hypothal pit, Flashcards
function of the hypoth
Integrates functions that maintain chemical and temperature homeostasis
Functions with the limbic system
Controls the release of hormones from the anterior and posterior pituitary
Synthesizes releasing hormones in cell bodies of neurons.
Two hypothalamic hormones are transported down the axon and stored in the nerve endings of the posterior pituitary
Hormones are released in pulses
hyposphysiotropic hormones
releasing and inhibiting hormones
flow of hormones from hypothalamus to ant pit
- hypophysioisotropic hormones are released from hypothal enter the capillaries
- hypothal cap rejoin to form the hypothalamic hypophyseal portal system and go into the ant pituitary
- drain into ant pit capillaries
- hypophysioisotropic hormones leave the blood across the ant pituitaty and control hormone release
- upon stimulation certain pituitary hormones are released
- ant pit join to form a vein and hormones are released to body
7 types of hypophysiotropic horomes
Thyrotropin-releasing hormone (TRH) Corticotropin-releasing hormone (CRH) Gonadotropin-releasing hormone (GnRH) Growth hormone-releasing hormone (GHRH) Growth hormone-release inhibiting hormone (GHIH) Prolactin-releasing factor (PRF) Prolactin-inhibiting hormone (PIH)
secretion is controlled by
Secretion is influenced by emotions and day/night (circadian) rhythm generated by pineal gland secretions
Secretion can be influenced by the metabolic state of the individual
Basophils vs acidophils
baso: gonadotropes, corticotropes thyrotrope
acid: lactotrope and somatotropes
receptors of basophils vs acidophils
basophils have g protrein receptors
acidophils have JAK/STAT linked cyokine receptors
growth hormone directs mainly to
adipose, liver and muscle
excess GH before epiphyseal plate will cause
gigantism
excess GH after epiphyseal closure will cause
acromegly
reduced childhood GH levels
dwarfism
reduced childhood tissue response
Laron dwarfism
Thyroid hormone effect of GH
Excess=
defiency =
excess=no effect
deficiency- decreased growth
Insulin effect on GH
Hyperinsulinmemia=
deficiency=
- excess growth.
2. inhibit
sex steroids effect om GH
Testosterone and estrogen can stimulate growth
Nuclei in the hypothalamus involved in axons to pos. pituitary
Supraoptic and paraventricular
pathway of pos pituitary
paraventricula or supraoptic nuclei
- travel through the pos pit stalk or the hypothamic hypophyseal tract to pos pot.
- stimulation and release
main 2 hormones of the pos pit
ADH
and
oxytocin
flow of secretion for ADH
nucleus to be transcribed to mRNA Preprovasopressin produced in ER moved to golgi where granules are formed grabules moved by microtubules neurophysin binds 5 AVP awaits stimulus for release
ADH function
Participates in body water regulation (water is lost from lungs, sweat, feces and urine on a daily bas
secretion of ADH is stimulated by
decrease in blood vol
decrease in bp
pain, fear, trauma , and stress
ADH– V2 in the kidneys
Decreases water excretion by kidneys
ADH– V1 in the kidneys
Constricts blood vessels (V1 receptors)- arteriolar smooth muscle
ADH– V1B
Increases adrenocorticortropin hormone (V1B receptors) secretion from the anterior pituitary
increase in osmolarity will cause
release of vasopressin
oxytocin function
Secretion is increased during labor
May also act to facilitate sperm transport in uterus (non-pregnant state)
Increases contraction of smooth muscle of vas deferens
