Hypothalamus and Anterior Pituitary Hypothalamus and Pituitary Gland o Hypothalamus receives input from cortex thalamus limbic system and internal o Hypothalamus provides a link between the external and internal environment and o Hypothalamus controls the anterior pituitary gland with different releasing and organs the endocrine system inhibiting hormones o Hypothalamus releases other hormones directly through the posterior pituitary Cell types of the Anterior Pituitary o 1 Somatotrophs secrete human Grown Hormone o 2 Thyrotrophs secrete Thyroid Stimulating Hormone o 3 Lactotrophs secrete Prolactin o 4 Gonadotrophs secrete Follicle Stimulating Hormone and Lutenizing o 5 Corticotrophs secrete Adrenocorticotropic Hormone and Melanocyte Hormone Stimulating Hormone Hypothalamus Growth Hormone Releasing Hormone GHRH Growth Hormone Inhibiting Hormone GHIH or Somatostatin Gonadotropin Releasing Hormone GnRH Lutenizing Hormone LH Growth Hormone GH or Somatotropin Thyroid Stimulating Hormone TSH Growth Hormone GH or Somatotropin Anterior Pituitary Prolactin Releasing Hormone PRH Prolactin Inhibiting Hormone PIH or Dopamine Corticotropin Releasing Hormone CRH Thyrotropin Releasing Hormone Human Growth Hormone Follicle Stimulating Hormone FSH Prolactin PRL Prolactin PRL Melanocyte Stimulating Hormone MSH Adrenocorticotropic Hormone ACTH or Corticotropin Melanocyte Stimulating Hormone MSH Thyroid Stimulating Hormone TSH or Thyrotropin o Produced by somatotrophs in anterior pituitary o Target cells are liver skeletal muscle cartilage bone o Within target cells increases synthesis of insulin like growth factors that act locally or enter bloodstream o Insulin like growth factors Increase cell growth and cell division by increasing the uptake of amino acids and synthesis of proteins Stimulate lipolysis in adipose tissue so fatty acids are used for ATP Decrease use of glucose for ATP production by most body cells so blood glucose levels remain high enough to supply brain o Regulation of hGH release hGH is released in bursts every few hours release is regulated by GHRH Growth hormone releasing hormone and GHIH Growth hormone inhibiting hormone Stimuli for GHRH Stimuli for GHIH Hypoglycemia deep sleep decreased fatty acids and increased amino acids in blood increased sympathetic stimulation Hyperglycemis REM sleep increased fatty acids and decreased amino acids in blood obesity low levels of thyroid hormones high levels of hGH Follicle Stimulating Hormone FSH o Gonadotropin releasing hormone GnRH from the hypothalamus stimulates gonadotrophs in anterior pituitary to produce FSH o In females FSH Stimulates secretion of estrogen Initiates the formation of follicles within the ovary o In males FSH Stimulates sperm production in testes Luteinizing Hormone LH o GnRH from hypothalamus stimulates gonadotrophs in anterior pituitary to produce LH o In females LH stimulates Secretion of estrogen and progesterone Ovulation Formation of corpus luteum o In males LH stimulates Secretion of testosterone Prolactin o Hypothalamus regulates lactotroph cells by secreting PRH and PIH dopamine o Lactotrophs in anterior pituitary produce prolactin o Under the right conditions prolactin causes milk production o Suckling reduces levels of hypothalamic inhibition and prolactin levels rise along with milk production Melanocyte Stimulating Hormone MSH o Secreted by corticotrophs in the anterior pituitary o Excessive levels of Corticotropin Releasing Hormone CRH from the hypothalamus increases Melanocyte Stimulating Hormone MSH release from the anterior pituitary o Prolactin Inhibiting Hormone PIH or Dopamine inhibits MSH release o Function unclear in humans but high levels increase skin pigmentation Adrenocorticotropic Hormone ACTH o Corticotropin Releasing Hormone CRH from the hypothalamus stimulates corticotrophs in the anterior pituitary to release ACTH o ACTH stimulates release of glucocorticoids mainly cortisol from adrenal cortex o ACTH release is also stimulated by hypoglycemia physical trauma and IL 1 Thyroid Stimulating Hormone TSH o Hypothalamus regulates thyrotrophs in anterior pituitary to produce TSH thyrotropin o TSH stimulates the synthesis and secretion of T3 and T4 thyroid hormones o Metabolic rate stimulated o Regulation of TSH release Hypothalamus releases thyrotropin releasing hormone TRH TRH causes release of TSH from anterior pituitary cells Thyroid glands activated to secrete more T3 and T4