chapter 19 - endocrine system Flashcards
gneral characteristics of the endocrine system
chronic regulation of homeostasis- slow and prolonged
interrelated with nervous system– hypothalamus and thalamus
ductless– hormones produced by specialized cells
substance synthesized by a specific organ or tissue and secreted
hormones
two types of secretion of hormones
paracrine and endocrine
secretion into the extracellular spaces
paracrine signaling
secretion when blood carries it to other sites
endocrine signaling
hormones act on specific target cells through
specific receptors for specific hormones
chemistry categories of hormones
steroids, peptides, amines, eicosanoids
lipid soluable hormones that can cross cell cell membranes. made from cholesterol. used in transduction– regulation of DNA transcription
steroid hormones
derived from tyrosine of trytophan. some are membrane soluble and some are not. most important ones are thyroid and adrenal medulla
amine hormones
short chain of amino acids– cannot cross the cell membrane. all pituitary hormones
peptide hormones
derived from fatty acids. most cross cell membrane. coordinate functions of extracellular fluid
eicosanoids
control hormone secretion through
negative feedback loop
how does neg feedback loop work in endocrine system
gland is sensitive to concentration of substance
- concentration exceeds = prevent gland from secreting hormone
- concentration decreases = secretion increases
RESULTS IN RELATIVELY STABLE CONC. OF BOTH SUBSTANCE AND HORMONE
sends signals to the pituitary gland
hypothalamus
significance of pitutary gland
really 2 glands– together = most important endocrine gland for regulation
does not make hormones. mostly hypothalamic axons
posterior pituitary
5 types of endocrine cells present. controlled by hypothalamic regulatory hormones
anterior pituitary
regulatory hormones found in the anterior pituitary
releasing and inhibitory
posterior pituitary gland that causes the contraction of muscles in the uterine wall,= and prostate; causes muscles associated with milk ejection to contract; significant emotional bonding
oxytocin
posterior pituitary horomone that cause kidney to decrease water excretion. also increases blood volume– rise in BP
antidiuretic hormone- ADH
posterior pituitary gland that increases melanin secretion
melanocyte stimulating hormone-MSH
cell type involved in melanocyte stimulating hormones
melanocytes
anterior pituitary hormone– testes produce sperm, follicular development in ovary, stimulate secretion of estrogen
follicle stimulating hormone- FSH
anterior pituitary hormone– promotes secretion of sex hormones and release of oocyte
luteinizing hormone- LH
anterior pituitary hormone
- inc size and rate of reproduction of body cells
- targets muscles and bones– mobilizes fat ad glucose
- enhances movmemnt of amino acids through membranes
- secreted throughout life, inc at puberty
growth hormone- GH
anterior pituitary hormone that controls secretion of thyroid hormones
thyroid stimulating homrone– TSH
anterior pituitary hormone– targets mammary tissue. milk production / secretion
prolactin- PRL
anterior pituitary hormone that stimulates adrenal cortex to produce corticosteroids
adrenocorticotropic hormone
involves 2 lobes and isthmus, follicular cells and parafollicular cells
thyroid gland
cell involved in thyroid gland that has a line follicle cavities– filled with thyroglogulin colloid; removes Iodine from blood; secrete T3 and T4
follicular cells
cell involved in thyroid gland that produce calcitronin
parafollicular cells
thyroid hormone that involves follicular cells
thyroxine and triiodothryonine
thyroid hormone that involves follicular cells that inc glycogenesis, inc protein synthesis, and inc growth
thryroxine T4
thyroid hormone that involves follicular cells thatinc glycogenesis, inc protein synthesis, and inc growth— 5x more potent
triiodothyronine- T3
thyroid hormone that involves parafollicular cells that dec blood Ca2+ and PO4– which inc renal excretion and inc osteoblast activity
calcitronin
posterior surface of thyroid– many tightly packed secretory cells
parathyroid glands
immature cells in the parathyroid glands
oxyphil and transitional cells
cells in the parathyroid glands that produce parathyroid hormone
chief cells
hormone found in parathyroid glands
parathyroid hormone- PTH
hormone found in the parathyroid gland that inc blood Ca2+– which dec Ca2+ and PO4 excretion, dec osteoclast activity, inc calcitrol
parathyroid hormone- PTH
thoracic cavity posterior to sternum– produces thymosin
thymus
enhances lymphocyte production and competence. most active in infacy and childhood
thymosin
adrenal cortex involves
glomerulosa, fasciculata, reticularis
adrenal glands involves
adrenal cortex and adrenal medulla
what is found in the adrenal medulla
chromaffin cells
found in the adrenal medulla– cells which are modified postganglionic cells of the SNS
chromaffin cells
components of the kidney
renin, erthropoietin, calcitrol
hormone of the kidney that starts the cascade to increase blood pressure
renin
hormone of kidney that involves erythrocyte production
erythropoletin EPO
hormone of the kindey that involves the increase absorption of digested Ca2+
calcitrol
found in the heart. supresses aldosterone and ADH. decreases blood volume and blood pressure
atrial natriuretic peptide
posterior to stomach– attached to dedenom by duct; endocrine and exocrine function
pancreas
islets of Lanagerhans
endocrine function
cells within the islets of langerhans
alpha, beta, delta
alpha cells in pancreas
glucugon
beta cells in pancreas
insulin
delta cells in pancreas
somatostatin
somatostatin
inhibits glucugon and insulin secretion. atagonizes GH
