Endocrine 3b+c Flashcards
Specialized glands and tissue of the endocrine system secrete____
hormones
Hormones_____
secreted into the blood, travel throughout the body
-only exert an effect on cells w/ receptors
CONTROL AND COORDINATE BODY FXNS
overlap w NS
Hormones characteristics
-specific rate/rhythm of secretion: diurnal, cyclic, dependence on circulating levels
-operate via feedback mechanisms
-only affect target cells w/ receptors
hormones are classified by
chemical structure-lipid soluble or water soluble, target organ, origin
possible hormone effects
-after plasma membrane permeability or membrane potential by opening/closing ion channels
-stimulate the synthesis of regulatory molecules (proteins)
-activate or deactivate enzyme systems
-induce secretory activity
-stimulate mitosis
endocrine organs
hypothalamus, pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus gland, pancreas, adrenal glands, ovaries, testes
lipid soluble hormones
-steroids
-hydrophobic signals
-circulate w. carrier protein
-receptor inside cell
1/2 life: hours to days
water-soluble hormones
-peptides, amines, glycoproteins
-hydrophilic
-circulate unbound
-receptors on cell membrane
1/2 life seconds to mins
examples of steroid hormones
cortisol, aldosterone, testosterone, estrogens
how steroid hormones work
- hormone diffuses
- gene activated
- protein synthesis
- new protein alters cell activity
examples of peptide hormones
insulin, glucagon, thyroid hormone, epinephrine, growth hormone, oxytocin
how peptide hormones work
- hormone binds to receptor
- cyclic AMP generated (2nd messenger)
- enzyme 1 –> 2-> 3activated
- Final product alters cell activity
hypothalamic-pituitary axis
anatomically and functionally connected
-hypothalamus secretes inhibiting/releasing hormones
-regulation secretion from pituitary
hypothalamus is link between ___and____
nervous and endocrine syestem
Pituitary hormones- anterior
-thyroid stimulating hormone (TSH)
-adrenocorticotropic hormone (ACTH)
-Prolactin (PRL)
-Growth hormone (GH)
-Follicle-stimulation hormone (FSH)
-Luteinizing hormone (LH)
TSH
stimulates secertion of throid hormone
ACTH
-stimulates adrenal cortex to secrete glucocorticoids
PRL
after birth stimulates mammary glands to synthesize milk
GH
stimulates mitosis and cellular differentiation
FSH
stimulates secretion of ovarian sex hormones, development of ovarian follicles and sperm production
LH
Stimulates:
-ovulation
-corpus luteum to secrete progesterone
-testes to secrete testosterone
Pituitary hormones posterior
Antidiuretic hormone( ADH), Oxytocin (OT)
ADH
Antidiuretic hormone
-acts of kidney, incr water retention
-also called vasopressin bc it can cause vasoconstriction
OT
-stimulates uterine contradiction during childbirth, flow of milk during lactation
-promotes feelings of sexual satisfaction and emotional bonding between partners