Hormones General Charac Flashcards
Neurotransmitters 1
Endocrine hormones 2
Neuroendocrine 3
Paracrines 4
Autocrines 5
Cytokines 6
1 axon terminals of neurons / control nerve c fct
2 by glands into blood / influence fct of c at another loca
3 secreted by neurons into blood / «~~~~
4 secreted by c into ecf / affect neighboring c of diff type
5 secreted by c into ecf / affect fct of the same c that produced them
6 peptides secreted by c into ecf / fct as autocrines , paracrines or endo
3 genrral classes of hormones
Proteins + polypeptides
Steroids secreted by adrenal cortex ovaries testes placenta
Derivatives of a.a tyrosine secreted by thyroid + adrenal medullae
Adrenal cortex
Ovaries
Placenta
Adrenal meddu
Cortisol , aldosterone
Estrogen , progesterone ( both) epinephrine, norepinephrine
Exocytosis
Secretion of hormones occurs when the vesicles fuse to the mbrn
Polypeptide+protein Hormones
Stored in secretory vesicles until needed
Steroid hormones
Synthesized from cholesterol, not stored
Exocytosis
Secrete epinephrine + norepinephrine
Negative feedback
Prevents over activity of hormones system
Positive feedback
Surges of hormones
Down regulation of receptors
The receptors proteins are often inactivated or destroyed
Up regulation of receptors
The stimulating hormone induces greater than nrml formation of receptors
Hypophysis
Small gland in hypophyseal fossa and connected to hypothalamus by pituiataru stalk
Anterior pituitary ( adenophysis )
Pars distalis : larger portion
Pars tuberalis : fotms a sheath around infun
Posterior pituitary ( neurohypophysis)
Pars nervosa : larger bulbar portion
Infundivulum
Secretiom by anterior pituitary
Controlled by hypothalamic realeasing and inhibitory
