Ex Phys: endocrine system

the endocrine system

works alongside the nervous system to coordinate and regulate nearly every body process including growth and metabolism, reprosuction, and stress response

target cell

a cell that possesses receptors specific for that hormone

steroid hormones

derived from cholesterol: lipophilic-soluble

ex. estrogen and cortisol

peptide hormones

made of amino acids: water-solubleex. insulin and growth hormones

amine hormones

derived from amino acids: may act like either type (either water or lipid soluble)

ex. epinephrine and thyroid hormones

lipid-soluble hormones (steroid hormones)

• can enter through the cell membrane

• bind to receptors inside the sytoplasm or nucleus

• form a hormone-receptor complex that turns specific genes on or off

• creates long-term effects like growth and adaptation

water-soluble hormones (peptide and amine hormones)

• cannot cross the membrane, must bind to a receptor on the enter of the cell

• this sctivates a second messenger, often called cAMP

• the second messenger triggers rapid changes in the cell

neural stimuli

triggered by nerve signals (for fast control when body needs innediate response)

humoral stimuli

triggered by changes in blood levels

hormonal stimuli

triggered by tropic hormones

negative feedback

stops release when balance is restored (inculin)

positive feedback

amplifies until event ends (contractions)

growth hormone (GH)

• pituitary

• protein synthesis, fat metabolism

thyroid-stimulation hormone (TSH)

• anterior pituitary

• stimulates thyriod gland

antidiuretic hormone (ADH)

• posterior pituitary

• water retention

oxytocin (OT)

• posterior pituitary

• stimulates contractions during childbirth