

growth hormone regulation

-___ stimulates GH release

-in response to: ____

-also hunger, stress, exercise

-____ inhibits GH release

-in response to: ____

GHRH, low glucose or GH levels

GHIH, high GH levels

GH secretion

-highest in (which period)____ of sleep?

-highest during childhood

-declines naturally with age

first 2 hrs

hypersecretion in GH imbalance

-usually due to anterior pituitary tumor

-can be halted with pituitary surgery or medications

.

hyposecretion in GH imbalance

-from congenital deficiency, brain injury, or pituitary tumor

.

gonadotropins

-____ hormone stimulates gamete production

→maturation of ovarian follicles (females), sperm production (males)

-____ hormone: stimulates release of sex hormones from gonads

-triggers ____ maturation & ovulation (females) & testosterone production (males)

-surge of GnRH at puberty triggers initial release

follicle, luteinizing, egg

prolactin

-stimulates ____ gland development & milk production

-most of the time ___ prevents release

-hormonal changes in pregnancy allow for release

-further stimulated by nursing:

→neuroendocrine reflex

→allows for continued milk

→inhibits GnRH secretion→reduced ovarian cycling

mammary, PIH

adrenocorticotropic hormone (ACTH)

-stimulates ___ glands to release corticosteroids

-secretion induced by ___ from hypothalamus

→circadian pattern: highest in morning

→also in response to stress, low blood glucose

adrenal, corticotropin releasing hormone (CRH)

thyroid stimulating hormone (TSH)

-stimulates development & activity of ____

-release triggered by ___ from what part of the brain? ____

thyroid, thyrotropin releasing hormone (TRH), hypothalamus

posterior pituitary consist of the following hormones:

oxytocin, antidiuretic

posterior pituitary hormone

-oxytocin (OT) & ____ hormone (ADH) produced by neurosecretory cells

-hormones transported to posterior pituitary via hypothalamic-hypophyseal tract

-____ induce release of hormones

antidiuretic, action potentials

oxytocin

-released in response to sensory stimuli

-promotes _____ ____ during labor

-promotes release of: ___

uterine contractions, milk in lactation

antidiuretic hormone (ADH)

-secreted in response to stimulation of _____ ____

-promotes water ____ from kidneys: reduction of urine output

hypothalamic osmoreceptors, retention

diabetes insipidus

-disorder of: ____

-from deficiency of reduced sensitivity in: ____

-extreme thirst, excessive output of dilute urine

fluid imbalance, ADH

.

.

.

.

.