Aim: How can hormones influence the reproductive

cycles in humans?

Who am I?

•Our bodies change. You grow taller & bigger. •Our sexual organs mature. •Hair appears where there was no hair before. •You may begin to feel attracted to another individual.

An Adolescent Going Through Puberty

Control of Reproductive Systems

The Hypothalamus & Pituitary Gland (in the

brain) produce hormones that

stimulate the gonads to produce sex hormones

What is a hormone?

• Hormones are chemical messengers

• There are many different hormones that have unique and specific functions

What is a target cell?

• The cell that a particular hormone will communicate its message to

How do hormones travel to their target cells?

• The Circulatory System!!

How do hormones recognize their target cells?

• Cells must bear a perfectly shaped RECEPTOR for the hormone in order to respond to them.

Hormonal Control of the Female Reproductive System:

Beginning at puberty, femalereproductive organs undergo a cycle of changes that prepare thebody for the possibility of pregnancy.

The hypothalamus, the pituitarygland, and the ovaries producehormones that control this cycleof change.

What is this cycle of change called?

Menstrual Cycle

How does a woman get ready to get pregnant?

An egg is produced & the lining of the uterus thickens to receive the embryo

Menstrual Cycle (28 Days)•Follicular Phase (13 Days)

•Ovulation (1 Day)

•Corpus Luteum Phase (14 Days)

Menstrual Cycle Stages

1) Follicular Stage:

• Follicle Stimulating Hormone (FSH) stimulates the ovary to produce estrogen and egg maturation

• Estrogen causes the lining of uterus to begin to thicken

• Duration: 10-14 days

2) Ovulation

•Increased levels of Leutinizing Hormone (LH) causes the release of an egg into the oviduct

•Around day 14

3) Corpus Luteum Phase

•Ovaries continue to secrete estrogen & progesterone to further thicken the lining of the uterus

•Duration 10-14 days

What is MENSTRUATION?

•Hormone levels decrease

•Shedding of the uterine lining and

unfertilized egg

•Duration: 3-7 days

What happens if fertilization does occur?

• The levels of progesterone will remain elevated in order to maintain the thickness of the uterine lining

• Nicknamed the “pregnancy hormone”

Hormones & the menstrual cycle

• Which hormones peak before ovulation?

• Which hormone peaks after ovulation?

http://www.msnbc.com/news/wld/graphics/menstrual_cycle_dw.htm

GirlsSecondary Sex Characteristics

•Hips widen•Pubic Hair•Breasts enlarge

Due to the hormones estrogenand progesterone.

Hormonal Regulation of the Testes:• Beginning at puberty,

the pituitary gland secretes FSH & LH.

• These hormones stimulate the testes to produce testosterone.

• Testosterone stimulates the production of sperm and other male sex characteristics.

BoysSecondary Sex Characteristics

•Voice Deepens•Facial Hair•Muscular

Development•Pubic Hair•Sperm Production

Due to the hormoneTestosterone.