Download AIM: What system of the human body regulates hormones?

AIM: What system of the
human body regulates
hormones?
Do Now: Hypothesize how
hormones communicate in the
human body? Explain in
detail…
Main Idea:
A system of the human body
regulated by hormonal
feedback mechanisms…
What is
a feedback
mechanism?
•It returns a system
back to a set
point once it
deviates
•EX: thermostat
What is •Organ that produces &
a gland? releases a substance
Exocrine •Release secretions
through ducts
gland
•Ex: sweat, tears,
digestive juices
Endocrine •Release secretions
gland
(hormones) directly
into bloodstream
What is a •Chemical messenger
hormone? •Substance that acts on
certain target cells and
tissues to produce a specific
response
What is •Cells hormones travel to
a target •Have receptors for
specific hormones
cell?
•No receptor  no effect
There are 2
types of
hormones:
•Steroid
•Non-steroid (amino
acid) aka protein type
Steroid
hormones:
•Ex: estrogen,
testosterone
•Work by causing cells
to initiate protein
synthesis
•Lipid soluble (can
diffuse through
membrane)
Non-steroid
hormones:
•Ex: insulin, growth
•Can’t diffuse/ they bind
to outside receptor 
activates an enzyme
inside cell
E
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AIM: How do the glands
of the E.S. maintain
homeostasis in the human
body?
Do Now: Describe the
difference between the
endocrine and the exocrine
glands…
1. HYPOTHALAMUS
• Small region of the brain
• Connected to the pituitary
• Directs the pituitary in it’s role
• ***LINKS THE ENDOCRINE TO
THE NERVOUS SYSTEM***
2. Pituitary
gland:
•Located at base of brain
•“master gland”
•Regulates
– Thyroid
– Adrenal
– Testes
– Ovaries
A. GH: GROWTH
HORMONE
•Controls growth
•Elongation of bones
B. ACTH:
• Stimulates production and
release of hormones from
adrenal glands
C TSH: Thyroid
Stimulating Hormone
• Stimulates production
and release of thyroxine
from the thyroid gland
3. Thyroid
gland:
•In the neck
•Thyroxine (regulates
metabolism)
•Calcitonin (regulates
Ca+)
4. Parathyroid •Sits on the Thyroid
gland
gland:
•Parathormone
•Increases blood Ca+ by
making bones release
the mineral
5. Adrenal
glands:
•Sit on top of kidneys
•Cortisol
– Raises blood glucose
– Reduces inflammation
•Epinephrine (aka
adrenaline)
•Norepinephrine
6. Pancreas:
• Release enzymes that
digest carbs, proteins and
fats
-Insulin (signals
liver to convert
glucose 
glycogen)
-Glucagon (binds to
liver cells – signals
to convert glycogen
 glucose
7. Gonads:
•Ovaries
– Estrogen
– progesterone
•Testes
– Androgens
•testosterone
AIM: How do hormones work to
maintain homeostasis?
Do Now: Name and describe
three hormones of the endocrine
system.
What processes are
regulated by hormonal
activity?
•
•
•
•
1.
2.
3.
4.
Overall metabolism
Homeostasis
Growth
Reproduction
•Are hormones
regulated?
•how?
FEEDBACK…
M
HORMONES
(usually Negative Feedback)
Allows for constant
adjustments to maintain a
“Set Point” or balance!!!
Positive Feedback…
• Continued released of a given
hormone by endocrine glands for
a determined length of time
(inhibited by negative feedback).
• Ex. Oxytocin and Prolactinencourages lactation of milk from
mammary glands of nursing
mothers.
NEGATIVE FEEDBACK
• Generally glands do not
secrete hormones at a
constant rate
• Varies with needs of body
• Most are counterbalanced by
a second hormone
Which
gland?
What is hypersecretion?
• Release of an excess
amount of a hormone
• OVERSECRETION
What is hyposecretion?
• Deficiency – not enough of
hormone is secreted
• UNDERSECRETION
Summary:
Explain what might happen
if the endocrine system fails
to regulate the amount of
hormones produced and
released? 1. Hyperthyroidism
2.Hypothyroidism
3. Dwarfism
4. Gigantism
Link to nervous system…
• Both involved in regulating activities of the
body and maintain homeostasis
• Hypothalamus: produces two hormones
– Oxytocin (contractions)
– Antidiuretic hormone (regulates h2o- nervous
system release it from axons in pituitary)
– Travels in blood to kidney to reabsorb more
h2o