Reproductive Systems

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Reproductive Systems

• This is posted online
• Take notes if you need to but DO NOT COPY WORD
  FOR WORD

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Human Sperm
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Human Egg
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Sperm fertilizing Egg
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Hormones

• Hormones are substances that act like messenger
  in the body. They travel through the bloodstream
  and cause certain cells to respond in specific
  ways
• Several hormones regulate the reproductive system

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Puberty

• Puberty is first experienced during the early to
  mid-teens it is when hormonal signals change
  the body so that it is able to reproduce
• When puberty begins, the pituitary gland at the
  base of the brain starts to produce FSH (follicle
  stimulation hormone.

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Puberty Cont.

• FSH travels through the bloodstream to the gonads
  (testes and ovaries)
• FSH signals the testes to produce sperm and the
  ovaries to produce mature eggs.
• Other hormones help in the development and
  maintenance of additional characteristics
  associated with being distinctly male or female
  these are call SECONDARY SEXUAL CHARACTERISTS

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Puberty in Males

• Other cells in the testes start to produce
  testosterone during puberty
• Testosterone directs the development of secondary
  sexual characterizes, such as the deepening of
  the voice, facial, underarm and pubic hair, and
  the broadening of shoulders

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Puberty in Females

• FSH also stimulates the ovaries to produce
  estrogen, which is also a reproductive hormone
  and responsible to secondary sexual
  characteristics
• Female secondary sexual characteristics include
  deposits of fat in the breasts and hips and the
  growth of the pubic and underarm hair

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Hormones and the Menstrual Cycle

• Before and after ovulation, the female
  reproductive system undergoes changes in a cycle
  that last approximately one month
• This cycle that normally last 28 days is called
  the menstrual cycle

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Hormones and the Menstrual Cycle Cont.

• The pituitary hormones tell the ovaries what to
  do and the ovarian hormones tell the uterus
  what to do
• This type of communication between different
  parts of the body is called feedback
• Positive feedback means that actions are
  stimulated or begun, while negative feedback
  occurs when action are inhibited or prevented

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Hormones and the Menstrual Cycle Cont.

• Two other important hormones in the menstrual
  cycle are luteinising hormone (otherwise known as
  LH) and progesterone.
• LH is released by the pituitary gland while
  progesterone is released by the ovary

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Hormones and the Menstrual Cycle Cont.

• Turn to page 86 in your text
• Read through figure 3.8 The effects of hormones
  during stage of the menstrual cycle

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Hormones and the Menstrual Cycle Cont.

• After an egg is released, the females body waits
  for a signal (sperm or fertilization)
• If a fertilized egg does not reach the uterus,
  progesterone is reduced in the bloodstream which
  cause the uterine lining to break down
• The lining is shed from the body in the process
  known as menstruation

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Menstruation

• The menstrual flow consisting of mainly dead
  cells and blood continues for approximately four
  to seven days
• When the progesterone level decreases
  substantially, the pituitary gland increase its
  production of FSH and the menstrual cycle starts
  over again.