the endocrine system
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THE ENDOCRINE SYSTEM. Made up of glands release hormones into the bloodstream Hormones travel throughout the body and relay information Works with nervous system to control body Coordinated by the hypothalamus receives messages from internal organs - PowerPoint PPT PresentationTRANSCRIPT
THE ENDOCRINE SYSTEM
Made up of glands release hormones into the bloodstream
Hormones travel throughout the body and relay information
Works with nervous system to control bodyCoordinated by the hypothalamus
receives messages from internal organs Stimulates pituitary gland when a change in
homeostasis occurs
PARTS OF THE ENDOCRINE SYSTEM1. Pituitary gland – “master” endocrine
gland2. Hypothalamus3. Pineal gland
4. Thyroid gland
5. Parathyroid gland
6. Adrenal gland
7. Pancreas
8. Ovaries or Testes
CHECK YOUR UNDERSTANDING… Which part of your brain meshes your
endocrine and nervous systems together?
Without looking at your notes, list as many parts of the endocrine system as you can
PITUITARY GLAND Controls all the other glands Secretes hormones (thyroid-stimulating
hormone, anti-diuretic hormone, growth hormone, and more)
HYPOTHALAMUS Secretes hormones controls pituitary gland
THYROID GLAND Regulates metabolism and growth
Main hormone is thyroxine – contains iodine (think iodized salt)Regulates Energy Use, Food Intake
PINEAL GLAND In brain – “third eye” Sensitive to light Releases melatonin to make you
sleepy
THYROID GLANDHypothyroidism: low thyroxin Lower energy, weight gain
THYROID GLANDGoiter: enlarged thyroid gland (low iodine)
PARATHYROID GLAND
Controls calcium levels in blood and bonesSecretes Parathyroid Hormone (PTH)
ADRENAL GLAND Produces adrenalin (epinephrine) and
noradrenalin (norepinephrine)Fight-or-flight response Increased…
heart rate and blood pressure
respiration ratemuscle efficiencyblood sugar levels
Also releases cortisol which wakes you up
PANCREAS
Controls blood sugar levels - Insulin
Also acts as a gland of the digestive system secreting digestive enzymes
REPRODUCTIVE GLANDS Gonads: ovaries and
testes
Ovaries produce estrogen and progesterone
Sex characteristicsBreastsWidening of hipsSoft skinPubic/underarm hair
REPRODUCTIVE GLANDS
Testes produce androgens, including testosterone
Sex characteristics facial, leg and body hairThicker skinLarge muscle massGrowth of Larynx (deep
voice)
Tammy Thomas – Pro bike racer
CHECK YOUR UNDERSTANDING… Which gland is your “master endocrine
gland”? Which glands sit on top of your kidneys
and make adrenaline? Which gland / hormone makes you get
fatter as you age? What hormones are secreted by YOUR
gonads? Which gland controls your blood sugar
levels, and with what hormone?
NEGATIVE FEEDBACK An increase in something inhibits the
process leading to the increase
Example: your gradesYour grades suckParents get on your caseYou try harder at schoolYour grades go upParents stop harping on youYou stop trying, grades go back down
Video: negative and positive feedback loops (first minute only)
NEGATIVE FEEDBACK LOOPWATER REGULATION You work out and get thirsty Hypothalamus senses you need water Hypothalamus tells pituitary gland to
release anti-diuretic hormone (ADH) Causes body to conserve water No longer thirsty (no more ADH)
What does a diuretic do?
NEGATIVE FEEDBACK LOOP
BLOOD GLUCOSE When you eat, blood
glucose levels go up
Pancreas senses this and releases insulin
Insulin tells cells to take in glucose – so blood glucose levels drop
NEGATIVE FEEDBACK LOOP
BLOOD GLUCOSE When blood glucose drops…
Pancreas senses this and releases glucagon
Glucagon tells liver to release glycogen (glucose)—so blood glucose levels rise
If you’re out of glycogen, hypothalamus stimulates your stomach and makes it growl
CHECK YOUR UNDERSTANDING…In your notebook, work with your partner to create your own example of a negative feedback loop. It does not have to be biological!
ENDOCRINE DISEASE
Two typesType I – juvenile onsetType II – adult-onset
TYPE I DIABETES: “JUVENILE” Pancreas doesn’t make insulin Therefore cells can’t take in glucose Glucose stays in blood—causes high
blood sugar Glucose appears in urine (not normally
there) Treatment
strict diet insulin injections
TYPE II DIABETES: ADULT-ONSET You eat WAY TOO MUCH sugar
Cells get overloaded with sugar
Cells shut down some insulin receptors, or receptors don’t work properly
Therefore cells no longer get enough glucose
Treatment - Diet
Diabetes animation