Download organs are part of the endocrine system?

Warm-up 4/15:
a. Describe the function of the
Endocrine System.
b. What tissues/ organs are part of
the endocrine system?
ENDOCRINE SYSTEM
pp 1031-1042
FUNCTION
• Controls body function with
chemical messengers
• Hormones: chemical messengers
• Glands: secrete chemicals/hormones
HORMONES
• Amino acid-based hormones: first messenger
binds to cell surface receptor causing second
messenger inside the cell to initiate cell activity
• Steroid hormones: diffuse through cell
membrane to bind to a protein which starts
transcription
GLANDS
• exocrine: secrete nonhormonal chemicals through
ducts (sweat, saliva, mucous, digestive, etc)
• endocrine: secrete hormones into the bloodstream
a. gonads: sex hormones
b. thyroid: metabolism
c. adrenal gland: adrenaline
d. pituitary: hormones that affect other glands
and growth hormones
e. pancreas: insulin and glucagons to regulate
sugar
f. thymus: stimulates formation of T-cells
FEEDBACK MECHANISMS
• Homeostasis: stable internal environment
• Last step of the series controls the first
NEGATIVE FEEDBACK
• A secondary substance inhibits production of
the initial stimulating substance
A = Insulin
B = glucagon (sugar)
Negative feedback loops are necessary for
homeostasis.
Negative Feedback Loop
Holding breath, CO2 levels
rise,
O2 / CO2 level returns to
normal
Control system forces
exhale, inhale
POSITIVE FEEDBACK
• A secondary substance stimulates production
of the initial stimulating substance
Birth
HW
• Worksheet: Nervous and Sense Organs (Due
Tuesday)
• Trifold Vocab: homeostasis, neuron, gland,
hormone, positive feedback loop, negative
feedback loop, synapse, neurotransmitter (Due
Wednesday)