Endocrine system Flashcards
Endocrine system function
Secretes hormones into the circulatory system
Endocrine hormone characteristics
- produces in small quantities
- secretes in intercellular space
- transported some distance in circulatory system
- acts on target tissues elsewhere in the body.
is pancreas exo and endocrine?
both
similarities of endocrine and nervous system
control and regulate the body
Differences in endocrine and nervous system
nervous (instantaneous electrical signal) and endocrine signal through vascular system
Nervous system characteristics
action potentials (electric), does not last long, frequency dependent
Endocrine system characteristics
Hormones (chemica), lasts min, days, lifetime), signal concentration dependents.
Types of chemical messengers in endocrine
autocrine, paracrine, neurotransmitter, and endocrine chemical messenger
Define autocrine chemical messenger
affects itself, signals itself (e.g., prostaglandin)
Define paracrine chemical messenger
signals cells locally, not transported in blood, (somatostatin)
Define neurotransmitter chemical messenger
electrical signals (action potentiors), another muscle or cell very localized. (e.g., acetylcholine)
Define endocrine chemical messenger
chemical signal entering the blood for transportation (estrogen). (E.g. estrogen)
Define the hormone stability; half-life and long half-life
half-life amount of time that hormone degrades and long half-life reamains at constant rate though time.
Example of half-life hormones
water soluble hormones, proteins epinephrine, Norepinephrine, rapid onset-short duration
Example of long half-life
lipid soluble attaches to plasma proteins (testorene)
define water soluble protein
amino acid/protein based. proteins, peptides, and ammino acid, derivates. e.g. thyroxine, epinephrine, tryptophan, melatonin. Transporter as free hormones, short half-life.
define lipid-soluble
cholesterol base or amino acid based. steroids and amino acids and fatty acids derivatives. Hydroxyl group (OH) in tail. cholesterol. progesterone, aldosterone, testosterone. cortisol and estradiol. Transports with binding proteins, long half-life
define chronic hormone secretion
constant secretion. e.g. thyroid. constant regulated. lipid hormones
define acute hormone secretion
in an instance due to reaction, e.g. epinephrine. water hormones.
define episodic hormone secretion
produced everyday at a certain time. e.g. female reproductine hormones. lipid hormones
Endocrine is regulated by 3 controls
Humoral control (substance other than endocrine gland), Neural Control (by nervous system) Hormonal Control (secretion activity of a hormone controlled by endocrine gland)