endocrine system Flashcards
Endocrine system
hormone system, regulates metabolic activites
endocrine glands?
secrete hormones into body fluids- thyroid, adrenal, pineal glands
hormones
chemical signaling messengers that coordinate different functions, travel slower than nerve impulses, but lead to longer term stimulations
when are hormones released?
presence of other hormones, humoral stimulation(ion/nutrient in the blood), autonomic neural stimulation
hormonal level is regulated by what system, negative or positive?
negative feedback system
classes of hormones?
amino acid-derived, peptides, lipid-derived
amino acid-derivatives hormones
synthesized from amino acids.
they include:
catecholamine(epinephrine, norpinehrine, dopamine) and melatonin
peptiedes
chains of amino acids. insulin and leptin
lipid-derivatives
synthesized from fatty acids. can diffuse across plasma membrane easily. local hormones, sending signals over a short distances, main class is steroid
steroid
lipid derivatives. bind to receptors in cytoplasm or nucleus, activate specific genes, transcription and translation levels of these genes increase, protein/enzyme level increase=response
thyroid hormone
lipid derivatives. complex modify transcription levels(nucleus) and increase ATP production(mitochondria)
central controller?
hypothalamus area of the brain regulates the endocrine system. Regulates the pituitary gland(produces&releases several hormones, also has anterior&posterior lobes)
pituitary gland-posterior lobe
(neurohypophysis) consists of neuroglia and axon from the the hypothalamus. hypothalamus synthesizes the hormones and migrate along axons into posterior to get released.
pituitary gland-anterior lobe
(adenohypophysis) filled with glandular tissue. secretes hormones that impact secretion of other endocrine glands.
anterior lobe 2 types of regulatory hormones that control this lobe
Releasing hormone(RH): stimulate the synthesis and secretion of hormone
Inhibiting hormone(IH):prevents the synthesis and secretion of hormones
6 hormones released by anterior pituitary
1)thyroid stimulating hormone(TSH)
2)Adrenocorticotropic hormone(ACTH)
3) follicle stimulating hormone(FSH)
4)Luteinizing Hormone (LH)
5)Prolactin
6)Growth hormone
Thyroid stimulating hormone(TSH)
controls secretion of thyroid hormone(thyroxine) from gland. increase in thyroid hormone->inhibit TSH release(negative feedback)
decrease in thyroid hormone->hypothalamus sends signal
Adrenocorticotropic hormone (ACTH)
controls secretion of glucorticoids(cortisol and androgen) hormones from the adrenal cortex. role in how body responds to stress
Follicle stimulating hormone (FSH)
stimulates follicle/sperm development