secretes hormones directly into the bloodstream
secretes hormones using ducts ex. gastrointestinal lumen
signaling molecules that modify the activity of the cell that secreted them
hydrophilic hormones (types)
peptides and amino-acid derivatives
hydrophilic hormones (method of action)
bind to receptors on the cell surface
Peptide hormones (where synthesized and modified?)
rough ER, golgi
Peptide hormones - hydrophilic / phobic?
Peptide hormones - method of action?
cell surface receptor which communicates with secondary messenger inside of cell
peptide hormones - duration of effect?
effects exerted rapidly, but short duration
can peptide hormones pass membranes?
Steroid hormones - what are they synthesized from, and where?
Cholesterol, smooth ER
steroid hormones - hydrophilic or phobic? can they cross membranes?
Steroid hormones - method of action?
crosses membrane, binds to a receptor in cytoplasm, transported to nucleus, and modifies transcription
Steroid hormones - duration of effect?
effects exerted slowly, and last for days to weeks
amount of hormone secreted is controlled by changes in the target the hormone is regulating.
hormones that regulate hormones
ACTH - what does it stimulate?
stimulates increased activity of cortisol
what portion of the brain controls the endocrine system? what does it release?
hypothalamus, tropic hormones
what is the role of CRH?
corticotropin releasing hormone, increase secretion of ACTH.
what is the hypothalamic-pituitary portal system?
miniature circulatory system for efficient transport of factors to the anterior pituitary.
how is the posterior pituitary and the hypothalamus connected?
where are the hormones made / secreted in the posterior pituitary?
the somas of the neuroendocrine cells are located in the hypothalamus and create the hormones, the axons are located in the posterior pituitary and secretes the hormones.
what hormones are secreted by the posterior pituitary?
ADH and oxytocin
hypothalamus gland function
releasing and inhibiting factors - anterior pituitary - modifies activity
Growth Hormone (GH)
AP, increase bone & muscle growth / Increase cell turnover
Mammary gland / milk production
Thyroid-stimulating hormone (TSH)
(tropic) Thyroid / increase synthesis & release of TH
Adrenocorticotropic hormone (ACTH)
(tropic) increase growth and secretory activity of adrenal cortex
Luteinizing hormone (LH)
(gonadotropic) ovary / ovulation, testes / testosterone syn
Follicle-stimulating hormone (FSH)
(gonadotropic) ovary / follicle development, testes / spermatogenesis