Micro 1 Flashcards
membrane impermeable hormones
hydrophilic. receptors are located on the cell surface, these act through secondary messengers.
EX: peptides, proteins, glycoproteins, amino acids
membrane permeable hormones
receptors are intracellular DNA binding proteins that affect transcription
EX: steroid and thyroid hormones
origin of pituitary gland
anterior is from oral ectoderm and is made of epithelial tissue while posterior is made from neural ectoderm
anterior pituitary
makes a variety of hormones that regulate body growth, milk, functions of other endocrine glands
posterior hypophysis
no secretory cells, stores and releases hormones made in the hypothalamus
chromophils
cells containing secretory granules that can interact with dyes used in histology: acidophils and basophils
chromophobes
cells that do not contain stained granules. this group includes stem cells, and cells that have released their granules
acidophils
cells that produce two types of protein hormones: somatotropic or growth hormone, and mammotropic hormone
basophils
cells that produce glycoprotein hormones (FSH, LH, TSH) and small polypeptide hormones (ACTH and LPH)
B-FLAT
cells of pars distalis and pars tuberalis
each cell type secretes only one hormone type, except for gonadotropic cells making FSH and LH and corticotropic cells making ACTH and B-LPH.
cells / hormones of pars intermedia
largely inactive in adults and contains colloid filled follicles and cysts (rathke’s) of unknown function
hormones secreted by the posterior pituitary
vasopressin and oxytocin
hypothalamus
regulates functions of adenohypophysis via releasing and inhibiting hormones. no direct neural connections. hormones carried to adenohypophysis via specialized blood vessels
zones of the adrenal cortex
glomerulosa, fasiciculata, reticularis.
medulla of adrenal gland
electron dense secretory granules that react with chromium and silver salts. produces catecholamines (epi and norepi)
thyroid follicular cells
regulated by TSH. hormones T3 and T4 regulate basal metabolic rate, body growth/development, and heat production
parafollicular cells of the thyroid
produce calcitonin that inhibits bone resorption and promotes calcification of bone. regulated by blood calcium levels
parathyroid chief cells
produce PTH (parathyroid hormone). increased blood calcium level
oxyphil cells of parathyroid
unknown function!
examples of hormone secretion by non-endocrine organs
heart: atrial natriuretic peptide
kidney: erythropoietin
stomach/small intestine: enteric hormones
adipose: leptin (regulats appetite and metabolism), adiponectin (regulates fatty acid and glucose metabolism and modulates sensitivity to insulin), androgens/estrogens
