Exam 1 - Hypothalamic-Pituitary Target Tissue Axis Flashcards
What are the alternate names for the anterior and posterior pituitary? What types of tissue are they composed of and how do hormones reach these areas from the hypothalamus?
anterior pituitary - adenohypophysis, glandular tissue, conencted by the hypothalamic-hypophyseal portal system
posterior pituitary - neurohypophysis, neural tissue, connected by neurosecretory neurons
What structure connects the pituitary gland to the hypothalamus?
infundibular stalk (which contains nerves and blood vessels)
What types of cells compose the anterior pituitary and what hormones do they produce?
thyrotrophs - thyroid stimulating hormone
gonadotroph - luteinizing hormone and follicle stimulating hormone
corticitroph - adenocorticotropic hormone
somatotroph - growth hormone
lactotroph - prolactin
How are the 5 types of cells organized in the anterior pituitary?
they aggregate in certain regions but are interspersed among one another
All anterior pituitary hormones are —, some are ——, and they are organized into # ——- based on their structure.
peptides/proteins
glycosylated
3 families
What are the three families of AP hormones?
somatomammotropins, glycoproteins, and pro-opiomelanocortins (POMC)
What defines the somatomammotropins and what AP hormones are in this family?
protein hormones
GH (growth hormone) and PRL (prolactin)
What defines the glycoproteins and what AP hormones are in this family?
a and B protein subunits plus carbohydrate moieties
The a subunit is identical for all AP glycoproteins while the B subunit confers specificity
The carbohydrate moiety increases half life and biological activity.
FSH (follicle stimulating hormone) and LH (luteinizing hormone) and TSH (thyroid stimulating hormone)
What defines pro-opiomelanocortins (POMC) and what AP hormones are in this family?
all derived from POMC, a large precursor protein
ACTH (adrenocorticotropic hormone)
What does growth hormone (GH) do?
stimulates growth (via insulin-like growth factor IGF-1) and affects metabolism
What does prolactin (PRL) do?
stimulate milk synthesis and secretion during lactation
What does follicle stimulating hormone (FSH) do?
stimulate follicular growth and estrogen production in ovaries, as well as regulating spermatogenesis in the testes
What does luteinizing hormone (LH) do?
regulate estrogen and progesterone production in ovaries and luteinization of the follicle, as well as regulates testosterone production in the testes
What are LH and FSH collectively called?
gonadotropic hormones
What does thyroid stimulating hormone (TSH) do?
stimulate synthesis and secretion of thyroid hormones (T3 and T4) by the thyroid gland
What does adrenocorticotropic hormone (ACTH) do?
stimulate synthesis and secretion of cortisol and DHEA (a weak androgen) by the adrenal cortex