Endocrine System
The Endocrine System
 Endocrine System
 the body’s “slow”
chemical
communication
system
 a set of glands that
secrete hormones
into the
bloodstream
Neural and Hormonal Systems
 Hormones
 chemical messengers, mostly those manufactured by
the endocrine glands, that are produced in one tissue
and affect another
 Pituitary Gland
 under the influence of the hypothalamus, the
pituitary regulates growth and controls other
endocrine glands
The effects of the pituitary are clearly shown here.
Entertainer David Frost stands between the world’s tallest and
smallest man.
The tallest man in history was 8 feet 11 inches tall.
He died at the age of 22, partly as a result of this
defect. The shortest known person was 23 inches
tall when she died at the age of 19. Today’s
medicines can handle most of these problems if
caught earlier enough, but these cases show what
happen if the pituitary gland goes awry.
Neural and Hormonal Systems
• Oxytocin– stimulates contractions of the
uterus during labor and secretion of milk
during nursing.
• Growth Hormone– stimulates the physical
development of bones and muscles.
Neural and Hormonal Systems
 Adrenal [ah-DREEN-el] Glands
 a pair of endocrine glands just above the kidneys
 secrete the hormones epinephrine (adrenaline) and
norepinephrine (noradrenaline), which help to arouse the
body in times of stress
 Cortisol– regulates metabolism and response to stress.
Neural and Hormonal Systems
• Pancreas Hormones
– Insulin– decreases blood sugar
– Glucagon– Increases blood sugar
Neural and Hormonal Systems
• Thyroid Hormone
– Thyroxin– regulates metabolism and growth
Neural and Hormonal Systems
• Sex Glands (Gonads)
– Female Sex Hormone– Estrogen (Ovary)
– Male Sex Hormone– Androgen (Testis)