Transcript Regents Biology

Endocrine System
Hormones
Reproduction
Updated 2015-2016.
Based on Notes by Kim Foglia
R.I.P.
Brief Review of the Endocrine System

Endocrine system releases hormones

glands which secrete
chemical signals into blood
chemicals cause changes
in other parts of body
 slow, long-lasting response

 growth hormones
 sex hormones
 response hormones
 metabolism hormones
 and more….
Hormones
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Hormones coordinate slower but longer–acting
responses to stimuli such as stress, dehydration,
and low blood glucose levels.
Hormones also regulate long–term developmental
processes by informing different parts of the body
how fast to grow or when to develop the
characteristics that distinguish male from female
or juvenile from adult.
Hormone–secreting organs, called endocrine
glands, are referred to as ductless glands because
they secrete their chemical messengers directly
into extracellular fluid. From there, the chemicals
diffuse into the circulation.
Glands
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Pineal

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Pituitary
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insulin, glucagon
Ovary

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adrenaline
Pancreas


thyroxine
Adrenal

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many hormones:
master gland
Thyroid

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melatonin
estrogen
Testes

testosterone
What do they do?
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Maintain homeostasis
blood sugar level
 temperature control

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Start a new process
growth
 fetal development
 sexual development

Body Temperature
Sex & Growth Hormones

Large scale body
changes

how do they work

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turn genes on
start new processes
in the body by
turning genes on
that were lying
“dormant”
Pituitary gland hormones
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Sex & reproductive hormones

FSH
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LH
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luteinizing hormone
stimulates ovaries & testes
prepares uterus for fertilized egg
oxytocin

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
follicle stimulating hormone
stimulates egg & sperm production
stimulates childbirth contractions
releases milk in nursing mothers
prolactin

milk production in nursing mothers
hormones
hormones
Reproductive hormones

Testosterone

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
from testes
sperm
production &
secondary sexual
characteristics
Estrogen

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from ovaries
egg production,
preparing uterus
for fertilized egg
& secondary
sexual
characteristics
Male reproductive system
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Testicles

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Scrotum

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where sperm mature
Vas deferens


sac that holds testicles outside of body
Epididymis


produces sperm & hormones
tubes for sperm to travel from testes to penis
Prostate, seminal vesicles,
Cowper’s (bulbourethal) glands

nutrient rich fluid to feed & protect sperm
Egg maturation in ovary
releases
progesterone
maintains
uterus
lining
produces estrogen
LH
Menstrual cycle

Controlled by
interaction of
4 hormones egg development
FSH & LH
 estrogen
 progesterone
FSH
ovulation = egg release

corpus luteum
estrogen
progesterone
lining of uterus
days 0
7
14
21
28
Feedback
Female reproductive cycle
egg
matures &
is released
(ovulation)
estrogen
builds up
uterus lining
corpus
luteum
ovary
progesterone
FSH & LH
maintains
uterus lining
fertilized egg
(zygote)
HCG
yes
pituitary
gland
pregnancy
GnRH
hypothalamus
no
corpus luteum breaks down
progesterone drops
menstruation
corpus
luteum
progesterone
maintains
uterus lining
Female hormones
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FSH & LH
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Estrogen
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released from pituitary
stimulates egg development & hormone release
peak release = release of egg (ovulation)
released from ovary cells around developing egg
stimulates growth of lining of uterus
decreasing levels causes menstruation
Progesterone
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
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released from “corpus luteum” in ovaries
 cells that used to take care of developing egg
stimulates blood supply to lining of uterus
decreasing levels causes menstruation
Fertilization
Any Questions??
2015-2016